KEPCO BHK-MG 200W User Manual

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Page 1

OPERATOR’S MANUAL

BHK-MG FULL RACK SERIES

VOLTAGE/CURRENT-STABILIZED DC SOURCE

KEPCO INC.

An ISO 9001 Company.

POWER SUPPLY

MODELS

BHK 300-0.6MG

BHK 500-0.4MG BHK 1000-0.2MG BHK 2000-0.1MG

IMPORTANT NOTES:

1) This manual is valid for the following Model and associated serial numbers:

MODEL SERIAL NO. REV. NO.

2) A Change Page may be included at the end of the manual. All applicable changes and revision number changes are documented with reference to the equipment serial numbers. Before using this Instruction Manual, check your equipment serial number to identify your model. If in doubt, contact your nearest Kepco Representative, or the Kepco Documentation Office in New York, (718) 461-7000, requesting the correct revision for your particular model and serial number.

3) The contents of this manual are protected by copyright. Reproduction of any part can be made only with the specific written permission of Kepco, Inc.

Data subject to change without notice.

KEPCO, INC. ! 131-38 SANFORD AVENUE ! FLUSHING, NY. 11355 U.S.A. ! TEL (718) 461-7000 ! FAX (718) 767-1102

email: hq@kepcopower.com ! World Wide Web: http://www.kepcopower.com

KEPCO®

THE POWER SUPPLIER™

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Declaration of Conformity

Application of Council directives:

Standard to which Conformity is declared:

EN61010-1:2001 (Safety requirements for electrical equipment for measurement,

control and laboratory use - Part 1)

Manufacturer's Name and Address:

Importer's Name and Address:

Type of Equipment:

Model No.:

73/23/EEC (LVD) 93/68/EEC (CE mark)

KEPCO INC. 131-38 SANFORD AVENUE FLUSHING, N.Y. 11355 USA

Component Power Supply

[PRODUCT MODEL NUMBER]

Year of Manufacture:

I, the undersigned, declare that the product specified above, when used in conjunction with the conditions of conformance set forth in the product instruction manual, complies with the requirements of the Low Voltage Directive 73/23/EEC, which forms the basis for application of the CE Mark to this product.

Place: KEPCO Inc.

131-38 Sanford Ave. Flushing, N.Y.11355 USA

Saul Kupferberg

(Full Name)

Date:

228-1348 DC-COMP/INST 022014 A

VP OF SALES

(position)

Page 4

Conditions of Conformance

When this product is used in applications governed by the requirements of the EEC, the following restrictions and conditions apply:

1. For European applications, requiring compliance to the Low Voltage Directive, 73/23/EEC, this power supply is considered a component product, designed for “built in“ applications. Because it is incomplete in construction, the end product enclosure must provide for compliance to any remaining electrical safety requirements and act as a fire enclosure. (EN61010-1:2001, Cl. 6, Cl. 7, Cl.8, and Cl. 9)

2. This power supply is designed for stationary installation, with mains power applied via a detachable power supply cord or via direct wiring to the source power terminal block.

3. This power supply is considered a Class 1 (earthed) product. It is intended for use as part of equipment meant for test, measurement and laboratory use, and is designed to operate from single phase, three wire power systems. This equipment must be installed within a suitably wired equipment rack, utilizing a three wire (grounded) mains connection. See wiring section of this manual for complete electrical wiring instructions. (EN61010-1:2001, Cl.6.10.1)

4. This power supply has secondary output circuits that are considered hazardous, and which exceed 240 VA at a potential of 2V or more.

5. The output wiring terminals of this power supply has not been evaluated for field wiring and, therefore, must be properly configured by the end product manufacturer prior to use.

6. This power supply employs a supplementary circuit protector in the form of a circuit breaker mounted on the front panel. This circuit breaker protects the power supply itself from damage in the event of a fault condition. For complete circuit protection of the end product, as well as the building wiring, it is required that a primary circuit protection device be fitted to the branch circuit wiring. (EN61010-1:2001, Cl. 9.5)

7. Hazardous voltages are present within this power supply during normal operation. All operator adjustments to the product are made via externally accessible switches, controls and signal lines as specified within the product operating instructions. There are no user or operator serviceable parts within the product enclosure. Refer all servicing to qualified and trained Kepco service technicians.

B 228-1351 COND/CONFORM 022014

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SAFETY INSTRUCTIONS

1. Installation, Operation and Service Precautions

This product is designed for use in accordance with EN 61010-1 and UL 3101 for Installation Category 2, Pollution Degree 2. Hazardous voltages are present within this product during normal operation. The product should never be operated with the cover removed unless equivalent protection of the operator from accidental contact with hazardous internal voltages is provided:

There are no operator serviceable parts or adjustments within the product enclosure. Refer all servicing to trained service technician.

Source power must be removed from the product prior to performing any servicing.

This product is factory set for the nominal a-c mains voltage indicated by the Voltage Range Selector switch located adjacent to the source power connection on the product's rear panel. To reconfigure the product input for other nominal mains voltages as listed herein, follow the applicable instructions shown in this manual. NOTE: Source power must be removed from the product prior to changing the setting of the Voltage Range Selector switch.

2. Grounding

This product is a Class 1 device which utilizes protective earthing to ensure operator safety.

The PROTECTIVE EARTHING CONDUCTOR TERMINAL must properly con-

nected prior to application of source power to the product (see instructions on installation herein) in order to ensure safety from electric shock.

PROTECTIVE EARTHING CONDUCTOR TERMINAL - This symbol indicates the point on the product to which the protective earthing conductor must be attached.

EARTH (GROUND) TERMINAL - This symbol is used to indicate a point which is connected to the PROTECTIVE EARTHING TERMINAL. The component installer/ assembler must ensure that this point is connected to the PROTECTIVE EARTHING TERMINAL.

CHASSIS TERMINAL -This symbol indicates frame (chassis) connection, which is supplied as a point of convenience for performance purposes (see instructions on grounding herein). This is not to be confused with the protective earthing point, and may not be used in place of it.

3. Electric Shock Hazards

This product outputs hazardous voltage and energy levels as a function of normal operation. Operators must be trained in its use and exercise caution as well as common sense during use to prevent accidental shock.

This symbol appears adjacent to any external terminals at which hazardous voltage

228-1353 SAFETY - (SWITCH) 022014 C/(D BLANK)

levels as high as 500V d-c may exist in the course of normal or single fault conditions.

This symbol appears adjacent to any external terminals at which hazardous voltage levels in excess of 500V d-c may exist in the course of normal or single fault conditions

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TABLE OF CONTENTS

SECTION PAGE

SECTION 1 - INTRODUCTION

1.1 Scope of Manual ..................................................................................................................................... 1-1

1.2 General Description................................................................................................................................. 1-1

1.3 Specifications .......................................................................................................................................... 1-1

1.4 Features .................................................................................................................................................. 1-8

1.4.1 Local Control...................................................................................................................................... 1-8

1.4.2 Remote Control.................................................................................................................................. 1-8

1.4.2.1 Digital Programming .................................................................................................................... 1-8

1.4.2.2 Analog Programming ................................................................................................................... 1-8

1.4.2.3 Analog Readback......................................................................................................................... 1-8

1.4.3 Digital Calibration............................................................................................................................... 1-8

1.4.4 Overvoltage/Overcurrent Protection .................................................................................................. 1-9

1.4.5 User-defined Voltage/Current Limits.................................................................................................. 1-9

1.4.6 Nonvolatile Storage of Programmed Sequences or Active Settings.................................................. 1-9

1.4.7 Current Scale..................................................................................................................................... 1-9

1.4.8 Fast Mode/Slow Mode Selection ....................................................................................................... 1-9

1.4.9 External Trigger Port.......................................................................................................................... 1-10

1.4.10 Built-in Protection............................................................................................................................... 1-10

1.4.11 Current Sink Capability...................................................................................................................... 1-11

1.4.12 Analog Readback and Flag Signals Available for Customer Use...................................................... 1-12

1.5 Equipment Supplied ................................................................................................................................ 1-12

1.6 Accessories ............................................................................................................................................. 1-13

1.7 Safety ...................................................................................................................................................... 1-13

SECTION 2 - INSTALLATION

2.1 Unpacking and Inspection ....................................................................................................................... 2-1

2.2 Terminations and Controls ...................................................................................................................... 2-1

2.3 Source Power Requirements .................................................................................................................. 2-6

2.4 Cooling .................................................................................................................................................... 2-6

2.5 Preliminary Operational Check................................................................................................................ 2-6

2.6 Installation ............................................................................................................................................... 2-8

2.6.1 Bench Top Use.................................................................................................................................. 2-8

2.6.2 Rack Mounting................................................................................................................................... 2-8

2.7 Wiring Instructions................................................................................................................................... 2-8

2.7.1 Safety Grounding............................................................................................................................... 2-8

2.7.2 Source Power Connections ............................................................................................................... 2-9

2.7.3 D-C Output Grounding....................................................................................................................... 2-9

2.7.4 Power Supply/Load Interface............................................................................................................. 2-9

2.7.4.1 Cable Recommendations............................................................................................................. 2-10

2.7.5 Load Connection - General................................................................................................................ 2-10

2.7.5.1 Local Sensing/Remote Sensing Select........................................................................................ 2-11

2.7.5.2 Fast Mode/Slow Mode Select ...................................................................................................... 2-11

2.7.5.3 Grounding Network Configuration................................................................................................ 2-11

2.7.5.4 Positive Output, Negative Terminal Grounded ............................................................................ 2-11

2.7.5.5 Negative Output, Positive Terminal Grounded ............................................................................ 2-12

2.8 Operating Configuration .......................................................................................................................... 2-13

2.9 Status Port............................................................................................................................................... 2-13

SECTION 3 - OPERATION

3.1 General.................................................................................................................................................... 3-1

3.2 Local Mode Operation ............................................................................................................................. 3-1

3.2.1 Front Panel Keypad and LCD............................................................................................................ 3-1

3.2.1.1 Command Entry Status................................................................................................................ 3-1

3.2.1.2 Data Entry Status......................................................................................................................... 3-1

3.2.1.3 Display (LCD)............................................................................................................................... 3-1

3.2.1.4 Keypad Functions ........................................................................................................................ 3-2

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3.2.2 Turning the Power Supply On........................................................................................................... 3-4

3.2.3 Error Conditions ................................................................................................................................ 3-5

3.2.4 Setting Local Mode ........................................................................................................................... 3-5

3.2.5 Adjusting LCD Contrast .................................................................................................................... 3-6

3.2.6 Enabling/Disabling Audible Beeps .................................................................................................... 3-6

3.2.7 Enabling/Disabling DC Output Power ............................................................................................... 3-6

3.2.7.1 Disabling DC Output when using Digital Inputs only (keypad and/or GPIB) ............................... 3-6

3.2.7.2 Disabling DC Output when using Analog control. ....................................................................... 3-6

3.2.7.3 Remote Shutdown using External Trigger Port ........................................................................... 3-7

3.2.7.4 Power Up DC Output Control...................................................................................................... 3-7

3.2.8 Reset Operation................................................................................................................................ 3-7

3.2.8.1 Setting Power-Up & Reset Current ............................................................................................. 3-7

3.2.9 Setting Output Voltage or Current..................................................................................................... 3-8

3.2.10 Changing Current Scale.................................................................................................................... 3-8

3.2.11 Setting Overvoltage or Overcurrent Protection ................................................................................. 3-9

3.2.12 Changing Maximum Voltage or Current Value ................................................................................. 3-10

3.2.13 Storing Power Supply Output Settings.............................................................................................. 3-10

3.2.14 Recalling Stored Output Settings...................................................................................................... 3-11

3.2.15 Firmware Version.............................................................................................................................. 3-11

3.2.16 Local Mode Programming of the Power Supply................................................................................ 3-11

3.2.16.1 Creating or Modifying a Program (Program Edit Mode).............................................................. 3-11

3.2.16.1.1 Modifying Programmed Time Interval..................................................................................... 3-12

3.2.16.1.2 Time Interval Accuracy........................................................................................................... 3-12

3.2.16.2 Running a Program ..................................................................................................................... 3-12

3.2.16.3 Stepping Through a Program...................................................................................................... 3-12

3.2.16.4 Cycling a Program....................................................................................................................... 3-14

3.2.16.5 Running a Program Once ........................................................................................................... 3-14

3.2.16.6 Stopping a Running Program...................................................................................................... 3-14

3.2.16.7 Sample Program ......................................................................................................................... 3-14

3.2.17 Calibration......................................................................................................................................... 3-15

3.3 Remote Mode Programming Using SCPI commands via IEEE 488 (GPIB). Bus .................................. 3-15

3.3.1 IEEE 488 (GPIB) Bus Protocol ......................................................................................................... 3-15

3.3.2 DCL Control ...................................................................................................................................... 3-17

3.3.3 Changing the GPIB Address............................................................................................................. 3-17

3.3.4 External Trigger ................................................................................................................................ 3-17

3.3.5 BHK-MG VISA Instrument driver ...................................................................................................... 3-18

3.3.6 Programming Techniques to Optimize performance ........................................................................ 3-18

3.3.6.1 Programming Voltage/Current Limit and Current/Voltage Limit .................................................. 3-18

3.3.6.2 Making Sure the Previous Command is Complete ..................................................................... 3-19

3.4 RS232-C Operation ................................................................................................................................ 3-20

3.4.1 Setting RS 232 Baud Rate................................................................................................................ 3-21

3.4.2 Serial Interface.................................................................................................................................. 3-21

3.4.3 RS 232 Implementation .................................................................................................................... 3-21

3.4.3.1 Echo Mode .................................................................................................................................. 3-22

3.4.3.2 Prompt Method............................................................................................................................ 3-22

3.4.3.3 XON XOFF Method..................................................................................................................... 3-22

3.4.4 Isolating RS 232 Communication Problems ..................................................................................... 3-23

3.5 SCPI Programming................................................................................................................................. 3-23

3.5.1 SCPI Messages ................................................................................................................................ 3-23

3.5.2 Common Commands/Queries .......................................................................................................... 3-24

3.5.3 SCPI Subsystem Command/Query Structure................................................................................... 3-24

3.5.3.1 ABORt Subsystem ...................................................................................................................... 3-24

3.5.3.2 INITiate Subsystem..................................................................................................................... 3-24

3.5.3.3 LIST Subsystem.......................................................................................................................... 3-24

3.5.3.4 MEASure Subsystem .................................................................................................................. 3-24

3.5.3.5 OUTPut Subsystem .................................................................................................................... 3-24

3.5.3.6 Instrument Subsystem ................................................................................................................ 3-24

ii BHK 500-0.4MG SVC 022014

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3.5.3.7 STATus Subsystem ..................................................................................................................... 3-25

3.5.3.8 System Subsystem ...................................................................................................................... 3-25

3.5.3.9 TRIGger subsystem..................................................................................................................... 3-25

3.5.3.10 [SOURce:]VOLTage and [SOURce:]CURRent Subsystems ....................................................... 3-25

3.5.3.11 CALibrate Subsystem .................................................................................................................. 3-25

3.5.4 Program Message Structure.............................................................................................................. 3-25

3.5.4.1 Keyword....................................................................................................................................... 3-26

3.5.4.2 Keyword Separator ...................................................................................................................... 3-26

3.5.4.3 Query Indicator ............................................................................................................................ 3-26

3.5.4.4 Data ............................................................................................................................................. 3-27

3.5.4.5 Data Separator............................................................................................................................. 3-27

3.5.4.6 Message Unit Separator .............................................................................................................. 3-27

3.5.4.7 Root Specifier .............................................................................................................................. 3-29

3.5.4.8 Message Terminator.................................................................................................................... 3-29

3.5.5 Understanding The Command Structure ........................................................................................... 3-29

3.5.6 Program Message Syntax Summary................................................................................................. 3-30

3.5.7 SCPI Program Examples................................................................................................................... 3-30

3.6 Remote Programming Using Analog Programming Terminals................................................................ 3-31

3.6.1 Analog Programming Warnings and Cautions................................................................................... 3-33

3.6.2 Programming with external resistance............................................................................................... 3-35

3.6.2.1 Voltage Mode............................................................................................................................... 3-37

3.6.2.2 Current Mode............................................................................................................................... 3-37

3.6.3 Programming with external voltage using a low impedance Voltage source..................................... 3-38

3.6.3.1 Voltage Mode............................................................................................................................... 3-42

3.6.3.2 Current Mode............................................................................................................................... 3-43

3.6.4 Programming with external voltage using a high impedance, low level (1V) Voltage source ............ 3-43

3.6.4.1 Voltage Mode............................................................................................................................... 3-46

3.6.4.2 Current Mode............................................................................................................................... 3-46

3.6.5 Programming with external current source (1 mA) ............................................................................ 3-47

3.6.5.1 Voltage Mode............................................................................................................................... 3-49

3.6.5.2 Current Mode............................................................................................................................... 3-49

3.7 Operating Modes..................................................................................................................................... 3-50

3.7.1 Slow/Fast mode of operation ............................................................................................................. 3-50

3.7.2 Series operation................................................................................................................................. 3-52

3.7.2.1 Automatic series operation .......................................................................................................... 3-53

3.7.2.2 Master-slave series operation (Automatic Tracking).................................................................... 3-56

3.7.2.2.1 Voltage Mode Operation .........................................................................................................3-56

3.7.2.2.2 Current Mode Operation .........................................................................................................3-59

3.7.3 Parallel operation............................................................................................................................... 3-61

3.7.3.1 Automatic parallel operation ........................................................................................................ 3-62

3.7.3.2 Master-slave parallel operation.................................................................................................... 3-64

3.7.3.2.1 Voltage Mode Operation .........................................................................................................3-65

3.7.3.2.2 Current Mode Operation .........................................................................................................3-67

SECTION 4 - CALIBRATION

4.1 General.................................................................................................................................................... 4-1

4.2 Equipment Required................................................................................................................................ 4-1

4.3 Calibration Procedures Using Front Panel Keypad ................................................................................. 4-1

4.3.1 Voltage Calibration ............................................................................................................................ 4-2

4.3.2 High Current Calibration .................................................................................................................... 4-3

4.3.3 Low Current Calibration..................................................................................................................... 4-4

4.4 Calibration Using VISA Driver ................................................................................................................. 4-5

4.4.1 GPIB Setup........................................................................................................................................ 4-5

4.4.2 Calibration Basics .............................................................................................................................. 4-5

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4.4.3 Calibration Procedure ....................................................................................................................... 4-7

4.5 Changing the Calibration Password ....................................................................................................... 4-9

4.6 Restoring Previous Calibration Values ................................................................................................... 4-10

4.7 Restoring Factory Calibration Values ..................................................................................................... 4-10

4.8 Calibration Storage ................................................................................................................................. 4-10

APPENDIX A - IEEE 488.2 COMMAND/QUERY DEFINITIONS

A-1 Introduction............................................................................................................................................. A-1

A.2 *CLS — Clear Status Command ............................................................................................................ A-1

A.3 *ESE — Standard Event Status Enable Command................................................................................ A-1

A.4 *ESE? — Standard Event Status Enable Query..................................................................................... A-1

A.5 *ESR? — Event Status Register Query.................................................................................................. A-2

A.6 *IDN? — Identification Query.................................................................................................................. A-2

A.7 *OPC — Operation Complete Command ............................................................................................... A-2

A.8 *OPC? — Operation Complete Query .................................................................................................... A-2

A.9 *RCL — Recall Command ...................................................................................................................... A-2

A.10 *RST — Reset Command....................................................................................................................... A-3

A.11 * SAV — Save Command....................................................................................................................... A-3

A.12 *SRE — Service Request Enable Command ......................................................................................... A-4

A.13 *SRE? — Service Request Enable Query .............................................................................................. A-4

A.14 *STB? — Status Byte Register Query .................................................................................................... A-4

A.15 *TRG — Trigger Command .................................................................................................................... A-4

A.16 *TST? — Self Test Query....................................................................................................................... A-4

APPENDIX B - SCPI COMMAND/QUERY DEFINITIONS

B-1 Introduction............................................................................................................................................. B-1

B.2 Numerical Values.................................................................................................................................... B-2

B.3 ABORt Command ................................................................................................................................... B-2

B.4 CAL Commands and Queries................................................................................................................. B-2

B.5 DISPlay:CONTrast Command ................................................................................................................ B-2

B.6 DISPlay:CONTrast? Query..................................................................................................................... B-2

B.7 DISPlay:MODE Command ..................................................................................................................... B-4

B.8 DISPlay:MODE? Query .......................................................................................................................... B-4

B.9 DISPlay:TEXT Command ....................................................................................................................... B-4

B.10 DISPlay:TEXT? Query............................................................................................................................ B-4

B.11 INITiate[:IMMediate] Command.............................................................................................................. B-4

B.12 INITiate:CONTinuous Command............................................................................................................ B-4

B.13 INITiate:CONTinuous? Query................................................................................................................. B-4

B.14 INSTrument:STATe Command............................................................................................................... B-5

B.15 INSTrument:STATe? Query ................................................................................................................... B-5

B.16 [SOURce:]LIST:CLEar Command .......................................................................................................... B-5

B.17 [SOURce:]LIST:COUNt Command......................................................................................................... B-5

B.18 [SOURce:]LIST:COUNt? Query.............................................................................................................. B-5

B.19 [SOURce:]LIST:COUNt:SKIP Command................................................................................................ B-5

B.20 [SOURce:]LIST:COUNt:SKIP? Query .................................................................................................... B-5

B.21 [SOURce:]LIST:CURRent Command ..................................................................................................... B-5

B.22 [SOURce:]LIST:CURRent? Query.......................................................................................................... B-6

B.23 [SOURce:]LIST:CURRent:POINts? Query ............................................................................................. B-6

B.24 [SOURce:]LIST:DIRection Command..................................................................................................... B-6

B.25 [SOURce:]LIST:DIRection? Query ......................................................................................................... B-6

B.26 [SOURce:]LIST:DWELl Command ......................................................................................................... B-6

B.27 [SOURce:]LIST:DWELl? Query.............................................................................................................. B-6

B.28 [SOURce:]LIST:DWELl:POINts? Query ................................................................................................. B-6

B.29 [SOURce:]LIST:QUERy Command ........................................................................................................ B-7

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B.30 [SOURce:]LIST:QUERy? Query............................................................................................................. B-7

B.31 [SOURce:]LIST:VOLTage Command..................................................................................................... B-7

B.32 [SOURce:]LIST:VOLTage? Query ......................................................................................................... B-7

B.33 [SOURce:]LIST:VOLTage:POINts? Query............................................................................................. B-7

B.34 MEASure[:SCALar]:CURRent[:DC]? Query ........................................................................................... B-9

B.35 MEASure:VOLTage[:SCALar][:DC]? Query ........................................................................................... B-9

B.36 OUTPut[:STATe] Command................................................................................................................... B-9

B.37 OUTPut[:STATe]? Query ....................................................................................................................... B-9

B.38 [SOURce:]CURRent[:LEVel][:IMMediate][:AMPlitude] Command.......................................................... B-10

B.39 [SOURce:]CURRent[:LEVel][:IMMediate][:AMPlitude]? Query .............................................................. B-10

B.40 [SOURce:]CURRent:LIMit[:HIGH] Command......................................................................................... B-10

B.41 [SOURce:]CURRent:LIMit[:HIGH]? Query ............................................................................................. B-10

B.42 [SOURce:]CURRent:MODE Command.................................................................................................. B-10

B.43 [SOURce:]CURRent:MODE? Query ...................................................................................................... B-11

B.44 [SOURce:]CURRent:PROTection[:LEVel] Command ............................................................................ B-11

B.45 [SOURce:]CURRent:PROTection[:LEVel]? Query ................................................................................. B-11

B.46 [SOURce:]CURRent:RANGe Command ................................................................................................ B-11

B.47 [SOURce:]CURRent:RANGe? Query..................................................................................................... B-11

B.48 [SOURce:]CURRent[:LEVel]:TRIGgered[:AMPlitude] Command........................................................... B-11

B.49 [SOURce:]CURRent[:LEVel]:TRIGgered[:AMPlitude]? Query ............................................................... B-12

B.50 [SOURce:]VOLTage[:LEVel][:IMMediate][:AMPlitude] Command.......................................................... B-12

B.51 [SOURce:]VOLTage[:LEVel][:IMMediate][:AMPlitude]? Query .............................................................. B-12

B.52 [SOURce:]VOLTage:LIMit[:HIGH] Command......................................................................................... B-12

B.53 [SOURce:]VOLTage:LIMit[:HIGH]? Query ............................................................................................. B-13

B.54 [SOURce:]VOLTage:MODE Command.................................................................................................. B-13

B.55 [SOURce:]VOLTage:MODE? Query ...................................................................................................... B-13

B.56 [SOURce:]VOLTage:PROTection[:LEVel] Command............................................................................ B-13

B.57 [SOURce:]VOLTage:PROTection[:LEVel]? Query................................................................................. B-13

B.58 [SOURce:]VOLTage[:LEVel]:TRIGgered[:AMPlitude] Command........................................................... B-13

B.59 [SOURce:]VOLTage[:LEVel]:TRIGgered[:AMPlitude]? Query ............................................................... B-14

B.60 [SOURce:]FUNCtion:MODE? Query ...................................................................................................... B-14

B.61 STATus:OPERation:CONDition? Query................................................................................................. B-14

B.62 STATus:OPERation:ENABle Command ................................................................................................ B-15

B.63 STATus:OPERation:ENABle? Query ..................................................................................................... B-15

B.64 STATus:OPERation[:EVENt]? Query..................................................................................................... B-15

B.65 STATus:PRESet Command ................................................................................................................... B-16

B.66 STATus:QUEStionable[:EVENt]? Query ................................................................................................ B-16

B.67 STATus:QUEStionable:CONDition? Query............................................................................................ B-16

B.68 STATus:QUEStionable:ENABle Command............................................................................................ B-16

B.69 STATus:QUEStionable:ENABle? Query ................................................................................................ B-16

B.70 SYSTem:BEEP Command..................................................................................................................... B-17

B.71 SYSTem:COMMunication:GPIB:ADDRess

B.72 SYSTem:COMMunication:GPIB:ADDRess? Query ............................................................................... B-17

B.73 SYSTem:COMMunication:SERial:BAUD Command.............................................................................. B-17

B.74 SYSTem:COMMunication:SERial:BAUD? Query................................................................................... B-17

B.75 SYSTem:COMMunication:SERial:ECHO Command ............................................................................. B-17

B.76 SYSTem:COMMunication:SERial:ECHO? Query .................................................................................. B-17

B.77 SYSTem:COMMunication:SERial:PACE Command.............................................................................. B-17

B.78 SYSTem:COMMunication:SERial:PACE? Query................................................................................... B-18

B.79 SYSTem:COMMunication:SERial:PROMpt CommanD ......................................................................... B-18

B.80 SYSTem:COMMunication:SERial:PROMpt? Query............................................................................... B-18

B.81 SYSTem:ERRor? Query ........................................................................................................................ B-18

B.82 SYSTem:ERRor:CODE? Query ............................................................................................................. B-18

Command......................................................................... B-17

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B.83 SYSTem:ERRor:CODE:ALL? Query ...................................................................................................... B-18

B.84 SYSTem:KLOCk Command ................................................................................................................... B-19

B.85 SYSTem:KLOCk? Query ........................................................................................................................ B-19

B.86 SYSTem:PASSword:CENable Command .............................................................................................. B-19

B.87 SYSTem:PASSword:CDISable Command............................................................................................. B-19

B.88 SYSTem:PASSword:NEW Command .................................................................................................... B-19

B.89 SYSTem:PASSword:STATe? Query ...................................................................................................... B-19

B.90 SYSTem:SECurity:IMMediate Command............................................................................................... B-20

B.91 SYSTem:VERSion? Query ..................................................................................................................... B-20

B.92 TRIGger:SOURce Command ................................................................................................................. B-20

vi BHK 500-0.4MG SVC 022014

Page 13

LIST OF FIGURES

FIGURE TITLE PAGE

1-1 BHK-MG Series Programmable Power Supply.............................................................................................. x

1-2 BHK Series Power Supply, Mechanical Outline Drawing............................................................................ 1-6

2-1 BHK-MG Series, Front Panel Controls, Indicators and Connectors............................................................ 2-1

2-2 BHK-MG Series, Rear Panel Controls and Connections ............................................................................ 2-3

2-3 LCD Power On Defaults.............................................................................................................................. 2-7

2-4 Local Sensing, Slow Mode Selected, Grounding Network Connected,

Floating Output (Factory Default Configuration)....................................................................................... 2-12

2-5 Remote Sensing, Fast Mode Selected, Positive Output Grounded ............................................................ 2-12

2-6 Status Port Opto-coupler Active “High” Configuration................................................................................. 2-13

2-7 Status Port Opto-coupler Active “Low” Configuration ................................................................................. 2-13

3-1 LCD Power On Defaults.............................................................................................................................. 3-5

3-2 Programming Example to Verify Previous Command has Completed........................................................ 3-20

3-3 RS 232 Implementation .............................................................................................................................. 3-22

3-4 Message Structure...................................................................................................................................... 3-27

3-5 Tree Diagram of SCPI Commands Used with BHK-MG Power Supply...................................................... 3-28

3-6 Typical Example Of BHK-MG Power Supply Program Using SCPI Commands......................................... 3-31

3-7 Analog Voltage Programming, Simplified Diagram ..................................................................................... 3-32

3-8 Analog Current Programming, Simplified Diagram ..................................................................................... 3-32

3-9 Analog Programming of Output Voltage (Voltage Mode)

or Voltage Limit (Current Mode) using Resistance.................................................................................. 3-35

3-10 Analog Programming of Output Current (Current Mode)

or Current Limit (Voltage Mode) using Resistance.................................................................................. 3-36

3-11 Analog Programming of Output Voltage (Voltage Mode) or Voltage Limit

(Current Mode) using Isolated (floating) Low Impedance Voltage Source (VS)...................................... 3-38

3-12 Analog Programming of Output Voltage (Voltage Mode) or Voltage

Limit (Current Mode) using Grounded Low Impedance Voltage Source (VS)......................................... 3-39

3-13 Analog Programming of Output Current (Current Mode) or Current Limit

(Voltage Mode) using Isolated (Floating) Low Impedance Voltage Source (VS) .................................... 3-40

3-14 Analog Programming of Output Current (Current Mode) or Current

Limit (Voltage Mode) using Grounded Low Impedance Voltage Source (VS) ........................................ 3-41

3-15 Analog Programming of Output Voltage (Voltage Mode) or Voltage

Limit (Current Mode) using High Impedance, Low Level (1V) Voltage Source (VS)............................... 3-44

3-16 Analog Programming of Output Current (Current Mode) or Current

Limit (Voltage Mode) using High Impedance, Low Level (1V) Voltage Source (VS)............................... 3-45

3-17 Analog Programming of Output Voltage (Voltage Mode) or Voltage

Limit (Current Mode) using Current Source (1mA) (CS)......................................................................... 3-47

3-18 Analog Programming of Output Current (Current Mode) or Current

Limit (Voltage Mode) using Current Source (1mA) (CS) ......................................................................... 3-48

3-19 Slow Mode/Fast Mode Operation ............................................................................................................... 3-51

3-20 Series Automatic Configuration .................................................................................................................. 3-55

3-21 Series Master-Slave (Voltage Mode) Configuration.................................................................................... 3-58

3-22 Series Master-Slave (Current Mode) Configuration .................................................................................... 3-59

3-23 Parallel Automatic Configuration................................................................................................................. 3-63

3-24 Parallel Master-Slave (Voltage Mode) Configuration .................................................................................. 3-65

3-25 Parallel Master-Slave (Current Mode) Configuration .................................................................................. 3-68

4-1 GPIB Setup Window ................................................................................................................................... 4-5

4-2 Main Panel (BHK 500-0.4MG, Typical) ....................................................................................................... 4-6

4-3 Calibration Panel......................................................................................................................................... 4-6

A-1 GPIB Commands ....................................................................................................................................... A-3

B-1 Programming the Output............................................................................................................................ B-3

B-2 Using Display Commands.......................................................................................................................... B-3

B-3 Using LIST Commands and Queries ......................................................................................................... B-8

B-4 Programming Current ................................................................................................................................ B-12

B-5 Programming Voltage ................................................................................................................................ B-14

B-6 Using Status Commands and Queries....................................................................................................... B-15

B-7 Using System Commands and Queries..................................................................................................... B-19

BHK 500-0.4MG SVC 022014

vii

Page 14

LIST OF TABLES

TABLE TITLE PAGE

1-1 Model Parameters ...................................................................................................................................... 1-2

1-2 BHK-MG 200W Specifications ................................................................................................................... 1-2

1-3 Connector A2J5 Signal Descriptions .......................................................................................................... 1-12

1-4 Equipment Supplied ................................................................................................................................... 1-12

1-5 Accessories ................................................................................................................................................ 1-13

1-6 Safety Symbols .......................................................................................................................................... 1-13

2-1 Controls, Indicators, and Connectors ......................................................................................................... 2-2

2-2 Trigger Port Pin Assignments ..................................................................................................................... 2-2

2-3 RS232C Port Input/Output Pin Assignments .............................................................................................. 2-3

2-4 Status Port Connector Pin Assignments .................................................................................................... 2-4

2-5 IEEE 488 Port Connector Pin Assignments ............................................................................................... 2-4

2-7 Voltage Programming Terminal Strip TB2, Terminal Assignments ............................................................ 2-5

2-8 Current Programming Terminal Strip TB3, Terminal Assignments ............................................................ 2-5

2-6 Rear Output Terminal Strip TB1 Terminal Assignments ............................................................................ 2-5

2-9 Internal Jumper Configuration .................................................................................................................... 2-13

3-1 LCD Messages ........................................................................................................................................... 3-2

3-2 Key Functions ............................................................................................................................................. 3-2

3-3 Error Conditions ......................................................................................................................................... 3-5

3-4 Memory Location Worksheet ...................................................................................................................... 3-13

3-5 Sample Program (Model BHK-MG 500-0.4MG) ......................................................................................... 3-15

3-6 IEEE 488 (GPIB) Bus Interface Functions ................................................................................................. 3-15

3-7 IEEE 488 (GPIB) Bus Command Mode Messages .................................................................................... 3-16

3-8 IEEE 488 (GPIB) Bus Data Mode Messages ............................................................................................. 3-17

3-9 Rules Governing Shortform Keywords ....................................................................................................... 3-26

3-10 Feedback Resistor and Current Sensing Resistor Values ......................................................................... 3-36

4-1 Calibration Panel Functions ....................................................................................................................... 4-7

4-2 Factory Default Calibration Passwords ...................................................................................................... 4-9

4-3 Calibration Storage ..................................................................................................................................... 4-11

A-1 IEEE 488.2 Command/query Index ............................................................................................................A-1

A-2 Standard Event Status Enable Register and Standard Event Status Register Bits ...................................A-1

A-3 Service Request Enable and Status Byte Register Bits .............................................................................A-4

B-1 SCPI Subsystem Command/query Index ...................................................................................................B-1

B-2 Operation Condition Register, Operation Enable Register,

and Operation Event Register Bits ..........................................................................................................B-14

B-3 Questionable Event Register, Questionable Condition Register

and Questionable Condition Enable Register Bits ...................................................................................B-16

B-4 Error Messages ..........................................................................................................................................B-20

viii BHK 500-0.4MG SVC 022014

Page 15

SERVICE

SAFETY INSTRUCTIONS

Read these safety instructions, as well as the applicable installation, operating and servicing instructions contained in this manual before using the power supply.

WARNING

Do not touch the output terminals. The high voltage output is dangerous. Electric shock can cause injury or death.

Do not remove the cover or disassemble the unit. There are no operator serviceable components or adjustments inside the unit. High voltage components inside the unit can cause serious injury even with input power disconnected.

CAUTION

If this power supply is used in OEM equipment, the OEM equipment manufacturer is responsible for attaching appropriate warning labels on the OEM equipment.

Operating the power supply outside the specified limits for input voltage, temperature, or other environmental conditions noted in this manual can damage the power supply and void the warranty.

Safety Messages

The BHK-MG can be controlled by digital and/or analog inputs. When OUTPUT is set to off from the keypad or the GPIB, an analog input will still produce an output from the BHK-MG which will be indicated on the LCD. If the output is greater than 8 Volts and the current is higher than 2 LSB’s, a shutdown sequence begins: the unit will beep, the LCD will flash DIGITAL IS OFF and SET ANALOG OFF, and the unit will shut down within 25 seconds unless the analog input is turned off. The beeping and controlled shutdown function can be overridden by a jumper option (see Table 2-9.)

There are no operator serviceable parts inside the case. Service must be referred to authorized personnel. Using the power supply in a manner not specified by Kepco. Inc. may impair the protection provided by the power supply. Observe all safety precautions noted throughout this manual. The following table lists symbols used on the power supply or in this manual where applicable.

SAFETY SYMBOLS

SYMBOL Meaning SYMBOL Meaning

WARNING: RISK OF ELECTRIC SHOCK. WARNING

CAUTION: REFER TO REFER-

ENCED PROCEDURE. CAUTION

INDICATES THE POSSIBILITY OF BODILY INJURY OR DEATH.

INDICATES THE POSSIBILITY OF EQUIPMENT DAMAGE.

BHK-MG 022014 ix

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FIGURE 1-1. BHK-MG SERIES PROGRAMMABLE POWER SUPPLY

x BHK-MG022014

Page 17

1.1 SCOPE OF MANUAL

This manual contains instructions for the installation and operation of the BHK-MG series of 200W output power stabilized voltage or current, d-c power supplies manufactured by KEPCO, Inc., Flushing, New York, U.S.A.

DANGEROUS AND LETHAL POTENTIALS ARE PRESENT, BOTH WITHIN THIS POWER SUPPLY, AND AT THE OUTPUT!

Before proceeding to use the power supply, read this manual very carefully. Caution must be used when working with, and making connections to, this power supply. Use only wires with the proper voltage rating for high voltage connections. Use the designated plugs for the front panel output. Be extremely careful when analog programming inputs are used, especially with the negative output of the power supply grounded.

Unless otherwise specified, always connect the test and measuring equipment to the input power source using an isolating transformer having a suitable isolating voltage rating. Follow all instructions regarding the grounding of the test set-up. Refer all servicing to qualified service personnel only.

SECTION 1 - INTRODUCTION

WARNING

1.2 GENERAL DESCRIPTION

The BHK-MG Power Supply Series (Figure 1-1) are full-range, automatic crossover, linear voltage/current stabilizers with a full rectangular output characteristic. Four single-output models are available, each of which have two output current ranges as listed in Table1-1.

Although designed as a stand-alone bench top unit, the full-rack cross section permits mounting in a standard 19-inch wide rack (see Table1-5). Connections can be made at both rear output terminals (recommended for rack mounted configurations) and front output terminals (recommended for bench applications). Sensing output terminals are available at the rear terminals only. These power supplies operate from either 115V or 230V a-c (nominal - switch selectable), 50 or 60 Hz (nominal) input source power. Since there are no internal adjustments, BHK-MG Power Supplies offer excellent output voltage/current stability and easy calibration.

Output voltage and current are displayed on an alphanumeric Liquid Crystal Display (LCD). Control of the BHK-MG can be either local, via the front panel keypad and display, or remote using either analog signals (applied to Analog Programming Terminals), or digital programming via either the IEEE 488.2 (GPIB) or RS 232 communication bus using SCPI commands. Both digital control (either local or remote) and analog control can be used simultaneously. Digital control is done with 12 bits of resolution over the entire voltage/current range.

1.3 SPECIFICATIONS

Table 1-1 lists the parameters applicable to individual models. Table 1-2 lists general specifications applicable to all models except where otherwise noted.

BHK-MG (OPR) 022014 1-1

Page 18

TABLE 1-1. MODEL PARAMETERS

OUTPUT

MODEL

NUMBER

BHK 300-0.6MG 0 - 300

BHK 500-0.4MG 0 - 500

BHK 1000-0.2MG 0 - 1000

BHK 2000-0.1MG 0 - 2000

VOLTAGE

RANGE

(VOLTS)

OUTPUT

CURRENT

RANGE

(mA)

0 - 600 180

0 - 60 18 33.3 0.008

0 - 400 200

0 - 40 20 83 0.007

0 - 200 200

0 - 20 20 333 0.003

0 - 100 200

0 - 10 20 1333 0.001

MAXIMUM

OUTPUT

POWER

(WATTS)

OUTPUT EQUIVALENT IMPEDANCE (FAST MODE)

VO LTA GE M O DE

(SERIES R–L)

(Ohms)

d-c

0.025 2.0

0.0625 3.6

0.25 6.0

1.0 35

L (mH)

CURRENT MODE (PARALLEL R–C)

(MOhms)

d-c

3.33 0.013

8.3 0.012

33 0.005

133 0.002

C (µF)

TABLE 1-2. BHK-MG 200W SPECIFICATIONS

SPECIFICATION RATING/DESCRIPTION CONDITION

INPUT CHARACTERISTICS

a-c Voltage nominal (switch selectable) 115/230V a-c Single phase

range (switch selectable) 105-125/210-250V a-c

Frequency nominal 50-60Hz

range 47-63Hz

Current 115V a-c 4.0A a-c 200W at output

230V a-c 2.1A a-c

OUTPUT CHARACTERISTICS

NOTE: Current specifications contained in this table refer to source current (delivered by the unit to the load). Sink current (absorbed

by the unit from the load) occurs when the output voltage is programmed to a lower value. The sink current is constant, from 45% to 55% of High Current scale rating; it flows until the output reaches the lower voltage.

Type of Stabilizer Linear with automatic

Adjustment range (Adjustment is either continuous using analog programming, or stepped using digital programming)

Digital Programming resolution

Digital Programming accuracy Voltage 0.025% of rating

Digital Data Readback accuracy

Source effect Voltage 0.001% E

Load effect Voltage 0.005% E

Voltage and Current 0.025% of rating Current measurement requires calibrated

Voltage 0 to 100% of rating See PAR. 1.4.2.2 and 1.4.2.3 for details

Current 0-100% of rating,

Current 0.05% of rating Both current scales

Voltage 0.05% of rating

Current 0.05% of rating Both current scales, 10-100% of rating

Current 0.002% I

Current 0.015% I

crossover

or 0-10% of rating

0.005% of rating Both current scales, <10% of rating (auto-

max Input voltage

max

max no load - full load

max short - full load

Voltage/Current

about analog programming and readback.

Use Menu program to change current scale (See PAR 3.2.10)

shunt (see PAR. 4.2)

matic 10X magnifier)

105-125/210-250V a-c

1-2 BHK-MG (OPR) 022014

Page 19

TABLE 1-2. BHK-MG 200W SPECIFICATIONS (Continued)

SPECIFICATION RATING/DESCRIPTION CONDITION

OUTPUT CHARACTERISTICS (CONTINUED)

Temperature effect (per degree C)

Time effect Voltage 0.01% E

Ripple

Voltage: Fast Mode

(rms/p-p)

Fast Mode = internal output

Current: Fast Mode capacitor not connected. Slow Mode (default) = internal output capacitor connected

Voltage 0.01% EO max Ambient temperature

Current 0.02% I

0.002% / 0.02% E

Slow Mode

0.001% / 0.01% E

0.02% / 0.2% I

Slow Mode

0.01% / 0.1% I

max

max 0.5-8.5 hours

max

0 to 50° C

Ambient temperature: 25° C

max

Minus output terminal connected to GND.

max

Current: Short with calibrated shunt.

Voltage: Nominal load

Programming rise time (R)/fall time (F)

Voltage: Fast Mode

Slow Mode

µs (R)/180µs (F)

180 90ms (R)/175ms (F)

Load ≥ EO max/IO max, Vout between zero and E sured between 10% and 90% of E

Current: Fast Mode

Slow Mode

µs (R)/200µs (F)

200 90ms (R)/175ms (F)

Load ≤ EO max/IO max, Iout between zero and I between 10% and 90% of I

Transient recovery to load change (Amplitude/time constant)

Small signal 3-dB Bandwidth (Fast Mode)

Voltage Fast Mode

Slow Mode

Current Fast Mode 50% I

Voltage 2.5 KHz Load = E

5% E

max/100 µsec

0.5% E

max/1 msec

max/100 µsec Iout = IO max

Vout=400 Vdc and load switched between infinity and 400/IO max

and load switched between

0.1 x E

Vprog out = 200V d-c (from keypad)

≤ E

max/IO max

max/IO max and

max/IO max,

Vv analog in = 0.2 V rms (from analog input terminal)

Current 2.3 KHz Load = E

max/IO max,

Iprog out = 200 x I keypad) Vc analog in = 0.2 V rms (from analog input terminal)

Slew rate (Fast Mode) Voltage >1.2% E

max (V/µs) Load ≥ EO max/IO max,

Measured as the chord of the exponential response to a square waveform between

Current >1.1% I

zero and E

max (mA/µs) Load = calibrated shunt

Measured as the chord of the exponential

response to a square waveform between zero and I

Overshoot None Turn ON/OFF

Output Impedance See Table 1-1.

Remote Sensing Range (default = local sensing)

D-C Isolation voltage BHK 300-0.6MG,

BHK 500-0.4MG,

0.5 V d-c per lead Provisions for 4-terminal (Kelvin) connection to load

1KV d-c or p-p plus max.

Between either output terminal and ground

output voltage

BHK 1000-0.2MG

BHK 2000-0.1MG 0.5KV d-c or p-p plus max.

Between either output terminal and ground

output voltage

max, mea-

max, measured

max

max/EO max (from

max and back to zero.

max

BHK-MG (OPR) 022014 1-3

Page 20

TABLE 1-2. BHK-MG 200W SPECIFICATIONS (Continued)

SPECIFICATION RATING/DESCRIPTION CONDITION

OUTPUT CHARACTERISTICS (CONTINUED)

Withstand voltage (All models) 1350V a-c/1 min Between shorted inputs and chassis

BHK 300-0.6MG 1950V d-c/1 min Between shorted outputs and chassis.

BHK 500-0.4MG 2250V d-c/1 min

BHK 1000-0.2MG

BHK 2000-0.1MG

Chassis connection to ground resistance

Leakage Current 25

Enable/Disable Output Power Local Front panel Keypad Enables/disables digital programming sig-

Remote - IEEE 488 (GPIB) port

Output Display Output voltage is displayed with two decimals for BHK 300-0.6MG and

Protection Overtemperature: See PAR. 1.4.10a

Overvoltage/Overcurrent: 0 to 1.1 x EOmax

Uneven voltage/current

in pass element:

Fan failure: See PAR. 1.4.10d

AC line failure: See PAR. 1.4.10e

Interruption between sens-

ing and power terminals:

Overload of main or

auxiliary power transformer:

Internal Output Capacitor (Default state = internal output capacitor connected.)

Reference Voltages for analog programming:

Status port Type Output transistor (open collector) from an optocoupler

Series Connection Automatic or Master-

Parallel Connection Automatic or Master-

BHK 300-0.6MG 20

BHK 500-0.4MG 10

BHK 1000-0.2MG 4

BHK 2000-0.1MG 2

Output Ratings Ic = 8mA d-c, Vceo = 40V d-c, Pd = 150mW@25° C

2800V d-c/1 min

100 mohms max. Between ground input connection and

chassis @ 30A

µA rms /100 uA p-p, for 115V a-c input voltage

(chassis to EARTH-GND)

nals only. Shutdown line is for disable only

- RS 232 port

- Trigger port (shutdown line)

BHK 500-0.4MG and one decimal for BHK 1000-0.2MG and BHK 2000-0.1MG.Output current for all models is displayed with two decimals when current range is set to High, and three decimals when current range is set to Low.

0 to 1.1 x IOmax (except BHK 300-0.6MG) 0 to 1.08 x IOmax (BHK 300-0.6MG only)

- removing the signal does not reenable the output (See PAR. 3.2.7.3).

See PAR. 1.4.4

See PAR. 1.4.10c

See PAR. 1.4.10f

See PAR. 1.4.10g

µF ±6%

µF±10%

All internal output capacitors are

non-polarized type.

µF±10%

+10 ±-0.2V d-c –10 ±-0.2V d-c

Logic Saturated transistor when AC line is present

For slave unit, use analog programming Slave Operation, limited by the d-c isolation limit voltage

Slave Operation

only.

For slave unit, use analog programming

only.

max.10 mA d-c

1-4 BHK-MG (OPR) 022014

Page 21

TABLE 1-2. BHK-MG 200W SPECIFICATIONS (Continued)

SPECIFICATION RATING/DESCRIPTION CONDITION

GENERAL (ENVIRONMENTAL) CHARACTERISTICS

Temperature Operating 0° to +50° C

Storage -20° to +70° C

Humidity

Shock 20g, 11msec ±50%

Vibration 5-10Hz 10mm

Cooling Built-in Fan, exhaust air to rear

0 to 95% RH

half sine

double amplitude

Non condensing

operating & storage

Non operating, 3-axes,

3 shocks each axis

Non operating, 3-axes,

1 hour each axis

PHYSICAL CHARACTERISTICS

Dimensions See Figure 1-2.

Weight English 45 lbs. Unpacked

Metric 20 Kg

a-c source connections Front Circuit Breaker, 2-pole

Rear Detachable IEC 3-wire

type connector Interlock switch, 1-pole

d-c output terminals Rear panel Terminal Block (11 posi-

tions),

Front panel Jacks (2) ±Output

Control Local: Digital control using front panel keypad(24 pads) and LCD

Remote: Digital control using rear panel IEEE 488 Bus (24 pin female connec-

tor). Analog control using two rear panel terminal strips (10 positions) for voltage and current

Digital display front panel

Voltage, current, mode, settings, menu, program, etc.

Interlock switch monitors plastic cover over rear panel terminals.

±Output, ±Sense, Ground, Internal Capacitor (–), Grounding Network

2 x 16 character alphanumeric LCD with LED backlight

BHK-MG (OPR) 022014 1-5

Page 22

FIGURE 1-2. BHK SERIES POWER SUPPLY, MECHANICAL OUTLINE DRAWING (SHEET 1 OF 2)

1-6 BHK-MG (OPR) 022014

Page 23

FIGURE 1-2. BHK SERIES POWER SUPPLY, MECHANICAL OUTLINE DRAWING (SHEET 2 OF 2)

BHK-MG (OPR) 022014 1-7

Page 24

1.4 FEATURES

1.4.1 LOCAL CONTROL

Front panel keypad entries and an LCD type display are utilized for setting and/or adjusting output voltage and current under local control. The keypad's keys are organized to either directly execute commands, or to introduce a program that can either be run once or cycled. Calibration of the unit is facilitated by a password -protected, menu-driven procedure from the front panel. Refer to PAR. 3.2 for more information.

1.4.2 REMOTE CONTROL

Remote control of the BHK-MG Power Supply can be accomplished either through digital or analog programming.

1.4.2.1 DIGITAL PROGRAMMING

Digital control is available directly via either the IEEE 488.2 (GPIB) or RS 232 bus using SCPI commands. Nearly all features available in local mode can be accessed in remote mode through digital programming. Refer to PAR’s. 3.3 and 3.5 for more information.

1.4.2.2 ANALOG PROGRAMMING

BHK-MG Power Supplies can also be controlled remotely using analog means, such as analog voltage or current, fixed or variable resistors, or a combination of them. This great flexibility is made possible by two uncommitted amplifiers (for voltage and current) and two reference voltages (+10V d-c and -10V d-c) available at the rear panel analog programming terminals. The chosen means of control (voltage, current, resistance, or a combination) must deliver 0 to –10V d-c at the output of the uncommitted amplifiers in order to have control over the entire range of the output voltage/current limit or output current/voltage limit. The analog programming port is not calibrated, however the zero point is accurate to less than 0.1%. The full scale tolerance is 2% maximum when using the preamplifier with external matched-pair resistors. Refer to PAR.

3.6 for more information about remote programming using the analog programming terminals.

1.4.2.3 ANALOG READBACK

The output voltage and current analog readback signals (uncalibrated), as well as some flag signals, are available for testing and customer usage via an internal connector (A2J5). Refer to Table 1-3 for details about A2J5 signals; refer to Table 1-5 to obtain the A2J5 mating connector. Wires (with isolation rated for at least the nominal output voltage of the unit) can be routed through the wire entry bushing at the rear panel (see Figure 2-2).

1.4.3 DIGITAL CALIBRATION

The BHK-MG Power Supply contains no internal adjustments. Calibration is done entirely via the front panel keypad and LCD, using a calibrated DVM and a corresponding precision shunt resistor. Calibration instructions appear on the front panel LCD after a password is entered.

Calibration constants for programming and read-back activities are calculated by the microcontroller and stored in the non-volatile memory. No internal adjustments are necessary The previous calibration is saved and can be restored if desired. The original factory calibration can also be restored. Refer to Section 4 for more information.

1-8 BHK-MG (OPR) 022014

Page 25

1.4.4 OVERVOLTAGE/OVERCURRENT PROTECTION

Overvoltage and Overcurrent protection values can be individually programmed. The range for overvoltage and overcurrent values are 0 to 1.1 x E

max, 0 to 1.1 x IOmax. If the output volt-

age/current is maintained at or above the overvoltage/overcurrent protection value for more than 9ms, the protection circuit latches the pass element off, discharges the output capacitor, trips the POWER circuit breaker to OFF and sends a flag on a dedicated line (status port connector). The default values are 1.1 x E

max for overvoltage protection, and 1.1 x IOmax for

overcurrent protection. Refer to PAR. 3.2.11 for more information.

1.4.5 USER-DEFINED VOLTAGE/CURRENT LIMITS

The BHK-MG Power Supply can be programmed not to exceed user-defined values that can be lower than the maximum values. For example, the BHK 500-0.4MG, which has maximum output values of 500V d-c, 0.4A d-c, can be limited to 100V d-c, 0.1A d-c for working with circuitry that might be damaged by higher levels. Once the limits are set, the power supply becomes, in effect a 100V d-c, 0.1A d-c supply and values exceeding the limit values will not be accepted. Refer to PAR. 3.2.12 for more information.

1.4.6 NONVOLATILE STORAGE OF PROGRAMMED SEQUENCES OR ACTIVE SETTINGS

The BHK-MG Power Supply contains 40 memory locations for each current range that can be used either to preprogram a sequence of output values or to store active settings. For programming sequences each memory location accommodates six parameters: output voltage, output current, overvoltage, overcurrent, time (how long the parameters are in effect) and the next address in the sequence. Values are stored in the nonvolatile memory, and are retained when the unit is turned off. Refer to PAR. 3.2.16 for more information.

The same 40 memory locations are also available to save the active programmed settings (voltage, current, overvoltage, overcurrent). The saved setting can be recalled by specifying the memory location. Refer to PAR’s. 3.2.13 and 3.2.14 for more information.

1.4.7 CURRENT SCALE

Output current of the power supply can be scaled down by a factor of 10, while at the same time increasing the current resolution by a factor of 10. For example the BHK 500-0.4MG has maximum output values of 500V d-c, 0.4A d-c and a current resolution of 0.1mA d-c; scaling down the output current results in a power supply with maximum values of 500V d-c, 0.04A d-c with a current resolution of 0.01mA d-c. Current scaling is easily accomplished using the Menu. Refer to PAR. 3.2.10 for more information.

Measurement of a decreasing output current of the power supply that falls below 8.98% ±0.01% of the rated value is automatically measured with increased resolution/accuracy by a factor of 10 until the current rises above 9.69% ±0.01% of rated value.

The factory setting is for the high current range, shown on the top line of the LCD in command entry status by the message “Ihigh.” The current scale setting is retained, and displayed upon turn-on as either Ihigh or Ilow.

1.4.8 FAST MODE/SLOW MODE SELECTION

BHK-MG Series Power Supplies can be configured by external strapping for either slow mode operation with the internal output capacitor connected to the output, or fast mode operation with the internal output capacitor disconnected from the output. The slow mode (default state) is recommended for voltage stabilization because of its low output noise and low recovery amplitude

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to a dynamically changing load. The fast mode offers a faster response to step or dynamic programming of the output voltage (in voltage mode), when the power supply is used as a power amplifier. Fast mode is also recommended for current stabilization because of its fast response to a dynamically changing load. Refer to PAR. 3.7.1 for more information.

1.4.9 EXTERNAL TRIGGER PORT

The external trigger port provides two functions: a trigger input can be used to restore the output to previously defined settings using SCPI commands (see PAR. 3.3.4) and a shutdown input can be used to immediately shut down the power supply output (see PAR. 3.2.7.3).

1.4.10 BUILT-IN PROTECTION

BHK-MG Series Power Supplies provide built-in protection against the following:

a. Overtemperature of the pass element. Heatsink temperature is monitored. If an overtem-

perature condition is maintained for more than 0.5ms, the following actions are initiated: the pass element is cut off and latched off, the output capacitor is discharged, the LCD displays the error message “BHK FAILURE“ and an error message is sent on the IEEE 488 Bus.

b. Overvoltage/overcurrent at the output. See PAR. 1.4.4

c. Uneven voltage/current in the pass element. Voltage is monitored across different transis-

tors of the pass element while current is monitored through the different branches. If uneven voltage/current continues for more than 11ms, the pass element is latched off, the output capacitor is discharged, the POWER circuit breaker is tripped to OFF and a flag is sent to the host computer on a dedicated line (Status Port connector)

d. Fan failure. If fan current drops below predetermined value continuously for more than

16ms, the pass element is latched off, the output capacitor is discharged, the LCD displays the error message “BHK FAILURE” and an error message is sent on IEEE 488 Bus.

e. AC line failure. If AC line is missing for more than 8 ms, a flag is sent to the host computer

on a dedicated line (Status Port connector). In addition, if the jumper at A7-J12 is installed (default state), the pass element is latched off, the output capacitor is discharged, and the POWER circuit breaker is tripped to OFF.

f. Interruption between the sensing and corresponding power output terminals. If there

is an interruption between the sensing and power terminals, two diodes connected in parallel between the sensing lead and the corresponding power lead (one forward biased and one reverse biased), allow the power supply to continue to function.

g. Overload of the main or auxiliary power transformer. If input current of the main trans-

former exceeds 7A a-c @ 115V a-c or 3.5A a-c @ 230V a-c, the input POWER circuit breaker is tripped to OFF, the pass element is latched off, the output capacitor is discharged, and a flag is sent to the Status Port connector. The reaction time is inversely proportional to the input overcurrent: from a minimum of 10ms for 10 times nominal overcurrent, to a maximum of 100 seconds for 25% above nominal current.

If input current of the auxiliary power transformer exceeds a predetermined value, in most cases the input POWER circuit breaker is tripped to OFF (if jumper A7J12 is installed), the pass element is latched off, the output capacitor is discharged, and a flag is sent to the Status Port connector. If the cause of the overload is a problem in the protection circuit, the input POWER circuit breaker may not trip off: the pass element will be latched off and the output capacitor will discharge more slowly, and a flag is sent to the status port. The reaction time in this case is determined by PTC (positive temperature coefficient) thermistor A5R1 between 30 and 100 seconds.

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h. Current Limit. The current through the main branch of the pass element is monitored. If this

current is maintained between 1.8 to 2.2 times larger than the nominal value for more than 11ms, the pass element is latched off, the output capacitor is discharged, and the POWER circuit breaker is tripped to OFF.

1.4.11 CURRENT SINK CAPABILITY

BHK-MG 200W Series power supplies are able to sink up to 5% of the nominal current when in voltage mode and 50% of the unit's maximum rated current when in current mode. The fixed current mode sink value is model dependent and has a tolerance of 10%. Since negative current is not displayed on the front panel meter, it is transparent to the user when the unit enters sink mode.

This capability is useful in applications such as capacitor testing, where the sink capability allows the rapid discharge of the device under test, permitting subsequent tests to be started earlier, thus increasing the throughput of the testing process.

The sink current in current mode is quite stable, allowing this feature to be used with the discharging process to determine the value of a capacitor under test by measuring the discharge time, using the formula C = T x I / V (the charge time, which is more accurate, can also be used in the formula), where

T = discharge or charge time V = change in voltage from fully charged to fully discharged, or vice versa.

I = discharging or charging current (BHK-MG charging current has a tolerance of

0.05% of nominal value, discharge current has a tolerance of 10% of nominal value)

The value of the capacitor under test can be calculated directly by measuring T and either using the above formula and the appropriate tolerance for I, or by comparing T to that of a known capacitor value.

Once the capacitor under test completely discharges, current from the power supply’s internal current generator will flow through the output protection diode (or, in some models, multiple diodes), resulting in a slight reverse voltage at the output which will be clamped to the value of the voltage drop across the diode(s).

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1.4.12 ANALOG READBACK AND FLAG SIGNALS AVAILABLE FOR CUSTOMER USE

Some internal signals produced by the unit are available at connector A2J5 for either monitoring or testing purposes. Refer to Table 1-3 for a description of available signals

TABLE 1-3. CONNECTOR A2J5 SIGNAL DESCRIPTIONS

SIGNAL PIN. NO. VALUE TYPE

Current Scale Flag 1

Step Down Flag 2

Power GND 3 N/A

V-C Mode Flag 4

Signal GND 5, 7 N/A

Current Monitor

(not calibrated)

Voltage Monitor

(not calibrated)

* Recommended load equal to or greater than 10K ohms.

≈ 0V for HIGH current scale > +13V for LOW current scale

< -11V for steady or step-up output > +11V for step-down output, or when protection circuit has functioned and “BHK FAILURE” error message is displayed

< -11V for CV (Constant Voltage) mode > +11V for CC (Constant Current) mode

0V ± 10mV (for IO = 0mA) to

+10V ± 0.12V (for IO = Full Scale)

0V ± 10mV (for EO = 0V to)

+10V ± 0.25V (for EO = Full Scale)

1.5 EQUIPMENT SUPPLIED

Equipment supplied with the unit is listed in Table 1-4.

Collector of PNP transistor (A2Q3) through 1K resistance.*

Output of open loop Op Amp (A2U4B) through 1K resistance.*

Recommended to be used as Return for signals at pins 1, 2, and 4.*

Output of open loop Op Amp (A2U4A) through 1K resistance.*

Recommended to be used as Return for signals at pins 6 and 8.*

Output of closed loop Op Amp (A2U7) *

Output of closed loop Op Amp (A2U1) *

TABLE 1-4. EQUIPMENT SUPPLIED

ITEM

Power Cord 118-0557 1

Plug, 2-contact for ± front panel output jacks 142-0489 1

Contact, pin type (used on plug 142-0489) 107-0361 2

Status Port mating connector 143-0296 1

Two-terminal Link for rear panel output 172-0300 2

Three-terminal Link for rear panel output 172-0305 2

Four-terminal Link for rear panel output (installed) 172-0407 2

Five-terminal Link for rear panel output 172-0321 1

Six-terminal Link for rear panel output 172-0408 1

PART NUMBER QUANTITY

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1.6 ACCESSORIES

Accessories for the BHK Power Supply are listed in Table 1-5.

TABLE 1-5. ACCESSORIES

ITEM FUNCTION

IEEE 488 (GPIB) Cable, 1m long Connect BHK-MG Power Supply to GPIB bus. SNC 488-1

IEEE 488 (GPIB) Cable, 2m long Connect BHK-MG Power Supply to GPIB bus. SNC 488-2

IEEE 488 (GPIB) Cable, 4m long Connect BHK-MG Power Supply to GPIB bus. SNC 488-4

Slide (2) Allows rack-mounted units to slide in and out. CS-01, -02, -03 (Kepco)

External Trigger Port mating connector Allows access to external trigger function. 142-0527 (Kepco)

RS 232 Port Adapter Cable Kit Contains RJ 45 Patch cord, two RS 232 adapt-

ers (one with male pins to connect to DTE equipment and one with female pins to connect to a personal computer), and an RS 232 Loop Back test Connector (to test RS 232 communication and aid in isolating RS 232 communication problems).

Mating connector for A2J5 (Analog Readback and Flags)

Allow user access to analog readback and flag signal; see Table 1-3 for details.

PART NUMBER

110-QD-14-2 (Jonathan)

SP-2501 (CUI)

KIT 219-0436

143-0359

1.7 SAFETY

There are no operator serviceable parts inside the case. Service must be referred to authorized personnel. Using the power supply in a manner not specified by Kepco. Inc. may impair the protection provided by the power supply. Observe all safety precautions noted throughout this manual. Table 1-6 lists symbols used on the power supply or in this manual where applicable.

TABLE 1-6. SAFETY SYMBOLS

SYMBOL MEANING

CAUTION: RISK OF ELECTRIC SHOCK.

CAUTION: REFER TO REFERENCED PROCEDURE.

WARNING INDICATES THE POSSIBILITY OF BODILY INJURY OR DEATH.

CAUTION INDICATES THE POSSIBILITY OF EQUIPMENT DAMAGE.

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SECTION 2 - INSTALLATION

2.1 UNPACKING AND INSPECTION

This instrument has been thoroughly inspected and tested prior to packing and is ready for operation. After careful unpacking, inspect for shipping damage before attempting to operate. Perform the preliminary operational check as outlined in PAR 2.5. If any indication of damage is found, file an immediate claim with the responsible transport service.

2.2 TERMINATIONS AND CONTROLS

a). Front Panel: Refer to Figure 2-1 and Table 2-1.

b). Rear Panel: Refer to Figure 2-2 and Table 2-1.

FIGURE 2-1. BHK-MG SERIES, FRONT PANEL CONTROLS, INDICATORS AND CONNECTORS

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TABLE 2-1. CONTROLS, INDICATORS, AND CONNECTORS

CONTROL, INDICATOR,

CONNECTOR

FRONT PANEL

A-C line indicator Lights to indicate unit turned on and a-c power applied.

FUNCTION

LCD 2 x 16 character Liquid Display with LED backlight. Shows voltage, current

Keypad 24 keys used for local operation of the power supply; Refer to Table 3-2 for

POWER circuit breaker Circuit breaker used to turn unit on and off.

(+) and (–) output jacks Provide front panel access to d-c output of power supply.

IEEE 488 PORT 24-pin GPIB connector used to connect to GPIB bus (see Table 2-5 for pin

RS 232 PORT 8-pin telephone jack type connector used to connect to RS 232 bus (see

STATUS PORT Notifies host computer either that a-c input is not present or a major failure of

EXTERNAL TRIGGER PORT 4-pin connector used to restore unit to pre-established setting or to shut down

OUTPUT TERMINALS barrier strip TB1 Provides Power Supply output connection points. (See Table 2-6 for terminal

V PROG terminal strip TB2 Provides input/output signals for analog programming of output voltage or

I PROG terminal strip TB3 Provides input/output signals for analog programming of output current or cur-

mode, settings, menu, program, etc.

details.

REAR PANEL

assignments).

Table 2-3 for pin assignments).

power supply has occurred.(see Table 2-4 for pin assignments).

the output. (see Table 2-2 for pin assignments). NOTE: Mating connector is a 3-pin plug.

assignments)

voltage limit. (See Table 2-7 for terminal assignments.)

rent limit. (See Table 2-8 for terminal assignments.)

AC SELECTOR switch Used to select between nominal input line voltage of 115 V a-c or 230 V a-c.

AC INPUT connector Provides a-c source power to unit.

Interlock switch Provides protection when terminal strip cover is removed by interrupting a-c

power to the unit.

TABLE 2-2. TRIGGER PORT PIN ASSIGNMENTS

CONNECTOR PIN SIGNAL NAME FUNCTION

1 Trigger- Shutdown RTN Return for TRIGGER and SHUTDOWN signals.

TRIGGER PORT (connector A1J2)

SHUTDOWN Logic 0 causes BHK output to go be disabled (see

PAR. 3.2.7.3).

TRIGGER Logic 0 triggers BHK to previously stored setting (see

PARs. 3.3.4 and B.92.)

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TABLE 2-3. RS232C PORT INPUT/OUTPUT PIN ASSIGNMENTS

CONNECTOR PIN SIGNAL NAME FUNCTION

1 RTN Return 1 Signal Ground

2 Not Used Not Used 2 Receive Data

3 TXD Transmit Data 3 Transmit Data

RXD Receive Data

RS 232

PORT

(connector A1J5)

5 RTN Return 5 Signal Ground

Not Used Not Used

RTN Return

8 RTN Return 8 Clear To Send (protocol not used)

Adapter Cable (P/N KIT 219-0436)

PIN FUNCTION

Data Terminal Ready (protocol not

used)

Data Set Ready (protocol not

used)

Request To Send (protocol not

used)

9 Signal Ground

FIGURE 2-2. BHK-MG SERIES, REAR PANEL CONTROLS AND CONNECTIONS

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TABLE 2-4. STATUS PORT CONNECTOR PIN ASSIGNMENTS

CONNECTOR PIN SIGNAL NAME FUNCTION

1 Not Used.

2 Not Used.

3 Not Used.

Emitter Emitter of LED-transistor optocoupler. Notifies host com-

puter of absence of a-c input or a major power supply failure, active “low” (see PAR 1.4.10), requires pin 7 to be connected to the “+“ of the host computer d-c supply as described in PAR. 2.9.

puter of absence of a-c input or a major power supply failure, active “high” (see PAR 1.4.10), requires pin 4 to be connected to the “–“ of the host computer d-c supply as described in PAR.2.9.

STATUS PORT

CONNECTOR A5J4

5 Not Used.

6 Not Used.

Collector Collector of LED-transistor optocoupler. Notifies host com-

8 Not Used.

9 Not Used.

TABLE 2-5. IEEE 488 PORT CONNECTOR PIN ASSIGNMENTS

CONNECTOR PIN SIGNAL NAME FUNCTION

IEEE 488

PORT

A1J1

5 EOI End or Identify

6 DAV Da ta Vali d

7 NRFD Not Ready for Data

8 NDAC Not Data Accepted

9 IFC Interface Clear

10 SRQ Service Request

11 ATN Attention

12 SHIELD Shield

13 D

14 D

15 D

16 D

17 REN Remote Enable

18 GND Ground (signal common)

19 GND Ground (signal common)

20 GND Ground (signal common)

21 GND Ground (signal common)

22 GND Ground (signal common)

23 GND Ground (signal common)

24 LOGIC GND Logic Ground

I01 I/O Line

I02 I/O Line

I03 I/O Line

I04 I/O Line

I05 I/O Line

I06 I/O Line

I07 I/O Line

I08 I/O Line

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TABLE 2-6. REAR OUTPUT TERMINAL STRIP TB1 TERMINAL ASSIGNMENTS

TERMINAL SIGNAL NAME FUNCTION

1 +S Positive sense connection

2 + OUT Positive d-c output connection

3 GND NET Grounding network connection

4 GND Ground (chassis) connection

5 – OUT Negative d-c output connection

6 –S Negative sense connection

7 – OUT C Connection to internal output capacitor

TABLE 2-7. VOLTAGE PROGRAMMING TERMINAL STRIP TB2, TERMINAL ASSIGNMENTS

TERMINAL SIGNAL NAME FUNCTION

1 –10V –10V d-c reference voltage

2 V(NINV) Noninverting input of uncommitted amplifier

3 SGND Signal common

4 V(+IN) Programming input for positive input signal

5 +10V +10V d-c reference voltage

6 V(INV) Inverting input of uncommitted amplifier

7 V(FBK) Internal feedback resistor; the other end is connected to

uncommitted amplifier output

8 V(OUT) Output of uncommitted amplifier

9 –V EXT External analog programming voltage input: 0 to –10V pro-

10 SGND Signal common

grams 0 to 100% of EOmax.

TABLE 2-8. CURRENT PROGRAMMING TERMINAL STRIP TB3, TERMINAL ASSIGNMENTS

TERMINAL SIGNAL NAME FUNCTION

1 –10V –10V d-c reference voltage

2 C(NINV) Noninverting input of uncommitted amplifier

3 SGND Signal common

4 C(+IN) Programming input for positive input signal

5 +10V +10V d-c reference voltage

6 C(INV) Inverting input of uncommitted amplifier

7 C(FBK) Internal feedback resistor; the other end is connected to

uncommitted amplifier output

8 C(OUT) Output of uncommitted amplifier

9 C EXT External analog programming voltage input: 0 to –10V pro-

10 SGND Signal common

grams 0 to 100% of IOmax. Usually connected to output of uncommitted amplifier.

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2.3 SOURCE POWER REQUIREMENTS

BEFORE APPLYING AC SOURCE POWER TO THE POWER SUPPLY, VERIFY THAT THE LINE VOLTAGE TO BE SUPPLIED MATCHES THE POSITION OF THE AC INPUT SELECTOR SWITCH AT THE REAR PANEL (FACTORY DEFAULT IS 115V).

This power supply operates with the installed circuit breaker from single phase AC mains power over the specified voltage and frequency ranges without adjustment or modification. The AC INPUT SELECTOR switch located on the rear panel (Figure 2-2) allows selection of either 115Vac or 230Vac source power.

The nominal AC current absorbed by the BHK-MG Power Supply from the power source is 3.7A a-c @115V a-c and 1.9A a-c @230V a-c; the power source must be able to deliver the nominal current as well as surge current ten times larger than nominal.

2.4 COOLING

The power devices used within the power supply are maintained within their operating temperature range by means of internal heat sink assemblies cooled by an internal (d-c type) cooling fan.

WARNING

ALL INLET AND EXHAUST OPENINGS AROUND THE POWER SUPPLY CASE MUST BE KEPT CLEAR OF OBSTRUCTION TO ENSURE PROPER AIR ENTRY AND EXHAUST.

Periodic cleaning of the power supply interior is recommended. If the power supply is rack mounted, or installed within a confined space, care must be taken that the ambient temperature, which is the temperature of the air immediately surrounding the power supply, does not rise above the specified limits (see Table 1-2).

2.5 PRELIMINARY OPERATIONAL CHECK

WARNING

BEFORE APPLYING AC SOURCE POWER TO THE POWER SUPPLY, VERIFY THAT THE LINE VOLTAGE TO BE SUPPLIED MATCHES THE POSITION OF THE AC INPUT SELECTOR SWITCH AT THE REAR PANEL (FACTORY DEFAULT IS 115V).

A simple operational check after unpacking and before equipment installation is advisable to ascertain whether the power supply has suffered damage resulting from shipping.

Refer to Figures 2-1 and 2-2 for location of operating controls and electrical connections. Tables 2-1 and 3-2 explain the functions of operating controls/indicators and keypad keys, respectively.

1. With POWER switch set to down (OFF) position, connect the power supply to source power.

2. With no load connected, set POWER switch to the up (ON) position. Each time the unit is turned on an internal self-test is performed and the power on indications (Figure 2-3) are visible. If these indications do not appear, the power supply will be inoperative.

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The alphanumeric display (LCD) indicates the model and GPIB address. After a few seconds, the display presents the power supply default values: Local mode (LOC), Current Scale High (Ihigh), Constant Voltage (CV) mode, 0.0V, 0.0A and command entry status (see Figure 2-3.). Overvoltage and overcurrent protection are set to the maximum values (PAR.

1.4.4), but are not displayed. When shipped from the factory, the digital control is set to off. To enable the output of the BHK-MG, press the OUTPUT ON/OFF key on the front panel

Loc CV

Ihigh

0.000A0.000V (:_:_:)

NOTE: (:_:_:) indicates blinking colon (:), Command Entry status

(=_=_=) indicates blinking equal sign (=), Data Entry status

FIGURE 2-3. LCD POWER ON DEFAULTS

NOTE: Six keys with dual functions are labeled with both a command and a number. The com-

mand is referred to when the unit is in (:_:_:) command entry status; the number is referred to when the unit is in (=_=_=) data entry status.

3. Allow unit to warm up for at least 15 minutes.

4. Connect a digital voltmeter (DVM) to the (+) and (-) jacks at the front panel.

5. Press VSET key. Verify bottom line of LCD reads Vset (=_=_=) 0.0 V. Use number

keys to enter nominal output voltage (e.g. for BHK 500-0.4MG, 500V is the nominal output voltage) and press ENTER. Output voltage will be displayed at bottom left of LCD. Verify the LCD reads CV (constant voltage mode).

NOTE: If tolerances specified in the following steps are exceeded, refer to Section 4 and reca-

librate the unit.

6. Compare the programmed output voltage value with the voltage reading of the DVM; the difference between the two should not exceed 0.025% of the nominal voltage of the unit.

7. Compare the voltage reading of the LCD with that of the DVM; the difference between the two should not exceed 0.05% of the nominal voltage of the unit.

8. Press VSET key and enter different value for output voltage, then repeat steps 6 and 7 using different values for programmed voltage.

9. Disable the output by pressing OUTPUT ON/OFF key; verify LCD reads 0.0V and 0.0mA.

10. Disconnect DVM and connect precision shunt (see PAR. 4.2) across front panel output terminals; connect DVM across shunt (sensing terminals).

11. Using VSET key, set output voltage to 30V.

12. Similarly, using ISET key, program output current to the nominal output current of the power supply (e.g., for BHK 500-0.4MG, 400mA is the nominal output current).

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13. Press OUTPUT ON/OFF key to enable the output of the unit. Verify the LCD reads CC

(constant current mode) and a small value for output voltage (RS x I where R

= resistance of shunt in ohms and I

= the actual value for current pro-

o (prog)

x 0.001) in volts,

o (prog)

grammed in step 12 in milliamperes.

14. Note DVM reading (V 1000/R

in milliamperes (mA).

15. Compare the programmed output current value (step 12) with the value shown indirectly by DVM (calculated in step 14); the difference between the two should not exceed 0.05% I

max ±(TOLRs)% IO, where IO is the output current and TOLRs is the tolerance of the pre-

cision shunt (step 10).

16. Compare the output current value shown by the LCD (step 13) with the value shown indirectly by DVM (calculated in step 14); the difference between the two should not exceed

0.05% I

max ±(TOLRs)% IO.

17. Repeat steps 15 and 16 using different values for programmed current.

18. Disable the output by pressing OUTPUT ON/OFF key, turn-off power supply and discon- nect the shunt.

2.6 INSTALLATION

2.6.1 BENCH TOP USE

The unit is designed to be used as a bench top instrument. Front panel output terminals are provided for easy access. However, if the application requires remote sensing, it is necessary to use rear output terminals for sensing connections.

) and calculate the output current using the formula IO =V

DVM

2.6.2 RACK MOUNTING

The unit can be mounted directly in a 19-inch wide rack, after the bench-type feet are removed. Optional slides (see Table 1-5) can be used. Installation of slides can improve access to the unit (see Figure 1-2).

2.7 WIRING INSTRUCTIONS

Interconnections between an a-c power source and the power supply, and between the power supply and its load are as critical as the interface between other types of electronic equipment. If optimum performance is expected, certain rules for the interconnection of source, power supply and load must be observed by the user. These rules are described in detail in the following paragraphs.

2.7.1 SAFETY GROUNDING

Local, national and international safety rules dictate the grounding of the metal cover and case of any instrument connected to the a-c power source, when such grounding is an intrinsic part of the safety aspect of the instrument. The ground terminal of the source power connector (Figure 2-2) is connected to the BHK-MG chassis and the instructions below suggest wiring methods which comply with these safety requirements; however, in the event that the specific installation for the power system is different from the recommended wiring, it is the customer's responsibility to ensure that all applicable electric codes for safety grounding requirements are met.

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2.7.2 SOURCE POWER CONNECTIONS

Source power is connected to the power supply via the three-wire input power cable supplied.

2.7.3 D-C OUTPUT GROUNDING

Connections between the power supply and the load and sensing connections may, despite precautions such as shielding, twisting of wire pairs, etc., be influenced by radiated noise, or “pickup”. To minimize the effects of this radiated noise the user should consider grounding one side of the power supply/load circuit. The success of d-c grounding requires careful analysis of each specific application, however, and this recommendation can only serve as a general guideline.

One of the most important considerations in establishing a successful grounding scheme is to avoid GROUND LOOPS. Ground loops are created when two or more points are grounded at different physical locations along the output circuit. Due to the interconnection impedance between the separated grounding points, a difference voltage and resultant current flow is superimposed on the load. The effect of this ground loop can be anything from an undesirable increase in output noise to disruption of power supply and/or load operation. The only way to avoid ground loops is to ensure that the entire output/load circuit is fully isolated from ground, and only then establish a single point along the output/load circuit as the single-wire ground point.

The exact location of the “best” d-c ground point is entirely dependent upon the specific application, and its selection requires a combination of analysis, good judgement and some amount of empirical testing. If there is a choice in selecting either the positive or negative output of the power supply for the d-c ground point, both sides should be tried, and preference given to the ground point producing the least noise. For single, isolated loads the d-c ground point is often best located directly at one of the output terminals of the power supply; when remote error sensing is employed, d-c ground may be established at the point of sense lead attachment. In the specific case of an internally-grounded load, the d-c ground point is automatically established at the load.

The output terminals (located on both the front or rear panel) for BHK-MG Power Supplies are d-c isolated (“floating”) from the chassis in order to permit the user maximum flexibility in selecting the best single point ground location. Output ripple specifications as measured at the output are equally valid for either side grounded. Care must be taken in measuring the ripple and noise at the power supply: measuring devices which are a-c line operated can often introduce additional ripple and noise into the circuit.

There is, unfortunately, no “best” method for interconnecting the load and power supply. Individual applications, location and nature of the load require careful analysis in each case. Grounding a single point in the output circuit can be of great importance. It is hoped that the preceding paragraphs will be of some assistance in most cases. For help in special applications or difficult problems, consult directly with Kepco's Application Engineering Department.

2.7.4 POWER SUPPLY/LOAD INTERFACE

The general function of a voltage or current stabilized power supply is to deliver the rated output quantities to the connected load. The load may have any conceivable characteristic: it may be fixed or variable, it may have predominantly resistive, capacitive or inductive parameters; it may be located very close to the power supply output terminals or it may be a considerable distance away. The perfect interface between a power supply and its load would mean that the specified performance at the output terminals would be transferred without impairment to any load, regardless of electrical characteristics or proximity to each other.

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The stabilized d-c power supply is definitely not an ideal voltage or current source, and practical interfaces definitely fall short of the ideal. All voltage-stabilized power supplies have a finite source impedance which increases with frequency, and all current-stabilized power supplies have a finite shunt impedance which decreases with frequency. The method of interface between the power supply output and the load must, therefore, take into account not only the size with regard to minimum voltage drop, but the configuration with regard to minimizing the impedance introduced by practical interconnection techniques (wire, bus bars, etc.). The series inductance of the load wire must be as small as possible as compared to the source inductance of the power supply: although the error sensing connection to the load compensates for the d-c voltage drop in the power leads, it cannot compensate for the undesirable output effects of the power lead inductance. These lead impedances (both power and sensing leads) are especially important if the load is a) constantly modulated or step-programmed, b) has primarily reactive characteristics, or c) where the dynamic output response of the power supply is critical to load performance.

2.7.4.1 CABLE RECOMMENDATIONS

For power cables (positive and negative) No. 20 or 22 AWG stranded wire is recommended for each (these sizes fit the plugs supplied for the front panel output connections). The wire insulation must be rated for nominal voltage of the power supply (e.g., 500V for BHK 500-0.4MG). If a float voltage is used, the wire insulation must be rated for the nominal voltage of the power supply plus the float voltage; the DC Isolation Voltage (see Table 1-2, under Output Characteristics) defines the maximum float voltage allowed. For noisy environments, tied pair (adjacent wires secured with cable ties) or twisted pair cables are recommended. It is recommended that cable length not exceed 50 feet; for longer cable lengths, contact Kepco.

Remote sensing is used to accurately control voltage at the load rather than at the output terminals of the power supply (local sensing) by compensating for voltage drop (0.5 V d-c per lead) in the power cables. For sense cables (positive and negative) No. 22 AWG stranded wire is recommended for each. For noisy environments, tied pair or twisted pair cables are recommended. It is recommended that cable length not exceed 50 feet; for longer cable lengths, contact Kepco.

2.7.5 LOAD CONNECTION - GENERAL

Load connections to the BHK-MG power supply are achieved via the rear output terminal strip (TB1); (+) and (-) outputs are also available at jacks located on the front panel. Configuration of the rear output terminal strip is facilitated by five types of links supplied with the unit:

• 2-terminal link: (qty 2)

• 3-terminal link: (qty 2)

• 4-terminal link: (qty 2)

• 5-terminal link: (qty 1)

• 6-terminal link: (qty 1)

These links are used to configure the power supply for local or remote sensing, slow or fast mode, insertion of the grounding network, isolated (floating) output, and negative or positive grounded output. The links allow many possible configurations using various combinations of the configurable parameters noted above.

The BHK-MG power supply is shipped from the factory configured as follows (factory default configuration): local sensing, grounding network connected, slow mode, output isolated from

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ground (floating). This configuration is obtained using two 4-terminal links connected as shown in Figure 2-4.

NOTE: REGARDLESS OF OUTPUT CONFIGURATION, OUTPUT SENSE LINES MUST BE

CONNECTED FOR PROPER OPERATION, EITHER LOCALLY, OR AT THE LOAD (REMOTE). OBSERVE POLARITIES: THE +S TERMINAL (TB1-1) MUST BE CONNECTED TO EITHER +OUT (TB1-2) (LOCAL) OR +LOAD (REMOTE), AND THE - S TERMINAL (TB1-6) MUST BE CONNECTED TO EITHER –OUT (TB1-5) (LOCAL) OR –LOAD (REMOTE).

Figures 2-4 and 2-5 are typical load connection diagrams illustrating the configurations explained in the following paragraphs.

2.7.5.1 LOCAL SENSING/REMOTE SENSING SELECT

Local sensing (factory default configuration) is established by connecting terminals TB1-1 (+S) to TB1-2 (+OUT) and TB1-5 (–OUT) to TB1-6 (–S) (see Figure 2-4). The power supply is shipped with these connections installed for local sensing.

Remote sensing is established by removing the links between TB1-1, TB1-2 and TB1-6, TB1-7. The +S and –S lines must be connected at the load (see Figure 2-5).

2.7.5.2 FAST MODE/SLOW MODE SELECT

Fast mode is established when there is no connection between TB1-6 (–S) and TB1-7 (–OUT C) (see Figure 2-5). Slow mode (factory default configuration) can be established by connecting TB1-6 to TB1-7, thus connecting the internal output capacitor to the output (see Figure 2-4).

2.7.5.3 GROUNDING NETWORK CONFIGURATION

When the output is floating there is a tendency for large changes in output voltage to affect the digital programming section, possibly resulting in an erroneous output. The parallel RC grounding network is designed to be connected to ground at the output when the output is floating to ensure that the digital programming section is not adversely affected by the dynamic swing of the output. The power supply is shipped with the grounding network connected: a connection between terminals TB1-3 (GND NET) and TB1-2 (+OUT). To disconnect the grounding network from the output, remove the connection across TB1-3 and TB1-2 (see Figure 2-4).

2.7.5.4 POSITIVE OUTPUT, NEGATIVE TERMINAL GROUNDED

To configure the BHK-MG as a positive output power supply (referenced to ground), connect the negative output terminal to ground: connect TB1-4 (GND - CHASSIS) to TB1-5 (–OUT). To avoid degraded load regulation in current mode it is necessary to remove the grounding network from the circuit by removing the link between TB1-2 (+OUT) and TB1-3 (GND NET).

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FIGURE 2-4. LOCAL SENSING, SLOW MODE SELECTED, GROUNDING NETWORK CONNECTED,

FLOATING OUTPUT (FACTORY DEFAULT CONFIGURATION)

2.7.5.5 NEGATIVE OUTPUT, POSITIVE TERMINAL GROUNDED

To configure the BHK-MG as a negative output power supply (referenced to ground), connect the positive output terminal to ground: use a 5-terminal link to connect TB1-4 (GND - CHASSIS) to TB1-2 (+OUT). Note that when the positive output is grounded, the ground network (TB1-3) is inoperative (see Figure 2-5).

FIGURE 2-5. REMOTE SENSING, FAST MODE SELECTED, POSITIVE OUTPUT GROUNDED

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2.8 OPERATING CONFIGURATION

The complete operating configuration is defined by jumper configuration of internal boards.

Table 2-9 lists the location of the internal jumpers and their function. This information is provided for reference purposes only, to indicate the configuration options available. Do not attempt to alter the jumper configuration. For assistance in changing any jumper-selected parameter contact Kepco Applications Engineering.

TABLE 2-9. INTERNAL JUMPER CONFIGURATION

LOCATION JUMPER

DEFAULT

STATUS

FUNCTION

J6 Not Installed May be installed temporarily to force the unit to enter First Time Calibration during

J12 Installed Enables input circuit breaker to trip when input power loss detected.

J13 Installed Enables protection circuit to cut off pass element and to send a flag to digital con-

J14 Installed Enables “share circuit” to act on protection circuit. The share circuit detects uneven

2.9 STATUS PORT

The status port opto-coupler can be configured for either active “high” (see Figure 2-6) or active “low” (see Figure 2-7).

power-up sequence. This requires the operator to enter the model and perform a full calibration of the unit.

trol.

voltage or current across the pass element.

FIGURE 2-6. STATUS PORT OPTO-COUPLER ACTIVE “HIGH” CONFIGURATION

FIGURE 2-7. STATUS PORT OPTO-COUPLER ACTIVE “LOW” CONFIGURATION

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SECTION 3 - OPERATION

3.1 GENERAL

This section explains how to operate the BHK-MG Power Supply. The power supply can be operated either in Local mode using the front panel keypad and LCD (PAR. 3.2), or in Remote mode using either SCPI commands via the GPIB bus (PARs. 3.3, 3.5) or analog programming via the rear panel terminals (PAR 3.6). Remote analog programming can be combined with either local programming using the front panel keyboard or remote programming using SCPI commands via the GPIB bus.

3.2 LOCAL MODE OPERATION

Local operation of the BHK-MG Power Supply is accomplished via the 24 key keypad on the front panel. All indications are provided by the 2-line LCD. Local mode operation includes a description of the interaction between the LCD and the front panel keypad. Each key of the front panel is described, with a reference to a paragraph detailing the use of that key.

3.2.1 FRONT PANEL KEYPAD AND LCD. (SEE FIGURE 2-1)

The front panel keypad is comprised of 24 keys, 13 dedicated to command functions, five dedicated to data functions, and six keys that have both command and data functions. When the power supply is in command entry status the command functions are effective; when the power supply is in data entry status the data functions are effective.

3.2.1.1 COMMAND ENTRY STATUS

Indicated by blinking colon (:) on bottom line of LCD; the power supply is waiting for a command to be entered. Valid command entry is accompanied by a brief audible beep; data will not be accepted (accompanied by longer audible buzz). The LCD indicates the actual voltage and current at the output terminals. When the output is disabled (LCD bottom line reads Output OFF), the power supply is in Command entry status even though the blinking colon is not visible.

NOTE: The blinking colon is indicated by (:_:_:) in this manual.

3.2.1.2 DATA ENTRY STATUS

Indicated by blinking equal sign (=); the power supply is waiting for data to be entered. Valid data entry is accompanied by a brief audible beep; commands will not be accepted (accompanied by longer audible buzz). Enter new value (the key erases data entered). Press ENTER to accept new setting, or CLEAR to exit without changing setting.

NOTE: The blinking equal sign is indicated by (=_=_=) in this manual.

3.2.1.3 DISPLAY (LCD)

The LCD is a 2-line display with a capacity of 16 characters per line. The information is generally arranged as shown in Table 3-1 (information that does not follow this format is self-explanatory).

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TABLE 3-1. LCD MESSAGES

LOCATION MESSAGE DESCRIPTION

Top left Loc/Rem Digital control status: either Remote or Local

top right CV/CC Constant voltage mode/constant current mode

Bottom

left:

Top or Bottom middle: (=_=_=) Data entry status

Bottom

right:

in command entry n.nV Actual output voltage

In data entry (parameter) e.g. OVset if OV SET key was pressed.

Bottom middle: (:_:_:) Command entry status

in command entry n.n mA Actual output current.

In data entry n.n V or n.n mA Present programmed value of parameter, replaced by data entered.

3.2.1.4 KEYPAD FUNCTIONS

Keypad functions are listed in Table 3-2. Six keys have dual functions, depending on whether the power supply is in command entry status (waiting for a command to be entered), or data entry status (waiting for a number to be entered). Command entry status is indicated by a blinking colon (:_:_:) and data entry status is indicated by a blinking equal sign (=_=_=).

NOTE: Keys with dual functions are labeled with both a command and a number. The com-

mand label is referred to when the unit is in (:_:_:) command entry status; the number is referred to when the unit is in (=_=_=) data entry status.

KEY

OUTPUT

ON/OFF

V SET Command Entry

I SET Command Entry

LOCAL Command Entry

RESET Command Entry

POWER SUPPLY STATUS ACTIVE

Command Entry

TABLE 3-2. KEY FUNCTIONS

DESCRIPTION

If top line of LCD reads Digital is OFF, press to enable the output. If output is on, press to disable the output controlled by digital means (keypad or GPIB setting). If analog control used, analog input must be turned off separately to disable the output.

Press to set output voltage. After V SET is pressed, previous setting is displayed. Data entry required to enter new value of output voltage; press ENTER to accept displayed value.

Press to set output current. After I SET is pressed, previous setting is displayed. Data entry required to enter new value of output current; press ENTER to accept displayed value.

If the power supply is in remote mode, keypad is disabled except for LOCAL key. Press to enable keypad. If LCD reads KEYPAD LOCKED, the LOCAL key is also disabled and can only be unlocked by remote operation.

Press to restore the power on default values: CV mode, output voltage = 0, output current value chosen from the POWER-UP OR RESET CURRENT submenu, overvoltage and overcurrent values per Table 1-2.

REFERENCE

PARAGRAPH

3.2.7

3.2.9

3.2.4, B.84

3.2.8

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TABLE 3-2. KEY FUNCTIONS (CONTINUED)

KEY

MENU Command Entry

OV SET

OC SET

CALIB

POWER SUPPLY

STATUS ACTIVE

Command Entry

Data Entry

Command Entry

Data Entry

Command Entry

Data Entry

DESCRIPTION

Press to enter Menu commands: press repeatedly to scroll through Menu functions: (1) set LCD contrast, (2) GPIB address, (3) Baud Rate, (4) Loop Back Test, (5) DCL control, (6) Power-Up Digital DC Output on/off, (7) speaker on/off, (8) change calibration password, (9) restore previous calibration values, (10) restore factory calibration values, (11) view firmware version number, (12) set Power-up and RESET current, (13) set maximum voltage, (14) set maximum current, (15) current scale. Press ENTER, RESET or CLEAR to exit Menu.

Press to set overvoltage protection value. Data entry required to enter the overvoltage protection value; press ENTER to accept displayed value.

Press to enter number 7. 3.2.1.2

Press to set overcurrent protection value. Data entry required to enter new overcurrent protection value; press ENTER to accept displayed value.

Press to enter number 8. 3.2.1.2

Press to enter Calibration status. Requires password entry; instructions appear on LCD.

Press to enter number 9. 3.2.1.2

REFERENCE

PARAGRAPH

(1) 3.2.5, (2) 3.3.3, (3) 3.4.1 (4) 3.4.4 (5) 3.3.2 (6) 3.2.7.4 (7,)3.2.6, (8) 4.5, (9) 4.6, (10) 4.7 (11) 3.2.15 (12) 3.2.8.1 (13, 14) 3.2.12, (15) 3.2.10

3.2.11

4.3

STORE Command Entry

EDIT

PROG

STEP

TIME

RUN

RECALL Command Entry

CLEAR Data Entry

1 Data Entry

Command Entry

Data Entry

Command Entry

Data Entry

Command Entry

Data Entry

Press to store present values of output voltage and current and overvoltage and overcurrent protection. Data entry required to select memory location where values are to be stored

Press to select the starting memory location to be edited. Then use or to view or modify the parameters of a specific memory location or to create a new program.

Press to select starting address of program to be executed one step at a time. Address is updated each time STEP is pressed.

Press to enter number 4. 3.2.1.2

Press to edit time value for specific memory location. Select memory location (data entry), then enter time value, 0.01 to 655.35 seconds (data entry).

Press to enter number 5. 3.2.1.2

Press to run a program. Requires data entry to select starting location. Press ENTER to accept displayed value.

Press to enter number 6. 3.2.1.2

Press to recall previously stored values of output voltage and current, and overvoltage and overcurrent protection. The previously stored output state (enabled or disabled) will also be recalled. Data entry required to select memory location containing values to be recalled; press ENTER to accept displayed value.

Press to exit Data Entry status; any numbers entered are lost. Restores Command Entry status

Press to enter number 1. 3.2.1.2

3.2.13

3.2.16.1

3.2.16.3

3.2.16.1.1

3.2.16.2

3.2.14

3.2.9

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TABLE 3-2. KEY FUNCTIONS (CONTINUED)

KEY

2Data Entry

3Data Entry

ENTER Data Entry

0Data Entry

( . ) Data Entry

POWER SUPPLY STATUS ACTIVE

Command Entry

Data Entry

Command Entry

Data Entry

DESCRIPTION

Press to enter number 2. 3.2.1.2

Press to enter number 3. 3.2.1.2

Press to accept data entered and return to Command Entry status. 3.2.9

— In CV (constant voltage), press to decrease output voltage by increment equal to voltage resolution (0.025% of EOmax). — In CC (constant current), press to decrease output current by increment equal to current resolution (0.025% of IOmax). — In EDIT PROG status, changes the parameter displayed on LCD for a specific memory location and decrements memory location displayed on LCD.

Erases number to left, or decreases value shown (e.g. Display Contrast setting). 3.2.9

Press to enter number 0. 3.2.1.2

Press to enter decimal point 3.2.1.2

— In CV (constant voltage), press to increase output voltage by increment equal to voltage resolution (0.025% of EOmax). — In CC (constant current), press to increase output current by increment equal to current resolution (0.025% of IOmax). — In EDIT PROG status, changes the parameter displayed on LCD for a specific memory location and increments memory location displayed on LCD

Increase value shown. 3.2.5

REFERENCE

PARAGRAPH

3.2.9, 3.2.16.1

3.2.2 TURNING THE POWER SUPPLY ON

CAUTION: DO NOT REPEATEDLY TOGGLE THE CIRCUIT BREAKER/SWITCH AS THIS

MAY CAUSE UNIT TO FAULT. ALLOW THE UNIT TO BE OFF FOR AT LEAST THREE (3) SECONDS BEFORE TURNING THE UNIT BACK ON TO GIVE THE POWER LOSS CIRCUIT TIME TO RESET.

Set Power ON/OFF circuit breaker/switch on front panel to the up position to turn the power supply on. If actuator does not lock when released, wait a few seconds before trying again. The circuit breaker is “trip-free” design; if overload exists or the protection is activated, contacts cannot be held closed by actuator. Setting the circuity breaker/switch to the down position shuts the power supply off.

When the power supply is turned on, the LCD briefly displays self test messages, then displays the power supply type on the top line (e.g., Kepco BHK 500) and GPIB addr. = nn on the bottom line, where BHK 500 is model BHK 500-0.4MG and nn is the GPIB address (factory default GPIB address = 6). After a few seconds, the bottom line of the LCD displays the voltage and current at the BHK-MG output. The top line displays either OFF or the current status of the unit as shown in Figure 3-1. The status of the unit upon power-up can be changed using the MENU key as detailed in PAR. 3.2.7.4. Power on defaults also include setting maximum values for overcurrent and overvoltage protection (PAR. 1.4.4), but are not displayed. If the unit fails a self-test, the LCD shows the last successful operation, and the unit beeps continually.

If the unit fails self-test during power-up, error messages are shown on the LCD. The failure will usually cause the test to be repeated, and if the unit passes the second test, power-up continues and the error message disappears. Refer to PAR. 3.2.3 for details.

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Loc OFF

I****

Loc CV

I****

0.000A0.000V (:_:_:)

(a) Default Display State for OUT OFF

@ Pwr-Up Selection (PAR. 3.2.7.4)

NOTE: (:_:_:) indicates blinking colon (:), Command Entry status

(=_=_=) indicates blinking equal sign (=), Data Entry status

**** indicates previously set current scale. High indicates high range, Low indicates low range.

FIGURE 3-1. LCD POWER ON DEFAULTS

3.2.3 ERROR CONDITIONS

Refer to Table 3-3 for how to proceed if any of the error conditions listed appear on the LCD for more than 90 seconds. For some errors the firmware repeats the action, and if the new attempt is successful, the error message will be deleted and normal operation will proceed.

TABLE 3-3. ERROR CONDITIONS

LCD DISPLAY SHOWS ACTION

When the microprocessor is not able to complete its power up sequence, it is possible that uncontrolled high output voltage may be present at the output. Turn off power supply immediately and disconnect any load. Measure the output using a voltmeter set to measure the maximum voltage that can be delivered by the power supply.

PROM FAILS CHECK Refer unit for service by authorized personnel.

RAM FAILS CHECK Refer unit for service by authorized personnel.

NvRAM & Dpot Err Restore Factory Calibration as described in PAR. 4.7, then verify that the

programmed voltage output is accurate. If problem continues, refer unit for service by authorized personnel.

NVRAM STATUS ERROR Restore Factory Calibration as described in PAR. 4.7, then verify that the

programmed voltage output is accurate. If problem continues, refer unit for service by authorized personnel.

PAGE FAILS CHECK Refer unit for service by authorized personnel.

CNFG FAILS CHECK Restore Factory Calibration as described in PAR. 4.7, then verify that the

Completely blank, or a blinking

underline in the upper left corner

programmed voltage output is accurate. If problem continues, refer unit for service by authorized personnel.

Refer unit for service by authorized personnel.

WARNING

(b) Default Display State for OUT ON

at Pwr-Up Selection (PAR. 3.2.7.4)

0.000A0.000V (:_:_:)

3.2.4 SETTING LOCAL MODE

When the power supply is turned on, it is automatically set to Local mode. If remote commands are accepted over the GPIB bus, the power supply will automatically go into Remote mode (Rem at the upper left of the LCD). Pressing the LOCAL key will restore Local mode. When in Remote mode, all keys except LOCAL are disabled.

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The BHK-MG incorporates a “keypad lockout” command which allows the LOCAL key to be disabled during remote operation, preventing inadvertent setting of the power supply to Local mode. When the keypad is locked, the LCD displays RwL in place of LOC. If the keypad is locked, it must be unlocked either by a remote command (see Appendix B, PAR. B.84), or cycling the power supply off then on.

3.2.5 ADJUSTING LCD CONTRAST

With the power supply in command entry status (:_:_:), press MENU key until LCD displays CONTRAST. Press or key to increase or decrease contrast for optimum viewing. The con-

trast can also be set directly by entering a number from 0 to 9. Press ENTER or CLEAR to exit menu.

3.2.6 ENABLING/DISABLING AUDIBLE BEEPS

With the power supply in command entry status (:_:_:), press MENU key until LCD displays SPEAKER. The top line indicates if the speaker is on or off (the factory default setting is speaker

on). Enter 1 to enable the speaker, or 0 to disable the speaker. Press ENTER or CLEAR to exit menu. Audible beeps associated with safety or failure messages are always enabled and can not be disabled.

3.2.7 ENABLING/DISABLING DC OUTPUT POWER

When the power supply is turned on, the output is automatically disabled or enabled depending on OUT on or off @Pwr-Up (see PAR. 3.2.7.4), and the bottom line of the LCD gives voltage and current measurements at the output.

3.2.7.1 DISABLING DC OUTPUT WHEN USING DIGITAL INPUTS ONLY (KEYPAD AND/OR GPIB)

To disable the output, press the red OUTPUT ON/OFF key; the top line of the LCD reads: OFF and the bottom line displays output voltage and current (zero). When the output is disabled, voltage and current are programmed to zero; the power supply remains in Command Entry status. Pressing the OUTPUT ON/OFF key again enables the output: the previously programmed values of voltage and current are restored and the LCD displays the mode (CV or CC) and actual values of output voltage and current.

3.2.7.2 DISABLING DC OUTPUT WHEN USING ANALOG CONTROL.

If analog control is used without digital programming, simply set the analog input to a value that brings the output voltage and current to zero without pressing the OUTPUT ON/OFF key.

To disable the output if both analog and digital (keypad and/or GPIB) control are used, first press the red OUTPUT ON/OFF key; the top line of the LCD reads: OFF and the bottom line displays output voltage and current controlled by analog means. Set the analog input to a value that brings the output current and voltage to zero. Pressing the OUTPUT ON/OFF key again enables the output: the previously programmed values of voltage and current (from the keypad or GPIB) are restored and the LCD displays the mode (CV or CC) and actual values of output voltage and current. Analog inputs must be restored separately to return to the output settings in effect when the output was disabled.

After disabling the output by pressing the OUTPUT ON/OFF key, if the analog input is causing more than approximately 8Vd-c to appear at the output terminals, or if current is being supplied to the load exceeds approximately 0.3% of full scale for the selected range, the unit will beep and enter a controlled shutdown for safety purposes. Shutdown can be avoided by setting the analog input to a value that brings the BHK-MG output below 8Vd-c and output current to less

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than 0.3% of full scale for the selected range within 25 seconds. For 15 seconds, the top line of the LCD alternately flashes the messages DIGITAL IS OFF and SET ANALOG OFF, while the bottom line of the LCD shows the actual output voltage and current. After 15 seconds, the bottom line will alternate a message showing the time remaining before shutdown (e.g POWER OFF 9 SEC) with the message SET ANALOG OFF . After the 10 second countdown the front panel circuit breaker will trip. (If (due to a defective protection circuit or faulty circuit breaker) the unit does not shut down, the LCD displays **BHK** **FAILURE ** and beeps constantly.)

3.2.7.3 REMOTE SHUTDOWN USING EXTERNAL TRIGGER PORT

A temporary short between pin 2 and pin 1 of the External Trigger port (or if pin 2 is at TTL logic 1, applying a temporary logic 0 to pin 2 referenced to pin 1) produces a shutdown signal which immediately shuts down the power supply output, and voltage and current are set to zero (0 LSB for voltage, and power up and reset value (see PAR. 3.2.8.1) for current). The DCL Control setting (see PAR. 3.3.2) determines the output settings when the output is reenabled: either restored to the voltage/current settings in effect at the time shutdown was initiated (“output unchanged”) or voltage and current still programmed to zero (“output = 0”).

NOTE: Turn off power to the unit or disable the output before inserting the plug in the External

Trigger port to avoid unintentionally initiating shutdown or trigger.

3.2.7.4 POWER UP DC OUTPUT CONTROL

The output of the power supply can be programmed to be either enabled or disabled upon power-up. With the power supply in command entry status (:_:_:), press the MENU key until LCD displays Out off @Pwr-Up or Out on @Pwr-Up. indicating whether the Digital DC Output will be on (enabled) or off (disabled) upon power-up. Press 1 to enable the Digital DC Output upon power up. This sets the output to zero volt and current to the Power-up and Reset current value. Press 0 to disable the output upon power up. Press CLEAR or RESET to exit menu and return to command entry status.

3.2.8 RESET OPERATION

RESET overrides all other local commands to reset the power supply to the power on defaults:

output voltage set to zero, output current set to the value specified as the power-up and reset current (see PAR. 3.2.8.1), overcurrent and overvoltage protection set to the maximum values per PAR. 1.4.4. The output is either enabled or disabled, as determined by the front panel DCL Control setting (enabled for “output = 0,” disabled for “output unchanged”) see PAR. 3.3.2 for details. The default configuration is for RESET to disable the output (output OFF). The power supply remains in command entry status. The current scale remains unchanged.

3.2.8.1 SETTING POWER-UP & RESET CURRENT

The factory setting of the power-up and reset current is 1.28% of Io max. This insures that the power supply is in voltage mode when the unit is initially turned on or a reset occurs. The user can change this value to be from 0 to 10% of the unit’s rated current. To change this setting, ensure the unit is in command entry status (:_:_:) and press the MENU key until the top line of the display presents the message PWR-UP & RESET and the bottom line shows ISET = n.n ma, where n.n is the present value of power-up and reset current. Press MENU key to leave the value unchanged. Press number keys followed by the ENTER key to validate a new value (the key erases data just entered) or CLEAR to exit without changing the setting.

If the value entered is higher than 10% of the rated current for the power supply, the bottom line of the LCD flashes Iset MAX = xx where xx = Iomax/10 (e.g., for BHK500-0.4MG, xx =

40.0mA). The unit remains in data entry status (=_=_=) waiting for a value equal to or less than the 10% of rated current.

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3.2.9 SETTING OUTPUT VOLTAGE OR CURRENT

V SET and I SET set output voltage and current limit, respectively, when the unit is in constant

voltage (CV) mode and set voltage limit and output current, respectively, when the unit is in constant current (CC) mode. The mode (CV or CC) is determined by the load together with the programmed settings. As long as the voltage across the load produces a current that is less than the I SET value, the unit operates in CV mode (voltage programmed to V SET value, current limited by I SET value). If the load changes to the point that current through the load reaches the I SET value, the unit automatically enters CC mode (current programmed to I SET value, volt- age limited by V SET value).

With the power supply in command entry status (:_:_:), press V SET (voltage) or I SET (current) key to put the power supply in data entry status (=_=_=). The lower right side of the LCD shows the programmed setting in effect when the key is pressed. Press ENTER or CLEAR to exit without changing setting. Enter new value (the key erases data just entered) and press ENTER to accept new setting or CLEAR to exit without changing setting.

NOTE: Although the LCD can display up to five decimal places, only two decimal places are

actually used for voltage and current settings (except that only one decimal place is used for setting voltage on Models BHK 1000-0.2MG and BHK 2000-0.1MG, and three decimal places are used for setting current on all models when current scale is set to Low range.).

With the power supply in command entry status (:_:_:), an alternative is to use key (increase) or key (decrease) to change the output by the minimum increment (0.025% of E

max for voltage, 0.025% of IOmax for current). In CC mode, these keys control output cur-

rent; in CV mode they control output voltage. When the unit switches from constant current (CC) to constant voltage (CV) mode, or from CV to CC mode the and keys are reassigned to the active parameter. Once the transition point is reached, each press of the key increases voltage, then current, changing the mode, from CV to CC or from CC to CV. The key has no effect after the maximum (or programmed limit) has been reached. If the value entered exceeds the maximum setting, the LCD bottom line flashes VsetMAX=n.n V or IsetMAX=n.n mA where n.n is the maximum setting (see PAR.3.2.12). The unit returns to {=_=_=) waiting for a value that does not exceed the maximum.

3.2.10 CHANGING CURRENT SCALE

The full scale output current can be changed from the maximum current rating (factory default) of the power supply (I

max) to a value ten times less (IOmax/10): e.g., for the BHK 500-0.4MG

power supply the full scale current can be either 400mA or 40mA. The relative accuracy and resolution are the same for both current programming scales because the power supply has two independent sensing resistors and the calibration is done separately; relative readback accuracy and resolution are ten times better for I

max/10 scale.

The current scale setting is stored in non-volatile memory and retained when the unit is turned off. When the unit is turned on, the stored current scale setting is in effect.

When the current scale is changed, the output is automatically turned off to avoid transients at the output. After the scale has been changed, press OUTPUT ON/OFF key to enable the output and restore the settings of the new current scale. Reprogram output voltage and current if the RESET key was pressed,

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With the power supply in command entry status (:_:_:), press MENU until the top line of the display presents the message FS CURRENT (=_=_=) <n> mA, where <n> represent the actual full scale of the current (I ENTER or CLEAR to exit menu without changing setting. Press 1 key to toggle between I and I

max/10; press ENTER to accept new full scale current and exit menu or CLEAR to exit

max or IOmax/10); the bottom line reads 1=TOGGLE. Press

max

without change.

When the full scale current is changed from High (I

• programmed current value remains unchanged if it is less than or equal to the Low maximum current, otherwise it is automatically limited to the Low maximum value.

• programmed overcurrent protection value remains unchanged if it is less than or equal to 1.1 x Low maximum current, otherwise it is automatically limited to (1.1 x Low maximum).

• maximum current value (PAR. 3.2.12) is restored.

• voltage and overvoltage protection settings are unchanged.

• the 40 nonvolatile memory locations for Low range are active.

• Trigger, power up and reset current are divided by 10.

When the full scale current is changed from Low (I

• programmed current value remains unchanged if it is less than or equal to the High maximum current, otherwise it is automatically limited to the High maximum value.

• programmed overcurrent protection value remains unchanged if it is less than or equal to 1.1 x High maximum current, otherwise it is automatically limited to (1.1 x High maximum).

• maximum current value (PAR 3.2.12) is restored from saved value

• voltage and overvoltage protection settings are unchanged.

• the 40 nonvolatile memory locations for High range are active.

• Trigger, power up and reset current are multiplied by 10.

max) to Low (IOmax/10):

max/10) to High (IOmax):

NOTES: 1. When changing from High to Low or Low to High range, even though the settings

for current and overcurrent are theoretically unchanged, they may actually be in error by up to 0.15% of full scale current due to rounding errors. To improve accuracy it is recommended that current and overcurrent be set using the keypad after changing range.

2. Changing current scale is not permitted when running a program (see PAR. 3.2.16).

All steps must use the same current scale.

3.2.11 SETTING OVERVOLTAGE OR OVERCURRENT PROTECTION

With the power supply in command entry status (:_:_:), press OV SET (overvoltage) or OC SET (overcurrent) to put the power supply in data entry status (=_=_=). The lower right side of the LCD shows the programmed setting in effect when the key is pressed. Press ENTER or CLEAR to exit without changing setting. Enter new value and press ENTER to accept new set-

ting (the key erases data just entered), or CLEAR to exit without changing setting.

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The value for overvoltage protection can be set within the range of 0 to 1.1 x EOmax; overcurrent can be set within the range of 0 to 1.1 x I for overvoltage protection and 1.1 x I

max for overcurrent protection.

max. The factory default values are 1.1 x EOmax

NOTE: Although the LCD can display up to five decimal places, only two decimal places are

3.2.12 CHANGING MAXIMUM VOLTAGE OR CURRENT VALUE

The default maximum values of voltage and current are determined by the model, e.g., 500V and 400mA for the BHK 500-0.4MG. These values can be lowered by the user to prevent inadvertent damage to a specific circuit under test by establishing software limits through the use of the MENU key. Lowering the maximum values of the BHK 500-0.4MG to 100V and 200mA, effectively makes the unit a 100V/200mA power supply.

Maximum values for current are independent for Low Range and High Range (see PAR.

3.2.10). With the power supply in command entry status (:_:_:), press MENU key until the LCD reads New MAXIMUM Vset (or Iset) (=_=_=) n.n where n.n is the maximum value setting to be changed (V for voltage, mA for current). Press CLEAR to exit menu without changing setting. Press ENTER to validate displayed value or press number keys to enter new value and press ENTER to accept new setting (the key erases data just entered), or CLEAR to exit without changing setting.

NOTE: Although the LCD can display up to five decimal places, only two decimal places are

If a value is entered that is higher than the rated maximum for the power supply, the bottom line of the LCD flashes Vset or Iset MAX = <Eomax or Iomax> where E rated maximum of the power supply. The unit remains in data entry status (=_=_=) waiting for a value equal to or less than the maximum value. Press CLEAR to exit without changing the value.

Once the maximum value has been changed, if a value higher than the new maximum is attempted to be programmed, the LCD flashes Vset (or Iset) MAX = n.n where n.n is the programmed maximum (V for voltage, mA for current).

NOTE: If the programmed output value is higher than the new maximum value established

with the MENU key, the output will be automatically limited to the new maximum value.

3.2.13 STORING POWER SUPPLY OUTPUT SETTINGS

The programmed settings of voltage, current, overvoltage protection and overcurrent protection can be stored in one of the 40 memory locations available for local programming (see PAR.

3.2.16). To accommodate the two current scales, there are actually 40 locations for High range

max or IOmax is the

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and 40 locations for Low range which are swapped each time the range is changed, so that only one set of 40 locations is active, depending on the current scale selected.

With the power supply in command entry status (:_:_:), press STORE key. The LCD reads STORE mem (=_=_=) nn where nn is the memory location where the settings are to be stored. Press CLEAR to exit without changing setting. Press ENTER to validate the existing location. Enter memory location (from 1 to 40) and press ENTER. The programmed voltage, current, overvoltage protection and overcurrent protection settings in effect when ENTER is pressed are stored in the selected memory location. To recall stored settings, see PAR. 3.2.14. The default value at power-up for the Store command is 01. During normal operation, the location last used is displayed.

3.2.14 RECALLING STORED OUTPUT SETTINGS

With the power supply in command entry status (:_:_:), press RECALL. The LCD reads RECALL mem (=_=_=) nn where nn is the memory location holding the settings to be

retrieved. Note that the location retrieved will correspond to the active current scale. The 40 memory locations are different for High and Low range (see PAR. 3.2.13). Press CLEAR to exit without changing setting. Press ENTER to validate the existing location. Enter memory location (from 1 to 40) and press ENTER. The stored settings for voltage, current, overvoltage protection and overcurrent protection replace the current values, and the unit returns to (:_:_:) command entry status. The default value at power-up for the Recall command is 01. During normal operation, the location last used is displayed.

3.2.15 FIRMWARE VERSION

To display the firmware version of the power supply, the power supply must be in command entry status (:_:_:). Press the MENU key until the LCD displays BHK XXXX,SSSSSS mm- dd-yyyy,V.zz where XXXX indicates the power supply model (e.g. XXXX = 1000 for BHK 1000-0.2MG), SSSSSS indicates the serial number, mm-dd-yyyy indicates the factory calibration date and V.zz indicates the firmware version. Press ENTER or CLEAR to exit menu and return to command entry status.

3.2.16 LOCAL MODE PROGRAMMING OF THE POWER SUPPLY.

Local mode programming offers the user 40 memory locations that can be used to program the power supply. Each location defines values for output voltage, output current, overcurrent protection, overvoltage protection, time duration (between 0.01 and 655.35 seconds) for the programmed settings, and the address of the next memory location in the program. The factory default values for all memory locations is: 0 Volts, 0 Amperes, overvoltage and overcurrent is set to Eomax+10% and Iomax+10%, respectively, time duration is set to 0.01 Sec, and next step is set to 0.

3.2.16.1 CREATING OR MODIFYING A PROGRAM (PROGRAM EDIT MODE)

Creating a program and modifying an existing program are identical except that a program modification requires only selected parameters to be changed rather than all new parameter values. With the power supply in command entry status (:_:_:), press EDIT PROG key. The top line indicates the STARTaddr.(=_=_=)nn, where nn is one of 40 memory location. To select a different address, enter new value and press ENTER.

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The top line of the LCD indicates the active memory location, e.g. ViewVAL Mem <n> where n is the memory location previously chosen. The bottom line of the LCD indicates the parameter on the left (Iset, Vset, OVset, OCset, TIMEval, NEXT STEP), the parameter’s value on the right, and data entry status (=_=_=) in the middle. To modify time values see PAR.3.2.16.1.1.

Press ENTER to accept displayed value, or enter new value and press ENTER to accept new setting (the LCD displays the next parameter). Press CLEAR to exit Program Edit mode without changing value. Use or key to scroll forward or backward to view next or previous parameter or memory location. For a program to run once, then stop, see PAR. 3.2.16.6; to cycle a program continuously, see 3.2.16.4. After all program values have been set, press CLEAR or ENTER to exit Program Edit mode. Setting up a program can be made easier by copying the Memory Location Worksheet (Table 3-5) and filling in the values before programming the power supply.

3.2.16.1.1 MODIFYING PROGRAMMED TIME INTERVAL

The TIME key offers a quick and easy way to change the time for any memory location. With the power supply in command entry status (:_:_:), press TIME key. The LCD displays TIME@nn (=_=_=) where nn is the current memory location of the TIME function. Press CLEAR to exit without changing setting. Press ENTER to validate the existing location or enter the new location and then press ENTER. The display now shows TIMEval = n.n s where n.n is the time value set for the selected location. The default time interval for all 40 steps is 0.01 second. Enter new value (between 0.01 and 655.35 seconds) and press ENTER to accept new value or press

CLEAR to exit without changing value. The unit returns to command entry status (:_:_:).

3.2.16.1.2 TIME INTERVAL ACCURACY

The accuracy of the time interval is ±1% through the entire time interval range.

3.2.16.2 RUNNING A PROGRAM

With the power supply in command entry status (:_:_:), press RUN key. The LCD bottom line indicates the start address of the program. Press ENTER key to run the program starting with that address. To change the starting address, enter new value and press ENTER to run the program. Press CLEAR to exit without running the program.

When the program is running, the LCD displays the actual voltage and current, however if all the steps are programmed for 0.01 second, the LCD reads *** RUNNING PROGRAM***.

3.2.16.3 STEPPING THROUGH A PROGRAM

Programmed voltage is present at the output as steps are executed.

The STEP function is useful for examining a program that has just been created or edited before running it in real-time. With the power supply in command entry status (:_:_:), press STEP key. The LCD bottom line indicates the start address of the program; press ENTER to begin stepping at that address. To change the starting address, enter new value and press ENTER to begin stepping at the new address, press CLEAR to exit without stepping through the program.

WARNING

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TABLE 3-4. MEMORY LOCATION WORKSHEET

MEMORY

LOCATION

I SET

(Current)

(mA)

V SET

(Voltage)

(V)

OCset

(Overcurrent

Protection)

(mA)

OV set

(Overvoltage

Protection)

(V)

TIMEval

(0. to 655.35)

(Sec)

NEXT STEP

(Next location

to execute)

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The LCD top line shows LOC to indicate local mode, aa bb where aa is the memory location just executed, bb is the NEXT STEP location, and shows CV (constant voltage) or CC (constant current) to indicate the actual operating mode. The LCD bottom line shows the output voltage and current measurements for the location just executed, and (:_:_:) indicates command status. Press STEP to execute location bb. The LCD will again display the location just executed, voltage and current measurements, and the NEXT STEP location. Continue to press STEP to execute the program one step at a time. The OUTPUT ON/OFF key can be used to turn the output on or off when in step mode.

Press CLEAR, or RESET to exit Step function: CLEAR keeps the output at the values established by that step (as permitted by the load). RESET restores the power on defaults (Figure 3-

1).

3.2.16.4 CYCLING A PROGRAM

To cycle a program, modify the program (see PAR. 3.2.16.1) and go to the last memory location to be executed and set the NEXT STEP address to the Starting address, causing the program to loop and repeat indefinitely. For example, if the last location is 14, and the starting location is 05, press EDIT PROG, enter 14, then press ENTER. Press until LCD reads ViewVAL Mem14 NEXT STEP (=_=_=). Enter 5 and press ENTER. When the program runs, it will start at loca- tion 05, continue to 14, then loop back to the location 05, and repeat indefinitely.

3.2.16.5 RUNNING A PROGRAM ONCE

To set up a program to stop after running once, modify the program (see PAR. 3.2.16.1) and go to the last memory location to be executed and set the NEXT STEP address to 0. For example, with the power supply in command entry status (:_:_:), press EDIT PROG. Enter the last memory location you want executed (e.g. 14), then press ENTER. Press key until LCD reads ViewVAL Mem14 NEXT STEP (=_=_=). Enter 0 and press ENTER. The program will now stop after memory location 14 is executed. When the program stops, the power supply will continue to provide the output specified by the last location (in the above example, location 14).

3.2.16.6 STOPPING A RUNNING PROGRAM

There are three ways to stop a program that is running:

• Press CLEAR key: the program stops after finishing the step (location) that was being executed when the key was pressed. The power supply output remains at the values specified by that step.

• Press RESET key: The program stops immediately and power on defaults are restored (see PAR. 3.2.8).

• Press OUTPUT ON/OFF key: the output is disabled (programmed to zero) and the program immediately stops at the step (location) that was being executed when the key was pressed. Pressing the OUTPUT ON/OFF key again restores the output to the values specified by the step in effect when the program was stopped.

3.2.16.7 SAMPLE PROGRAM

Table 3-5 shows a sample program designed to cycle continuously; if the NEXT STEP value for location 3 is set to 00, the program will run once and stop.

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TABLE 3-5. SAMPLE PROGRAM (MODEL BHK-MG 500-0.4MG)

MEMORY

LOCATION

1 400 420 440 550 1.5 02

2 400 500 440 550 1.8 03

3 400 250 440 550 1.0 01

NOTE: For each cell of a program OC set and OV set must be at least 2% above the maximum values of voltage and cur-

rent expected at the load. The limit parameter (I set for voltage mode, or V set for current mode) must be at least 1% above the maximum load current (for I set) or load voltage (for V set).

I SET

(Current)

(mA)

V SET

(Voltage)

(V)

OC set

(Overcurrent

Protection)

(mA)

OV set

(Overvoltage

Protection)

(V)

TIMEval

(0.01 to 655.35)

(Sec)

NEXT STEP

(Next location

to execute)

3.2.17 CALIBRATION

See Section 4.

3.3 REMOTE MODE PROGRAMMING USING SCPI COMMANDS VIA IEEE 488 (GPIB). BUS

BHK-MG Power Supplies may be programmed over a control bus using SCPI (Standard Commands for Programmable Instruments). SCPI provides a common language conforming to IEEE

488.2 for instruments used in an automatic test system. The control bus used must be the IEEE 488 standard communication bus (General Purpose Interface Bus, GPIB). Refer to Table 2-1 for input/output signal allocations.) Most power supply functions available from the keypad can be programmed via remote commands, in addition to some that are not available from the keypad (e.g. triggering, and local lockout).

This section includes a discussion of GPIB bus protocols (PAR. 3.3.1), instructions for changing the GPIB address (PAR. 3.3.3), a discussion of the VISA (Virtual Instrumentation Software Architecture) driver supplied with the unit (PAR. 3.3.5), followed by a detailed explanation of SCPI programming (PAR. 3.5)

3.3.1 IEEE 488 (GPIB) BUS PROTOCOL

Table 3-6 defines the interface capabilities of the BHK-MG power supply (Talker/Listener) relative to the IEEE 488 (GPIB) bus (reference document ANSI/IEEE Std 488: IEEE Standard Digital Interface for Programmable Instrumentation) communicating with a Host Computer—Controller (Talker/Listener). Tables 3-7 and 3-8 define the messages sent to the BHK-MG, or received by the BHK-MG, via the IEEE 488 bus in IEEE 488 command mode and IEEE 488 data mode, respectively. These messages are enabled during the “handshake” cycle, with the BHK-MG power supply operating as either a Talker or a Listener.

TABLE 3-6. IEEE 488 (GPIB) BUS INTERFACE FUNCTIONS

FUNCTION

Source Handshake SH1 Complete Capability (Interface can receive multiline messages)

Acceptor Handshake AH1 Complete Capability (Interface can receive multiline messages)

Ta lk er T 6

SUBSET

SYMBOL

Basic talker, serial poll, unaddress if MLA (My Listen Address) (one-byte address)

COMMENTS

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TABLE 3-6. IEEE 488 (GPIB) BUS INTERFACE FUNCTIONS (CONTINUED)

FUNCTION

Listener L4 Basic listener, unaddress if MTA (My Talk Address) (one-byte address).

Service Request SR1

Remote/Local RL1

Parallel Poll PP0 No Capability

Device Clear DC1

Device Trigger DT1 Respond to *TRG and <GET> trigger functions.

Controller C0 No Capability

SUBSET

SYMBOL

Complete Capability. The interface sets the SRQ line true if there is an enabled service request condition.

Complete capability. Interface selects either local or remote information. In local mode the BHK-MG executes front panel commands, but can be set to remote mode via IEEE 488 bus. When in Remote mode all front panel keys are disabled except LOCAL. LOCAL key can be disabled using keypad lockout command (see Appendix B, PAR. B.84) so that only the controller or a power on condition can restore Local mode.

Complete Capability. BHK-MG accepts DCL (Device Clear) and SDC (Selected Device Clear).

COMMENTS

TABLE 3-7. IEEE 488 (GPIB) BUS COMMAND MODE MESSAGES

MNEMONIC

MESSAGE

DESCRIPTION

COMMENTS

DCL Device Clear Received

GET Group Execute Trigger Received

GTL Go To Local Received

IFC Interface Clear Received

LLO Local Lockout Received

MLA My Listen Address Received

MTA My Talk Address Received

OTA Other Talk Address Received (Not Used)

RFD Ready for Data Received or Sent

SDC Selected Device Clear Received

SPD Serial Poll Disable Received

SPE Serial Poll Enable Received

SRQ Service Request Sent

UNL Unlisten Received

UNT Untalk Received

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TABLE 3-8. IEEE 488 (GPIB) BUS DATA MODE MESSAGES

MNEMONIC MESSAGE DESCRIPTION COMMENTS

DAB

END

EOS

RQS

STB

3.3.2 DCL CONTROL

The device clear (DCL) and selected device clear can be set to operate in two modes. In the “output = 0” mode, when the device clear is received the output is disabled; when the output is enabled, the output of the power supply is set to zero volts and current is set to the power-up and reset current value (see PAR. 3.2.8.1). In the “output unchanged” mode sending DCL or selected DCL disables the output, but has no effect on output voltage and current as required by IEEE specification 488.2 so that when the output is enabled, the settings in effect when DCL was issued are restored. Note that the DCL setting also affects the operation of RESET (see PAR. 3.2.8). The factory default value is “output=0” mode.

To change the DCL mode the unit must be in command entry mode (:_:_:), then depress the

MENU key until the top line of the display shows the current setting: either DCL OUTP = 0 or DCL = OUTP UNCHNG. Depress 1 for “output unchanged” mode where the output is unaffected

by DCL; depress 0 for “output = 0V” mode where DCL sets the output to 0 volts and current is set to the power-up and reset current value (see PAR. 3.2.8.1).

Data Byte Received or Sent

End Received or Sent

End of String Received or Sent

Request Service Sent

Status Byte Sent

3.3.3 CHANGING THE GPIB ADDRESS

When the power supply is in command entry status (:_:_:), press MENU key until the top line of the LCD indicates the current GPIB address. Enter new value and press ENTER to accept new setting, or CLEAR to exit without changing setting. The GPIB address default value is set to 6.

3.3.4 EXTERNAL TRIGGER

The External Trigger Port can be used to restore the power supply output to settings previously defined using SCPI commands. This can be done by applying a temporary short between pin 4 and pin 1 of the External Trigger Port, (or if pin 4 is at TTL logic 1, applying a temporary logic 0 to pin 4 referenced to pin 1).

NOTE: Turn off power to the unit or disable the output before inserting the plug in the External

Trigger port to avoid unintentionally initiating shutdown or trigger.

The following remote SCPI commands must be sent before the external trigger at pin 4 activated:

• The values to be set upon receiving the external trigger at pin 4 must be programmed using VOLT:TRIG (PAR B.58) and CURR:TRIG (PAR B.48) commands.

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• Choose external trigger source by sending TRIG:SOUR EXT (PAR. B.92)

• Choose continuous action (by sending INIT:CONT ON (PAR B.12).

NOTE: The output must be enabled prior to activating the external trigger at pin 4 of the External

Trigger port in order for the external trigger to work properly.

3.3.5 BHK-MG VISA INSTRUMENT DRIVER

The VISA instrument driver simplifies programming with a VISA compatible GPIB controller. and Includes 1) source code (C) for all VISA functions, and 2) a complete programming reference manual which can be used to program one or more BHK-MG power supplies using a virtual front panel observed on a computer monitor.

Download the latest VISA driver from the Kepco website at

http://www.kepcopower.com/drivers.htm

Although the software drivers supplied by Kepco are VISA compliant, they also require the installation of the proper 32-bit VISA driver from your GPIB card supplier. Many vendors supply this software with the hardware; National Instruments (http://www.natinst.com) has the driver for their cards available on the internet at a file transfer site (ftp://ftp.natinst.com — find the folder for support and VISA drivers). The driver to be installed is the win16 driver, even if your system is running under Windows 95 or Windows NT.

3.3.6 PROGRAMMING TECHNIQUES TO OPTIMIZE PERFORMANCE

3.3.6.1 PROGRAMMING VOLTAGE/CURRENT LIMIT AND CURRENT/VOLTAGE LIMIT

Kepco's auto-crossover digital supplies can operate in either voltage mode with current limit, or current mode with voltage limit. The operating mode is determined by the voltage and current commands received, as well as the load. Each time voltage and current commands are received, the unit must evaluate the commands and the load conditions to determine the proper operating mode. Reducing the number of times this evaluation must be made is desirable because Kepco's digital auto-crossover supplies employ two separate feedback loops. Each time there is a potential mode change, there is always an uncontrolled period of a few milliseconds while the two feedback loops compete for control of the output. By changing only the active parameter (e.g., voltage for voltage mode), there is no doubt as to what the operating mode will be, so the unit is never uncontrolled, response is quick and no transients are possible. Recommended programming techniques are:

1. Minimize programmed mode (voltage or current) changes. Unless absolutely required by the test parameters, allow the power supply to automatically switch modes as determined by the load. This will improve response time and reduce undesirable transients. For those power supplies that employ relays (Kepco's MBT with “R” option, MAT and MST) this will also increase the life of the relay.

2. Once the mode (voltage or current) is programmed, program the active parameter to zero and the complementary limit parameter to the maximum anticipated for application. Then program only the active parameter. The active parameter is the parameter that controls the output, e.g., voltage controls the output in voltage mode.

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3. Never program both the active and complementary limit parameter to zero. This can result in long response times. Set the active parameter to zero and the complementary limit parameter to a minimum, e.g., 10% of maximum, to ensure that the active mode is defined.

3.3.6.2 MAKING SURE THE PREVIOUS COMMAND IS COMPLETE

Some SCPI commands require a flash memory update and can take an indeterminate amount on time to complete. These commands are:

•*SAV

•CAL:SAVE

• SOUR:CURR:LIM

• SOUR:VOLT:LIM

• SYST:COMM:GPIB:ADDR

• SYST:COMM:SER:BAUD

• SYST:COMM:SER:ECHO

• SYST:COMM:SER:PACE

• SYST:COMM:SER:PROMpt

• SYST:PASS:NEW

• SYST:SEC:IMM

When sending these via the GPIB, these commands require a query to be added to the command string to verify the previous command is complete. When the command is complete, the unit updates the status byte and indicates MAV (Message Available, bit 4 - see Table A-3) is true. MAV indicates that there is a response to be received by the computer, so when it becomes set, the unit is ready for its next command after reading back the data from the query that was added to the command string.

When sending the above commands via the RS 232 bus, data flow control must be enabled (XON) using the SYST:COMM:SER:PACE command (see PAR. B.77) must be enabled for the unit to properly update flash memory.

The *OPC? query is ideal to check if the previous command is complete since it returns either a 1 or 0. It is important that it be sent as a part of the same string as the command that causes a flash update. As an example, sending CAL:SAVE 12/31/2005;:*opc? or *opc?;:CAL:SAVE 12/31/2005 are valid command strings. Sensing the commands separately will not verify that the previous command is complete. Figure 3-2 is a program written in C, incorporating these techniques.

Failure to provide an adequate delay can result in:

• Commands that are not processed,

• The following command may be received in error, causing an error in the transmission,

• Unit lock-up requiring power cycling of the unit. If working via the GPIB bus, sending Interface Clear and Device Clear followed by *RST will unlock the unit.

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#include <formatio.h> #include <utility.h> #include <gpib.h> #include <ansi_c.h>

/*Overhead for the use of a NATIONAL INSTRUMENTS gpib interface */ int unit_desc; // handle for the national instruments controller int GPIbus=0; // GPIB card 0 int adr=6; // Power Supply address char status_byte; // status byte from the power supply

#define MAV 0x10 /* bit 4 of the status byte is the Message AVailable bit by 488.2 specification */

/* Function Send_with_wait

INPUT: string to be sent to power supply

Description: adds the *OPC? query and performs serial polls to wait for the command to be completed.

int Send_with_wait(char *command); char snd[501]; // data to be sent to the power supply char rcv [10]; // data from power supply int j;

sprintf(snd,”%s;:*OPC?,command); // Add *OPC? to the command

Send(GPIbus, adr, snd, strlen(snd), 2); // Send the data to the power supply for (j=0;j<500;j++)( // loop until ready (5 seconds max) Delay(.05); // Wait for command to complete ibrsp(unit_desc,&status_byte); // get status byte if ((status_byte& 0x10) ==0x10) break;) // by looking for data in string Receive (GPIbus, adr, rev, rev_buf_size,10); // so the error queue will not receive a 410 error }

main( // test code to show operation of function. unit_desc=ibdev(GPIbus,adr,adr/256,T100ms,1,0x40a);Delay(.005); Send (GPIbus,adr,”VOLT 10;curr .01”,sizeof(“VOLT 10;curr .01”),NLEND; Send_with_wait(“*SAV 10”); }

// so there is a response from the // power supply

FIGURE 3-2. PROGRAMMING EXAMPLE TO VERIFY PREVIOUS COMMAND HAS COMPLETED

3.4 RS232-C OPERATION

The BHK-MG may be operated via an RS232-C terminal, or from a PC using a terminal emulation program. The default settings are as follows:

• Baud rate: 9600

• Parity: None

•Data Bits8

• Stop Bits 1

• Echo ON

•XON OFF

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To change baud rate refer to PAR’s. B.73 and B.74. To select prompt refer to PAR’s. B.79 and B.80. To select echo refer to PAR’s. B.75 and B.76. To select XON/XOFF, refer to PAR’s. B.77, B.78.

3.4.1 SETTING RS 232 BAUD RATE

When the power supply is in local mode, command entry status , press MENU key until LCD displays BAUD RATE =. The top line of the LCD indicates the current RS 232 baud rate (default = 9600). Use and keys to scroll through the available baud rate settings (19200, 9600, 4800 or 2400). Press ENTER to accept new setting (new baud rate is effective immediately), or

CLEAR to exit without changing setting.

3.4.2 SERIAL INTERFACE

The serial interface behaves like the GPIB interface in that the command is parsed after receiving a control character of either a Line Feed or Carriage Return. The serial interface supports six special control characters. The three special control characters are:

Backspace (08

) Causes the last character in the input buffer to be removed from the

input buffer queue.

Carriage Return (0D

Line Feed (0A

) Causes the input buffer to be parsed by the BHK-MG.

3.4.3 RS 232 IMPLEMENTATION

The following paragraphs are provided to help the user understand how the RS 232 serial interface is implemented in the BHK-MG. Since the RS 232 protocol does not use a parity bit, the echo mode is the default method used to ensure reliable communication between the command originator (computer) and the BHK-MG power supply, thus avoiding a more complex “handshake” protocol.

When the BHK-MG is in the RS 232 echo mode it returns all data sent to the host controller. The BHK-MG provides two additional options that allow handshake communication: the Prompt method and the XON XOFF method. In standard echo mode the controller must verify that each character is echoed back by the BHK-MG. As shown in Figure 3-3, there are times when the BHK-MG does not echo back the character from the controller, requiring that the controller resend the character. By using the handshake options (prompt and XON XOFF) the host controller can ensure that serial data interrupts occurring after parsing of the incoming message do not result in lost data.

Figure 3-3 illustrates the default echo mode, the prompt method and the XON XOFF method described in the following paragraphs.

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FIGURE 3-3. RS 232 IMPLEMENTATION

Only three control characters (characters between 00H and 1FH) are acknowledged by the power supply:

• Carriage Return (CR, 0D

• Line Feed (LF, 0A

• Back Space (BS, 08

BS deletes the last character entered, with the exception of CR or LF characters. Either the CR or LF character acts as the line terminator, initiating parsing of the ASCII data sent to the BHKMG by the command originator. When the line is parsed, the BHK-MG sends the line terminator sequence CR LF to the command originator.

All non-control characters are sent via the serial port of the command originator. The control character BS is echoed as BS Space BS. Only the first control character is returned in response to either a CR LF or LF CR character sequence (see Figure 3-3).

3.4.3.1 ECHO MODE

In echo mode each byte (character) is echoed back to the sender where it is verified as the same character that was just sent.

3.4.3.2 PROMPT METHOD

)

The command originator sends a message line (command) to the BHK-MG and waits until the prompt sequence CR LF > (3E

, 6210) is received. The BHK-MG sends the prompt sequence

CR LF > to the command originator indicating the power supply is ready to receive the next command and data will not be lost.

3.4.3.3 XON XOFF METHOD

The XON XOFF method allows the BHK-MG to control when the command originator is allowed to send data. The command originator can only send data after the XON (transmission on) character (011 XOFF (transmission off) character (013

) has been received; the command originator stops sending data after receiving the

), and waits until the XON character is received before

sending additional data.

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Control characters, either CR or LF, are returned as XOFF CR if echo mode is on, and as XOFF if echo mode is off. XOFF stops data from the command originator and the BHK-MG returns the normal sequence of CR LF (if echo mode is enabled).

3.4.4 ISOLATING RS 232 COMMUNICATION PROBLEMS

A Loop Back test can be run from the front panel to aid in isolating RS 232 communication problems. The unit is designed to pass the test only with the Loop Back test connector (part of Kit 219-0436, see Table 1-5) installed.

1. With the power supply in local mode, command entry status , press MENU key until LCD

reads LOOP BACK TEST UNTESTED 1=RUN.

2. Press the 1 key to run the test with the Loop Back Test connector NOT installed and verify

the LCD reads FAILED. If the LCD reads PASSED, the power supply is defective and requires repair.

3. Install the loop back test connector into RS 232 port and press the 1 key to rerun the test. If

the LCD reads PASSED, the power supply is operating properly. If the LCD reads FAILED, the unit requires repair.

4. To test the integrity of the cable assembly connecting the power supply RS 232 port to the computer, remove the Loop Back test connector from the power supply RS 232 port and connect the cable in its place. With the DB9 adapter installed on the opposite end of the cable, connect a short jumper wire between pins 2 and 3 of the adapter connector and repeat the test of (3) above. If the LCD display reads FAILED, the cord is either the improper type (not null modem) or is defective. If the LCD display reads PASSED, the cable is correct; remove the jumper and reconnect the cable to the computer.

If each of the above steps is completed successfully, the problem lies in the computer hardware and/or software. Refer to the Product Support area of the Kepco website for additional information regarding RS 232 communications problems: www.kepcopower.com/support.

3.5 SCPI PROGRAMMING

SCPI (Standard Commands for Programmable Instruments) is a programming language conforming to the protocols and standards established by IEEE 488.2 (reference document ANSI/IEEE Std 488.2, IEEE Standard Codes, Formats, Protocols, and Common Commands). SCPI commands are sent to the BHK-MG Power Supply as ASCII output strings within the selected programming language (PASCAL, BASIC, etc.) in accordance with the manufacturer’s requirements for the particular GPIB controller card used.

Different programming languages (e.g., BASIC, C, PASCAL, etc.) have different ways of representing data that is to be put on the IEEE 488 bus. It is up to the programmer to determine how to output the character sequence required for the programming language used. Address information (GPIB address) must be included before the command sequence. (See PAR.3.3.3 to establish the BHK-MG Power Supply GPIB address.)

3.5.1 SCPI MESSAGES

There are two kinds of SCPI messages: program messages from controller to power supply, and response messages from the power supply to the controller. Program messages consist of one or more properly formatted commands/queries and instruct the power supply to perform an action; the controller may send a program message at any time. Response messages consist of

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formatted data; the data can contain information regarding operating parameters, power supply state, status, or error conditions.

3.5.2 COMMON COMMANDS/QUERIES

Common commands and queries are defined by the IEEE 488.2 standard to perform overall power supply functions (such as identification, status, or synchronization) unrelated to specific power supply operation (such as setting voltage/current). Common commands and queries are preceded by an asterisk (*) and are defined and explained in Appendix A (see Table 4-4). Refer also to syntax considerations (PARs 3.4.3 through 3.4.6).

3.5.3 SCPI SUBSYSTEM COMMAND/QUERY STRUCTURE

Subsystem commands/queries are related to specific power supply functions (such as setting output voltage, current limit, etc.) Figure 3-5 is a tree diagram illustrating the structure of SCPI subsystem commands used in the BHK-MG Power Supply with the “root” at the left side, and specific commands forming the branches. The following paragraphs introduce the subsystems; subsystem commands are defined and explained in Appendix B.

3.5.3.1 ABORT SUBSYSTEM

This subsystem allows pending trigger levels to be cancelled.

3.5.3.2 INITIATE SUBSYSTEM

This subsystem enables the trigger system. When a trigger is enabled, the triggering action will occur upon receipt of a GPIB <GET>, *TRG or TRIGger command. If a trigger circuit is not enabled, all trigger commands are ignored.

3.5.3.3 LIST SUBSYSTEM

The LIST subsystem is represented by 250 memory locations (groups of settings) which are stored in the volatile memory. Each setting contains values for: Current, Voltage, and Time. The range for the first two values is the maximum available range for the specific power supply. The Time setting is between 0.01 and 655.35 seconds.

3.5.3.4 MEASURE SUBSYSTEM

This query subsystem returns the voltage and current measured at the power supply's output terminals.

3.5.3.5 OUTPUT SUBSYSTEM

This subsystem controls the power supply's voltage and current outputs

3.5.3.6 INSTRUMENT SUBSYSTEM

This subsystem controls the power supply's voltage and current outputs and allows compatibility with other vendor’s products

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3.5.3.7 STATUS SUBSYSTEM

This subsystem programs the power supply status register. The power supply has two groups of status registers: Operation and Questionable. Each group consists of three registers: Condition, Enable, and Event.

3.5.3.8 SYSTEM SUBSYSTEM

This subsystem controls the RS 232 port, as well as system errors, passwords, security, language, beep, version and keyboard lockout

3.5.3.9 TRIGGER SUBSYSTEM

This subsystem controls the remote triggering of the power supply.

3.5.3.10 [SOURCE:]VOLTAGE AND [SOURCE:]CURRENT SUBSYSTEMS

These subsystems program the output voltage and current of the power supply.

3.5.3.11 CALIBRATE SUBSYSTEM

The BHK-MG series of power supplies support software calibration. A full calibration consist of a voltage calibration and a current calibration. Both voltage and current calibrations consist of a zero and a full scale calibration. There are two ways to perform the calibration: locally using the front panel keys, or remotely sending commands through the GPIB bus. These two ways cannot be combined.

In order to enter the calibration mode the correct calibration access code (password) must be entered. If the password has been forgotten call the factory and a secret password (which has been assigned to your power supply) will be provided. During the calibration, new calibration data is computed which is than stored in the non volatile memory.

The equipment required for calibration is specified in PAR. 4.2.

Because the voltage measured will be used as reference for calibration, the DVM itself must be calibrated accurately. During voltage calibration, the voltage, overvoltage and voltage readback are calibrated and during current calibration the current, overcurrent and current readback are calibrated. The normal procedure is to calibrate voltage first and then current. However, you do not have to do a complete calibration each time. If required, you may calibrate only the voltage or the current and then proceed to saving the calibration results. For voltage calibration all loads must be disconnected and the sense terminals connected to the corresponding output terminals. The digital voltmeter will be connected to the output of the power supply. For current calibration after disconnecting all loads an appropriate shunt resistor will be connected across output terminals and the digital voltmeter will be connected across the sense terminals of the shunt resistor.

3.5.4 PROGRAM MESSAGE STRUCTURE

SCPI program messages (commands from controller to power supply) consist of one or more message units ending in a message terminator (required by Kepco power modules). The message terminator is not part of the syntax; it is defined by the way your programming language indicates the end of a line (“newline” character). The message unit is a keyword consisting of a single command or query word followed by a message terminator (e.g., CURR?<newline> or TRIG<end-of-line>). The message unit may include a data parameter after the keyword sepa-

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rated by a space; the parameter is usually numeric (e.g., CURR 5<newline>), but may also be a string (e.g., OUTP ON<newline>). Figure 3-4 illustrates the message structure, showing how message units are combined. The following subparagraphs explain each component of the message structure.

NOTE: An alternative to using the message structure for multiple messages defined in the fol-

lowing paragraphs is to send each command as a separate line. In this case each command must use the full syntax shown in Appendix B.

3.5.4.1 KEYWORD

Keywords are instructions recognized by a decoder within the BHK-MG, referred to as a “parser.” Each keyword describes a command function; all keywords used by the BHK-MG are listed in Figure 4-1.

Each keyword has a long form and a short form. For the long form the word is spelled out completely (e.g. STATUS, OUTPUT, VOLTAGE, and TRIGGER are long form keywords). For the short form only the first three or four letters of the long form are used (e.g., STAT, VOLT, OUTP, and TRIG). The rules governing short form keywords are presented in Table 4-5.

TABLE 3-9. RULES GOVERNING SHORTFORM KEYWORDS

IF NUMBER OF LETTERS IN

LONGFORM KEYWORD IS:

4 OR FEWER (DOES NOT MATTER) ALL LONG FORM LETTERS MODE

5 OR MORE

AND FOURTH LETTER

IS A VOWEL?

You must use the rules above when using keywords. Using an arbitrary short form such as ENABL for ENAB (ENABLE) or IMME for IMM (IMMEDIATE) will result in an error. Regardless of which form chosen, you must include all the letters required by that form.

To identify the short form and long form in this manual, keywords are written in upper case letters to represent the short form, followed by lower case letters indicating the long form (e.g., IMMediate, EVENt, and OUTPut). The parser, however, is not sensitive to case (e.g., outp, OutP, OUTPUt, ouTPut, or OUTp are all valid).

3.5.4.2 KEYWORD SEPARATOR

If a command has two or more keywords, adjacent keywords must be separated by a colon (:) which acts as the keyword separator (e.g., CURR:LEV:TRIG). The colon can also act as a root specifier (paragraph 3.4.4.7).

3.5.4.3 QUERY INDICATOR

YES

THEN SHORT FORM

CONSISTS OF:

THE FIRST FOUR

LONG FORM LETTERS

THE FIRST THREE

LONG FORM LETTERS

EXAMPLES

MEASure, OUTPut, EVENt

LEVel, IMMediate, ERRor

The question mark (?) following a keyword is a query indicator. This changes the command into a query. If there is more than one keyword in the command, the query indicator follows the last keyword. (e.g., VOLT? and MEAS:CURR?).

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KEYWORD

ROOT SPECIFIER

MESSAGE UNIT SEPARATOR

DATA SEPARATOR

DATA

DATA SEPARATOR

KEYWORD

KEYWORD SEPARATOR

KEYWORD

3.5.4.4 DATA

Some commands require data to accompany the keyword either in the form of a numeric value or character string. Data always follows the last keyword of a command or query (e.g., VOLT:LEV:TRIG 14 or SOUR:VOLT? MAX

DATA

CURR:LEV 3.5;:OUTP ON;:CURR?<NL>

FIGURE 3-4. MESSAGE STRUCTURE

MESSAGE UNIT SEPARATOR

ROOT SPECIFIER

KEYWORD

QUERY INDICATOR

MESSAGE TERMINATOR

MESSAGE UNIT

3.5.4.5 DATA SEPARATOR

Data must be separated from the last keyword by a space (e.g., VOLT:LEV:TRIG 14 or SOUR:VOLT? MAX

3.5.4.6 MESSAGE UNIT SEPARATOR

When two or more message units are combined in a program message, they must be separated by a semicolon (;) (e.g., VOLT 15;MEAS:VOLT? and CURR 12; CURR:TRIG 12.5).

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ROOT : (colon)

ABORt subsystem

ABORt

INITiate subsystem

INITiate

[:IMMediate]

:CONTinuous bool :CONTinuous?

CALibrate subsystem

CALibrate

:COPY :DUMP :CURRent

:LEVel (MIN | MAX | MAG | PROT)

[:DATA] val :PASS “RESTore

:SAVE :VOLTage

:LEVel (MIN | MAX | PROT)

[:DATA] val :ZERO

MEASure subsystem

MEASure

[:SCALar]:CURRent[:DC]? [:SCALar]:[VOLTage][:DC]?

INSTRument subsystem

INSTrument

:STATe? :STATe (ON | OFF)

OUTPut subsystem

OUTPut

[:STATe] ON or OFF [:STATe]?

DISPlay subsystem

DISPlay

:CONTrast 0.0 to 0.9 :CONTrast ?

:MODE :MODE? :TEXT :TEXT?

!See PAR. 3.3.6.2 and Figure 3-2 for

special programming considerations.

[SOURce:] subsystem

[SOURce:] CURRent

[:LEVel]

[:IMMediate]

[:AMPLitude] val [:AMPLitude]? MIN, MAX

:TRIGgered

[:AMPLitude] val [:AMPLitude]?

:LIMit

[:HIGH] val

[:HIGH]? MIN, MAX :MODE (LIST | FIX) :MODE? LIST, FIX :PROTection val :PROTection? :RANGe (UPPer | LOWer) :RANGe?

VOLTage

[:LEVel]

[:IMMediate]

:TRIGgered

:LIMit

[:HIGH] val

[:HIGH]? MIN, MAX :MODE (LIST | FIX) :MODE? LIST, FIX :PROTection val :PROTection?

FUNCtion

:MODE?

[:AMPLitude] val [:AMPLitude]? MIN, MAX

[:AMPLitude] val [:AMPLitude]?

STATus subsystem

STATus

:OPERation

:CONDition?

:ENABle val

:ENABle?

[:EVENt]? :PRESet :QUEStionable

:CONDition?

:ENABle val

:ENABle?

[:EVENt]?

TRIGGER subsystem

TRIGger

:SOURce

SYSTem subsystem

SYSTem

:BEEP :COMM:GPIB:ADDR val :COMM:GPIB:ADDR? :COMM:SER

:BAUD val :BAUD? :ECHO :ECHO? ON, OFF :PACE :PACE? NONE, XON :PROMpt :PROMpt? ON, OFF

:ERRor

? :CODE?

:KLOCk <boolean> :KLOCk? :PASSword

[:CENAble] (code) :CDISenable (code) :NEW (OLD | NEW) :STATe?

:SECUrity

:IMMediate

:VERSion?

:ALL?

LIST subsystem

LIST

:CLE :COUNt val :COUNt? :COUNt:SKIP val :COUNt:SKIP? :CURRent

[:LEVel] val

[:LEVel]? : :POINt? :DWELl val :DWELl? :DIR val :DIR? :DWELl? : :POINt? :QUERy val :QUERy? :VOLTage

[:LEVel] val

[:LEVel]? : :POINt?

FIGURE 3-5. TREE DIAGRAM OF SCPI COMMANDS USED WITH BHK-MG POWER SUPPLY

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3.5.4.7 ROOT SPECIFIER

The root specifier is a colon (:) that precedes the first keyword of a program message. This places the parser at the root (top left, Figure 4-3) of the command tree. Note the difference between using the colon as a keyword separator and a root specifier in the following examples:

VOLT:LEV:IMM 16 Both colons are keyword separators.

:CURR:LEV:IMM 4 The first colon is the root specifier, the other two are keyword separators.

VOLT:LEV 6;:CURR:LEV 15 The second colon is the root specifier, the first and third are keyword separators

:INIT ON;:TRIG;:MEAS:CURR?;VOLT? The first three colons are root specifiers.

3.5.4.8 MESSAGE TERMINATOR

The message terminator defines the end of a message. One message terminator is permitted:

• new line (<NL>), ASCII 10 (decimal) or 0A (hex)

NOTE: Kepco power supplies require a message terminator at the end of each program mes-

sage. The examples shown in this manual assume a message terminator will be added at the end of each message. Where a message terminator is shown it is represented as <NL> regardless of the actual terminator character.

3.5.5 UNDERSTANDING THE COMMAND STRUCTURE

Understanding the command structure requires an understanding of the subsystem command tree illustrated in Figure 3-5. The “root” is located at the top left corner of the diagram. The parser goes to the root if:

• a message terminator is recognized by the parser

• a root specifier is recognized by the parser

Optional keywords are enclosed in brackets [ ] for identification; optional keywords can be omitted and the power supply will respond as if they were included in the message. The root level keyword [SOURce] is an optional keyword. Starting at the root, there are various branches or paths corresponding to the subsystems. The root keywords for the BHK-MG Power Supply are :ABORt, :CALibrate, :DISPlay, :INITiate, :LIST, :MEASure, :OUTPut, [:SOURce], :STATus, :SYSTem and :TRIGger. Because the [SOURce] keyword is optional, the parser moves the path to the next level, so that VOLTage, CURRent, and FUNCtion commands are at the root level.

Each time the parser encounters a keyword separator, the parser moves to the next indented level of the tree diagram. As an example, the STATus branch is a root level branch that has three sub-branches: OPERation, PRESet, and QUEStionable. The following illustrates how SCPI code is interpreted by the parser:

STAT:PRES<NL>

The parser returns to the root due to the message terminator.

STAT:OPER?;PRES<NL>

The parser moves one level in from STAT. The next command is expected at the level defined by the colon in front of OPER?. Thus you can combine the following message units STAT:OPER? and STAT:PRES;

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STAT:OPER:COND?;ENAB 16<NL>

After the OPER:COND? message unit, the parser moves in one level from OPER, allowing the abbreviated notation for STAT:OPER:ENAB.

3.5.6 PROGRAM MESSAGE SYNTAX SUMMARY

• Common commands begin with an asterisk (*).

• Queries end with a question mark (?).

• Program messages consist of a root keyword and, in some cases, one or more message units separated by a colon (:) followed by a message terminator. Several message units of a program message may be separated by a semicolon (;) without repeating the root keyword.

• If a program message has more than one message unit, then a colon (:) must precede the next keyword in order to set the parser back to the root (otherwise the next keyword will be taken as a subunit of the previous message unit).

e.g., the command meas:volt?;curr? will read output voltage and output current since both volt? and curr? are interpreted as subunits of the meas command.

• Several commands may be sent as one message; a line feed terminates the message. Commands sent together are separated by a semicolon (;). The first command in a message starts at the root, therefor a colon (:) at the beginning is not mandatory.

e.g., the command meas:volt?;:curr? will read output voltage and programmed current since the colon preceding curr? indicates that curr? is not part of the meas command and starts at the root.

• UPPER case letters in mnemonics are mandatory (short form). Lower case letters may either be omitted, or must be specified completely (long form) e.g., INSTrument (long form) has the same effect as INST (short form).

• Commands/queries may be given in upper/lower case (long form) e.g., SoUrCe is allowed.

• Text shown between brackets [ ] is optional. e.g., :[SOUR]VOLT:[LEV] TRIG has the same effect as :VOLT TRIG

3.5.7 SCPI PROGRAM EXAMPLES

Refer to Appendix B, Figures B-1 through B-7 for examples illustrating the use of SCPI commands.

Figure 3-6 is an example of a program using SCPI commands to program the BHK-MG Power Supply. The program illustrated is for a configuration using an IBM PC or compatible with a National Instruments GPIB interface card. (It will be necessary to consult the manufacturer’s data to achieve comparable functions with an interface card from a different manufacturer.) This program sets output voltage (Voltage mode) or voltage limit (Current mode) to 5V, and current limit (Voltage mode) or output current (Current mode) to 1A, then reads the measured (actual) voltage and current, then prints the measurements.

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/**************************************************************************/ /* Sample Program For KEPCO power supply, using National Instruments */ /* GPIB interface card and IBM PC or compatible computer */ /**************************************************************************/

#include <stdio.h> #include "decl.h"

char rd_str[80]; // Input buffer char dat_str[80]; // Output buffer int bd,adr;

main() {

adr = ibfind("DEV6"); // Open DEV6 (defined by IBCONF) bd = ibfind ("GPIB0"); // Open GPIB card ibsic (bd); // Send Interface Clear ibsre(bd,1); // Set remote line true

strcpy(dat_str,"VOLT 5;CURR 1"); // Define a set command strcat(dat_str,"\r\n"); // Append delimiter ibwrt(adr,dat_str,strlen(dat_str)); // Send string to power supply

strcpy(dat_str,"MEAS:VOLT?;CURR?"); // Define a measure command strcat(dat_str,"\r\n"); // Append delimiter ibwrt(adr,dat_str,strlen(dat_str)); // Send string to power supply

strset(rd_str,'\0'); // Clear input buffer ibrd(adr,rd_str,64); // Read result of measure printf("received : %s\n",rd_str); // Print voltage and current

}

FIGURE 3-6. TYPICAL EXAMPLE OF BHK-MG POWER SUPPLY PROGRAM USING SCPI COMMANDS

3.6 REMOTE PROGRAMMING USING ANALOG PROGRAMMING TERMINALS

The BHK-MG power supply is designed with separate, but similar, circuits for analog voltage programming (Figure 3-7) and analog current programming (Figure 3-8). The voltage programming circuit is used for programming output voltage if the unit is in voltage mode, or voltage limit if the unit is in current mode. Similarly, the current programming circuit programs output current in current mode, and current limit in voltage mode.

For each circuit, the digital programming section provides a voltage (DP (V) for voltage, DP (C) for current), between zero and -10V d-c, applied to the input of a summing and correction amplifier. This amplifier drives, in turn, the voltage error amplifier and the pass element to produce the output. Each circuit also includes an uncommitted amplifier which can be configured to be summed with the output of the digital programming section at the input of the summing and correction amplifier. Configuration of the uncommitted amplifiers is accomplished at the ANALOG PROGRAMMING TERMINALS at the rear panel: VOLTAGE PROG. terminal strip TB2 for voltage, CURRENT PROG. terminal strip TB3 for current.

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FIGURE 3-7. ANALOG VOLTAGE PROGRAMMING, SIMPLIFIED DIAGRAM

FIGURE 3-8. ANALOG CURRENT PROGRAMMING, SIMPLIFIED DIAGRAM

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If digital programming is at zero, analog programming requires a voltage between zero and –10V d-c to be applied to terminal 9 (TB2 for voltage, TB3 for current). If digital programming is combined with analog programming, the voltage range for the signal applied to terminal 9 is:

Voltage programming: TB2-9: 0 to

Current programming: TB3-9: 0 to



10 Eout

–





10 I



out

–

----------------------

Eomax

--------------------

I omax

V–

where:

Eout Iout

= digitally programmed output voltage/voltage limit

= digitally programmed output current/current limit

The uncommitted amplifiers can be configured to produce the required voltage from a number of analog sources. Some basic analog configurations are presented in the following paragraphs:

• External resistance

• Low impedance voltage source

• Grounded voltage source

• High impedance voltage source

• Current source

Different analog sources can be used simultaneously; e.g., resistance can be sued to control voltage programming while a grounded voltage source controls current programming. Analog programming can also be combined with digital programming (either locally via the keypad or remotely via the GPIB bus) since the two programming methods are summed together. For example, for the BHK 500-0.4MG Power Supply, if the output is programmed digitally to 200V, and an analog signal which would produce a 100V output is applied to the uncommitted amplified, the output would go to 300V (assuming the value of the load and the programmed value of output current allow the power supply to remain in voltage mode).

NOTE: It is important to remember that BOTH voltage and current channels must be pro-

grammed (e.g., if analog programming of voltage mode is used, the current limit must be programmed by either analog or digital programming).

The availability of the two uncommitted amplifiers, ±10V d-c reference voltages and the two summing amplifiers, means that many configurations are possible for analog control of the power supply.

3.6.1 ANALOG PROGRAMMING WARNINGS AND CAUTIONS

WARNING

THE POWER SUPPLY PRODUCES DANGEROUS VOLTAGES WHICH CAN BE LETHAL. ALWAYS OBSERVE THE FOLLOWING PRECAUTIONS.

a. Always connect the chassis of the power supply to a good AC ground (earth) con-

nected to OUTPUT TERMINALS terminal strip TB1, terminal 4.

NOTE: All connections must be tight, whether at the terminal strips of the power supply or at

external equipment.

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b. Use high voltage rated cables (at least 3kV) for all connections, even for programming

connections. Where required use twisted pair cable or shielded single or pair cable (shield to chassis), rated for high voltage.

c. Even though the BHK-MG Power Supply will discharge the output capacitor at turn-off,

verify that the output is safe before making any attempt to connect or disconnect the load.

d. Verify that the input circuit breaker is off and remove the line cord before connecting or

disconnecting the load or other external components to analog programming terminals.

e. If possible, connect one side of the output to ground (either side may be grounded).

The power supply can also operate with the output “floating” with respect to ground.

WARNING

The following warnings and cautions apply to the output terminals:

• If the external equipment (e.g., Digital Voltmeter) has floating inputs and the power supply is operating with +OUT terminal connected to ground, connect the LOW input of the external equipment to +OUT terminal of the power supply.

• If the external equipment (e.g., Digital Voltmeter) has floating inputs and the power supply is working with –OUT terminal connected to ground, connect the LOW input of the external equipment to –OUT terminal of the power supply.

• If the power supply outputs should stay isolated from ground, any external equipment connected to the output terminal should be connected to a-c source power using an isolating transformer, or should have floating inputs.

NOTE: Any isolating transformer used for connecting test equipment to a-c source power

should have the isolation rated to a value higher than the maximum output voltage of the power supply.

WARNING

The following warnings and cautions apply to the analog programming terminals because the analog control circuitry operates at the +OUTPUT potential and the common of the analog control circuitry is connected to the +OUT terminal (TB1) through the sensing resistor (Rs) of the power supply.

• If the power supply is operating with +OUT terminal connected to ground, do not connect grounded inputs or outputs of any external equipment to power supply analog programming terminals. If this situation is unavoidable, connect the external equipment to a-c source power using an isolating transformer. For external equipment with grounded output only, use the uncommitted amplifier of the power supply in differential configuration.

• If the power supply is operating with –OUT terminal connected to ground, the external programming source must be isolated up to the maximum output voltage plus 1KV. The programming source must be either battery powered or powered through an isolation transformer and feature “fully insulated controls and chassis.”

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• If the power supply must operate isolated from ground (floating), any external equipment connected to the ANALOG PROGRAMING TERMINALS must also be isolated (battery operated or connected to a-c source power using an isolating transformer).

Safety Messages

The BHK-MG can be controlled by digital and/or analog inputs. When OUTPUT is set to off from the keypad or the GPIB, an analog input will still produce an output from the BHK-MG which will be indicated on the LCD. If the analog input is causing more than 8Vd-c to appear at the output terminals, or if current being supplied to the load exceeds 1mA, the unit will beep and enter a controlled shutdown for safety purposes unless the override jumper has been installed (see Table 2-9).

3.6.2 PROGRAMMING WITH EXTERNAL RESISTANCE

Figures 3-9 and 3-10 are simplified diagrams of the BHK-MG showing the jumper configuration and external connections required for analog programming using an external resistance. Figures 3-9 shows programming of either output voltage when the unit is in voltage mode, or voltage limit when the unit is in current mode. Figure 3-10 is a similar diagram for programming either output current when the unit is in current mode, or current limit when the unit is in voltage mode.

FIGURE 3-9. ANALOG PROGRAMMING OF OUTPUT VOLTAGE (VOLTAGE MODE)

OR VOLTAGE LIMIT (CURRENT MODE) USING RESISTANCE

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FIGURE 3-10. ANALOG PROGRAMMING OF OUTPUT CURRENT (CURRENT MODE)

OR CURRENT LIMIT (VOLTAGE MODE) USING RESISTANCE

For either voltage programming or current programming, the external resistor R

connected

EXT

across terminals 6 and 8 of VOLTAGE PROG terminal strip TB2 or CURRENT PROG. terminal strip TB3 functions as a feedback resistor for the internal uncommitted amplifier dedicated to voltage or current programming. This uncommitted amplifier is configured to amplify and invert the +10V reference applied via terminals 4 and 6 of TB2 or TB3. The output of the uncommitted amplifier is applied via terminals 8 and 9 of TB2 or TB3 to a summing network at the input of the summing and correction amplifier. For voltage programming, the other input to the summing and correction amplifier, DP (V), is from the voltage portion of the digital programming circuitry (either from the keypad or the GPIB bus). For current programming, the other input to the summing and correction amplifier, DP (C), is from the current portion of the digital programming circuitry (either from the keypad or the GPIB bus).

TABLE 3-10. FEEDBACK RESISTOR AND CURRENT SENSING RESISTOR VALUES

RESISTOR SCALE BHK 500-0.4MG BHK 1000-0.2MG BHK 2000-0.1MB

Voltage Feedback Resistor R 500K* 1000K* 2000K*

Current Sensing Resistor Rs HIGH CURRENT 0.0025K* 0.005K* 0.010K*

LOW CURRENT 0.025K* 0.05K* 0.10K*

* All resistors are 1% tolerance.

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3.6.2.1 VOLTAGE MODE

With the power supply in voltage mode (see Figure 3-9) and the digitally programmed output voltage at zero, varying the external resistor from 0 to 10K causes the output voltage of the power supply to vary linearly from 0 to Eomax with a slope of (0.0001 x Eomax) volts per ohm. The following equation gives the output voltage as determined by external resistance R

EXT

Eo = (–1) (10V) x (R

= (–1) (0.1 x R) x R = –0.1R x R

where

= External resistance (K-ohms), variable from 0 to 10K ohms. This resistance can take

EXT

the form of a rheostat, a fixed resistor, or a group of resistors which are step-switched by mechanical, electrical or electronic means (step-switching must be “make before break”). Use only high quality resistor(s) having a temperature coefficient of 20 parts per million or better and a wattage rating of 0.5W minimum.

R = Internal feedback resistance equal to correction resistance (K-ohms), determined by

Model (see Table 3-10).

NOTE: Output voltage is referenced to +OUT and output current is negative leaving +OUT ter-

minal. This convention applies to voltage and current programming calculations of PAR. 3.6.

3.6.2.2 CURRENT MODE

With the power supply in current mode (see Figure 3-10) and the digitally programmed output voltage at zero, varying the external resistor from 0 to 10K causes the output current of the power supply to vary linearly from 0 to Iomax with a slope of (0.0001 x Iomax) mA per ohm. The following equation gives the output current as determined by external resistance R

EXT

/10K) x (–1) (10K/10K) x (–1) (R/10K)

EXT

(V d-c)

EXT

Io = [ (–1) (10V) x (R

= (–1) (0.1/ Rs) x R = (–0.1/Rs) x R

/10K) x (–1) (1K/10K) x (–1) (1K/1K) ]/Rs

EXT

(mA d-c)

EXT

where

Rs = Internal shunt resistance (K-ohms), determined by Model (see Table 3-10). (See above for definition of R

BHK-MG (OPR) 022014 3-37

EXT

Page 82

3.6.3 PROGRAMMING WITH EXTERNAL VOLTAGE USING A LOW IMPEDANCE VOLTAGE SOURCE

Figures 3-11 through 3-14 are simplified diagrams of the BHK-MG showing the jumper configuration and external connections required for analog programming using a low impedance voltage source. Figure 3-11 shows an isolated voltage source, Figure 3-12 shows a grounded voltage source for programming of either output voltage when the unit is in voltage mode, or voltage limit when the unit is in current mode. Figures 3-13 (isolated voltage source) and 3-14 (grounded voltage source) are similar diagrams for programming either output current when the unit is in current mode, or current limit when the unit is in voltage mode.

FIGURE 3-11. ANALOG PROGRAMMING OF OUTPUT VOLTAGE (VOLTAGE MODE) OR VOLTAGE LIMIT

(CURRENT MODE) USING ISOLATED (FLOATING) LOW IMPEDANCE VOLTAGE SOURCE (VS)

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FIGURE 3-12. ANALOG PROGRAMMING OF OUTPUT VOLTAGE (VOLTAGE MODE) OR VOLTAGE

LIMIT (CURRENT MODE) USING GROUNDED LOW IMPEDANCE VOLTAGE SOURCE (VS)

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FIGURE 3-13. ANALOG PROGRAMMING OF OUTPUT CURRENT (CURRENT MODE) OR CURRENT LIMIT

(VOLTAGE MODE) USING ISOLATED (FLOATING) LOW IMPEDANCE VOLTAGE SOURCE (VS)

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FIGURE 3-14. ANALOG PROGRAMMING OF OUTPUT CURRENT (CURRENT MODE) OR CURRENT

LIMIT (VOLTAGE MODE) USING GROUNDED LOW IMPEDANCE VOLTAGE SOURCE (VS)

The external voltage source is applied to the input of the uncommitted amplifier which is configured either as an inverting repeater (Figures 3-11 and 3-13) for isolated voltage sources or a differential amplifier having a gain of –1 (Figures 3-12 and 3-14) for grounded voltage sources. The positive voltage is applied to the inverting input of the uncommitted amplifier referenced to internal signal ground. The voltage source impedance should be low compared to the 10K input impedance into the programming terminals of the power supply.

CAUTION

Observe the following to avoid damage to the power supply. For isolated voltage sources

(Figures 3-11 and 3-13), the external voltage source output must be isolated from ground (floating output), or be powered from an a-c source that is isolated from ground to avoid short-circuiting the internal sensing resistor,. If neither of these options are practical, use the grounded voltage source configurations shown in Figures 3-12 and 3-14.

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3.6.3.1 VOLTAGE MODE

With the power supply in voltage mode (see Figure 3-11 or 3-12) and the digitally programmed output voltage at zero, varying the low impedance voltage source from 0 to +10V causes the output voltage of the power supply to vary linearly from 0 to Eomax with a slope of (0.1 x Eomax) volts per volt. The following equations give the output voltage as determined by a low impedance voltage source V

ANALOG PROGRAMMING, DIGITAL PROGRAMMING = 0:

Eo = (–1) (V

EXT

= (–1) (0.1 x R) x V = –0.1R x V

where

R = Internal feedback resistance (K-ohms), determined by Model (see Table 3-10).

= External low impedance voltage source. This source can be either a d-c source deliver-

EXT

ing a positive output voltage, or a function generator with an internal positive bias. If the bias is not available from the function generator, use the digital programming feature of the BHK-MG to provide proper bias to avoid clipping the waveform at the output of the power supply.

ANALOG PROGRAMMING COMBINED WITH DIGITAL PROGRAMMING:

Eo = –(0.1 x R x V

EXT

) x (10K/10K) x (–1) (10K/10K) x (–1) (R/10K)

EXT

(V d-c)

EXT

) – EoutDP (V d-c)

EXT

where

Eout

= Output voltage programmed digitally (from either local keypad or remote GPIB bus)

(See above for definitions of R and V

EXT

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3.6.3.2 CURRENT MODE

With the power supply in current mode (see Figure 3-13 or 3-14) and the digitally programmed output voltage at zero, varying the low impedance voltage source from 0 to +10V causes the output current of the power supply to vary linearly from 0 to Iomax with a slope of (0.1 x Iomax) mA per volt. The following equations give the output current as determined by the low impedance voltage source V

ANALOG PROGRAMMING, DIGITAL PROGRAMMING = 0:

Io = [ (–1) (V

EXT

= (–1) (0.1/ Rs) x V = –(0.1/Rs) x V

where

Rs =Internal shunt resistance (K-ohms), determined by Model (see Table 3-10). (See above for definition of V

ANALOG PROGRAMMING COMBINED WITH DIGITAL PROGRAMMING:

Io = –(0.1/Rs) x V

where

Iout

= Output current programmed digitally (from either local keypad or remote GPIB bus)

(See above for definitions of Rs and V

EXT

) x (10K/10K) x (–1) (1K/10K) x (–1) (1K/1K) ]/Rs

(mA d-c)

EXT

(mA d-c)

EXT

– IoutDP (mA d-c)

EXT

3.6.4 PROGRAMMING WITH EXTERNAL VOLTAGE USING A HIGH IMPEDANCE, LOW LEVEL (1V) VOLTAGE SOURCE

Figures 3-15 and 3-16 are simplified diagrams of the BHK-MG showing the jumper configuration and external connections required for analog programming using a high impedance, low level (1V), voltage source. Figure 3-15 shows the configuration for programming of either output voltage when the unit is in voltage mode, or voltage limit when the unit is in current mode. Figure 316 is a similar diagrams for programming either output current when the unit is in current mode, or current limit when the unit is in voltage mode

CAUTION

Observe the following to avoid damage to the power supply. The external voltage source

output must be isolated from ground (floating output), or be powered from an a-c source that is isolated from ground to avoid short-circuiting the internal sensing resistor.

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FIGURE 3-15. ANALOG PROGRAMMING OF OUTPUT VOLTAGE (VOLTAGE MODE) OR VOLTAGE

LIMIT (CURRENT MODE) USING HIGH IMPEDANCE, LOW LEVEL (1V) VOLTAGE SOURCE (VS)

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FIGURE 3-16. ANALOG PROGRAMMING OF OUTPUT CURRENT (CURRENT MODE) OR CURRENT

LIMIT (VOLTAGE MODE) USING HIGH IMPEDANCE, LOW LEVEL (1V) VOLTAGE SOURCE (VS)

The external voltage source is applied to the input of the uncommitted amplifier which is configured as a noninverting amplifier having a gain of 10.

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3.6.4.1 VOLTAGE MODE

With the power supply in voltage mode (see Figure 3-15) and the digitally programmed output voltage at zero, varying the high impedance voltage source from 0 to –1V causes the output voltage of the power supply to vary linearly from 0 to Eomax with a slope of (Eomax) volts per volt. The following equations give the output voltage as determined by a high impedance voltage source V

EXT

ANALOG PROGRAMMING, DIGITAL PROGRAMMING = 0:

Eo = (V

) x (11.1K/1.1K) x (–1) (10K/10K) x (–1) (R/10K)

EXT

= –(R) x |V

where

R = Internal feedback resistance equal to correction resistance (K-ohms), determined by

Model (see Table 3-10).

= External low impedance voltage source. This source can be either a d-c source deliver-

EXT

ing a negative output voltage, or a function generator with an internal negative bias. If the bias is not available from the function generator, use the digital programming feature of the BHK-MG to provide proper bias to avoid clipping the waveform at the output of the power supply.

ANALOG PROGRAMMING COMBINED WITH DIGITAL PROGRAMMING:

Eo = –(R x |V

EXT

| (V d-c)

EXT

|) – EoutDP (V d-c)

where

Eout

= Output voltage programmed digitally (from either local keypad or remote GPIB bus)

(See above for definitions of R and V

3.6.4.2 CURRENT MODE

With the power supply in current mode (see Figure 3-16) and the digitally programmed output voltage at zero, varying the high impedance voltage source from 0 to –1V causes the output current of the power supply to vary linearly from 0 to Iomax with a slope of (Iomax) mA per volt. The following equations give the output current as determined by the low impedance voltage source V

EXT

ANALOG PROGRAMMING, DIGITAL PROGRAMMING = 0:

Io = [ (V

) x (11.1K/1.1K) x (–1 ) (1K/10K) x (–1) (1K/1K) ]/Rs

EXT

= –(1/Rs) x |V

where

Rs =Internal shunt resistance (kOhms), determined by Model (see Table 3-10). (See above for definition of V

ANALOG PROGRAMMING COMBINED WITH DIGITAL PROGRAMMING:

Io = –(1/Rs) x |V

| (mA d-c)

EXT

| – IoutDP (mA d-c)

EXT

where

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Iout

= Output current programmed digitally (from either local keypad or remote GPIB bus)

(See above for definitions of Rs and V

EXT

3.6.5 PROGRAMMING WITH EXTERNAL CURRENT SOURCE (1 mA)

Figures 3-17 and 3-18 are simplified diagrams of the BHK-MG showing the jumper configuration and external connections required for analog programming using a current source (1mA). Figure 3-17 shows the configuration for programming of either output voltage when the unit is in voltage mode, or voltage limit when the unit is in current mode. Figure 3-18 is a similar diagrams for programming either output current when the unit is in current mode, or current limit when the unit is in voltage mode

CAUTION

Observe the following to avoid damage to the power supply. The external current source

output must be isolated from ground (floating output), or be powered from an a-c source that is isolated from ground to avoid short-circuiting the internal sensing resistor.

FIGURE 3-17. ANALOG PROGRAMMING OF OUTPUT VOLTAGE (VOLTAGE MODE) OR VOLTAGE

LIMIT (CURRENT MODE) USING CURRENT SOURCE (1mA) (CS)

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FIGURE 3-18. ANALOG PROGRAMMING OF OUTPUT CURRENT (CURRENT MODE) OR CURRENT

LIMIT (VOLTAGE MODE) USING CURRENT SOURCE (1mA) (CS)

The external current source is applied to the inverting input of the uncommitted amplifier which is configured as a current-voltage converter.

CAUTION

Observe the following to avoid damage to the power supply. The external current source

output must be isolated from ground (floating output), or be powered from an a-c source that is isolated from ground to avoid short-circuiting the internal sensing resistor.

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3.6.5.1 VOLTAGE MODE

With the power supply in voltage mode (see Figure 3-17) and the digitally programmed output voltage at zero, varying the external current source from 0 to 1mA causes the output voltage of the power supply to vary linearly from 0 to Eomax with a slope of (Eomax) volts per mA. The following equations give the output voltage as determined by the external current source I

ANALOG PROGRAMMING, DIGITAL PROGRAMMING = 0:

Eo = (–1)I

= –(R) x I

EXT

where

R = Internal feedback resistance equal to correction resistance (K-ohms), determined by

Model (see Table 3-10).

= External current source. This source can be either a d-c source or a function generator

EXT

with an internal bias delivering a constant current. If the bias is not available from the function generator, use the digital programming feature of the BHK-MG to provide proper bias to avoid clipping waveform at the output of the power supply.

ANALOG PROGRAMMING COMBINED WITH DIGITAL PROGRAMMING:

Eo = –(R x I

) – EoutDP (V d-c)

EXT

where

x (10K) x (–1) (10K/10K) x (–1) (R/10K)

(V d-c)

EXT

Eout

= Output voltage programmed digitally (from either local keypad or remote GPIB bus)

(See above for definitions of R and V

3.6.5.2 CURRENT MODE

With the power supply in current mode (see Figure 3-18) and the digitally programmed output voltage at zero, varying the external current source from 0 to 1mA causes the output current of the power supply to vary linearly from 0 to Iomax with a slope of (Iomax) mA per mA. The following equations give the output current as determined by the external current source I

ANALOG PROGRAMMING, DIGITAL PROGRAMMING = 0:

Io = [ (–1) I

EXT

= –(1/Rs) x I

where

Rs =Internal shunt resistance (K-ohms), determined by Model (see Table 3-10). (See above for definition of V

ANALOG PROGRAMMING COMBINED WITH DIGITAL PROGRAMMING:

Io = –(1/Rs) x I

where

Iout

= Output current programmed digitally (from either local keypad or remote GPIB bus)

(See above for definitions of Rs and I

EXT

x (10K) x (–1) (1K/10K) x (–1) (1K/1K) ]/Rs

(mA d-c)

EXT

– IoutDP (mA d-c)

EXT

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3.7 OPERATING MODES

This section describes the following operating modes for the BHK-MG power supply

• Slow/Fast Mode

• Series Operation

• Automatic Series Operation

• Master-Slave Series Operation

• Parallel Operation

• Automatic Parallel Operation

• Master-Slave Parallel Operation

3.7.1 SLOW/FAST MODE OF OPERATION

In slow mode of operation the internal output capacitor C

is connected across the sensing

OUT

terminals via TB1, terminal 7 (-OUT.C) and terminal 6 (-S). This effectively increases the main feedback capacitance by adding the internal feedback capacitor for slow mode C mode capacitor C

(see Figure 3-19). When internal output capacitor C

is across the out-

OUT

. to the fast

put, output noise is reduced, and, in voltage mode, the amplitude of transients caused by dynamic load changes is also reduced. The disadvantage of slow mode is that programming time is increased. Therefore, slow mode is recommended for voltage mode applications where low noise and low amplitude recovery transients due to dynamic load changes are important.

In fast mode of operation the internal output capacitor is disconnected from the sensing terminals, by removing the link between TB1, terminal 7 (-OUT.C) and terminal 6 (-S). This also effectively reduces the main feedback capacitance by removing the internal capacitor for slow mode, C

from the circuit. This configuration reduces the programming time in voltage mode and, in

current mode, reduces the duration of transients caused by dynamic load changes; the disadvantage is that output noise is increased. Therefore, the fast mode of operation is recommended for voltage mode applications when a quick response to programming is important (e.g., when the power supply is effectively operating as a power amplifier), and for current mode applications when quick recovery time at load changes is desired.

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FIGURE 3-19. SLOW MODE/FAST MODE OPERATION

If desired, an external output capacitor can also to be used; the following instructions apply when using an external output capacitor:

a. Use a capacitor rated to more than the maximum output voltage of the power supply. If

a series combination of polarized type capacitors is used, potential equalizer resistors in parallel with each capacitor should be installed and attention should be paid to the polarity of the capacitors: the “plus” terminal of each capacitor is connected to the “minus” terminal of the next capacitor, if present, or to +OUT terminal of the power supply (see Figure 3-19).

b. If precise control of the voltage across the external capacitor is desired, use remote

sensing: connect the sensing leads and power leads across the external output capacitor and connect the load to the external capacitor.

c. If the external capacitor has a value much smaller than internal output capacitor C

OUT

(see Table 1-2), then it is not necessary to connect the internal capacitor at the output using the link between terminals TB1-6 and TB1-7. If the external capacitor is compara-

BHK-MG (OPR) 022014 3-51

Page 96

ble or larger than the internal C the output by installing the link between terminals TB1-6 and TB1-7, in order to increase the main feedback capacitance.

Isolate all external circuitry connected to the ungrounded (“live”) output terminal of the power supply; isolation should be rated to more than maximum output voltage.

3.7.2 SERIES OPERATION

Kepco BHK-MG power supplies can be series-connected to increase output voltage if the precautions outlined below are followed. Two basic series-connection methods are generally used: automatic (PAR. 3.7.2.1) and master-slave (PAR. 3.7.2.2).

HANDLING HIGH VOLTAGE, LOW IMPEDANCE EQUIPMENT IS DANGEROUS, AND POTENTIALLY LETHAL. OBSERVE ALL PRECAUTIONS LISTED IN PAR. 3.6.1., AS WELL AS THE PRECAUTIONS LISTED BELOW.

a. Do not exceed the specified isolation voltage limit (see Table 1-2). If the isolation volt-

age might be exceeded, limit the excursion of one power supply output: e.g., if two BHK 2000-0.1MG models are to be series-connected, the output of one must be restricted to 0.5 kV (limiting the series combination to a maximum of 2.5kV), because the isolation voltage for this model is 2kV + 0.5kV (see Table 1-2).

, it is advisable to connect the internal C

OUT

CAUTION

WARNING

OUT

across

b. Connect the chassis ground terminal, TB1-4, of all series-connected power supplies to

a good a-c ground (earth ground).

c. If necessary, the grounding network can be used for each one of the series-connected

power supplies within the limits of the maximum isolation voltage (see Table 1-2) of the Model BHK-MG Series (refer to PAR. 2.7.5.3 for additional information regarding use of the grounding network).

d. The series combination of BHK-MG power supplies can operate either isolated from

ground (floating) or with either of the two output terminals of the series combination grounded. When analog programming is used, however, it is recommended that the positive output terminal of the series combination be grounded to avoid potentially hazardous conditions requiring the use of fully insulated external equipment (see precautions of PAR. 3.6.1).

If the negative output terminal is grounded, special precautions are required when using external programming sources: THE PROGRAMMING SOURCE MUST BE ISOLATED AND INSULATED for the sum of the voltages of the series combination. The programming source must be either battery powered or powered through an isolation transformer and have “fully insulated controls and chassis” features (see also PAR. 3.6.1).

e. Each BHK-MG power supply contains an internal, reverse-biased diode across the out-

put which protects the power supply by limiting the opposite polarity voltage at the output. This diode is rated for the nominal output voltage of each model (see Table 1-1). When BHK-MG power supplies are series-connected, this diode will protect each sup-

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ply against a short circuit at the load, with one exception. The current rating of the reverse-biased diode used on model BHK 2000-0.1MG is 0.2A. When this unit is connected in series with a model BHK 500-0.4MG, which has a maximum current rating of

0.4A, it is necessary to connect an external (reverse-biased) diode across the output of the 2000V unit which is rated for 3kV reversed voltage and 0.4A direct current.

NOTE: The simplified schematic diagrams (Figures 3-20 through 3-22) illustrating the associ-

ated interconnections show the power supplies configured in either slow mode for units operating in voltage mode or fast mode for units operating in current mode, however other combinations are also possible. Due to the low current involved, the units are shown using local sensing since the drop across the power leads is usually negligible compared to the output voltage. However, when very precise control of output voltage applied to the load is desired, remote sensing should be used. Contact Kepco Applications Engineering when special configurations are indicated.

3.7.2.1 AUTOMATIC SERIES OPERATION

This operating configuration (see Figure 3-20) is characterized by the fact that each power supply is independent and must be controlled (programmed) individually, either remotely—via either the GPIB bus or by analog means—or locally via the keypad. Practical considerations suggest that the units operate in voltage mode - current limit, controlled from the local keypad. The output voltage and current of the series combination are given by the following equations:

Eo = Eo

Io = Eo / R

+Eo

LOAD

where

Eo, Io are output values of the series combination (in Volts and milliamperes, respectively) Eo

, EoB are the individual output voltages for two series-connected power supplies (in

Volts) R

is the load value (in K-ohms).

LOAD

The maximum current delivered by the series combination is dictated by the power supply with the lowest nominal current and correspondingly, the highest nominal output voltage. For the current limit to operate properly, set the desired value of current limit (for the series combination) at the power supply with the highest nominal output voltage; set the current limit of the other power supply to a larger value (1% larger or more).

RECOMMENDED PROCEDURE. The following steps are recommended to ensure the combination of power supplies configured for automatic series operation (power assembly) is properly connected and set up properly.

1. With the units turned off, perform all external wiring (see Figure 3-20). If possible, use a

properly rated switch between the power supply and the load.

2. Apply power to the units:

a. If a load switch is used, open the switch. Set POWER switch of both units to up position

to turn power on.

b. If load switch is not used, set POWER switch of both units to up position to turn power

on, then press OUTPUT ON/OFF key once on each unit to disable the output.

3. Program Unit A as follows:

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NOTE: If using two different BHK models, e.g., 500-0.4MG and 1000-0.2MG, unit A must be

the one with the lower current capacity: 1000-0.2MG

a. Program IsetA to the current limit for the power assembly.

EomaxA

b. Program VsetA to: (to nearest volt) where:

Vset Eo

--------------------------------------------------------------- -

EomaxA EomaxB+()

• Eo is the output voltage of the power assembly,

• EomaxA is the rated maximum output voltage for unit A (e.g. 500 for the BHK 500-

0.4MG),

• EomaxB is the rated maximum output voltage for unit B.

c. Program overcurrent value of unit A (IocsetA) to 1.1 x current limit for power assembly

(step 3a).

d. Program overvoltage value of unit A (VovsetA) to 1.1 x VsetA (step 3b).

4. Program unit B as follows:.

a. Program IsetB to approximately 1.01 to 1.02 x IsetA (step 3a). This maximum current

limit is never used except in the unlikely event that the current limit of Unit A is not working.

b. Program VsetB to (Eo – VsetA) (VsetA is set in step 3b).

c. Program overcurrent value of unit B (IocsetB) to 1.1 x IsetB (step 4a).

d. Program overvoltage value of unit B (VovsetB) to 1.1 x VsetB (step 4b).

5. To apply power to the load:

a. If load switch used, close the switch.

b. If load switch not used, press POWER ON/OFF key (once) on unit B, then unit A.

6. To disable power to the load:

a. If load switch used, open the switch.

b. If load switch not used, press POWER ON/OFF key once: first on unit A, then on unit B.

c. Alternative: Turn both units off by setting POWER switch to off (down) position, first on

unit A, then on unit B.

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FIGURE 3-20. SERIES AUTOMATIC CONFIGURATION

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Page 100

3.7.2.2 MASTER-SLAVE SERIES OPERATION (AUTOMATIC TRACKING)

This configuration is characterized by the fact that only the master power supply is programmed (controlled), while the slave power supply follows the command of the master in a ratio which may be predetermined by the user. This method is, therefore, often termed automatic tracking.

A master-slave series combination with a single slave is shown in Figure 3-21 configured to operate in voltage mode, and in Figure 3-22 to operate in current mode. The master can be controlled either remotely—via either the GPIB bus or by analog means—or locally via the keypad. The slave can only be programmed by analog programming using external resistance (see also PAR. 3.6.2). The external resistor (R

) becomes the input resistor of the uncommitted ampli-

EXT

fier (slave) which is configured as an inverting amplifier.

3.7.2.2.1 VOLTAGE MODE OPERATION

When the series combination (Figure 3-21) is operating in voltage mode, both units are in voltage mode: the master receives voltage programming commands and the slave tracks the output voltage of the master.

The output voltage of the series combination in voltage mode is given by the equation,

Eo = Eo

= Eo =Eo

+ EoS

+ [EoM x (10/R

+ [EoM x (EomaxS/R

EXT

) x (EomaxS/10) ]

)]

EXT

(eq1)

where

, EoS are the output voltages of the master and slave unit, respectively, in Volts

Eomax R

When R maximum value of Eomax = Eomax

When R Eomax = 2 x Eomax

When the value of R

is the maximum output voltage of the slave unit, in Volts

is the external programming resistor of the slave unit, in K-ohms.

EXT

(K-ohms) = EomaxM (Volts), then Eo = EoM + EoM x EomaxS/EomaxM, with the

EXT

(K-ohms) = EomaxS (Volts), then Eo = 2 x EoM, having the maximum value

EXT

(in K-ohms) equals EomaxM (in Volts), as the master is programmed,

EXT

+ EomaxS.

the slave will automatically follow proportionally, so the when the master is at maximum output voltage, the slave will also be at its own maximum output voltage. This combination is practical when connecting different BHK-MG models in series.

The output of the series combination will be double the output voltage of the master if the value of R

(in K-ohms) equals EomaxS (in Volts).

EXT

When the maximum master and slave output voltages are different, the value of R ohms) must always be equal to, or greater than Eomax will be programmed to a voltage higher than Eomax

(in Volts), otherwise the slave supply

, resulting in an overvoltage condition.

EXT

(in K-

3-56 BHK-MG (OPR) 022014

KEPCO BHK-MG 200W User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

SECTION 1 - INTRODUCTION

SECTION 2 - INSTALLATION

SECTION 3 - OPERATION

SECTION 4 - CALIBRATION

APPENDIX A - IEEE 488.2 COMMAND/QUERY DEFINITIONS

APPENDIX B - SCPI COMMAND/QUERY DEFINITIONS

FIGURE 1-1. BHK-MG SERIES PROGRAMMABLE POWER SUPPLY

1.1 SCOPE OF MANUAL

SECTION 1 - INTRODUCTION

1.2 GENERAL DESCRIPTION

1.3 SPECIFICATIONS

TABLE 1-1. MODEL PARAMETERS

TABLE 1-2. BHK-MG 200W SPECIFICATIONS

1.4 FEATURES

1.4.1 LOCAL CONTROL

1.4.2 REMOTE CONTROL

1.4.2.1 DIGITAL PROGRAMMING

1.4.2.2 ANALOG PROGRAMMING

1.4.2.3 ANALOG READBACK

1.4.3 DIGITAL CALIBRATION

1.4.4 OVERVOLTAGE/OVERCURRENT PROTECTION

1.4.5 USER-DEFINED VOLTAGE/CURRENT LIMITS

1.4.6 NONVOLATILE STORAGE OF PROGRAMMED SEQUENCES OR ACTIVE SETTINGS

1.4.7 CURRENT SCALE

1.4.8 FAST MODE/SLOW MODE SELECTION

1.4.9 EXTERNAL TRIGGER PORT

1.4.10 BUILT-IN PROTECTION

1.4.11 CURRENT SINK CAPABILITY

1.4.12 ANALOG READBACK AND FLAG SIGNALS AVAILABLE FOR CUSTOMER USE

TABLE 1-3. CONNECTOR A2J5 SIGNAL DESCRIPTIONS

1.5 EQUIPMENT SUPPLIED

TABLE 1-4. EQUIPMENT SUPPLIED

1.6 ACCESSORIES

TABLE 1-5. ACCESSORIES

1.7 SAFETY

TABLE 1-6. SAFETY SYMBOLS

SECTION 2 - INSTALLATION

2.1 UNPACKING AND INSPECTION

2.2 TERMINATIONS AND CONTROLS

FIGURE 2-1. BHK-MG SERIES, FRONT PANEL CONTROLS, INDICATORS AND CONNECTORS

TABLE 2-1. CONTROLS, INDICATORS, AND CONNECTORS

TABLE 2-2. TRIGGER PORT PIN ASSIGNMENTS

TABLE 2-3. RS232C PORT INPUT/OUTPUT PIN ASSIGNMENTS

FIGURE 2-2. BHK-MG SERIES, REAR PANEL CONTROLS AND CONNECTIONS

TABLE 2-4. STATUS PORT CONNECTOR PIN ASSIGNMENTS

TABLE 2-5. IEEE 488 PORT CONNECTOR PIN ASSIGNMENTS

TABLE 2-6. REAR OUTPUT TERMINAL STRIP TB1 TERMINAL ASSIGNMENTS

TABLE 2-7. VOLTAGE PROGRAMMING TERMINAL STRIP TB2, TERMINAL ASSIGNMENTS

TABLE 2-8. CURRENT PROGRAMMING TERMINAL STRIP TB3, TERMINAL ASSIGNMENTS

2.3 SOURCE POWER REQUIREMENTS

2.4 COOLING

2.5 PRELIMINARY OPERATIONAL CHECK

FIGURE 2-3. LCD POWER ON DEFAULTS

2.6 INSTALLATION

2.6.1 BENCH TOP USE

2.6.2 RACK MOUNTING

2.7 WIRING INSTRUCTIONS

2.7.1 SAFETY GROUNDING

2.7.2 SOURCE POWER CONNECTIONS

2.7.3 D-C OUTPUT GROUNDING

2.7.4 POWER SUPPLY/LOAD INTERFACE

2.7.4.1 CABLE RECOMMENDATIONS

2.7.5 LOAD CONNECTION - GENERAL

2.7.5.1 LOCAL SENSING/REMOTE SENSING SELECT

2.7.5.2 FAST MODE/SLOW MODE SELECT

2.7.5.3 GROUNDING NETWORK CONFIGURATION

2.7.5.4 POSITIVE OUTPUT, NEGATIVE TERMINAL GROUNDED

2.7.5.5 NEGATIVE OUTPUT, POSITIVE TERMINAL GROUNDED

FIGURE 2-5. REMOTE SENSING, FAST MODE SELECTED, POSITIVE OUTPUT GROUNDED

2.8 OPERATING CONFIGURATION

TABLE 2-9. INTERNAL JUMPER CONFIGURATION

2.9 STATUS PORT

FIGURE 2-6. STATUS PORT OPTO-COUPLER ACTIVE “HIGH” CONFIGURATION

FIGURE 2-7. STATUS PORT OPTO-COUPLER ACTIVE “LOW” CONFIGURATION

SECTION 3 - OPERATION

3.1 GENERAL