Agilent Technologies 664XA Series Operating instructions

PROGRAMMING GUIDE
GPIB DC POWER SUPPLIES
Agilent Technologies Models
664xA, 665xA, 667xA, 668xA, and 669xA
AgilentPart No. 5964-8269 Printed in Malaysia
Microfiche Part No. 5964-8270 July, 2001

2
Safety Guidelines
The beginning of the power supply Operating Manual has a Safety Summary page. Be sure you are familiar with the
information on that page before programming the power supply for operation from a controller.
ENERGY HAZARD. Power supplies with high output currents (such as the Series 668xA/669xA)
can provide more than 240 VA at more than 2 V. If the output connections touch, severe arcing may
occur resulting in burns, ignition or welding of parts. Take proper precautions before remotely
programming the output circuits.
Printing History
The edition and current revision of this guide are indicated below. Reprints of this guide containing minor corrections and
updates may have the same printing date. Revised editions are identified by a new printing date. A revised edition
incorporates all new or corrected material since the previous printing. Changes to the guide occurring between revisions are
covered by change sheets shipped with the guide.
Edition 1......... July, 2001
© Copyright 2001 Agilent Technologies Inc.
This document contains proprietary information protected by copyright. All rights are reserved. No part of this document
may be photocopied, reproduced, or translated into another language without the prior consent of Agilent Technologies.
The information contained in this document is subject to change without notice.

3
Contents
Safety Guidelines 2
Printing History 2
Contents 3
GENERAL INFORMATION 7
About this Guide 7
Documentation Summary 7
User’s Guide 7
External Documents 7
Prerequisites for Using this Guide 8
VXIplug&play Power Product Instrument Drivers 8
Downloading and Installing the Driver 8
Accessing Online Help 8
REMOTE PROGRAMMING 9
GPIB Capabilities Of The Power Supply 9
Introduction To SCPI 9
Conventions 9
SCPI Messages 10
Types of SCPI Commands 10
Structure of a SCPI Message 10
Parts of a SCPI Message 11
Traversing the Command Tree 12
Including Common Commands 14
SCPI Queries 14
Value Coupling 14
SCPI Data Formats 14
Examples 15
Controlling Output 16
Saving and Recalling States 17
Writing to the Display 17
Programming Status 17
Programming the Digital I/O Port 18
System Considerations 18
The GPIB Address 18
DOS Drivers 20
Agilent BASIC Controllers 20
Sample Program Code 20
LANGUAGE DICTIONARY 25
Introduction 25
Parameters 25
Related Commands 25
Order of Presentation 25
Common Commands 25
Subsystem Commands 25
Description Of Common Commands 26
*CLS 27
*ESE 27
*ESR? 28
*IDN? 28

4
*OPC 28
*OPC? 29
*OPT? 29
*PSC 29
*RCL 30
*RST 31
*SAV 31
*SRE 32
*STB? 32
*TRG 33
*TST? 33
*WAI 33
Description of Subsystem Commands 34
ABOR 34
Calibration Commands 34
Current Subsystem 35
CURR 35
CURR:TRIG 35
CURR:PROT:STAT 35
DIG:DATA 36
Display Subsystem 36
DISP 36
DISP:MODE 37
DISP:TEXT 37
Initiate Subsystem 38
INIT 38
INIT:CONT 38
Measure Subsystem 38
MEAS:CURR? 38
MEAS:VOLT? 38
Output Subsystem 39
OUTP 39
OUTP:PROT:CLE 39
OUTP:PROT:DEL 39
OUTP:REL 40
OUTP:REL:POL 40
Status Subsystem 41
STAT:PRES 41
Status Operation Registers 41
STAT:OPER? 41
STAT:OPER:COND? 41
STAT:OPER:ENAB 42
STAT:OPER NTR 42
STAT:OPER PTR 42
Status Questionable Registers 43
STAT:OUES? 43
STAT:QUES:COND? 43
STAT:QUES:ENAB 43
STAT:QUES NTR 44
STAT:QUES PTR 44
System Commands 44
SYST:ERR? 44
SYST:LANG 45
SYST:VERS? 45
Trigger Subsystem 45

5
TRIG 45
TRIG:SOUR 46
Voltage Subsystem 46
VOLT 46
VOLT:TRIG 46
VOLT:PROT 47
Command Summary 47
Programming Parameters 49
STATUS REPORTING 51
Power Supply Status Structure 51
Operation Status Group 51
Register Functions 51
Register Commands 51
Questionable Status Group 53
Register Functions 53
Register Commands 53
Standard Event Status Group 53
Register Functions 53
Register Commands 53
Status Byte Register 54
The RQS Bit 54
The MSS Bit 54
Determining the Cause of a Service Interrupt 54
Service Request Enable Register 54
Output Queue 54
Initial Conditions At Power On 54
Status Registers 54
The PON (Power-On) Bit 55
Examples 55
Servicing an Operation Status Mode Event 55
Adding More Operation Events 56
Servicing Questionable Status Events 56
Monitoring Both Phases of a Status Transition 56
SCPI Command Completion 57
DFI (Discrete Fault Indicator) 57
RI (Remote Inhibit) 57
ERROR MESSAGES 59
Power Supply Hardware Error Messages 59
Calibration Error Messages 59
System Error Messages 59
SCPI CONFORMANCE INFORMATION 61
SCPI Version 61
SCPI Confirmed Commands 61
SCPI Approved Commands 61
NON-SCPI Commands 62
COMPATIBILITY LANGUAGE 63
INDEX 67

Introduction 7
1
General Information
About this Guide
This guide provides remote programming information for the following series of GPIB programmable power supplies:
•AGILENT Series 664xA, 665xA, 667xA, 668xA, and 669xA
You will find the following information in the rest of this guide:
Chapter 2 Introduction to SCPI messages structure, syntax, and data formats. Examples of SCPI programs.
Chapter 3 Dictionary of SCPI commands. Table of programming parameters.
Chapter 4 Description of the status registers.
Chapter 5 Error messages.
Appendix A SCPI conformance information.
Appendix B Use of the alternate Compatibility programming language.
Documentation Summary
User’s Guide
The Operating Guide, shipped with the power supply, has information helpful to programming the power supply and
explains the SCPI commands used for remote calibration. Sample calibration and verification programs are included.
External Documents
SCPI References
The following documents will assist you with programming in SCPI:
•Standard Commands for Programmable Instruments Volume 1, Syntax and Style
•Standard Commands for Programmable Instruments Volume 2, Command References
•Standard Commands for Programmable Instruments Volume 3, Data Interchange Format
•Standard Commands for Programmable Instruments Volume 4, Instrument Classes
To obtain a copy of the above documents, contact: Fred Bode, Executive Director, SCPI Consortium, 8380 Hercules Drive,
Suite P3, Ls Mesa, CA 91942, USA
GPIB References
The most important GPIB documents are your controller programming manuals - Agilent BASIC, GPIB Command Library
for MS DOS, etc. Refer to these for all non-SCPI commands (for example: Local Lockout).
The following are two formal documents concerning the GPIB interface:
aANSI/IEEE Std. 488.1-1987 IEEE Standard Digital Interface for Programmable Instrumentation. Defines the
technical details of the GPIB interface. While much of the information is beyond the need of most programmers, it can serve
to clarify terms used in this guide and in related documents.
aANSI/IEEE Std. 488.2-1987 IEEE Standard Codes, Formats, Protocols, and Common Commands. Recommended
as a reference only if you intend to do fairly sophisticated programming. Helpful for finding precise definitions of certain
types of SCPI message formats, data types, or common commands.
The previous two documents are available from the IEEE (Institute of Electrical and Electronics Engineers), 345 East 47th
Street, New York, NY 10017, USA. The WEB address is www.ieee.org.

8 Introduction
Prerequisites for Using this Guide
This organization of this guide assumes that you know or can learn the following information:
1. How to program in your controller language (Agilent BASIC, QUICKBASIC, C, etc.).
2. The basics of the GPIB (IEEE 488).
3. How to program I/O statements for an IEEE 488 bus instrument. From a programming aspect, the power supply is
simply a bus instrument.
4. How to format ASCII statements within you I/O programming statements. SCPI commands are nothing more than
ASCII data strings incorporated within those I/O statements.
5. The basic operating principles of the power supply as explained in “Chapter 5 – Front Panel Operation” of the
Operating Guide.
6. How to set the GPIB address of the power supply. This cannot be done remotely, but only from the supply’s front
panel (see System Considerations in “Chapter 2 – Remote Programming”).
VXIplug&play Power Product Instrument Drivers
VXIplug&play instrument drivers for Microsoft Windows 95 and Windows NT are now available on the Web at
http://www.agilent.com/find/drivers. These instrument drivers provide a high-level programming interface to your Agilent
Technologies instrument. VXIplug&play instrument drivers are an alternative to programming your instrument with SCPI
command strings. Because the instrument driver's function calls work together on top of the VISA I/O library, a single
instrument driver can be used with multiple application environments.
Supported Applications System Requirements
aAgilent VEE
aMicrosoft Visual BASIC
aMicrosoft Visual C/C++
aBorland C/C++
aNational Instruments LabVIEW
aNational Instruments LabWindows/CVI
The VXIplug&play Power Products instrument driver
complies with the following:
aMicrosoft Windows 95
aMicrosoft Windows NT
aHP VISA revision F.01.02
aNational Instruments VISA 1.1
Downloading and Installing the Driver
NOTE: Before installing the VXIplug&play instrument driver, make sure that you have one of the supported applications
installed and running on your computer.
1. Access Agilent Technologies' Web site at http://www.agilent.com/find/drivers.
2. Select the instrument for which you need the driver.
3. Click on the driver, either Windows 95 or Windows NT, and download the executable file to your pc.
4. Locate the file that you downloaded from the Web. From the Start menu select Run <path>:\agxxxx.exe - where
<path> is the directory path where the file is located, and agxxxx is the instrument driver that you downloaded .
5. Follow the directions on the screen to install the software. The default installation selections will work in most
cases. The readme.txt file contains product updates or corrections that are not documented in the on-line help. If
you decide to install this file, use any text editor to open and read it.
6. To use the VXIplug&play instrument driver, follow the directions in the VXIplug&play online help under
“Introduction to Programming”.
Accessing Online Help
A comprehensive online programming reference is provided with the driver. It describes how to get started using the
instrument driver with Agilent VEE, LabVIEW, and LabWindows. It includes complete descriptions of all function calls
as well as example programs in C/C++ and Visual BASIC.
aTo access the online help when you have chosen the default Vxipnp start folder, click on the Start button and select
Programs | Vxipnp | Agxxxx Help (32-bit).
- where agxxxx is the instrument driver.

Remote Programming 9
2
Remote Programming
GPIB Capabilities Of The Power Supply
All power supply functions except for setting the GPIB address are programmable over the IEEE 488 bus (also known as
the General Purpose Interface Bus or "GPIB"). The IEEE 488.1 capabilities of the power supply are listed in the
Supplemental Characteristics of the Operating Guide. The power supply operates from a GPIB address that is set from the
front panel (see System Considerations at the end of this chapter).
Introduction To SCPI
lmportant Learn the basics of power supply operation (see "Chapter 5 - Front Panel Operation" in the power supply
Operating Guide) before using SCPI.
SCPI (Standard Commands for Programmable Instruments) is a programming language for controlling instrument functions
over the GPIB (IEEE 488) instrument bus. SCPI is intended to function with standard GPIB hardware and conforms to the
IEEE Standard Digital Interface for Programmable Instrumentation. SCPI is layered on top of the hardware portion of
IEEE 488.2. The same SCPI commands and parameters control the same functions in different classes of instruments. For
example, you would use the same DISPlay command to control the power supply display state and the display state of a
SCPI-compatible multimeter.
Note HPSL and TMSL (Test and Measurement System Language) were earlier versions of SCPI. If you have
programmed in either, then you probably can go directly to "Chapter 3 - Language Dictionary".
Conventions
The following conventions are used throughout this chapter:
Angle brackets < > Items within angle brackets are parameter abbreviations. For example,
<NR1> indicates a specific form of numerical data.
Vertical bar | Vertical bars separate one of two or more alternative parameters. For
example, 0|OFF indicates that you may enter either "0" or "OFF" for the
required parameter.
Square
Brackets
[ ] Items within square brackets are optional. The representation
[SOURce]:CURRent means that SOURce may be omitted.
Braces { } Braces indicate parameters that may be repeated zero or more times. It is
used especially for showing arrays. The notation<A>{<,B>} shows that
"A" is a required parameter, while "B" may be omitted or may be entered
one or more times.
Boldface font Boldface font is used to emphasize syntax in command definitions.
TRIGger:DELay <NRf> shows a command syntax.
Computer font Computer font is used to show program text within normal text.
TRIGger:DELay .5 represents program text.

10 Remote Programming
SCPI Messages
There are two types of SCPI messages, program and response.
•A program message consists of one or more properly formatted SCPI commands sent from the controller to
the power supply. The message, which may be sent at any time, requests the power supply to perform some action.
•A response message consists of data in a specific SCPI format sent from the power supply to the controller.
The power supply sends the message only when commanded by a special program message called a "query."
Types of SCPI Commands
SCPI has two types of commands, common and subsystem.
Common Commands
Common commands (see Figure 3-1) generally are not related to specific operation but to controlling overall power supply
functions, such as reset, status, and synchronization. All common commands consist of a three-letter nmemonic preceded
by an asterisk:
*RST *IDN? *SRE 8
Subsystem Commands
Subsystem commands (see Figure 3-2) perform specific power supply functions. They are organized into an inverted tree
structure with the "root" at the top. Some are single commands while others are grouped under other subsystems.
Structure of a SCPI Message
SCPI messages consist of one or more message units ending in a message terminator. The terminator is not part of the
syntax, but implicit in the way your programming language indicates the end of a line (such as a newline or end-of-line
character).
The Message Unit
The simplest SCPI command is a single message unit consisting of a command header (or keyword) followed by a message
terminator.
ABOR
VOLT?
The message unit may include a parameter after the header. The parameter usually is numeric, but it can be a string:
VOLT 20
VOLT MAX
Combining Message Units
The following command message (see Figure 2-1) is briefly described here, with more details in subsequent paragraphs.
VOLT:LEV 4.5;PROT 4.8;:CURR?<NL>