Series 2268
850-Watt Programmable DC Power Supplies
Reference Manual
2268S-901-01 Rev. A / January 2015
*P2268S90101A*
2268S-901-01
A Greater Measure of Condence
A Tektr onix Company
850 Watt DC Power Supplies
Series 2268
Reference Manual
© 2015, Keithley Instruments
Cleveland, Ohio, U.S.A.
All rights reserved.
Any unauthorized reproduction, photocopy, or use of the information herein, in whole or in part,
without the prior written approval of Keithley Instruments is strictly prohibited.
All Keithley Instruments product names are trademarks or registered trademarks of Keithley
Instruments. Other brand names are trademarks or registered trademarks of their respective holders.
Document number: 2268S-901-01 Rev. A / January 2015
Safety Precautions
The following safety precautions should be observed before using this product and any associated instrumentation. Although
some instruments and accessories would normally be used with nonhazardous voltages, there are situations where hazardous
conditions may be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions
required to avoid possible injury. Read and follow all installation, operation, and maintenance information carefully before using
the product. Refer to the user documentation for complete product specifications.
If the product is used in a manner not specified, the protection provided by the product warranty may be impaired.
The types of product users are:
Responsible body is the individual or group responsible for the use and maintenance of equipment, for ensuring that the
equipment is operated within its specifications and operating limits, and for ensuring that operators are adequately trained.
Operators use the product for its intended function. They must be trained in electrical safety procedures and proper use of the
instrument. They must be protected from electric shock and contact with hazardous live circuits.
Maintenance personnel perform routine procedures on the product to keep it operating properly, for example, setting the line
voltage or replacing consumable materials. Maintenance procedures are described in the user documentation. The procedures
explicitly state if the operator may perform them. Otherwise, they should be performed only by service personnel.
Service personnel are trained to work on live circuits, perform safe installations, and repair products. Only properly trained
service personnel may perform installation and service procedures.
Keithley Instruments products are designed for use with electrical signals that are measurement, control, and data I/O
connections, with low transient overvoltages, and must not be directly connected to mains voltage or to voltage sources with high
transient overvoltages. Measurement Category II (as referenced in IEC 60664) connections require protection for high transient
overvoltages often associated with local AC mains connections. Certain Keithley measuring instruments may be connected to
mains. These instruments will be marked as category II or higher.
Unless explicitly allowed in the specifications, operating manual, and instrument labels, do not connect any instrument to mains.
Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector jacks or test
fixtures. The American National Standards Institute (ANSI) states that a shock hazard exists when voltage levels greater than
30 V RMS, 42.4 V peak, or 60 VDC are present. A good safety practice is to expect that hazardous voltage is present in any
unknown circuit before measuring.
Operators of this product must be protected from electric shock at all times. The responsible body must ensure that operators are
prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential
human contact. Product operators in these circumstances must be trained to protect themselves from the risk of electric shock. If
the circuit is capable of operating at or above 1000 V, no conductive part of the circuit may be exposed.
Do not connect switching cards directly to unlimited power circuits. They are intended to be used with impedance-limited
sources. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective
devices to limit fault current and voltage to the card.
Before operating an instrument, ensure that the line cord is connected to a properly-grounded power receptacle. Inspect the
connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.
When installing equipment where access to the main power cord is restricted, such as rack mounting, a separate main input
power disconnect device must be provided in close proximity to the equipment and within easy reach of the operator.
For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the circuit under
test. ALWAYS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting
cables or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth)
ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the
voltage being measured.
2268S-901-01 Rev. A / January 2015 i
For safety, instruments and accessories must be used in accordance with the operating instructions. If the instruments or
accessories are used in a manner not specified in the operating instructions, the protection provided by the equipment may be
impaired.
Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating
information, and as shown on the instrument or test fixture panels, or switching card.
When fuses are used in a product, replace with the same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as protective earth (safety ground)
connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use
of a lid interlock.
screw is present, connect it to protective earth (safety ground) using the wire recommended in the user documentation.
If a
The
user documentation in all cases where the symbol is marked on the instrument.
The
contact with these voltages.
The symbol on an instrument shows that the surface may be hot. Avoid personal contact to prevent burns.
The
If this
properly disposed of according to federal, state, and local laws.
The WARNING heading in the user documentation explains dangers that might result in personal injury or death. Always read
the associated information very carefully before performing the indicated procedure.
The CAUTION heading in the user documentation explains hazards that could damage the instrument. Such damage may
invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits — including the power
transformer, test leads, and input jacks — must be purchased from Keithley Instruments. Standard fuses with applicable national
safety approvals may be used if the rating and type are the same. Other components that are not safety-related may be
purchased from other suppliers as long as they are equivalent to the original component (note that selected parts should be
purchased only through Keithley Instruments to maintain accuracy and functionality of the product). If you are unsure about the
applicability of a replacement component, call a Keithley Instruments office for information.
symbol on an instrument means caution, risk of danger. The user must refer to the operating instructions located in the
symbol on an instrument means caution, risk of electric shock. Use standard safety precautions to avoid personal
symbol indicates a connection terminal to the equipment frame.
symbol is on a product, it indicates that mercury is present in the display lamp. Please note that the lamp must be
To clean an instrument, use a damp cloth or mild, water-based cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that consist of a circuit board with no
case or chassis (e.g., a data acquisition board for installation into a computer) should never require cleaning if handled according
to instructions. If the board becomes contaminated and operation is affected, the board should be returned to the factory for
proper cleaning/servicing.
Safety precaution revision as of January 2013.
ii 2268S-901-01 Rev. A / January 2015
Table of Contents
INTRODUCTION ...................................................................................................................... 11
ELCOME ........................................................................................................................... 11
W
XTENDED WARRANTY ........................................................................................................ 11
E
C
ONTACT INFORMATION ....................................................................................................... 11
EATURES AND OPTIONS ..................................................................................................... 12
F
U
NPACKING AND INSPECTING ............................................................................................... 12
Inspect for Damage ...................................................................................................................... 12
Shipment Contents ....................................................................................................................... 12
S
ERIES 2268 850-WATT MODELS ........................................................................................ 13
ACK MOUNT KIT OPTIONS .................................................................................................. 13
R
F
RONT PANEL FAMILIARIZATION ........................................................................................... 13
R
EAR PANEL FAMILIARIZATION ............................................................................................. 15
INSTALLATION ....................................................................................................................... 17
B
ASIC SETUP PROCEDURE ................................................................................................... 17
TEP 1: INSPECTING AND CLEANING ..................................................................................... 18
S
Initial Inspection............................................................................................................................ 18
Periodic Cleaning ......................................................................................................................... 18
S
TEP 2: LOCATION AND MOUNTING ....................................................................................... 19
Rack Mounting ............................................................................................................................. 19
Ventilation ..................................................................................................................................... 19
S
TEP 3: CONNECTING AC INPUT POWER .............................................................................. 20
AC Input Connector ...................................................................................................................... 20
S
TEP 4: SELECTING LOAD WIRES ......................................................................................... 21
Load Wiring .................................................................................................................................. 21
Insulation Rating........................................................................................................................... 21
Current Carrying Capacity ............................................................................................................ 21
Maximum Load Wiring Length For Operation With Sense Lines ................................................. 22
Noise and Impedance Effects ...................................................................................................... 22
S
TEP 5: PERFORMING FUNCTIONAL TESTS ............................................................................ 23
Powering the Power Supply On/Off ............................................................................................. 23
Voltage and Current Mode Operation Checks ............................................................................. 24
S
TEP 6: CONNECTING LOADS ............................................................................................... 25
DC Output Connectors ................................................................................................................. 25
20 V-40 V Models ......................................................................................................................... 25
60 V-150 V Models ....................................................................................................................... 25
Inductive Loads and Batteries ...................................................................................................... 26
Connecting Single Loads ............................................................................................................. 27
Connecting Multiple Loads ........................................................................................................... 27
S
TEP 7: CONNECTING REMOTE SENSING .............................................................................. 28
2268S-901-01 Rev. A / January 2015 iii
Table of Contents Series 2268 850 Watt DC Power Supplies Reference Manual
LOCAL OPERATION ............................................................................................................... 30
NTRODUCTION .................................................................................................................... 30
I
C
ONFIGURING SETTINGS FROM THE FRONT PANEL ................................................................ 30
Using the Rotary Adjust/Enter Control ......................................................................................... 30
Coarse and Fine Adjustment Modes ............................................................................................ 31
N
AVIGATING THE MENU SYSTEM ........................................................................................... 32
Setting VOLTS and AMPS Modes ............................................................................................... 32
Normal Display Mode and Inactivity Timeout ............................................................................... 33
D
ISPLAY MESSAGES ON THE FRONT PANEL ........................................................................... 35
S
TANDARD (LOCAL) OPERATION ........................................................................................... 37
O
PERATING MODES ............................................................................................................. 37
Constant Voltage (CV) Mode Operation ...................................................................................... 37
Constant Current (CC) Mode Operation ...................................................................................... 38
Constant Power (CP) Mode Operation ........................................................................................ 38
Automatic Mode Crossover .......................................................................................................... 38
S
HIPPED CONFIGURATION (LOCAL OPERATION) .................................................................... 41
NABLING THE OUTPUT ........................................................................................................ 41
E
E
NABLING THE AUXILIARY OUTPUT ....................................................................................... 42
O
UTPUT AUTO START MODE (AUTO RESTART) ...................................................................... 42
UXILIARY AUTO START MODE ............................................................................................. 43
A
C
ONSTANT POWER MODE .................................................................................................... 43
LARMS AND ERRORS.......................................................................................................... 44
A
C
LEARING ALARMS .............................................................................................................. 45
Clearing Triggered and Manual Alarms ....................................................................................... 45
Clearing a Flash Failure Alarm ..................................................................................................... 45
Clearing Automatic Alarms ........................................................................................................... 46
Front Panel Alarm LED ................................................................................................................ 46
Alarm Masking .............................................................................................................................. 47
Alarm Output Latching ................................................................................................................. 48
S
ETTING FOLDBACK MODE ................................................................................................... 49
ESETTING ACTIVATED FOLDBACK PROTECTION ................................................................... 50
R
U
SING OVER VOLTAGE PROTECTION (OVP) .......................................................................... 50
Defining the OVP Set Point .......................................................................................................... 50
U
SING UNDER VOLTAGE PROTECTION (UVP) ........................................................................ 51
Defining the UVP Set Point .......................................................................................................... 51
O
VER CURRENT PROTECTION (OCP) ................................................................................... 51
U
SING OVER TEMPERATURE PROTECTION LOCK (OTP) ......................................................... 52
Defining the OTP Mode ................................................................................................................ 52
Resetting in Latch Mode .............................................................................................................. 52
U
SING THE EXTERNAL SHUTDOWN FUNCTION ....................................................................... 53
Activating the External Shutdown Function ................................................................................. 53
Controlling the External Shutdown Function ................................................................................ 53
Defining the Polarity of the External Shutdown Signal................................................................. 54
iv 2268S-901-01 Rev. A / January 2015
Series 2268
of Contents
850 Watt DC Power Supplies Reference Manual Table
LOOP PROTECTION .............................................................................................................. 54
Setting up Loop Protection ........................................................................................................... 54
I
NTERLOCK FUNCTION.......................................................................................................... 56
Defining the Interlock Mode ......................................................................................................... 56
O
UTPUT PROTECTION .......................................................................................................... 56
Programming Voltage Output Preset ........................................................................................... 56
Programming Current Output Preset ........................................................................................... 57
P
OWER ON STATUS SIGNAL ................................................................................................. 57
H
ARDWARE MALFUNCTION ALARMS ...................................................................................... 58
C
URRENT CONFIGURATION MEMORY SETTINGS .................................................................... 58
SER SETTING MEMORY LOCATIONS .................................................................................... 59
U
Saving User Setting Memory Locations ....................................................................................... 59
Recalling User Setting Memory Locations ................................................................................... 60
L
OCAL LOCKOUT ................................................................................................................. 61
Enabling Local Lockout ................................................................................................................ 61
Disabling Local Lockout ............................................................................................................... 61
R
ESETTING THE POWER SUPPLY .......................................................................................... 62
U
SING MULTIPLE POWER SUPPLIES ...................................................................................... 63
ONFIGURING MULTIPLE SUPPLIES FOR SERIES OPERATION .................................................. 64
C
Load Considerations .................................................................................................................... 64
Connecting to the Load in Local Sensing Mode .......................................................................... 65
Connecting to the Load in Remote Sensing Mode ...................................................................... 66
C
ONFIGURING MULTIPLE SUPPLIES FOR CURRENT SHARING OPERATION (APG METHOD) ....... 67
Setting up the Controller Unit ....................................................................................................... 67
Setting up the Slave Units ............................................................................................................ 68
Setting Over Voltage Protection (OVP) ........................................................................................ 68
Setting Foldback Protection ......................................................................................................... 69
C
ONNECTING TO THE LOAD IN LOCAL SENSING MODE (PARALLEL CONTROL METHOD) ............ 69
ONNECTING TO THE LOAD IN REMOTE SENSING MODE (PARALLEL CONTROL METHOD) ......... 70
C
P
OWER SAVING CONTROL (SLEEP MODE) ............................................................................. 70
ANALOG PROGRAMMING & ISOLATED ANALOG PROGRAMMING .................................. 72
NTRODUCTION .................................................................................................................... 72
I
A
NALOG PROGRAMMING (APG) OF OUTPUT VOLTAGE AND OUTPUT CURRENT ....................... 72
EMOTE PROGRAMMING OPTIONS........................................................................................ 73
R
Analog Monitor Signals ................................................................................................................ 73
Auxiliary Outputs .......................................................................................................................... 73
Analog Programming (APG) Connector J1 .................................................................................. 74
Making Control Connections ........................................................................................................ 75
Wiring ........................................................................................................................................... 76
A
NALOG PROGRAMMING MODE ............................................................................................ 76
Analog Programming With External Voltage Source ................................................................... 76
Voltage-Controlled Voltage APG Setup ....................................................................................... 77
2268S-901-01 Rev. A / January 2015 v
Table of Contents Series 2268 850 Watt DC Power Supplies Reference Manual
Voltage-Controlled Current APG Setup ....................................................................................... 79
A
NALOG PROGRAMMING WITH EXTERNAL RESISTOR.............................................................. 81
Resistive-Controlled Voltage APG Setup ..................................................................................... 82
Resistive-Controlled Current APG Setup ..................................................................................... 84
V
OLTAGE AND CURRENT READBACK ..................................................................................... 86
I
SOLATED ANALOG PROGRAMMING MODE (ISOL) .................................................................. 87
AUX Output and Isolated Analog Programming (ISOL) Connector ............................................. 87
Making ISOL Control Connections ............................................................................................... 89
ISOL Programming With External Voltage Source ...................................................................... 89
Voltage-Controlled Voltage ISOL Setup ...................................................................................... 90
Voltage-Controlled Current ISOL Setup ....................................................................................... 92
A
NALOG PROGRAMMING WITH EXTERNAL RESISTOR.............................................................. 94
Resistive-Controlled Voltage ISOL Setup .................................................................................... 95
Resistive-Controlled Current ISOL Setup .................................................................................... 97
V
OLTAGE AND CURRENT READBACK (ISOLATED) ................................................................... 99
Q
UERY REMOTE CONTROL SOURCE STATE .......................................................................... 99
REMOTE OPERATION .......................................................................................................... 101
I
NTRODUCTION .................................................................................................................. 101
ARDWARE AND CONNECTION SETUP ................................................................................. 101
H
C
ONFIGURING REMOTE CONTROL USING RS-232 ............................................................... 102
RS-232 Communication Cable with RJ-45 to DB-9 ................................................................... 103
RS-232 Communication Cable with RJ-45 to DB-25 ................................................................. 104
C
ONFIGURING REMOTE CONTROL USING RS-485 ............................................................... 106
RS-485 Communication Cable with RJ-45 to DB-9 ................................................................... 106
RS-485 Communication Cable with Two RJ-45s ....................................................................... 107
C
ONFIGURING REMOTE CONTROL USING USB .................................................................... 108
Setting Up the PC to Use the USB Connection ......................................................................... 108
C
ONFIGURING REMOTE CONROL USING GPIB .................................................................... 114
GPIB Pin Description ................................................................................................................. 114
Communication with Your Device .............................................................................................. 115
Selecting a Communication Port ................................................................................................ 115
C
ONFIGURING REMOTE CONTROL USING ETHERNET/LAN (ENET) ....................................... 117
ULTIPLE POWER SUPPLY CONNECTIONS TO RS-485 BUS .................................................. 118
M
Multiple Power Supply Setup ..................................................................................................... 118
T
ERMINAL CONFIGURATION ................................................................................................ 119
Data Format ............................................................................................................................... 119
End of Message ......................................................................................................................... 119
HyperTerminal ............................................................................................................................ 119
S
ELECTING THE APPROPRIATE COMMUNICATION PORT ........................................................ 122
Data Rate Setting (Kbps) ........................................................................................................... 122
Multichannel Address Setting ..................................................................................................... 123
Remote Interface Addressing ..................................................................................................... 123
vi 2268S-901-01 Rev. A / January 2015
Series 2268
of Contents
850 Watt DC Power Supplies Reference Manual Table
Multichannel Commands Explained ........................................................................................... 124
S
TATUS REPORTING IN SCPI ............................................................................................. 125
S
TATUS REGISTERS MODEL FROM IEEE 488.2 ................................................................... 127
Status Byte ................................................................................................................................. 128
Error/Event Queue (ERR) .......................................................................................................... 128
Questionable Status Register Summary (QSR) ......................................................................... 128
Message Available (MAV) .......................................................................................................... 129
Standard Event Status Summary (ESB) .................................................................................... 129
Master Summary Status (MSS) ................................................................................................. 129
Request Service (RQS) .............................................................................................................. 129
Operation Status Register Summary (OSR) .............................................................................. 130
Standard Event Status Register (SESR) ................................................................................... 131
S
TANDARD SCPI REGISTER STRUCTURE ............................................................................ 134
OPER
ATION STATUS REGISTER ......................................................................................... 135
Current Share Sub-Register ....................................................................................................... 137
Operation Status Register Commands ...................................................................................... 138
Current Sharing Sub-Register Commands ................................................................................ 139
Shutdown Sub-Register Commands .......................................................................................... 140
Protection Sub-Register Commands.......................................................................................... 141
QUES
TIONABLE STATUS REGISTER ................................................................................... 142
VOLTage Sub-Register .............................................................................................................. 144
TEMPerature Sub-Register ........................................................................................................ 144
Questionable Status Register Commands ................................................................................. 145
Voltage Status Register Commands .......................................................................................... 146
Temperature Status Register Commands ................................................................................. 147
SCPI
ERROR/EVENT QUEUE .............................................................................................. 148
R
ESET COMMAND .............................................................................................................. 150
C
LEAR ALL STATUS REGISTERS ......................................................................................... 151
Clear Status Command .............................................................................................................. 151
SCPI Preset Status .................................................................................................................... 151
C
OMMAND LINE HELP SYSTEM ........................................................................................... 152
Querying Help for all Command Headers .................................................................................. 152
Querying Help for Legacy Command Headers .......................................................................... 153
L
OCKING AND UNLOCKING THE FRONT PANEL ..................................................................... 154
UTO SEQUENCE PROGRAMMING ....................................................................................... 154
A
C
ONFIGURE OTHER PROTECTION MECHANISMS .................................................................. 160
Foldback Protection ................................................................................................................... 160
Over Temperature Protection ..................................................................................................... 161
Loop Protection Enable/Disable ................................................................................................. 161
Interlock Enable/Disable ............................................................................................................ 161
S
AVE AND RECALL ............................................................................................................. 162
S
ET ANALOG PROGRAMMING LEVEL ................................................................................... 162
ET REMOTE PROGRAMMING INTERFACE ............................................................................ 162
S
2268S-901-01 Rev. A / January 2015 vii
Table of Contents Series 2268 850 Watt DC Power Supplies Reference Manual
PROTECTION MASK (ENABLE ALARMS) ............................................................................... 163
LAN/ETHERNET SETUP AND COMMUNICATION ............................................................... 164
NTRODUCTION .................................................................................................................. 164
I
S
ETTING UP LAN/ETHERNET .............................................................................................. 164
ASICS ............................................................................................................................. 164
B
Communication Cable Requirements ........................................................................................ 164
ENET Connector ........................................................................................................................ 165
ENET Connector LEDs .............................................................................................................. 166
L
OCAL AREA NETWORK (LAN) ........................................................................................... 166
Media Access Control (MAC) Address....................................................................................... 166
Communication Configuration .................................................................................................... 166
LAN Connection ......................................................................................................................... 167
Direct-to-PC Connection ............................................................................................................ 167
Private Network Connection ....................................................................................................... 167
C
ONNECTING TO A NETWORK ............................................................................................. 169
Connecting with PC on Same Side of Router as Power Supply ................................................ 169
Connecting with Power Supply Hidden Behind a Router ........................................................... 170
Socket Port Number ................................................................................................................... 172
Instrument Drivers and Application Software ............................................................................. 173
LXI
DISCOVERY BROWSER SOFTWARE ............................................................................... 173
S
ETTING LAN PARAMETERS ............................................................................................... 173
Setting LAN Parameters via Serial or USB Port ........................................................................ 173
Setting LAN Parameters via Web Interface ............................................................................... 173
S
ETTING A STATIC IP ADDRESS THROUGH ETHERNET, USB, AND SERIAL INTERFACES .......... 176
Ethernet ...................................................................................................................................... 176
USB ............................................................................................................................................ 177
RS232 (SERIAL) ........................................................................................................................ 184
SYSTEM
COMMANDS .................................................................................................... 190
Subsystem Syntax...................................................................................................................... 190
CALIBRATION AND TROUBLESHOOTING ......................................................................... 193
NTRODUCTION .................................................................................................................. 193
I
M
AIN VOLTAGE AND CURRENT CALIBRATION PRINCIPLE ...................................................... 194
Understanding the Problem ....................................................................................................... 194
Step 1: Gain Calibration ............................................................................................................. 195
Step 2: Offset Calibration ........................................................................................................... 195
Step 3: Recalibrate Gain ............................................................................................................ 196
S
TORING CALIBRATION DATA ............................................................................................. 196
C
ALIBRATING THE OUTPUT VOLTAGE .................................................................................. 197
Gain Calibration.......................................................................................................................... 197
Offset Calibration........................................................................................................................ 197
C
ALIBRATING THE OUTPUT CURRENT.................................................................................. 198
Gain Calibration.......................................................................................................................... 198
viii 2268S-901-01 Rev. A / January 2015
Series 2268
of Contents
850 Watt DC Power Supplies Reference Manual Table
Offset Calibration........................................................................................................................ 198
O
VER VOLTAGE PROTECTION CALIBRATION ........................................................................ 199
N
ON-ISOLATED ANALOG PROGRAMMING CALIBRATION ......................................................... 200
Non-isolated Voltage Monitoring Calibration .............................................................................. 200
Non-isolated Current Monitoring Calibration .............................................................................. 201
Non-isolated Voltage Programming of Voltage Calibration ....................................................... 202
Non-isolated Resistive Programming of Voltage Calibration ..................................................... 203
Non-isolated Voltage Programming of Current Calibration ........................................................ 204
Non-isolated Resistive Programming of Current Calibration ..................................................... 205
C
ALIBRATION PROCEDURE FOR ISOLATED MODES ............................................................... 206
Isolated Voltage Monitoring Calibration ..................................................................................... 206
Isolated Current Monitoring Calibration ..................................................................................... 207
Isolated Voltage Programming of Voltage Calibration ............................................................... 208
Isolated Resistive Programming of Voltage Calibration ............................................................. 209
Isolated Voltage Programming of Current Calibration ............................................................... 210
Isolated Resistive Programming of Current Calibration ............................................................. 211
APG
CALIBRATION ............................................................................................................ 212
Calibrating the Input Voltage APG Signal .................................................................................. 212
Calibrating the Input Current APG Signal .................................................................................. 213
R
ESTORE FACTORY CALIBRATION ...................................................................................... 214
R
ESTORE DEFAULT CALIBRATION ....................................................................................... 214
SER DIAGNOSTICS ........................................................................................................... 214
U
E
MERGENCY SHUTDOWN ................................................................................................... 215
NUSUAL OR ERRATIC OPERATION ..................................................................................... 215
U
T
ROUBLESHOOTING FOR OPERATORS ................................................................................. 215
SCPI COMMAND REFERENCE ............................................................................................ 216
CONFORMANCE INFORMATION ................................................................................... 216
SCPI
Codes and Standards ................................................................................................................ 216
IEEE 488.2/SCPI Syntax and Style............................................................................................ 217
SCPI Command Hierarchy ......................................................................................................... 217
Using SCPI Commands ............................................................................................................. 218
Parameter Types ........................................................................................................................ 221
SCPI
COMMAND TREE ....................................................................................................... 222
COMMAND SUMMARY ................................................................................................ 228
SCPI
IEEE 488.2 Commands .............................................................................................................. 228
Readback Commands ................................................................................................................ 230
SCPI Commands for Output Control .......................................................................................... 231
SCPI Commands for Calibration ................................................................................................ 232
SCPI Commands to Clear All Protection Mechanisms .............................................................. 234
SCPI Commands for Foldback Protection ................................................................................. 234
SCPI Commands for Power ....................................................................................................... 234
SCPI Commands for Triggering ................................................................................................. 235
System Commands .................................................................................................................... 235
2268S-901-01 Rev. A / January 2015 ix
Table of Contents Series 2268 850 Watt DC Power Supplies Reference Manual
Status Commands ...................................................................................................................... 237
Protection Commands ................................................................................................................ 242
Auto Sequence Commands ....................................................................................................... 242
ERROR MESSAGES.............................................................................................................. 243
RROR MESSAGES ............................................................................................................ 243
E
Command Error List ................................................................................................................... 244
Execution Error List .................................................................................................................... 245
Device-Specific Error List ........................................................................................................... 246
Query Error List .......................................................................................................................... 246
SPECIFICATIONS .................................................................................................................. 247
PECIFICATIONS ................................................................................................................ 247
S
Output Performance Specifications............................................................................................ 247
Environmental Specifications (Indoor use) ................................................................................ 248
Mechanical Specifications .......................................................................................................... 248
Regulatory Approvals ................................................................................................................. 248
M
ECHANICAL DIMENSIONS ................................................................................................. 249
x 2268S-901-01 Rev. A / January 2015
In this section:
Supply.
WELCOME
Section 1
Introduction
This section describes the features of the 2268 Series 850 Watt Power
Thank you for choosing a Keithley Instruments product. The Series 2268 850-Watt DC
power supply is designed for use in the laboratory and for test applications. It also has
excellent regulation and low output voltage ripple. The digital displays provide accurate
readings of voltage and current and also provide for easy, precise setting of output values
using digital entry of current and voltage values. Output voltage can be set from the front
panel, using a remote analog voltage or resistance, or over any of the digital interfa ces: LAN,
USB, GPIB, or RS-485. Voltage and current analog outputs are also available for remote
monitoring and analog control.
EXTENDED WARRANTY
Additional years of warranty coverage are available on many products. These valuable
contracts protect you from unbudgeted service expenses and provide additional years of
protection at a fraction of th e price o f a repa ir. Exte nded w arranties are av ailable o n new and
existing products. Contact your local Keithley Instruments representative for details.
CONTACT INFORMATION
If you have any questions after you review the information in this documentation, please
contact your local Keithley Instruments office, sales partner, or distributor, or ca ll Ke ithley
Instruments corporate headquarters (toll-free inside the U.S. and Canada only) at
1-800-935-5595, or from outside the U.S. at +1-440-248-0400.
2268S-901-01 Rev. A / January 2015 11
Introduction Series 2268 850 Watt DC Power Supplies Reference Manual
FEATURES AND OPTIONS
The Series 2268 Programmable DC Power Supply provides stable, variable output voltage
and current for a broad range of development and system requirements. The power supplies
have a high power density, numerous indus try standard interfaces, and a num ber of excellent
features:
• RS-232, RS-485, GPIB, Ethernet (ENET), analog programming (APG), and USB
built-in ports
• Seamless switching between front panel and any digital interface (RS-232, RS-485,
USB, GPIB or ENET)
• Simultaneous digital displays for both voltage and current
• Front panel control by rotary Adjust/Enter knob, permitting high resolution output
setting
• Active Power Factor Correction (PFC) reduces input current and input current harmonics
• Automatic crossover system allowing the power supply to switch between Constant
Current, Constant Voltage and Constant Power operating modes
• Parallel or series connection among multiple units to produce greater diversity or to use
in higher power applications
• Short-circuit protection of DC outputs, providing greater operating safety
• Built-in APG and ISOL interface to provide a galvanically isolated analog voltage
control of the output, master/slave output tracking, and remote Enable/Disable for safety
and precision
• Remote output voltage sensing to automatically compensate for cable losses.
• Software calibrated
• Three user setting memory locations
UNPACKING AND INSPECTING
Inspect for Damage
Upon receiving the Model 2268, careful ly unpack the unit, and inspec t for any obvious signs
of physical damage that might have occurred during shipment. Notify the shipping agent of
any damage immediately.
Shipment Contents
The following items are included with every Series 2268 order:
• Series 2268 power supply
• Series 2268 product information CD-ROM
• AC line power cord
• Series 2268 additional accessories, as ordered
12 2268S-901-01 Rev. A / January 2015
Series 2268 850 Watt DC Power Supplies Reference Manual Introduction
Model
Output Voltage
Output Current
2268-20-42
0-20 V
0-42 A
2268-40-21
0-40 V
0-21 A
2268-60-14
0-60 V
0-14 A
2268-80-10.5
0-80 V
0-10.5 A
2268-100-8.5
0-100 V
0-8.5 A
2268-150-5.6
0-150 V
0-5.6 A
Important: We recommend that you provide additional rear support to the
Series 2268 when mounting it in a rack.
Number of Units
Model Number
Item
Description
1
Front panel power switch
2
Front panel display see Figure 2
3
Air intake vents
SERIES 2268 850-WATT MODELS
RACK MOUNT KIT OPTIONS
Rack-mount kits are available for the Series 2268 instruments. The table below shows the
available models. Complete details and installa tion instructions are in cluded in the docum ent
that ships with each rack-mount kit.
Single 2268-RMK-1
Dual 2268-RMK-2
FRONT PANEL FAMILIARIZATION
Figure 1: Series 2268 850-Watt Front Panel
2268S-901-01 Rev. A / January 2015 13
Introduction Series 2268 850 Watt DC Power Supplies Reference Manual
Item
Description
1
Rotary Adjust/Enter control
2
Constant Voltage (CV) Mode LED (green)
3
Constant Current (CC) Mode LED (green)
4
Output Current Display
5
Model Identification Label
6
Output Voltage Display
7
Alarm Indicator LED (red)
8
OUTPUT ENABLE Main button
9
OUTPUT ENABLE Aux button
10
9-Position Mode Control (For detailed information, see
Figure 2: Series 2268 850-Watt Front Panel Display and Controls
“Configuring Settings from the Front Panel” on page 30).
14 2268S-901-01 Rev. A / January 2015
Series 2268 850 Watt DC Power Supplies Reference Manual Introduction
REAR PANEL FAMILIARIZATION
Figure 3: Series 2268 850-Watt, 20 V to 40 V Rear Panel
Figure 4: Series 2268 850-Watt, 60 V to 150 V Rear Panel
2268S-901-01 Rev. A / January 2015 15
Introduction Series 2268 850 Watt DC Power Supplies Reference Manual
Item
Description
1
20 V– 40 V Models: DC Output Terminal Positive (6.5 mm hole diameter)
60 V–150 V Models: DC Output Connectors Positive
2
20 V– 40 V Models: DC Output Terminal Negative (6.5 mm hole diameter)
60 V–150 V Models: DC Output Connectors Negative
3 (J2)
Ethernet (ENET) or GPIB Connector
4 (J4)
RS-232/RS-485 Connector In Port
5
AC Input Connector (IEC Type)
6
Chassis Ground Stud
7 (J1)
Analog Programming (APG) Connector. For pin information, see page 74.
8 (J3)
AUX Output and Isolated Analog Programming (ISOL) Connector. For pin
information, see page 87.
9 (J5)
USB Connector
10 (J6)
RS-485 Connector Multichannel Port
11
Ethernet/LAN Connector
12
Fan Exhaust Vents
16 2268S-901-01 Rev. A / January 2015
1
Inspect
Inspect the power supply.
“Step 1: Inspecting and
2
Install
Install the power supply
“Step 2: Location and Mounting”
3
Connect Input
Connect AC input power.
“Step 3: Connecting AC
4
Select Wires
Select wires that are
“Step 4: Selecting Load Wires”
5
Test
Perform functional tests for
“Step 5: Performing
6
Connect Loads
Connect the load wires to
“Step 6: Connecting Loads”
7
Connect
Connect remote sensing
“Step 7: Connecting
In this section:
This section provides information and procedures for inspecting, installing, and testing the
power supply.
BASIC SETUP PROCEDURE
Below is a summary of the basic setup procedure with references to the relevant sections in
this section. Refer to this table if you are unfamiliar with the installat ion requirements for the
power supply. Complete each step in the sequence give
Section 2
Installation
n.
Step Description Action Reference
Cleaning” on page 18.
(benchtop or rack mount).
Ensure adequate
ventilation.
Power
correctly rated for the
maximum DC output
current.
voltage mode operation,
current mode operation, and
front panel controls.
the DC output.
Remote
Sensing (if
required)
connectors on power supply
to load.
on page 19.
Input Power” on page 20.
on page 21.
Functional Tests” on page
23.
on page 25.
Remote Sensing” on page
28.
2268S-901-01 Rev. A / January 2015 17
Installation Series 2268 850 Watt DC Power Supplies Reference Manual
STEP 1: INSPECTING AND CLEANING
Initial Inspection
When you first receive your unit, perform a physical check:
1. Inspect the unit for any scratches and cracks, broken switches, connectors or
displays.
2. Ensure that the packing box contains a power cord.
3. If you see external damage or suspect internal damage, contact the carrier
immediately.
Periodic Cleaning
The power supply only requires periodic cleaning, not routine servicing. Whenever a unit is
removed from operation, clean the metal surfaces with naphtha or an equivalent solvent, and
clean the front panel with a weak solution of soap and water. Use low-pressure compressed
air to blow dust from components on the printed circuit boards.
18 2268S-901-01 Rev. A / January 2015
Series 2268 850 Watt DC Power Supplies Reference Manual Installation
STEP 2: LOCATION AND MOUNTING
The power supply may be rack-mounted or used in benchtop applications.
Rack Mounting
Keithley offers a Single and a Dual Rack Kit (2268-RMK-1 and 2268-RMK-2). See "Rack
Mount Kit Options" on page 13 for information about available rack mount kits. To purchase
a rack mount kit, contact your local Keithley Instruments o ffice, sales partner, or dis tributor,
or call Keithley Instruments corporate headquarters (toll-free inside the U.S. and Canada
only) at 1-800-935-5595, or from outside the U.S. at +1-440-248-0400.
Ventilation
Whether operating the pow er supply in a ra ck or on a bench, allow ai r to re ach the ventilatio n
inlets on the front and rear of the unit for cooling. The direction of airflow is from the front of
the unit to the back of the unit. Ventilat ion space is not required at the top, bottom or sides of
the power supply.
2268S-901-01 Rev. A / January 2015 19
Installation Series 2268 850 Watt DC Power Supplies Reference Manual
The AC input cord is the disconn ect device f or the power su pply . The plug must
STEP 3: CONNECTING AC INPUT POWER
WARNING: Shock hazard
Disconnect AC power from the unit before re moving the cover. E ven with the
front panel power switch in the Off position, live line voltages are exposed when
the cover is removed. Repairs must be made by an Authorized Service Center.
WARNING: Shock hazard
There is a potential shock hazard if the power supply chassis and cover are not
connected to an electrical ground via the safety ground in the AC input
connector. Ensure that the power supply is connected to a grounded AC outlet
with the recommended AC input cord configured for the available line voltage
as described in this section.
WARNING: Shock hazard
be a non-locking plug which is readily identifiable by and accessible to the
operator. The input cord must be no longer than 9.84 feet (3 m).
AC Input Connector
The AC input connector is a standard IEC 16 A 250 V male connector located on the rear
panel of the power supply. The AC input cord provided is rated for 30 A, 300 V.
20 2268S-901-01 Rev. A / January 2015
Series 2268 850 Watt DC Power Supplies Reference Manual Installation
Wire Size
(AWG)
Maximum
Current (Amps)
Wire Size
(AWG)
Maximum
Current (Amps)
20
2.5 6 61
18 4 4
97
16 6 2
155
14
10 1 192
12
16
1/0
247
10
21
2/0
303 8 36
n/a
n/a
STEP 4: SELECTING LOAD WIRES
This section provides recommendations for selecting minimum load wire sizes.
Load Wiring
To select the wiring for connecting the load to the power supply, consider the following
factors:
• Insulation rating of the wire. Current carrying capacity of the wire.
• Maximum load wiring length for operation with remote sense lines.
• Electrical noise and impedance effects of the load lines.
Insulation Rating
Use load wiring with a minim um insulation rating equiv alent to the m aximum output voltage
of the power supply.
Current Carrying Capaci ty
The load wiring must have a current carrying capacity greater than the output rating of the
power supply to ensure that the load wiring will not be damaged if the load is shorted. The
table that follo ws shows the maxim um current ra ting for v arious gaug es of wir e rated for 10 5
°C operation, based on a maximum current density of 450 A/cm
2
.
Operating at the maximum current rating shown in the table below resu lts in an
approximately 30 °C temperature rise for an appropriately-sized load wire operating in free
air. Where load wiring must operate in areas with elevated ambient temperatures or bundles
with other wiring, use larger gauges or wiring rated for higher temperatures.
Current Carrying Capacity for Load Wi ring
2268S-901-01 Rev. A / January 2015 21
Installation Series 2268 850 Watt DC Power Supplies Reference Manual
WIRE GAUGE (AW G)
LOAD CURRENT (AMPS)
Maximum Load Wiring Length For Operation With Sense Lines
Figure 5: Maximum Load Wire Length for 1 V Line Drop
WIRE LENGTH (FEET)
Noise and Impedance Effects
To minimize noise pickup or radiation, use shielded twisted pair wiring of the shortest
possible length for load sense wires. Connect the shield to the power supply chassis. Where
shielding is impossible or impractical, simply twisting the wires together will offer some
noise immunity.
22 2268S-901-01 Rev. A / January 2015
Series 2268 850 Watt DC Power Supplies Reference Manual Installation
STEP 5: PERFORMING FUNCTIONAL TESTS
The functional test procedures include:
• Power-on and front panel functional checks
• Voltage mode operation and current mode operation checks.
For information on local operation, see the section on “Local Operation” on page 30 for
adjusting front panel controls and settings.
Powering the Power Supply On/Off
To power on the power supply:
1. Ensure that the front panel power switch is in the Off position.
2. Ensure that the AC line voltage is within operating range.
3. Connect the line cord to a grounded AC outlet.
4. Turn the front panel power switch to the On position.
After a short power-on delay, illuminates on the output voltage and curren t
displays, followed by
.
After approximately 1 second, the display returns to normal status.
To power off the power supply:
Turn the front panel power switch to the Off position.
will blink on the display. The ALARM LED illuminates. After a short delay,
all lights on the display will not be illuminated.
2268S-901-01 Rev. A / January 2015 23
Installation Series 2268 850 Watt DC Power Supplies Reference Manual
Voltage and Current Mode Oper a ti on Check s
To perform the voltage and current mode operation checks:
1. Ensure that the front panel power switch is in the On position and the output is
disconnected.
2. If the OUTPUT ENABLE Main button is illuminated, press the button to turn off
the output.
3. To check voltage mode operation, turn the 9-position mode control to the VOLTS
position.
The voltage set point will blink dimming and then return to full brightness. For more
information, see the section on “Local Operation” starting on page 30.
4. Adjust the voltage to 5 V.
5. To check current mode operation, turn the 9-position mode control to AMPS
position.
Verify that the current set point is blinking in the output current display.
6. Adjust the current to 1 A.
7. Press the OUTPUT ENABLE Main button to turn On.
8. Turn the front panel power switch to the Off position.
9. Turn the front panel power switch to the On position.
10. Connect a short circuit across the output terminals. Use leads of sufficient current
carrying capacity. (See “Step 4: Selecting Load Wires” on page 21.)
11. Press the OUTPUT ENABLE Main bu tton to enable th e output. The button will be
illuminated when the output is enabled.
CC Mode LED illuminates and the voltage and current are displayed. CC Mode LED
illuminates and the preset load current is displayed.
12. Turn the front panel power switch to the Off position.
24 2268S-901-01 Rev. A / January 2015
Series 2268 850 Watt DC Power Supplies Reference Manual Installation
operating at an output
hazardous voltages, ensure that the load and its connections have no accessible
inals, ensure terminals of opposite
STEP 6: CONNECTING LOADS
This section describes how to connect loads to the power supply for both single and m ultiple
loads.
WARNING: Shock hazard
There is a shock hazard at the power supply output when
greater than 40 V. To protect personnel against accidental contact with
live parts.
CAUTION: Cable damage
When making connections to the output term
polarity do not touch. Load cables and sense wires should be provided with
strain relief.
DC Output Connectors
WARNING: Shock hazard
Disconnect the AC input before making any connections. A shock hazard may
be present at the output terminals. Allow 15 second s after the AC power has
been removed before making any connections.
20 V-40 V Models
The 20 V-40 V models are equipped with output terminals, as shown in Figure 3.
60 V-150 V Models
The 60 V-150 V models are equipped with output connectors, as shown in Figure 4. These
models have output currents that may require users to use wire diameters that would not fit
into a single output connector, so there are two output connectors in pa rallel to increase the
potential current carrying capacity of load wiring.
2268S-901-01 Rev. A / January 2015 25
Installation Series 2268 850 Watt DC Power Supplies Reference Manual
The power supply requires freewheeling and blocking diodes across the
supply from damage caused by power being fed back into the supply and
Selecting
The diode must have a voltage rating at least 20% greater than the power
power supply's output rating. C onnect the cathode to th e positive output and th e
or a varistor ac ross the output t o
protect the power supply. The breakdown voltage rating for the TVS or varistor
Inductive Loads and Batterie s
CAUTION
output while driving inductive loads or batteries to protect the power
from high voltage transients.
Diodes
supply's output voltage and have a current rating greater than or equal to the
anode to the return.
Where positive load transients such as back EMF from a motor may occur,
connect a Transient Voltage Suppressor (TVS)
must be approximately 10% higher than the rated supply output.
Figure 6: Diode Placement
26 2268S-901-01 Rev. A / January 2015
Series 2268 850 Watt DC Power Supplies Reference Manual Installation
Terminal
Power Supply
Terminal
Load
– Local Sense
+ Output
+ Local Sense
– Output
Connecting Single Loads
Figure 7 shows the recommended load connections for a single load which is sensing its
voltage locally. Loca l sens e li nes show n ar e the d efaul t connec tions at the r ear pan el A PG J1
connector. The load lines should use the largest gauge and shortest leng th of w ire p ossible to
ensure optimal performance.
You do not need remote sensing for basic operation of your power supply. However, if you
wish to correct any small drops in your load lines, then use the remote sensing feature. See
“Step 7: Connecting Remote Sensing” on page 28for more inform ation.
Figure 7: Connecting Single Loads
Connecting Multiple Loads
The proper connection of distributed loads is an important aspect of power supply use. The
common method of connection is a radial load connection. Power is connected to each load
individually from a single pair of terminals designated as the positive and negative
distribution terminals. This pair of terminals may be the power supply output terminals, the
load terminals, or a dis tinct set of term inals especia lly estab lished f or di stribu tion u se. I n this
scheme, there are no ground loops and the effect of one load upon another is minimized.
2268S-901-01 Rev. A / January 2015 27
Installation Series 2268 850 Watt DC Power Supplies Reference Manual
Output +
Load
Pin J1.1 on APG
connector
Output terminals on
power supply
Output –
Chassis ground stud
+SNS
-SNS
Pin J1.6 on APG
connector
STEP 7: CONNECTING REMOTE SENSING
WARNING: Shock hazard
There is a potential shock hazard at the sense connectors when using a power
supply at an output greater than 40 V. Select wiring with a minimum insulation
rating equivalent to the maximum output voltage of the power supply for use as
local sense jumpers or for remote sense wires. Ensure that connections at the
load end are shielded to prevent contact with hazardous voltages.
Remote sen sing pe rm its y ou to sh if t th e r egu latio n po int of the power supply from the outpu t
terminals to the load or other distribution terminals.
Use shielded twisted pair wiring of 20 to 26 AWG for best noise performance. Make sure that
the shielded twisted pair wiring insulation is rated higher than the maximum output voltage
of the power supply. If possible, one end of the shield of the sense lines shoul d be attached to
the chassis ground of the power supply.
Figure 8: Remote Sense Connection
To connect the remote sense wires:
1. Ensure that the front panel power switch is in the Off position.
2. Using a small flat blad e screw driver, rem ove the two sense jumpers from pins J1.1
and J1.2, and from pins J1.5 and J1.6 on the APG Connector.
28 2268S-901-01 Rev. A / January 2015
Loading...