Xantrex GPIB-XT, GPIB-HPD User Guide

Internal GPIB Interface
for XT/HPD Series
Programmable DC
Power Supplies

GPIB-XT
GPIB-HPD

Operating Manual

Operating Manual for

Internal GPIB Interface
for XT 60 Watt and
HPD 300 Watt Series

Programmable DC
Power Supplies

Limited

Warranty

What does this warranty cover and how long does it last?

This Limited Warranty is provided by Xantrex Technology, Inc. (“Xantrex”) and
covers defects in workmanship and materials in your GPIB Interface Card. This
warranty lasts for a Warranty Period of 5 years from the date of purchase at point of
sale to you, the original end user customer.

What will Xantrex do?

Xantrex will, at its option, repair or replace the defective product free of charge,
provided that you notify Xantrex of the product defect within the Warranty Period,
and provided that Xantrex through inspection establishes the existence of such a
defect and that it is covered by this Limited Warranty.

Xantrex will, at its option, use new and/or reconditioned parts in performing
warranty repair and building replacement products. Xantrex reserves the right to use
parts or products of original or improved design in the repair or replacement. If
Xantrex repairs or replaces a product, its warranty continues for the remaining
portion of the original Warranty Period or 90 days from the date of the return
shipment to the customer, whichever is greater. All replaced products and all parts
removed from repaired products become the property of Xantrex.

Xantrex covers both parts and labor necessary to repair the product, and return
shipment to the customer via a Xantrex-selected non-expedited surface freight
within the contiguous United States and Canada. Alaska and Hawaii are excluded.
Contact Xantrex Customer Service for details on freight policy for return shipments
outside of the contiguous United States and Canada.

How do you get service?

If your product requires troubleshooting or warranty service, contact your merchant.
If you are unable to contact your merchant, or the merchant is unable to provide
service, contact Xantrex directly at:

Phone: [phone]

Toll Free North America: 1 800 667 8422

Fax: [phone]

Email: [e-mail]

ii Operating Manual for GPIB for XT/HPD Series Power Supply

Direct returns may be performed according to the Xantrex Return Material
Authorization Policy described in your product manual. For some products, Xantrex
maintains a network of regional Authorized Service Centers. Call Xantrex or check
our website to see if your product can be repaired at one of these facilities.

In any warranty claim, dated proof of purchase must accompany the product and the
product must not have been disassembled or modified without prior written
authorization by Xantrex.

Proof of purchase may be in any one of the following forms:

• The dated purchase receipt from the original purchase of the product at point of

sale to the end user, or

• The dated dealer invoice or purchase receipt showing original equipment

manufacturer (OEM) status, or

• The dated invoice or purchase receipt showing the product exchanged under

warranty

What does this warranty not cover?

This Limited Warranty does not cover normal wear and tear of the product or costs
related to the removal, installation, or troubleshooting of the customer’s electrical
systems. This warranty does not apply to and Xantrex will not be responsible for any
defect in or damage to:

a. the product if it has been misused, neglected, improperly installed, physically

damaged or altered, either internally or externally, or damaged from improper
use or use in an unsuitable environment;

b. the product if it has been subjected to fire, water, generalized corrosion,

biological infestations, and high input voltage from lightning strikes;

c. the product if repairs have been done to it other than by Xantrex or its authorized

service centers (hereafter “ASCs”);

d. the product if it is used as a component part of a product expressly warranted by

another manufacturer;

e. the product if its original identification (trade-mark, serial number) markings

have been defaced, altered, or removed.

Release 1.1 iii

Disclaimer Product

THIS LIMITED WARRANTY IS THE SOLE AND EXCLUSIVE WARRANTY PROVIDED
BY XANTREX IN CONNECTION WITH YOUR XANTREX PRODUCT AND IS, WHERE
PERMITTED BY LAW, IN LIEU OF ALL OTHER WARRANTIES, CONDITIONS,
GUARANTEES, REPRESENTATIONS, OBLIGATIONS AND LIABILITIES, EXPRESS
OR IMPLIED, STATUTORY OR OTHERWISE IN CONNECTION WITH THE PRODUCT,
HOWEVER ARISING (WHETHER BY CONTRACT, TORT, NEGLIGENCE, PRINCIPLES
OF MANUFACTURER’S LIABILITY, OPERATION OF LAW, CONDUCT, STATEMENT
OR OTHERWISE), INCLUDING WITHOUT RESTRICTION ANY IMPLIED WARRANTY
OR CONDITION OF QUALITY, MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. ANY IMPLIED WARRANTY OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE TO THE EXTENT REQUIRED UNDER
APPLICABLE LAW TO APPLY TO THE PRODUCT SHALL BE LIMITED IN DURATION
TO THE PERIOD STIPULATED UNDER THIS LIMITED WARRANTY.

IN NO EVENT WILL XANTREX BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
INCIDENTAL OR CONSEQUENTIAL DAMAGES, LOSSES, COSTS OR EXPENSES
HOWEVER ARISING WHETHER IN CONTRACT OR TORT INCLUDING WITHOUT
RESTRICTION ANY ECONOMIC LOSSES OF ANY KIND, ANY LOSS OR DAMAGE TO
PROPERTY, ANY PERSONAL INJURY, ANY DAMAGE OR INJURY ARISING FROM OR
AS A RESULT OF MISUSE OR ABUSE, OR THE INCORRECT INSTALLATION,
INTEGRATION OR OPERATION OF THE PRODUCT.

Exclusions If this product is a consumer product, federal law does not allow an exclusion of

implied warranties. To the extent you are entitled to implied warranties under federal
law, to the extent permitted by applicable law they are limited to the duration of this
Limited Warranty. Some states and provinces do not allow limitations or exclusions
on implied warranties or on the duration of an implied warranty or on the limitation
or exclusion of incidental or consequential damages, so the above limitation(s) or
exclusion(s) may not apply to you. This Limited Warranty gives you specific legal
rights. You may have other rights which may vary from state to state or province to
province.

iv Operating Manual for GPIB for XT/HPD Series Power Supply

Information WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, UNLESS

SPECIFICALLY AGREED TO BY IT IN WRITING, XANTREX
a. MAKES NO WARRANTY AS TO THE ACCURACY, SUFFICIENCY OR SUITABILITY

OF ANY TECHNICAL OR OTHER INFORMATION PROVIDED IN MANUALS OR
OTHER DOCUMENTATION PROVIDED BY IT IN CONNECTION WITH THE
PRODUCT; AND

b. ASSUMES NO RESPONSIBILITY OR LIABILITY FOR LOSSES, DAMAGES,

COSTS OR EXPENSES, WHETHER SPECIAL, DIRECT, INDIRECT,
CONSEQUENTIAL OR INCIDENTAL, WHICH MIGHT ARISE OUT OF THE USE OF
SUCH INFORMATION.

THE USE OF ANY SUCH INFORMATION WILL BE ENTIRELY AT THE USER’S RISK.

WARNING:

Limitations

on Use

Please refer to your product user manual for limitations on uses of the product.
Specifically, please note that this power supply is not intended for use in connection
with life support systems and Xantrex makes no warranty or representation in
connection with any use of the product for such purposes.

Xantrex Technology, Inc.
8999 Nelson Way
Burnaby, British Columbia
Canada V5A 4B5

Information

About Your

Power

Supply

Please record the following information when you first open your Power Supply
package:

Model Number ______________________________________________

Serial Number ______________________________________________

Purchased From ______________________________________________

Purchase Date ______________________________________________

Release Release 1.1 (2002-06)

Copyright © 2002 Xantrex Technology Inc. All rights reserved.

Printed in Canada

Release 1.1 v

Power

!

!

Supply

Safety

WARNING—High Energy and High Voltage

Exercise caution when using and calibrating a power supply. High energy levels
can be stored at the output voltage terminals on a power supply in normal
operation. In addition, potentially lethal voltages exist in the power circuit and on
the output and sense connectors of a power supply with a rated output greater
than 40 V. Filter capacitors store potentially dangerous energy for some time after
power is removed.

CAUTION

Operate the power supply in an environment free of flammable gases or fumes.
To ensure that the power supply’s safety features are not compromised, use the
power supply as specified in this manual and do not substitute parts or make any
unauthorized modifications. Contact the service technician for service and repair
help. Repairs must be made by experienced service technicians only.

Warnings,

Cautions,

and Notes

Warnings, cautions, and notes are defined and formatted in this manual as shown
below.

WARNING

Describes a potential hazard which could result in injury or death, or, a procedure
which, if not performed correctly, could result in injury or death.

CAUTION

Describes a procedure which, if not performed correctly, could result in damage
to data, equipment, or systems.

Note

Describes additional operating information which may affect the performance of the
equipment.

vi Operating Manual for GPIB for XT/HPD Series Power Supply

About This Manual

This technical manual is for the internal GPIB interface, a microprocessor-controlled
option card for XT and HPD Series DC output power supplies. This manual provides
you with descriptions and specifications, user options, and configuration
instructions, in addition to a command set which enables you to manage the power
supply from an external source. Error messages and calibration procedures are also
included.

This manual is designed for the user who is familiar with basic electrical theory
especially as it applies to the operation of power supplies. This implies a recognition
of Constant Voltage and Constant Current operation modes and the control of input
and output power, as well as the observance of safe techniques while effecting supply
or pin connections and any changes in switch settings. The user should also have
experience with a computer-based communications software package.

Refer to your power supply manual for installation, configuration, and operating
procedures for your power supply.

Main Sections

Section 1 Features and Specifications Describes the power supply and lists

its features and specifications.

Section 2 Installation and Configuration Gives basic setup procedures.

Describes inspection, cleaning, shipping, and storage procedures. Includes
additional options for configuring the GPIB interface for operation.

Section 3 Operation Lists the complete command set, status registers, and error

codes.

Section 4 Calibration Provides detailed procedures for voltage and current

mode calibration as well as over voltage protection (OVP) calibration. Includes
calibration for programming and readback accuracy.

Manual Revisions

The current release of this manual is listed below. Updates may be issued as an
addendum.

Release 1.1 (2002-06)

Release 1.1 vii

About This Manual

viii Operating Manual for GPIB for XT/HPD Series Power Supply

Contents

About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Section 1.

Features and

Specifications

Section 2.

Installation

and

Configuration

Section 3. Operation

Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Features and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Programmable Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Readback Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Basic Setup Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

OVP Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

IEEE-488 Primary Address Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Remote/Local Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Remote/Local Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

LOC Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Local Mode Disable Jumper J95 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

IEEE-488 Controller Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Power On Service Request (PON SRQ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

User Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Connector J7 User Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

J7 Cable Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

GPIB Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Multiline Control Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Device Clear. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Device Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Parallel Poll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Service Request. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Serial Poll. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Command Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Manual Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Command Format and Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Command Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Command Terminators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Command Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Command Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Accumulated Status, Status, and Fault Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Release 1.1 ix

Contents

Diagnostic LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Section 4.

Calibration

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Voltage Mode Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Voltage Calibration Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Voltage Program Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Voltage Readback Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Current Mode Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Current Calibration Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Current Program Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Current Readback Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Over Voltage Protection (OVP) Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

x

Operating Manual for GPIB for XT/HPD Series Power Supply

Section 1. Features and Specifications

Description

The internal GPIB interface card allows you to operate your power supply from a
computer controller via the IEEE-488 communications bus. See Figure 1.1, “Sample
Configuration using GPIB Interface”.

The GPIB interface allows complete remote programming of your power supply,
including status reporting, settings query, and interrupt generation with
user-designated fault conditions. Both the voltage and current output are precisely
programmed directly in volts and amps with 16-bit resolution. Additionally, the
built-in DVM and current shunt measure the actual power supply output and provide
16-bit readback. The programming command set is easy-to-use and includes
software calibration commands. The interface card comes standard with several
protection features such as programmable over voltage protection, foldback, load
isolation signal, and soft limits.

Figure 1.1 Sample Configuration using GPIB Interface

Release 1.1 11

Features and Specifications

Features and Functions

Features and Functions

Features • 16-bit programming and readback of voltage and current

• Programmable soft limits for voltage and current

• Programmable over voltage protection with reset

• Easy-to-use, self-documenting command set

• Isolated user-programmable signals such as fault, polarity, isolation, and

auxiliary signals

• LED status signals: error, addressed, service request, over voltage protection,

and remote operation

• Foldback in CV or CC mode with reset

• Software calibration

Programmable

Functions

Readback

Functions

• Output voltage and current

• Soft limits for voltage and current

• Overvoltage protection

• Output enable/disable

• Maskable fault interrupt

• Hold and trigger

• User-programmable output relay signals

• Actual measured voltage and current

• Voltage and current settings

• Soft voltage and current limits

• Overvoltage protection setting

• Present and accumulated power supply status

• Programming error codes

• Fault codes

• Power supply model and version identification

• Firmware revision levels

12 Operating Manual for GPIB for XT/HPD Series Power Supply

Features and Specifications

Specifications

The specifications in this section are warranted at 25°C ±5°C unless otherwise
specified. All specifications are subject to change without notice.

Table 1.1 Specifications for XT 60 W Series Supply with GPIB Interface Installed

Models 7-6 15-4 20-3 30-2 60-1 120-0.5 250-0.25

Program Resolution

Voltage
Current
OVP

Program Accuracy
Voltage

Current

OVP

Readback Resolution

Voltage
Current

Readback Accuracy

Voltage

Current

1. Apply accuracy specifications according to the following voltage program accuracy example:
Set a model XT 15-4 power supply to 10 volts.
The expected result will be within the range of 10 volts ± 20mV ± 0.1% of the set voltage of 10 volts.

1

1

1.1mV

1.0mA

1.0mV

10mV
±0.1%
110mA
±0.15%
70mV

1.1mV

1.0mA

10mV
±0.15%
110mA
±0.15%

2.4mV

0.6mA

2.4mV

20mV
±0.1%
70mA
±0.15%
150mV

2.4mV

0.6mA

10mV
±0.1%
70mA
±0.15%

3.1mV

0.5mA

3.1mV

20mV
±0.15%
50mA
±0.15%
200mV

3.1mV

0.5mA

10mV
±0.1%
50mA
±0.15%

4.7mV

0.3mA

4.7mV

30mV
±0.15%
40mA
±0.15%
300mV

4.7mV

0.3mA

15mV
±0.1%
40mA
±0.15%

9.3mV

0.2mA

9.3mV

200mV
±0.15%
26mA
±0.2%
600mV

9.3mV

0.2mA

35mV
±0.15%
26mA
±0.2%

17mV

0.1mA
17mV

400mV
±0.15%
13mA
±0.2%

1.2V

17mV

0.1mA

70mV
±0.15%
13mA
±0.2%

34mV

0.08mA
34mV

800mV
±0.15%
7mA
±0.2%

2.4V

34mV

0.08mA

140mV
±0.15%
7mA
±0.2%

Specifications

Release 1.1 13

Features and Specifications

Specifications

Table 1.2 Specifications for HPD 300 W Series Supply with GPIB Interface Installed

Models 15-20 30-10 60-5

Program Resolution

Voltage
Current
OVP

Program Accuracy
Voltage

Current

OVP

Readback Resolution

Voltage
Current

Readback Accuracy

Voltage

Current

1. Apply accuracy specifications according to the following voltage program accuracy example:
Set a model HPD 15-20 power supply to 10 volts.
The expected result will be within the range of 10 volts ± 60mV ± 0.1% of the set voltage of
10 volts.

2.4mV

2.8mA

2.4mV

1

60mV
±0.1%
75mA
±0.12%

1.5V

2.4mV

2.8mA

1

45mV
±0.3%
75mA
±0.12%

4.7mV

1.4mA

4.7mV

70mV
±0.1%
50mA
±0.12%
3V

4.7mV

1.4mA

90mV
±0.3%
40mA
±0.12%

9.3mV

0.7mA

9.3mV

90mV
±0.12%
25mA
±0.1%
6V

9.3mV

0.7mA

175mV
±0.3%
25mA
±0.1%

14 Operating Manual for GPIB for XT/HPD Series Power Supply

Section 2. Installation and Configuration

!

Introduction

To use this product, you must have the following equipment:

• a compatible model of DC output power supply

• IEEE-488 connector and cable

• computer with an IEEE-488 interface card

• Computer-based communications software package

The GPIB interface is usually installed in a power supply at the factory. Your local
distributor or service center can also install the interface, especially for use in a
previously-purchased supply already on site. The GPIB interface card will be
calibrated and configured with default settings. You will need to configure the supply
for your system using the “Basic Setup Procedure” on page 18. Refer also to
Figure 2.1, pg. 16, Figure 2.2, pg. 16 and Figure 2.3, pg. 17 for drawings of the front
panel, the interface subplate, and the GPIB interface printed circuit board (PCB).

Initial Inspection

CAUTION

If you remove the unit's cover, use proper static control techniques to avoid damage
to static-sensitive components on the printed circuit board.

On first receiving your unit, perform a quick physical check.

• Ensure each package contains a power supply with its GPIB interface board

installed, and manuals for the power supply and the GPIB interface. Any
additional parts shipped with the power supply will be identified in the supply's
documentation.

• Inspect the unit for any signs of physical damage such as scratches, cracks, or

broken switches, connectors, or displays.

• Check the printed circuit board and components if you suspect internal damage.

If the unit is damaged, save all packing materials and notify the carrier immediately.
For additional information, please see the section titled, “Returning Power Supplies
to the Manufacturer” in the manual shipped with your complete unit.

Release 1.1 15

Installation and Configuration

Initial Inspection

Over Voltage Protection (OVP) LED

Figure 2.1 Power Supply Front Panel with GPIB Interface Installed

Remote Mode (REM) LED

Service Request (SRQ) LED

OVP Potentiometer

Error (ERR) LED

Addressed (ADR) LED

0

1

SW1 Switch:

1 Remote Mode Selection
2 Power ON Request (PON SRQ) Selection
4-8 A1-A5 Primary Address Selection

J8 IEEE Port

J7 User Signal Connector

Figure 2.2 Power Supply Rear Panel with GPIB Interface Installed

16 Operating Manual for GPIB for XT/HPD Series Power Supply

Installation and Configuration

JUMPER SELECTION

J217 Local OVP control selection [closed] [default]. See page 19.

[open] Front Panel OVP Control.

J117 User TTL shutdown (S/D) selection [1-2] User TTL S/D line active low.

See page 26.
[2-3] [default] User TTL S/D line active high.

J217 Local Mode Disable Selection [closed] [default]. See page 23.

[open] Software control of power supply only

Note: All other jumpers are not user-selectable.

Initial Inspection

LED INDICATORS

CR141 Red Diagnostic LED Bus error or soft restart on Slave circuitry.

CR14 Red Diagnostic LED Soft restart on Master circuitry.

CR13 Green Diagnostic LED Bus error on Master circuitry.

EPROMS

U958 Slave EPROM See revision number stamped on EPROM.

U18 Master EPROM See revision number stamped on EPROM.

CONNECTORS

J6 IEEE 488 Bus Connector (J8 on rear panel subplate)

J10 User Signal Connector (J7 on rear panel subplate)

Figure 2.3 GPIB Interface PCB

Release 1.1 17

Installation and Configuration

Basic Setup Procedure

Basic Setup Procedure

This procedure can be used as a quick reference for those familiar with the
configuration requirements for the GPIB interface as installed in the DC power
supply. For those who want more information, each step refers to more detailed
procedures located in subsequent sections. Execute each step of the procedure in the
sequence given. Unless indicated otherwise, all procedures apply to the XT and HPD
series power supplies.

Table 2. 1 Setup Procedure

Step # Description Action Reference

1 OVP Selection By default, you control the over voltage

protection (OVP) function via remote
operation.

2 Primary Address

Selection

3 Remote/Local

Operation

4 IEEE-488

Controller
Connection

5 Power ON Power on the unit. Before proceeding,

6 Configure

Computer
Controller

7 Test Test the link by communicating with the

* This text uses National Instruments' IBIC (Interface Bus Interactive Control) program commands

Use GPIB interface rear panel switches
SW1-4 to SW1-8 to select a unique
primary address. Setting the address
identifies the power supply to the
computer controller in a GPIB system.

Set the unit to remote mode using the
rear panel switch SW1-1 (open)

Connect the IEEE-488 bus to the supply
at connector J8.

check to ensure that the green REM
LED on the front panel is on.

Configure the controller to match the
power supply identification and
characteristics using one of the available
programs.

power supply.

developed for their GPIB interface for computer controllers as examples only.

See

“OVP Selection” on page 19

See “IEEE-488 Primary Address

Selection” on page 20

See “Remote/Local Operation” on

page 21

See “IEEE-488 Controller

Connection” on page 23

See “User Signals” on page 25 for
information about Local/Remote
OVP, TTL Shutdown, and auxiliary
connector J7 user signals.

One such program is IBCONF
(Interface Bus Configuration) from
National Instruments. This program
is used here as an example only.

Example: VSET2;ISET1
This command string sets power
supply voltage to 2V and its current
limit to 1A.
Example: ibwrt "vset2;iset1" As
above, using IBIC. *

18 Operating Manual for GPIB for XT/HPD Series Power Supply

OVP Selection

Installation and Configuration

OVP Selection

Over voltage protection (OVP) on the GPIB Interface is set at the factory for remote
software operation. When operating the power supply in remote mode, you control
the OVP trip level using the OVSET software command. If you return the power
supply to local operation, the control of the OVP trip level switches to the front panel
potentiometer.

Jumper J217 is the OVP control jumper. Opening jumper J217 disables remote OVP
control of the power supply, limiting control of the OVP trip level to the front panel
potentiometer. The local mode disable jumper, J95, also affects the location of OVP
control. Table 2.2 shows the jumper settings and OVP programming selection. See
“Remote/Local Operation” on page 21 for a detailed description of the local mode
disable jumper, J95

Table 2.2 OVP Control Mode Selection

PCB Jumper
J217 Position

Closed (default) Closed (default) Software or Front Panel OVP control

Closed Open Software OVP control only
Open Closed Front Panel OVP control only
Open Open Front Panel OVP control only

PCB Jumper J95
Position

OVP Programming Selection

(dependent on the power supply operating state)

Release 1.1 19

Installation and Configuration

IEEE-488 Primary Address Selection

IEEE-488 Primary Address Selection

1. Assign a primary address to each power supply: Choose a number between 0 and

30 which is unique to your IEEE-488 bus, that is, different from other device
addresses on the same bus.

2. Locate switch SW1 on the GPIB interface rear panel. See “Power Supply Rear

Panel with GPIB Interface Installed” on page 16 for the interface subplate
drawing.

3. Use switch positions A1 to A5 to set the primary address for the power supply.

See Table 2.3, “IEEE-488 Primary Address Selection”.

Switch 0 = (OFF, OPEN) Switch 1 = (ON, CLOSED)

Table 2.3 IEEE-488 Primary Address Selection

Address A5A4A3A2A1Address A5A4A3A2A1

0 0000016 10000

1 0000117 10001

2 0001018 10010

3 0001119 10011

4 0010020 10100

5 0010121 10101

6 0011022 10110

7 0011123 10111

8 0100024 11000

9 0100125 11001

10 0101026 11010

11 0101127 11011

12 0110028 11100

13 0110129 11101

14 0111030 11110

15 01111

Note: Ensure you assign one address to each GPIB controller board as well.

20 Operating Manual for GPIB for XT/HPD Series Power Supply

Remote/Local Operation

You can enable or disable remote or local operation of your power supply in one of
three ways:

• Rear panel Remote/Local switch SW1-1, or

• GPIB LOC command, or

• Local Mode Disable Jumper J95 selection.

Installation and Configuration

Remote/Local Operation

Remote/Local

Switch

Use the rear panel Remote/Local switch SW1-1 to toggle between remote and local
operation without losing programmed values. To locate the switch, refer to the
“Power Supply Rear Panel with GPIB Interface Installed” on page 16.

Rear Panel SW1-1 Position Operation Selected

Open Unit in remote mode

Closed Unit in local mode

Powering up in remote mode will result in the default operating conditions in
Table 2.4. See also “Command Reference” on page 40.

Release 1.1 21

Installation and Configuration

Remote/Local Operation

Table 2.4 Remote Mode Power On Conditions

Condition Default Settings 7.5-140 Model Example

Voltage 0 V VSET 0

Current 0 A ISET 0

Soft Voltage Limit VMAX (see models) VMAX 7.5

Soft Current Limit IMAX (see models) IMAX 140

OVP Trip Voltage Model VMAX + 10% OVSET 8.25

Delay 0.5 s DLY 0.5S

Foldback Protection OFF FOLD OFF

Output ON OUT ON

Hold OFF HOLD OFF

Unmask NONE UNMASK NONE

Service Request Capability OFF SRQ OFF

LOC

Command

AUXA OFF AUXA OFF

AUXB OFF AUXB OFF

The LOC command overrides the Remote/Local switch. Use LOC to enable or
disable one or all slave supplies to operate in local mode. See “Command Reference”
on page 40.

22 Operating Manual for GPIB for XT/HPD Series Power Supply

Installation and Configuration

!

Remote/Local Operation

Local Mode

Disable

Jumper J95

IEEE-488

Controller

Connection

You can disable local control of the power supply by removing jumper J95 on the
PCB. We recommend that you remove jumper J95 only if you never plan to control
the power supply from the front panel. When the Local Mode Disable Jumper J95 is
closed, you can select between operating the power supply in either local mode or
remote mode by using the rear panel remote/local switch or by using the software
commands. With jumper J95 open, you can only operate the power supply in remote
mode. Opening the J95 jumper disables the rear panel remote/local switch and the
front panel voltage and current limit potentiometers. You cannot return to local mode
using software commands without closing jumper J95.

Table 2.5 Local Mode Disable Jumper J95 Selection

Jumper J95 Position Operating State

Closed Remote or Local control of Power Supply
Open Software Control Only

Note: The location of over voltage protection control is dependent on the position of
jumper J95 and of OVP control jumper J217. Table 2.2, on page 19 shows how
jumper position affects the location of OVP control.

CAUTION

Do not operate power supplies at different chassis potentials. The interface
connection system is not capable of handling the resulting excessive ground
currents.

Use an approved IEEE-488 connector and cable when connecting the GPIB Interface
to your IEEE-488 GPIB network. Refer to Figure 2.2, “Power Supply Rear Panel
with GPIB Interface Installed” on page 16 for the location of the power supply
mating connector, J8.

Release 1.1 23

Installation and Configuration

Remote/Local Operation

Power On

Service

Request

(PON SRQ)

Setting the rear panel PON SRQ switch SW1-2 to open causes the power supply to
send a service request to the computer controller when the power supply is turned on
or when it re initializes after a momentary power interrupt. When a service request
is sent, the front panel SRQ LED will also turn on. You can clear the service request
and turn off the SRQ LED by performing a serial poll. See also “Command
Reference” on page 40 for information about the SRQ command.

Table 2.6 Enable Switch Selection

Rear Panel Switch SW1-2 PON SRQ State

Open PON SRQ Enabled
Closed PON SRQ Disabled

24 Operating Manual for GPIB for XT/HPD Series Power Supply

User Signals

Installation and Configuration

User Signals

Connector J7

User Signals

Auxiliary connector J7, located on the GPIB interface rear panel, provides several
signals to increase your operating control of the supply. These signals are dependent
on the operator's design and uses. The operation of the J7 signal requires that you
provide external Vcc and ground. To locate the connector, refer to the GPIB interface
subplate drawing in Figure 2.2, on page 21. See Figure 2.4, “User Signals J7
Connector” on page 25 for pin descriptions.

J7-1 External TTL shutdown input signal

J7-2 Polarity signal, open collector
(asserted by VSET -x)

J7-3 Isolation signal, open collector
(asserted by OUT OFF)

J7-4 Fault signal, open collector
(asserted when bit set in fault register)

J7
J7-5 External Vcc, 18V maximum
(supplied by connecting and operating an external source)

J7-6 External ground and shutdown return
(supplied by connecting and operating an external source)

J7-7 Open collector user signal
(asserted by AUXA ON)

J7-8 Open collector user signal

(asserted by AUXB ON)

Figure 2.4 User Signals J7 Connector

Release 1.1 25

Installation and Configuration

User Signals

J7 Cable

Connection

R96

R96

R96

R96

R96

VCCS

5

C

U72

4N35

E

4

VCCS

/E

/C

/A

/B

7

U75

4N35

8

9

10

5

6

1

2

3

4

6

1
A

KB
2

6

1

U74

2

3

MCT6

45

1

2

MCT6

3

45

U73

1

A

KB

CR62

2

C

5

E

4

8

7

6

8

7

6

1

6

1

5

1

4

1

R61

3

1

2

R61
10k

R61

10k

R61

10k

10k

R61
10k

R63
511

/E

/D

/C

/B

/A

SHUTDOWN

EXT_VCC

AUXB

FAULT

AUXA

POLARITY

ISOLATION

EXT_GND

J7- 1

J7- 5

J7- 8

J7- 4

J7- 11
J7- 12

J7- 7

J7- 2

J7- 3

J7- 6

Figure 2.5 J7 User Signal Connector Circuit Block Diagram

Use a standard 8-position RJ45 connector and data cable to connect to J7. Add a
ferrite block to reduce radiated emission. The one inch square ferrite block with
built-in housing clip is packaged and shipped with the power supply interface card.

To install the ferrite block:

1. Position the block no more than 5 cm (2 in.) from the power supply end of the
J7 user cable.

2. Open the ferrite block housing.

3. Loop the cable through the ferrite block. See Figure 2.6, “J7 User Cable with
Ferrite Block” on page 27.

4. Close the housing clip.

The ferrite block ensures that the power supply system meets radiated emission
requirement 89/336/EEC for CE mark approval. See the power supply's operating
manual for noise specifications.

26 Operating Manual for GPIB for XT/HPD Series Power Supply

Ferrite Block

Figure 2.6 J7 User Cable with Ferrite Block

Installation and Configuration

User Signals

J7 User Cable

To User Custom InterfaceTo J7 Connector

Release 1.1 27

Installation and Configuration

User Signals

28 Operating Manual for GPIB for XT/HPD Series Power Supply

Section 3. Operation

Introduction

This section covers GPIB interface programming, starting with IEEE-488 functions,
continuing with an extensive set of GPIB commands, error codes, and status and
fault register information.

GPIB Operation

A GPIB interface controller card enables you to control an IEEE-488 bus system via
computer, identifying which of its interconnected devices are to send and receive
data. Interconnected devices could include programmable AC or DC power supplies,
oscilloscopes, signal generators, digital voltmeters, universal counters, readouts,
relays, and printers.

Use the GPIB interface to relay GPIB instructions from a computer controller to a
power supply located at a selected IEEE-488 address and then to return responses
from the power supply to the computer. You will also use the computer controller to
issue commands such as output voltage level and status queries.

Note: This text employs National Instruments' IBIC (Interface Bus Interactive
Control) program commands developed for their GPIB interface for computer
controllers as examples only.

Release 1.1 29

Operation

GPIB Operation

Table 3. 1 IEEE-488.1 Interface Functions Implemented

Mnemonic Capability Description

SH1 Source Handshake Device must properly transfer a multiline message.

Multiline Control Functions

Interface
Functions

AH1 Acceptor Handshake Device must properly receive remote multiline

messages.

T6 Talker Device must be able to transmit.

L4 Listener Device must receive commands and data.

DC1 Device Clear Device can be initialized to a previously determined

state.

DT1 Device Trigger A device function can be initiated by a talker on the

bus.

E1 Open Collector Drivers Describes the type of electrical drivers in a device.

PP1 Parallel Poll Upon controller request, device must uniquely

identify itself if it requires service.

RL1 Remote/Local Device must be able to operate from front panel and

via remote information from bus.

SR1 Service Request Device can asynchronously request service from

controller.

SP1 Serial Poll All talkers on the bus assume a serial poll mode.

Each device when addressed will provide an 8-bit
word of status information.

Multiline

Control

Functions

The GPIB interface and the computer controller implement the Acceptor Handshake,
Source Handshake, Listener, and Talker functions. No user action is required. The
unit's ADR (Addressed) LED turns on when the power supply is addressed to listen
or talk.

Device Clear The power supply will implement Device Clear regardless of whether it is in local or

remote control. Device Clear is typically used to send all or selected devices to a
known state with a single command. The power supply will be set to Initial (Power
On) Conditions after Device Clear.

Example:

ibclr Low level command directed to entire bus, or

ibwrt"clr" Device-dependent command directed to a

specific device.

30 Operating Manual for GPIB for XT/HPD Series Power Supply

Operation

GPIB Operation

Device

Trigger

Device Trigger will implement the most recently programmed values whether the
unit is in local or remote control. If the power supply is in local mode, the new values
will be implemented when it is switched from local to remote control. Device
Trigger is typically used to synchronize the operation of a number of addressed
devices.

Example: Use HOLD Command to set values to be executed when triggered. See
“Command Reference” on page 40.

Then use:.

ibtrg Command directed to entire bus, or

ibwrt"trg" Command directed to a specific device.

Parallel Poll Parallel Poll allows the computer controller to determine quickly which of a number

of instruments on the bus requested service. The parallel poll response corresponds
to bit 7 of the serial poll status byte. Parallel Poll does not reset the service request.
The power supply must be configured remotely to respond to a parallel poll with
either a "1" or "0" on one of the DIO lines if the unit is requesting service.

Example:

ibrpp Conduct a parallel poll.

Service

Request

Service request is a uniline message asserted by the power supply at power on and
for fault conditions. Six (6) power supply conditions are defined as faults: CV, CC,
OV, SD, FOLD, and ERR. See “Accumulated Status, Status, and Fault Registers” on
page 48 for more information. Power ON (PON) can also be flagged in the fault
register if the supply's rear panel power on service request (PON SRQ) switch is set
to ON. See “Power On Service Request (PON SRQ)” on page 24.

Enabling or disabling a condition from asserting service request does not affect the
condition within the power supply, nor the external status indicators.

Release 1.1 31

Operation

GPIB Operation

Serial Poll In a serial poll, the controller polls each device.

Example:

ibrsp Return serial poll byte.

The power supply responds with a 8-bit status byte defined as follows:

Table 3.2 Serial Poll Status Register

Bit
Position

0 (LSB) 1 Fault - Set when any bit in the fault

Decimal
Weight

Description Reset By

register is set by a fault condition in the
supply. See also

Status, Status, and Fault Registers”
on page 48

1 2 Not used

2 4 Not used

3 8 Not used

416Ready - Set when power supply is

ready to accept commands.

532Error (ERR) - Set when ERR bit

asserted in status register. See also

.

“Accumulated Status, Status, and
Fault Registers” on page 48

664Request Service (SRQ) - Set when

power supply requests service.

7 (MSB) 128 Power On (PON) - Set when unit

initializes at power on.

FAULT? query to reset

“Accumulated

Power supply, during
command processing
period

ERR? query or a new
error-free command

.

Serial Poll

CLR or Device Clear

32 Operating Manual for GPIB for XT/HPD Series Power Supply

Command Syntax

Operation

Command Syntax

Manual

Conventions

The manual uses these conventions when displaying command information. These
characters are not part of the command but are used to denote parameters used with
the command.

< > (angle brackets) Angle brackets enclose a parameter. Do not include

the angle brackets in the command line you send to
the computer.

/ (slash) Separates two alternative parameters. When a slash

separates two parameters, you can use either
parameter to achieve the same result.
Example:

Entering

COMPUTER ENTRY Words typed on the computer are shown in Arial

text, full capitals.

<1/ON>

1 or ON will achieve the same result.

Release 1.1 33

Operation

Command Syntax

Command Format and Parameters

The device-dependent language for the GPIB Interface consists of commands and
parameters. A command is a one word code which either gives instructions to the
interface or asks for information from the interface. A command may be followed by
one or more parameters, a short code that changes the state of the power supply or
the state of the bit register. Table 3.3, “Command Parameters” lists the parameters
that affect the command set.

Format:

COMMAND or
COMMAND <parameter> or
COMMAND <parameter>,<parameter>

• You can enter commands in upper or lower case lettering.

Example: MASK FOLD = mask fold

• Do not further abbreviate command names or parameters.

Example: MASK FOLD ≠ MK FOLD

MASK FOLD ≠ MASK FD

• Use a space between the command and the first parameter. Any number of

consecutive spaces is treated as one space. Numeric data may contain leading
spaces. Embedded spaces between digits or between a digit and a decimal point
are not accepted.

Example: MASK FOLD = MASK FOLD

VOUT 3.4 = VOUT 3.4

VOUT 3.4 ≠ VOUT 3. 4

• Use commas between parameters in those commands with more than one

parameter, and between mnemonic parameters as in the MASK and UNMASK
commands. Only one comma is allowed and it may be preceded or followed by
any number of spaces.

Example: MASK CV, OV, FOLD

34 Operating Manual for GPIB for XT/HPD Series Power Supply

Command Syntax

Table 3.3 Command Parameters

Parameter Description Form

<current> The current in amps or milliamps. If no unit is

given, the default unit is amps.

<seconds> The time in seconds or milliseconds. If no unit

is given, the default unit is seconds.

<voltage> The voltage in volts or millivolts. If no unit is

given, the default unit is volts.

<fault mask> A combination of CV, CC, CV, OV, SD and

FOLD. See MASK and UNMASK commands
in the command reference for use of the ALL
and NONE parameters.

<status mask> A combination of CV, CC, OV, SD, FOLD,

ERR, and REM. See MASK and UNMASK
commands in the command reference for use
of the ALL and NONE parameters.

<other> Command-specific parameters such as 1, 0,

ON, OFF, ALL or NONE.

<float>
<float>A
<float>mA

<float>
<float>s
<float>ms

<float>
<float>V
<float>mV

See registers
on page 48.

See registers
on page 48.

Operation

Floating Point Number <float> Variables sent with command parameters are

floating point numbers. Table 3.4 defines the structure of floating point numbers for
use with the software commands.

Table 3.4 Floating Point Numbers

Floating Number Definition Example

The floating point number has four significant fig­ures. It can be of either sign, positive or negative.

A floating point number can have a decimal point. 0.123

Scientific Notation
Use E or e after the number for a base ten exponent.
An integer of either sign must follow an exponent.

Release 1.1 35

1.234

-1.234
+1.234

1.2

123.4

123.0E-1

1.2E-1

10.00E+1

Operation

Command Syntax

Command

Strings

Command

Terminators

If you send more than one command line, separate the commands with a semicolon.
The semicolon may be preceded or followed by spaces.

Example:

ISET 2.0A ; VSET 5V

ISET 2.0A ; VSET 5V

Terminators indicate the end of a command string and tell the power supply to
execute the command. The termination character is LF (Line Feed).

Format:

COMMAND1 <parameter1>; COMMAND2 <parameter1>, <parameter2><LF>

Most computer controllers automatically send LF with output statements.

You may also terminate commands by asserting EOI on the GPIB concurrently with
the last byte of the command.

Example:

VMAX 5.25

E
O

I

All data sent by the power supply to the computer controller is terminated by a
carriage return and a line feed character. EOI is asserted concurrently with a linefeed.

Example:

VMAX 5.250<CR><LF>

E
O

I

Order You may send commands in any order, keeping in mind that only those commands

received after a HOLD and before a TRG (trigger) will be released by the TRG
command. In addition, only these commands received after a supply disable and
before a RST (reset) or OUT ON command will be released by the RST command
or the OUT command. Commands are executed in the order they are received.

36 Operating Manual for GPIB for XT/HPD Series Power Supply

Command Summary

Use these commands to control the operation of the supply. They are listed here by
function: PROGRAMMING, QUERY, CALIBRATION, and STATUS commands.
See “Command Reference” on page 40 for more detailed information about each
command and its use.

Table 3.5 Programming Commands

Command Description

AUXA Selects the state of the AUXA output signal on the J7-7 connector.

AUXB Selects the state of the AUXB output signal on the J7-8 connector.

CLR Initializes the power supply to its Power ON (PON) state.

DLY Sets a programmable time delay which is executed by the supply

FOLD Sets foldback mode for the supply.

HOLD Enables or disables voltage/current setting hold mode for the supply.

IMAX Sets an upper soft limit on the programmed output current for the

ISET Sets the output current of the supply in amps (default) or in milliamps.

LOC Enables or disables the supply to operate in local mode.

OUT Enables or disables voltage/current output for the supply.

OVSET Sets the over voltage protection trip point for the supply in volts

RST Resets the supply to the present voltage and current settings if the

SRQ Enables or disables the power supply's ability to generate a service

TRG Implements programmed voltage and current settings which had been

VMAX Sets an upper soft limit on the supply’s programmed output voltage.

VSET Sets the output voltage of the power supply in volts (default) or in

Operation

Command Summary

before reporting fault conditions after a new output voltage or current is
specified.

supply.

(default) or in millivolts.

output is disabled by OVP or foldback protection.

request.

in hold mode.

millivolts.

Release 1.1 37

Operation

Command Summary

Table 3.6 Query Commands

Command Description

AUXA? Asks for the state of the set value for the AUXA command

AUXB? Asks for the state of the set value for the AUXB command

CMODE? Asks for the power supply’s calibration mode status.

DLY? Asks for the programmable time delay setting before the supply

reports fault conditions.

ERR? Asks for the most recent remote programming error which occurred in

the supply since the last time the error query command (ERR?) was
used.

FOLD? Asks for the supply’s present foldback setting.

HOLD? Asks for the present hold mode setting.

ID? Asks for the power supply’s model name and master EPROM version.

IMAX? Asks for the supply’s soft current limit setting.

IOUT? Measures the supply’s actual current output.

ISET? Asks for the supply’s present output current limit setting.

LOC? Queries the present enabled/disabled status of local mode operation

for the supply.

OUT? Asks for the present enabled/disabled status of the supply’s output.

OVSET? Asks for the supply’s present over voltage protection limit.

ROM? Asks for the version number of the master and slave EPROMs on the

interface PCB.

SRQ? Asks for the present enabled/disabled status of the IEEE-488 Service

Requests generated by the supply.

VMAX? Asks for the supply’s soft voltage limit setting.

VOUT? Measures the supply’s actual voltage output.

VSET? Asks for the supply’s present output voltage setting.

38 Operating Manual for GPIB for XT/HPD Series Power Supply

Command Summary

Table 3.7 Calibration Commands

Command Description

CMODE Places the supply into calibration mode.

IDATA Calculates the slope and intercept for current programming.

IHI Sets the current output to the high calibration point.

ILO Sets the current output to the low calibration point.

IRDAT Calculates the slope and intercept for current readback.

IRHI Sets the current output to the high readback point.

IRLO Sets the current output to the low readback point.

OVCAL Calibrates the over voltage protection (OVP).

VDATA Calculates the slope and intercept for voltage programming.

VHI Sets the voltage output to the high calibration point.

VLO Sets the voltage output to the low calibration point.

VRDAT Calculates the slope and intercept for voltage readback.

VRHI Sets the voltage output to the high readback point.

VRLO Sets the voltage output to the low readback point.

Operation

Table 3.8 Status Commands

Command Description

ASTS? Asks for the supply’s accumulated status register.

FAULT? Asks for the supply’s fault register for the status preset operating

conditions.

MASK Prevents the supply's previously unmasked operating conditions from

setting bits in the fault register.

STS? Asks for the supply’s present status register.

UNMASK Enables you to select those supply's operating conditions that you are

most interested in monitoring for fault occurrence.

UNMASK? Asks for the supply's fault conditions which are currently enabled

(unmasked).

Release 1.1 39

Operation

Command Reference

Command Reference

Table 3. 9 Command Reference

Command Description

ASTS? Returns the supply’s accumulated status register. The accumulated status

register stores any bit that was entered in the status register since the
accumulated status query command (ASTS?) was last used, regardless of
whether the condition still exists. Bits in the accumulated status register
represent the bits and conditions of the bits in the status register. A bit in the
accumulated status register will be set at 1 if the corresponding bit in the
status register has been 1 (TRUE) at any time since the register was last
read. See
The ASTS? query clears the accumulated status register.
Response: ASTS <status mask> where status mask is the decimal
equivalent of the total bit weights for the operating conditions as listed in the
status register.

AUXA <1/ON>,<0/OFF> Sets the AUXA output signal level at rear panel connector J7-7. Active low.

Initial value: AUXA 0

AUXA? Returns the present set value of the AUXA output signal.

Response: AUXA 0 (OFF)

AUXB <1/ON>,<0/OFF> Sets the AUXB output signal level at rear panel connector J7-8. Active low.

Initial value: AUXB 0

AUXB? Returns the present set value of the AUXB output signal.

Response: AUXB 0 (OFF)

CLR Initializes the power supply to its power ON condition. If issued while in local

mode, CLR will force power supply settings to register default values as in
but these default settings will not come into effect until the power supply is
switched to remote mode operation. The CLR commands will clear faults
from the fault register. CLR will not reset CMODE.

CMODE <1/ON>,<0/OFF> CMODE ON places the power supply into calibration mode for processing

calibration commands.
Initial value: CMODE OFF or CMODE 0

CMODE? Returns the power supply’s calibration mode status.

Response: CMODE 0 (disabled)

“Accumulated Status, Status, and Fault Registers” on page 48.

AUXA 1 (ON)

AUXB 1 (ON)

CMODE 1 (enabled)

40 Operating Manual for GPIB for XT/HPD Series Power Supply

Operation

Command Reference

Command Description

DLY <seconds> Sets a programmable time delay employed by the supply before reporting

fault conditions. The power supply uses the time delay after receiving a new
output voltage or current setting via VSET or ISET, or after receiving RST,
TRG, or OUT ON commands. During the time delay, the power supply
disables CV, CC, and FOLD conditions from generating faults, preventing
possible nuisance foldback if the supply momentarily switches modes while
changing an output setting.
Range: 0 to 32 seconds, with 32ms resolution
Initial value: 0.5 second

DLY? Returns the setting of the programmable time delay before the supply

reports fault conditions.
Response: DLY <seconds>

ERR? Returns the most recent remote programming error. When the power supply

detects a programming error, it lights the ERR LED and sets the ERR bit in
the accumulated status and fault registers. If the error bit has been masked
using the MASK command, then the ERR bit in the registers will not set.
Once an error is detected, the remaining portion of the command line is
discarded. An error query clears the ERR bit in the accumulated status
register. See
Response: ERR <error number> Example: ERR 0 (if no error)

FAULT? Returns the state of the fault register. A bit is set in the fault register when a

fault arises for that condition. Lists the conditions which activate a fault bit.
You can use the MASK command to disable bits from being set in the fault
register.
When a bit is set in the fault register it also asserts a signal on the J7-4 user
signal line. You can tie the J7-4 fault line signal to the power supply's own
External Shutdown user line, J7-1, so that the shutdown signal goes low
(active) in the case of a user-defined fault.
The FAULT? query clears bits in the supply's fault register and fault line.
Response: FAULT <fault mask> where fault mask is the decimal equivalent
of the total bit weights for the operating conditions as listed in the fault
register. See

.

48

FOLD
<2/CC>, <1/CV>,
<0/OFF>

Sets foldback mode for the supply. Foldback protection disables the power
supply output when the output enters the fold condition. Reset with the RST
command.
Example: Specify FOLD 1 or FOLD CV (Constant Voltage) when you want
the supply to operate in Constant Current mode and have foldback
protection disable the output if the supply switches to Constant Voltage
mode.
Initial value: FOLD 0/OFF

“Error Codes” on page 49.

“Accumulated Status, Status, and Fault Registers” on page

Release 1.1 41

Operation

Command Reference

Command Description

FOLD? Returns the supply’s present foldback setting.

Response: FOLD <mode> where mode is:

0 (OFF) or
1 (CV or Constant Voltage mode) or
2 (CC or Constant Current mode)

HOLD <1/ON>,<0/OFF> Enables or disables voltage/current setting hold mode for the supply. When

HOLD ON is specified, hold mode is enabled so that all voltage and current
settings which would normally be applied immediately are held until a TRG
(trigger) command is received. This feature allows you to synchronize the
operation of several supplies.
Initial value: HOLD OFF or HOLD 0

HOLD? Returns the present hold mode setting.

Response: HOLD 0 (OFF or disabled) or

HOLD 1 (ON or enabled)

ID? Returns the power supply model and the master EPROM version.

Response: ID <model name><version>

IDATA <Ilo>,<Ihi> Calculates and records the slope and offset for programmed current using

ILO and IHI data. Set CMODE ON before using this command. See also the
calibration procedures in Section 4.
<Ilo> and <Ihi> are in <current> format.

IHI In response to this command, the power supply sends a programmed

current value to the output terminal. This value is at the high end of the
power supply’s current range and is read by an external device connected
as part of the calibration procedure. Refer to this value as IHI and record it
to use as input with the IDATA command. Set CMODE ON before using this
command. See also the calibration procedures in Section 4.

ILO In response to this command, the power supply sends a programmed

current value to the output terminal. This value is at the low end of the
power supply’s current range and is read by an external device connected
as part of the calibration procedure. Refer to this value as ILO and record it
to use as input with the IDATA command. Set CMODE ON before using this
command. See also the calibration procedures in Section 4.

IMAX <current> Sets an upper soft limit on the supply’s programmed output current. If the

soft limit is exceeded, or if the soft limit value is lower than the present
output current setting, the supply will ignore the command, turn on the
ERR LED, and set the ERR bit in the bit registers.
Range: 0 to model maximum output current (IMAX)
Initial value: model IMAX

IMAX? Returns the supply’s soft current limit setting.

Response: IMAX <current>

IOUT? Measures and returns the supply’s actual current output using the built-in

current readback circuitry.
Response: IOUT <current>

42 Operating Manual for GPIB for XT/HPD Series Power Supply

Operation

Command Reference

Command Description

IRDAT <Ilo>,<Ihi> Calculates and records the slope and offset for readback voltage using

IRLO and IRHI data. Set CMODE ON before using this command. See also
the calibration procedures in Section 4.
<Ilo> and <Ihi> are in <current> format.

IRHI The power supply outputs a current value to an external device connected

as part of the calibration procedure and records a current readback value
internally. These values are at the high end of the programmed current
range. Refer to the output value as IRHI and record it to use as input with
the IRDAT command. Set CMODE ON before using this command. See
also the calibration procedures in Section 4.

IRLO The power supply outputs a current value to an external device connected

as part of the calibration procedure and records a current readback value
internally. These values are at the low end of the programmed current
range. Refer to the output value as IRLO and record it to use as input with
the IRDAT command. Set CMODE ON before using this command. See
also the calibration procedures in Section 4.

ISET <current> Sets the power supply’s output current in amps (default) or in milliamps.

This programmed current is the actual output in CC mode or the current
limit in CV mode.
Range: 0 to model maximum output current (IMAX)
Initial value: 0 amps

ISET? Returns the supply’s present output current setting. Does not apply to

current settings which are being held. See HOLD command.
Response: ISET <current>

MASK <mnemonics> Disables the supply's previously unmasked operating conditions from

setting bits in the fault and status registers. See

“Accumulated Status,

Status, and Fault Registers” on page 48. Mnemonics are separated from

each other by commas and may be sent in any order.
Mnemonics: CV, CC, OV, SD, FOLD, ERR, PON, ALL, NONE
Note: UNMASK NONE = MASK ALL (Initial value)

MASK NONE = UNMASK ALL

Release 1.1 43

Operation

Command Reference

Command Description

OUT <1/ON>,<0/OFF> Enables or disables the supply’s voltage/current output. The supply will

continue to accept new commands while the output is disabled but these
will not be implemented until OUT ON or OUT 1 is received. OUT ON is the
default setting. When you start the supply in remote mode, the output is
enabled.
OUT OFF (or OUT 0) also sets the isolation signal on the rear panel J7
connector, line 3. You can use the to trip external relays to isolate the power
supply from the load.
Initial value: OUT ON (or OUT 1) for output enabled

OUT? Returns the present enabled/disabled status of the supply’s output

voltage/current.
Response: OUT 1 output enabled or

OUT 0 output disabled

OVCAL Causes the master controller to perform automatic calibration of the

supply’s over voltage protection circuitry. Set CMODE ON before using this
command. Ensure jumper J217 on the GPIB Interface PCB is connected for
remote operation.

OVSET <voltage> Sets the supply’s over voltage protection trip point in volts (default) or in

millivolts. If the trip point is exceeded, or if the trip point value is lower than
the present output voltage setting, the supply will ignore the command, turn
on the ERR LED, and set the ERR bit in the accumulated status register.
Reset with the RST command.
Range: 0 to 110% of model maximum output voltage (VMAX)
Initial value: 110% of model VMAX

OVSET? Returns the supply’s present over voltage protection limit.

Response: OVSET <voltage>

ROM? Returns the version number of the master and slave EPROMs located on

the interface PCB.
Response: ROM M:<version> S:<version>

RST Resets the supply to present voltage and current settings if the output is

disabled by over voltage or foldback protection. Output values may be
changed via VSET, ISET, and OVSET while the unit is disabled, but those
values will not take effect until RST is applied.

44 Operating Manual for GPIB for XT/HPD Series Power Supply

Operation

Command Reference

Command Description

SRQ <1/ON>,<0/OFF> SRQ ON enables the supply to respond to a variety of fault conditions with a

request for service to the IEEE-488 bus controller. With SRQ ON, the SRQ
line will be asserted true whenever the FAULT bit in the supply's serial poll
register changes from 0 to 1. Therefore, the mask register, in addition to
specifying which conditions set the FAULT bit, also determines which
conditions can generate service requests. Ten power supply conditions are
defined as faults: CB, CC, OV, OTP, SD, ERR, FOLD, ACF, OPF, SNSP.
Use the FAULT? query to discover which condition caused the service
request. See

. A request for service at Power ON (PON SRQ) is set via a rear panel

48

switch on the supply. See

page 24

is cleared by a FAULT? query.

SRQ? Returns the supply's present ability to generate service requests.

Response: SRQ 0 (disabled)

STS? Returns the supply’s present status register. Status conditions are stored in

the status register. Each bit represents a separate condition. When the
condition is true, the corresponding bit is 1 (true). Bits remain set in the
status register as long as the condition is true. See

“Accumulated Status, Status, and Fault Registers” on page

“Power On Service Request (PON SRQ)” on

. SRQ remains disabled until the FAULT bit in the serial poll register

SRQ 1 (enabled)

“Accumulated Status,

Status, and Fault Registers” on page 48.

Response: STS <status mask> where status mask is the decimal equivalent
of the total bit weights for the operating conditions as listed in the status
register.

TRG Causes programmed voltage and current settings which had been in hold

mode to be applied. The supply operates with previous values until the TRG
(trigger) command is sent.

UNMASK <mnemonics> Selects the supply operating conditions that you are most interested in

monitoring for fault occurrence. Mnemonics describing the conditions are
separated from each other by commas, and may be sent in any order.
Specifying one or more mnemonics which describe the conditions (or the
decimal equivalent of their total bit weight) enables the selected conditions
to set bits in the supply’s fault and status registers during operation. A bit is
set in the fault register when the corresponding bit in the status register
changes from 0 to 1 and the corresponding bit in the mask register is 1. See

“Accumulated Status, Status, and Fault Registers” on page 48.

Mnemonics: CV, CC, OV, SD, FOLD, ERR, PON, ALL, NONE
Initial value: UNMASK NONE

UNMASK? Returns the supply's fault conditions which are currently enabled

(unmasked).
Response: UNMASK <fault mask> where fault mask is the decimal
equivalent of the total bit weights for the operating conditions as listed in the
status and fault registers See

Registers” on page 48

“Accumulated Status, Status, and Fault

.

Release 1.1 45

Operation

Command Reference

Command Description

VDATA <Vlo>,<Vhi> Calculates and records the slope and offset for programmed voltage using

VLO and VHI data. Set CMODE ON before using this command. See also
the calibration procedures in Section 4.
<Vlo> and <Vhi> are in <voltage> format.

VHI In response to this command, the power supply sends a programmed

voltage value to the output terminal. This value is at the high end of the
power supply’s voltage range and is read by an external device connected
as part of the calibration procedure. Refer to this value as VHI and record it
to use as input with the VDATA command. Set CMODE ON before using
this command. See also the calibration procedures in Section 4.

VLO In response to this command, the power supply sends a programmed

voltage value to the output terminal. This value is at the low end of the
power supply’s voltage range and is read by an external voltmeter
connected as part of the calibration procedure. Refer to this value as VLO
and record it to use as input with the VDATA command. Set CMODE ON
before using this command. See also the calibration procedures in
Section 4.

VMAX <voltage> Sets an upper soft limit on the supply’s programmed output voltage. If the

soft limit is exceeded, or if the soft limit value is lower than the present
output voltage setting, the supply will ignore the command, turn on the
ERR LED, and set the ERR bit in the accumulated status register.
Range: 0 to model maximum output voltage (VMAX)
Initial value: model VMAX

VMAX? Returns the supply’s soft voltage limit setting.

Response: VMAX <voltage>

VOUT? Measures and returns the supply’s actual voltage output using the built-in

voltage readback circuitry.
Response: VOUT <voltage>

VRDAT <Vlo>,<Vhi> Calculates and records the slope and offset for readback voltage using

VRLO and VRHI data. Set CMODE ON before using this command. See
also the calibration procedures in Section 4 .
<Vlo> and <Vhi> are in <voltage> format.

VRHI The power supply outputs a voltage value to an external voltmeter

connected as part of the calibration procedure and records a voltage
readback value internally. These values are at the high end of the
programmed voltage range. Refer to the output value as VRHI and record it
to use as input with the VRDAT command. Set CMODE ON before using
this command. See also the calibration procedures in Section 4.

46 Operating Manual for GPIB for XT/HPD Series Power Supply

Operation

Command Reference

Command Description

VRLO The power supply outputs a voltage value to an external voltmeter

connected as part of the calibration procedure and records a voltage
readback value internally. These values are at the low end of the
programmed voltage range. Refer to the output value as VRLO and record it
to use as input with the VRDAT command. Set CMODE ON before using
this command. See also the calibration procedures in Section 4.

VSET <voltage>
or
VSET <-voltage>

Sets the power supply’s output voltage in volts (default) or in millivolts. This
programmed voltage is the actual output in CV (constant voltage) mode or
the voltage limit in CC (constant current) mode.
If you enter a negative voltage value, the power supply will assert a signal
on the J7-4 user signal line. You can use the user signal to trip external
relays to switch the output polarity.
Range: 0 to model maximum output voltage (VMAX)
Initial value: 0 volts

VSET? Returns the power supply’s present output voltage setting. Does not apply

to voltage settings which are being held. See HOLD command.
Response: VSET <voltage>

Release 1.1 47

Operation

Accumulated Status, Status, and Fault Registers

Accumulated Status, Status, and Fault Registers

The GPIB option card uses three separate registers which are always active. They
are the accumulated status, status, and fault registers. You can use the status
commands shown in Table 3.8, “Status Commands” to activate the registers. The
bit register has eight conditions, each assigned a bit weight. When querying a
register, the controller returns a response which is the sum of the weights of all
relevant conditions.

Example:

ASTS? Query the Accumulated Status register.

ASTS 771 Controller response.

771 = 512 + 256 + 2 + 1 = PON + REM + CC + CV

The accumulated status register shows that PON, REM, CC and CV have all been
active since the last accumulated register query.

Table 3.10 shows the mnemonics and bit weights which correspond to each register
condition. You can control conditions in the fault and status register by using the
MASK and UNMASK commands.

Table 3.10 Accumulated Status, Status, and Fault Registers

Condition Mnemonic Bit Position Bit Weight

Constant voltage operation CV 0 1

Constant current operation CC 1 2

Not used – 2 4

Overvoltage protection tripped OV 3 8

Not used – 4 16

Supply external shutdown active (J7-1) SD 5 32

Foldback mode operation FOLD 6 64

Remote programming error ERR 7 128

Power ON (accumulated status, status
registers only)

Remote mode (accumulated status, status
registers only)

PON 8 256

REM 9 512

Notes:

1. Only CV, CC, OV, SD, ERR, PON and FOLD can be masked or unmasked.

2. The error (ERR) bit is reset in the accumulated status, status, and serial poll registers with an
error query (ERR?).

3. The accumulated status register is cleared with an accumulated status query (ASTS?).

4. A fault is cleared with a fault query (FAULT?).

48 Operating Manual for GPIB for XT/HPD Series Power Supply

Error Codes

Operation

Error Codes

If the ERR flag in the accumulated status or fault registers has been activated, an
ERR? query will return an error number which corresponds to an event described
in the following table. The ERR? query will also clear the ERR bit in the register.

Table 3.11 Error Codes

ERROR # ERROR IDENTIFICATION EXPLANATION

0No Errors

4 Unrecognized Character Received a character such as @,*,$.

Improper Number Received a numeric character but the

characters were not a proper number.
Example: VSET,±10.3

Unrecognized String Received an invalid command.

Syntax Error Received an incorrectly placed word,

number, separator, or terminator.
Example: OFF SRQ, VOUT 6, MASK,
ERR

5 Number Out of Range Specified a value for the command

which was outside of the allowed range.

6 Attempt to Exceed Soft Limits Attempted to program a voltage or

current greater than the soft limit.
Example: VMAX 500; VSET 550 LF

7 Improper Soft Limit Attempted to program a soft limit less

than the output value.

8 Data Requested without a

Query Being Sent

9 OVP Set Below Output Sent an OVSET command with a trip

10 Slave Processor Not

Responding

12 Illegal Calibration Attempted calibration when the supply

The controller requested data from the
power supply without first sending a
query command.

value lower than the output voltage.

The interface PCB slave processor did
not respond.

was not in calibration mode. See
CMODE command.

Release 1.1 49

Operation

Troubleshooting

Troubleshooting

WARNING

Exercise caution when using and servicing power supplies. High energy levels
can be stored at the output voltage terminals on all power supplies in normal
operation. In addition, potentially lethal voltages exist in the power circuit and the
output connector of power supplies which are rated at 40V and over. Filter
capacitors store potentially dangerous energy for some time after power is
removed.

Diagnostic

LEDs

This section describes the diagnostic LEDs found on the GPIB interface.

Computer Operating Properly (COP) LEDs The GPIB interface provides

three diagnostic LEDs, located at CR13, CR14, and CR141 on its PCB. Refer to
Figure 2.3, ‘GPIB Interface PCB” on page 17, for their locations. At present, these
LEDs turn on to signal COP events for the interface's microprocessors. Issue a RST
(reset) command to turn off the diagnostic LEDs.

The green COP LED at circuit designation CR13 indicates that the GPIB interface
microprocessor successfully recovered from an illegal operating code. The event is
transparent to the GPIB communications bus and the GPIB interface continues to
function normally.

The red COP LED at CR14 indicates that a transparent restart caused by noise in
the master processor circuitry has occurred.

The red COP LED at CR141 indicates that a transparent restart caused by noise in
the slave processor circuitry has occurred.

50 Operating Manual for GPIB for XT/HPD Series Power Supply

Section 4. Calibration

Introduction

WARNING

Exercise caution when using and servicing power supplies. High energy levels can
be stored at the output voltage terminals on all power supplies in normal operation. In
addition, potentially lethal voltages exist in the power circuit and the output connector
of power supplies which are rated at 40V and over. Filter capacitors store potentially
dangerous energy for some time after power is removed.

You can calibrate the GPIB interface by adjusting the signal levels on the interface
card so that they correspond to the expected signal levels on the power supply's main
assembly. You may need to recalibrate the interface if you replace parts either on the
interface board or on the main power supply board, or if the unit falls out of
specification due to component aging drifts.

You can calibrate the GPIB Interface for:

• Voltage program

• Voltage readback

• Current program

• Current readback

• Overvoltage protection

The following equipment will be required to accurately calibrate your unit:

• Digital Voltmeter, 5 1/2 digit, 0.1% accuracy or better, with test leads

• Current sensing shunt resistor, rated for 150% of maximum output current,

0.25% accuracy or better

• Connection wires rated for the unit's maximum output current and voltage

• A GPIB equipped computer to send the calibration commands to the unit

Calibrate the unit according to the following procedures, referring to “Command
Reference” for more information about the calibration commands used.

The calibration procedures in this section are designed to be performed at an ambient
temperature of 25°C ± 5°C.

Release 1.1 51

Calibration

Voltage Mode Calibration

Voltage Mode Calibration

Voltage

Calibration

Setup

Voltage

Program

Calibration

Procedure

1. Disconnect the load from the power supply which is to be calibrated.

2. Connect a voltmeter across the load terminals of the power supply being tested.

Figure 4.1 Voltage Calibration Setup

1. Set the power supply for calibration as in Figure 4.1.

2. Activate calibration mode by sending command CMODE ON or CMODE 1 to the power supply.

3. Send command VLO; ILO to the power supply. Measure and record the output
shown on the external voltmeter.

4. Send command VHI; IHI to the supply. Measure and record the output voltage
as shown on the external voltmeter.

5. Send the command VDATA <vlo>,<vhi> where <vlo> and <vhi> are the values
read from the voltmeter when the VLO and VHI commands were sent. When the
power supply is calibrated, the low to high voltage program calibration values
are stored as constants.

6. Program the supply at various levels using the VSET command to confirm that
the calibration was successful and that linearity is observed. See the voltage
program accuracy specification in Section 1.

7. Turn off calibration mode by sending the command CMODE OFF or CMODE 0
to the power supply.

52 Operating Manual for GPIB for XT/HPD Series Power Supply

Calibration

Voltage Mode Calibration

Voltage

Readback

Calibration

Procedure

1. Set the power supply for calibration as in Figure 4.1.

2. Activate calibration mode by sending command CMODE ON or CMODE 1 to

the power supply.

3. Send command VRLO; IRLO to the power supply. Wait for the supply to settle.

Measure and record the output shown on the external voltmeter. Send VRLO
again.

4. Send VRHI; IRHI to the supply. Wait for the supply to settle. Measure and

record the output voltage shown on the external voltmeter. Send VRHI again.

5. Send the command VRDAT <vlo>,<vhi> where <vlo> and <vhi> are the values

read from the voltmeter after the VRLO and VRHI commands were sent. The
processor calculates the offset value required to calibrate the power supply.
When the power supply is calibrated, the low to high voltage readback
calibration values (offsets) are stored as constants.

6. Use commands VSET and VOUT? commands to confirm that the calibration

was successful and that linearity is observed. Refer to the voltage readback
accuracy specification in Section 1.

7. Turn off calibration mode by sending the command CMODE OFF or CMODE 0

to the power supply.

Release 1.1 53

Calibration

Current Mode Calibration

Current Mode Calibration

Current

Calibration

Setup

Current

Program

Calibration

Procedure

1. Disconnect the load from the power supply to be calibrated.

2. Connect a shunt across the supply's output terminals.

3. Connect a voltmeter across the shunt.

Figure 4.2 Current Calibration Setup

1. Connect the shunt and voltmeter to the power supply as shown in Figure 4.2.

2. Activate calibration mode by sending command CMODE ON or CMODE 1 to
the power supply.

3. Send command ILO; VLO to the power supply. Measure and record the output
shown on the external voltmeter.

4. Send command IHI; VHI to the supply Measure and record the output voltage
shown on the external voltmeter.

5. Calculate ILO and IHI from the voltages read from the external voltmeter and
the shunt resistance. I=V/R.

6. Send the command IDATA <ilo>,<ihi> to the power supply. <ilo> and <ihi> are
the current values obtained from sending the ILO and IHI commands to the
power supply. When the power supply is calibrated, the low to high current
program calibration values are stored as constants.

7. Program the supply at various levels using the ISET command to confirm that
the calibration was successful and that linearity is observed. Refer to the current
program accuracy specification in Section 1.

8. Turn off calibration mode by sending the command CMODE OFF or CMODE 0
to the power supply.

54 Operating Manual for GPIB for XT/HPD Series Power Supply

Calibration

Current Mode Calibration

Current

Readback

Calibration

Procedure

1. Connect the current shunt and voltmeter to the power supply as shown in

Figure 4.2.

2. Activate calibration mode by sending command CMODE ON or CMODE 1 to

the power supply.

3. Send command IRLO; VRLO to the power supply. Wait for the supply to settle.

Measure and record the output voltage shown on the external voltmeter. Send
IRLO again.

4. Send command IRHI; VRHI to the supply. Wait for the supply to settle. Measure

and record the output voltage shown on the external voltmeter. Send IRHI again.

5. Calculate IRLO and IRHI from the voltages taken from the external voltmeter

and the shunt resistance. I=V/R.

6. Send the command IRDAT <ilo>,<ihi> to the power supply. <ilo> and <ihi> are

the current values obtained from sending the IRLO and IRHI commands to the
power supply. When the power supply is calibrated, the low to high current
readback calibration values are stored as constants.

7. Program the supply at various levels using the ISET command to confirm that

the calibration was successful and that linearity is observed. Refer to the current
readback accuracy specification in Section 1.

8. Turn off calibration mode by sending the command CMODE OFF or CMODE 0

to the power supply.

Release 1.1 55

Calibration

Over Voltage Protection (OVP) Calibration

Over Voltage Protection (OVP) Calibration

We recommend that you perform OVP calibration every six months. Connecting a
digital voltmeter as in “Voltage Calibration Setup” is optional.

1. Disconnect all loads from the power supply.

2. Ensure that jumper J217 on the interface PCB is CLOSED to enable remote
OVP calibration (Jumper J217 is closed at the factory).

3. Activate calibration mode by sending command CMODE ON or CMODE 1 to
the power supply.

4. Send the command OVCAL to the power supply. The ADR LED will light
during OVP calibration. Calibration is complete when the ADR LED turns off.
This may take a few minutes.

5. Use the OVSET, OVSET?, and VSET commands to trip the OVP level,
confirming that the calibration was successful. When you trip the OVP level, the
red OVP LED will light and the voltage will drop to zero. Send the command
RST to clear the OVP condition. Refer to the OVP program accuracy
specification in Section 1.

6. Turn off calibration mode by sending the command CMODE OFF or CMODE 0
to the power supply.

56 Operating Manual for GPIB for XT/HPD Series Power Supply

Xantrex Technology Inc.

8999 Nelson Way
Burnaby, British Columbia
Canada V5A 4B5

604 422 8595 Tel
604 421 3056 Fax
800 667 8422 Toll Free North America

[e-mail]
www.xantrex.com

TM-GP6H-01XN

PRINTED IN CANADA