Agilent N3300A Programming Guide

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Programming Guide

Agilent Technologies

DC Electronic Loads

Models N3300A, N3301A, N3302A, N3303A

N3304A, N3305A, N3306A, and N3307A

Part No. 5964-8198 Printed in Malaysia Microfiche No 5964-8199 March, 2002

Safety Summary

The beginning of the electronic load User’s Guide has a Safety Summary page. Be sure you are familiar with the information on this page before programming the electronic load from a controller.

Printing History

The edition and current revision of this manual are indicated below. Reprints of this manual 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 date. Changes to the manual occurring between revisions are covered by change sheets shipped with the manual.

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.

Safety Summary 2 Printing History 2 Table of Contents 3

1 - GENERAL INFORMATION 9

About this Guide 9

Documentation Summary 9

External References 9

SCPI References 9 GPIB References 10

VXIplug&play Power Products Instrument Drivers 10

Supported Applications 10 System Requirements 10 Downloading and Installing the Driver 10 Accessing Online Help 11

2 - INTRODUCTION TO PROGRAMMING 13

GPIB Capabilities of the Electronic Load 13

GPIB Address 13

RS-232 Capabilities of the Electronic Load 14

RS-232 Data Format 14 RS-232 Flow Control 14

Introduction to SCPI 15

Conventions Used in This Guide 15

Types of SCPI Commands 15

Multiple Commands in a Message 16 Moving Among Subsystems 16 Including Common Commands 16 Using Queries 17

Types of SCPI Messages 17

The Message Unit 17 Headers 17 Query Indicator 18 Message Unit Separator 18 Root Specifier 18 Message Terminator 18

SCPI Data Formats 18

Numerical Data Formats 18 Suffixes and Multipliers 19 Response Data Types 19

SCPI Command Completion 19 Using Device Clear 20 RS-232 Troubleshooting 20 SCPI Conformance Information 21

SCPI Conformed Commands 21 Non-SCPI Commands 21

3 - PROGRAMMING EXAMPLES 23

Introduction 23 Programming the Input 23

Power-on Initialization 23 Enabling the Input 23 Input Voltage 23 Input Current 24 Setting the Triggered Voltage or Current Levels 24

Programming Transients 25

Continuous Transients 25 Pulse Transients 25 Toggled Transients 26

Programming Lists 26

Programming Lists for Multiple Channels 28

Triggering Transients and Lists 29

SCPI Triggering Nomenclature 29 List Trigger Model 29 Initiating List Triggers 30 Specifying a Trigger Delay 30 Generating Transient and List Triggers 30

Making Measurements 31

Voltage and Current Measurements 31

Triggering Measurements 33

SCPI Triggering Nomenclature 33 Measurement Trigger Model 33 Initiating the Measurement Trigger System 34 Generating Measurement Triggers 34

Controlling Measurement Samples 35

Varying the Sampling Rate 35 Measurement Delay 35 Multiple Measurements 35

Synchronizing Transients and Measurements 36

Measuring Triggered Transients or Lists 36 Measuring Dwell-Paced Lists 37

Programming the Status Registers 38

Power-On Conditions 41 Channel Status Group 41 Channel Summary Group 41 Questionable Status Group 41 Standard Event Status Group 41 Operation Status Group 42 Status Byte Register 42 Determining the Cause of a Service Interrupt 43 Servicing Standard Event Status and Questionable Status Events 43

Programming Examples 44

CC Mode Example 44 CV Mode Example 44 CR Mode Example 45 Continuous Transient Operation Example 45 Pulsed Transient Operation Example 46 Synchronous Toggled Transient Operation Example 46 Battery Testing Example 47 Power Supply Testing Example 49 C++ Programming Example 50

4 - LANGUAGE DICTIONARY 53

Introduction 53

Subsystem Commands 53 Common Commands 54 Programming Parameters 54

Calibration Commands 55

CALibrate:DATA 55 CALibrate:IMON:LEVel 55 CALibrate:IPR:LEVel 55 CALibrate:LEVel 55 CALibrate:PASSword 56 CALibrate:SAVE 56 CALibrate:STATe 56

Channel Commands 57

CHANnel INSTrument 57

Input Commands 58

[SOURce:]INPut OUTPut 58 [SOURce:]INPut:PROTection:CLEar OUTput:PROTection:CLEar 58 [SOURce:]INPut:SHORt OUTPut:SHORt 58 [SOURce:]CURRent 59 [SOURce:]CURRent:MODE 59 [SOURce:]CURRent:PROTection 59 [SOURce:]CURRent:PROTection:DELay 60 [SOURce:]CURRent:PROTection:STATe 60 [SOURce:]CURRent:RANGe 60 [SOURce:]CURRent:SLEW 61 [SOURce:]CURRent:SLEW:NEGative 61 [SOURce:]CURRent:SLEW:POSitive 61 [SOURce:]CURRent:TLEVel 62 [SOURce:]CURRent:TRIGgered 62 [SOURce:]FUNCtion [SOURce:]MODE 62 [SOURce:]FUNCtion:MODE 63 [SOURce:]RESistance 63 [SOURce:]RESistance:MODE 63 [SOURce:]RESistance:RANGe 64 [SOURce:]RESistance:SLEW 64 [SOURce:]RESistance:SLEW:NEGative 64 [SOURce:]RESistance:SLEW:POSitive 65 [SOURce:]RESistance:TLEVel 65 [SOURce:]RESistance:TRIGgered 65 [SOURce:]VOLTage 66 [SOURce:]VOLTage:MODE 66 [SOURce:]VOLTage:RANGe 66 [SOURce:]VOLTage:SLEW 67 [SOURce:]VOLTage:SLEW:NEGative 67 [SOURce:]VOLTage:SLEW:POSitive 68 [SOURce:]VOLTage:TLEVel 68 [SOURce:]VOLTage:TRIGgered 68

Measurement Commands 69

ABORt 69 MEASure:ARRay:CURRent? FETCh:ARRay:CURRent? 69 MEASure:ARRay:POWer? FETCh:ARRay:POWer? 69 MEASure:ARRay:VOLTage? FETCh:ARRay:VOLTage? 70

MEASure:CURRent? FETCh:CURRent? 70 MEASure:CURRent:ACDC? FETCh:CURRent:ACDC? 70 MEASure:CURRent:MAXimum? FETCh:CURRent:MAXimum? 70 MEASure:CURRent:MINimum? FETCh:CURRent:MINimum? 71 MEASure:POWer? FETCh:POWer? 71 MEASure:POWer:MAXimum? FETCh:POWer:MAXimum? 71 MEASure:POWer:MINimum? FETCh:POWer:MINimum? 71 MEASure:VOLTage? FETCh:VOLTage? 72 MEASure:VOLTage:ACDC? FETCh:VOLTage:ACDC? 72 MEASure:VOLTage:MAXimum? FETCh:VOLTage:MAXimum? 72 MEASure:VOLTage:MINimum? FETCh:VOLTage:MINimum? 72 SENSe:CURRent:RANGe 73 SENSe:SWEep:POINts 73 SENSe:SWEep:OFFSet 73 SENSe:SWEep:TINTerval 74 SENSe:WINDow 74 SENSe:VOLTage:RANGe 74

Port Commands 75

PORT0 75 PORT1 75

List Commands 76

[SOURce:]LIST:COUNt 76 [SOURce:]LIST:CURRent [SOURce:]LIST:CURRent:POINts? 76 [SOURce:]LIST:CURRent:RANGe [SOURce:]LIST:CURRent:RANGe:POINts? 77 [SOURce:]LIST:CURRent:SLEW [SOURce:]LIST:CURRent:SLEW:POINts? 77 [SOURce:]LIST:CURRent:SLEW:NEGative 78 [SOURce:]LIST:CURRent:SLEW:POSitive 78 [SOURce:]LIST:CURRent:TLEVel [SOURce:]LIST:CURRent:TLEVel:POINts? 78 [SOURce:]LIST:FUNCtion [SOURce:]LIST:MODE [SOURce:]LIST:FUNCtion:POINTs? 79 [SOURce:]LIST:DWELl [SOURce:]LIST:DWELl:POINts? 79 [SOURce:]LIST:RESistance [SOURce:]LIST:RESistance:POINts? 80 [SOURce:]LIST:RESistance:RANGe [SOURce:]LIST:RESistance:RANGe:POINts? 80 [SOURce:]LIST:RESistance:SLEW [SOURce:]LIST:RESistance:SLEW:POINts? 81 [SOURce:]LIST:RESistance:SLEW:NEGative 81 [SOURce:]LIST:RESistance:SLEW:POSitive 81 [SOURce:]LIST:RESistance:TLEVel [SOURce:]LIST:RESistance:TLEVel:POINTs? 82 [SOURce:]LIST:STEP 82 [SOURce:]LIST:TRANsient [SOURce:]LIST:TRANsient:POINts? 82 [SOURce:]LIST:TRANsient:DCYCle [SOURce:]LIST:TRANsient:DCYCle:POINts? 83 [SOURce:]LIST:TRANsient:FREQuency [SOURce:]LIST:TRANsient:FREQuency:POINts? 83 [SOURce:]LIST:TRANsient:MODE [SOURce:]LIST:TRANsient:MODE:POINts? 83 [SOURce:]LIST:TRANsient:TWIDth [SOURce:]LIST:TRANsient:TWIDth:POINts? 84 [SOURce:]LIST:VOLTage [SOURce:]LIST:VOLTage:POINts? 84 [SOURce:]LIST:VOLTage:RANGe [SOURce:]LIST:VOLTage:RANGe:POINTs? 84 [SOURce:]LIST:VOLTage:SLEW [SOURce:]LIST:VOLTage:SLEW:POINts? 85 [SOURce:]LIST:VOLTage:SLEW:NEGative 85 [SOURce:]LIST:VOLTage:SLEW:POSitive 86 [SOURce:]LIST:VOLTage:TLEVel [SOURce:]LIST:VOLTage:TLEVel:POINts? 86

Transient Commands 87

[SOURce:]TRANsient 87 [SOURce:]TRANsient:DCYCle 87 [SOURce:]TRANsient:FREQuency 87 [SOURce:]TRANsient:MODE 88 [SOURce:]TRANsient:LMODE 88 [SOURce:]TRANsient:TWIDth 88

Status Commands 89

Bit Configuration of Channel Status Registers 89 STATus:CHANnel? 89 STATus:CHANnel:CONDition? 89 STATus:CHANnel:ENABle 89 STATus:CSUM? 90 STATus:CSUMmary:ENABle 90 Bit Configuration of Operation Status Registers 90 STATus:OPERation? 90 STATus:OPERation:CONDition? 90 STATus:OPERation:ENABle 91 STATus:OPERation:NTRansition STATus:OPERation:PTRansition 91 Bit Configuration of Questionable Status Registers 92 STATus:QUEStionable? 92 STATus:QUEStionable:CONDition? 92 STATus:QUEStionable:ENABle 92

System Commands 93

SYSTem:ERRor? 93 SYSTem:LOCal 93 SYSTem:REMote 93 SYSTem:RWLock 93 SYSTem:VERSion? 93

Trigger Commands 94

ABORt 94 INITiate:SEQuence INITiate:NAME 94 INITiate:SEQuence2 INITiate:NAME 94 INITiate:CONTinuous:SEQuence INITiate:CONTinuous:NAME 95 TRIGger 95 TRIGger:DELay 95 TRIGger:SEQuence2:COUNt 96 TRIGger:SOURce 96 TRIGger:TIMer 96

Common Commands 97

*CLS 97 *ESE 97 Bit Configuration of Standard Event Status Enable Register 98 *ESR? 98 *IDN? 98 *OPC 98 *OPT? 99 *PSC 99 *RCL 99 *RDT? 100 *RST 100 *SAV 101 *SRE 101 *STB? 101 Bit Configuration of Status Byte Register 102 *TRG 102 *TST? 102 *WAI 102

A - SCPI COMMAND TREE 103

Command Syntax 103

B - ERROR MESSAGES 107

Error Number List 107

C - COMPARING N3300A ELECTRONIC LOADS WITH EARLIER MODELS 111

Introduction 111

INDEX 115

General Information

About this Guide

This manual contains programming information for the Agilent Technologies N3301A, N3302A, N3303A, N3304A, N3305A, N3306A, and N3307A Electronic Load modules when installed in an Agilent Technologies N3300A and N3301A Electronic Load mainframes. These units will be referred to as "electronic load" throughout this manual. You will find the following information in the rest of this guide:

Chapter 1 Introduction to this guide. Chapter 2 Introduction to SCPI messages structure, syntax, and data formats. Chapter 3 Introduction to programming the electronic load with SCPI commands. Chapter 4 Dictionary of SCPI commands. Appendix A SCPI command tree. Appendix B Error messages Appendix C Comparison With Earlier Models

Documentation Summary

The following documents that are related to this Programming Guide have additional helpful information for using the electronic load.

 Quick Start Guide - located in the front part of the User's Guide. Information on how to quickly get

started using the electronic load.

 User's Guide. Includes specifications and supplemental characteristics, how to use the front

panel, how to connect to the instrument, and calibration procedures.

External References

SCPI References

The following documents will assist you with programming in SCPI:

 Beginner's Guide to SCPI. Part No. H2325-90001. Highly recommended for anyone who has not

had previous experience programming with SCPI.

 Tutorial Description of the GPIB . Part No. 5952-0156. Highly recommended for those not familiar

with the IEEE 488.1 and 488.2 standards.

To obtain a copy of the above documents, contact your local Agilent Technologies Sales and Support Office.

1 - General Information

GPIB References

The most important GPIB documents are your controller programming manuals - GW 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:

 ANSI/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.

 ANSI/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 above two documents are available from the IEEE (Institute of Electrical and Electronics Engineers), 345 East 47th Street, New York, NY 10017, USA.

VXIplug&play Power Products 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 electronic load. 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

y Agilent VEE y Microsoft Visual BASIC y Microsoft Visual C/C++ y Borland C/C++ y National Instruments LabVIEW y National Instruments LabWindows/CVI

System Requirements

The VXIplug&play instrument driver complies with the following:

y Microsoft Windows 95 y Microsoft Windows NT 4.0 y HP VISA revision F.01.02 y National 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.

General Information - 1

1. Access Agilent Technologies W eb 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 for your specific driver 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.

y To 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.

Introduction to Programming

GPIB Capabilities of the Electronic Load

All electronic load functions except for setting the GPIB address are programmable over the GPIB. The IEEE 488.2 capabilities of the electronic load are described in Table 2-1. Refer to Appendix A of your User's Guide for its exact capabilities.

Table 2-1. IEEE 488 Capabilities of Electronic Loads

GPIB Capabilities Response Interface

Function

Talker/Listener

Service Request The electronic load sets the SRQ line true if there is an enabled

Remote/Local

Device Trigger

Group Execute Trigger

Device Clear

All electronic load functions except for setting the GPIB address are programmable over the GPIB. The electronic load can send and receive messages over the GPIB. Status information is sent using a serial poll. Front panel annunciators indicate the present GPIB state of the electronic load.

service request condition. Refer to Chapter 3 - Status Reporting for more information. In local mode, the electronic load is controlled from the front panel but will also execute commands sent over the GPIB. The electronic load powers up in local mode and remains in local mode until it receives a command over the GPIB. Once the electronic load is in remote mode the front panel RMT annunciator is on, all front panel keys (except

metering mode. Pressing electronic load to local mode. lockout so that only the controller or the power switch can return the

electronic load to local mode. The electronic load will respond to the device trigger function. DT1

The electronic load will respond to the group execute trigger function. GET

The electronic load responds to the Device Clear (DCL) and Selected Device Clear (SDC) interface commands. They cause the electronic load to clear any activity that would prevent it from receiving and executing a new command (including *WAI and *OPC?). DCL and SDC do not change any programmed settings.

) are disabled, and the display is in normal

on the front panel returns the

can be disabled using local

AH1, SH1, T6. L4

SR1

RL1

DCL, SDC

GPIB Address

The electronic load operates from a GPIB address that is set from the front panel. To set the GPIB address, press the Address key on the front panel and enter the address using the Entry keys. The address can be set from 0 to 30. The GPIB address is stored in non-volatile memory.

2 - Introduction to Programming

RS-232 Capabilities of the Electronic Load

The electronic load provides an RS-232 programming interface, which is activated by commands located under the front panel Address key. All SCPI commands are available through RS-232 programming. When the RS-232 interface is selected, the GPIB interface is disabled.

The EIA RS-232 Standard defines the interconnections between Data Terminal Equipment (DTE) and Data Communications Equipment (DCE). The electronic load is designed to be a DTE. It can be connected to another DTE such as a PC COM port through a null modem cable.

NOTE: The RS-232 settings in your program must match the settings specified in the front panel

Address menu. Press the front panel Address key if you need to change the settings.

RS-232 Data Format

The RS-232 data is a 10-bit word with one start bit and one stop bit. The number of start and stop bits is not programmable. However, the following parity options are selectable using the front panel Address key:

EVEN ODD MARK SPACE NONE

Parity options are stored in non-volatile memory.

Baud Rate

The front panel Address key lets you select one of the following baud rates, which is stored in non-volatile memory: 300 600 1200 2400 4800 9600

Seven data bits with even parity Seven data bits with odd parity Seven data bits with mark parity (parity is always true) Seven data bits with space parity (parity is always false) Eight data bits without parity

RS-232 Flow Control

The RS-232 interface supports the following flow control options that are selected using the front panel Address key. For each case, the electronic load will send a maximum of five characters after holdoff is asserted by the controller. The electronic load is capable of receiving as many as fifteen additional characters after it asserts holdoff.

RTS-CTS

NONE

Flow control options are stored in non-volatile memory.

The electronic load asserts its Request to Send (RTS) line to signal hold-off when its input buffer is almost full, and it interprets its Clear to Send (CTS) line as a hold-off signal from the controller. There is no flow control.

Introduction to Programming - 2

Introduction to SCPI

SCPI (Standard Commands for Programmable Instruments) is a programming language for controlling instrument functions over the GPIB and RS-232 interface. 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.

Conventions Used in This Guide

Angle brackets < > Items within angle brackets are parameter abbreviations. For example,

<NR1> indicates a specific form of numerical data.

Vertical bar | Vertical bars separate alternative parameters. For example, NORM | TEXT

indicates that either "TEXT" or "NORM" can be used as a parameter.

Square Brackets [ ] Items within square brackets are optional. The representation [SOURce:].

VOLTage 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 parameter "A" must be entered, while parameter "B" may be omitted or may be entered one or more times.

Computer font Computer font is used to show program lines in text.

OUTPUT 723 "TRIGger:COUNt:CURRent 10" shows a program line.

Types of SCPI Commands

SCPI has two types of commands, common and subsystem.

♦ Common commands generally are not related to specific operation but to controlling overall

electronic load functions, such as reset, status, and synchronization. All common commands consist of a three-letter mnemonic preceded by an asterisk: *RST *IDN? *SRE 8

♦ Subsystem commands perform specific electronic load functions. They are organized into an

inverted tree structure with the "root" at the top. The following figure shows a portion of a subsystem command tree, from which you access the commands located along the various paths. You can see the complete tree in Appendix A.

ROOT

:CURRent [:LEVel]

:MODE

:PROTection

:STATus

:OPERation [:EVENt]?

[:IMMediate]

[:LEVel]

:DELay

Figure 2-1. Partial Command Tree

:CONDition?

2 - Introduction to Programming

Multiple Commands in a Message

Multiple SCPI commands can be combined and sent as a single message with one message terminator. There are two important considerations when sending several commands within a single message:

♦ Use a semicolon to separate commands within a message.

♦ There is an implied header path that affects how commands are interpreted by the electronic load.

The header path can be thought of as a string that gets inserted before each command within a message. For the first command in a message, the header path is a null string. For each subsequent command the header path is defined as the characters that make up the headers of the previous command in the message up to and including the last colon separator. An example of a message with two commands is:

CURR:LEV 3;PROT:STAT OFF

which shows the use of the semicolon separating the two commands, and also illustrates the header path concept. Note that with the second command, the leading header "CURR" was omitted because after the "CURR:LEV 3" command, the header path became defined as "CURR" and thus the instrument interpreted the second command as:

CURR:PROT:STAT OFF

In fact, it would have been syntactically incorrect to include the "CURR" explicitly in the second command, since the result after combining it with the header path would be:

CURR:CURR:PROT:STAT OFF

which is incorrect.

Moving Among Subsystems

In order to combine commands from different subsystems, you need to be able to reset the header path to a null string within a message. You do this by beginning the command with a colon (:), which discards any previous header path. For example, you could clear the output protection and check the status of the Operation Condition register in one message by using a root specifier as follows:

OUTPut:PROTection:CLEAr;:STATus:OPERation:CONDition?

The following message shows how to combine commands from different subsystems as well as within the same subsystem:

VOLTage:LEVel 20;PROTection 28; :CURRent:LEVel 3;PROTection:STATe ON

Note the use of the optional header LEVel to maintain the correct path within the voltage and current subsystems, and the use of the root specifier to move between subsystems.

Including Common Commands

You can combine common commands with subsystem commands in the same message. Treat the common command as a message unit by separating it with a semicolon (the message unit separator). Common commands do not affect the header path; you may insert them anywhere in the message.

VOLTage:TRIGgered 17.5;:INITialize;*TRG

OUTPut OFF;*RCL 2;OUTPut ON

Introduction to Programming - 2

Using Queries

Observe the following precautions with queries:

♦ Set up the proper number of variables for the returned data. For example, if you are reading back

a measurement array, you must dimension the array according to the number of measurements that you have placed in the measurement buffer.

♦ Read back all the results of a query before sending another command to the electronic load.

Otherwise a Query Interrupted error will occur and the unreturned data will be lost.

Types of 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 electronic load. The message, which may be sent at any time, requests the electronic load to perform some action.

♦ A response message consists of data in a specific SCPI format sent from the electronic load to

the controller. The electronic load sends the message only when commanded by a program message called a "query."

The following figure illustrates SCPI message structure:

Data

Headers

Header Separator

Message Unit Separators

Figure 2-2. Command Message Structure

Message Unit

;

Query Indicator

; : CURR?

Message Terminator

Root Specifier

<NL>VOLT:LEV 20 TLEV 30

The Message Unit

The simplest SCPI command is a single message unit consisting of a command header (or keyword) followed by a message terminator. The message unit may include a parameter after the header. The parameter can be numeric or a string.

ABORt<NL> VOLTage 20<NL>

Headers

Headers, also referred to as keywords, are instructions recognized by the electronic load. Headers may be either in the long form or the short form. In the long form, the header is completely spelled out, such as VOLTAGE, STATUS, and DELAY. In the short form, the header has only the first three or four letters, such as VOLT, STAT, and DEL.

2 - Introduction to Programming

Query Indicator

Following a header with a question mark turns it into a query (VOLTage?, VOLTage:PROTection?). If a query contains a parameter, place the query indicator at the end of the last header (VOLTage:PROTection? MAX).

Message Unit Separator

When two or more message units are combined into a compound message, separate the units with a semicolon (STATus:OPERation?;QUEStionable?).

Root Specifier

When it precedes the first header of a message unit, the colon becomes the root specifier. It tells the command parser that this is the root or the top node of the command tree.

Message Terminator

A terminator informs SCPI that it has reached the end of a message. Three permitted messages terminators are:

♦ newline (<NL>), which is ASCII decimal 10 or hex 0A. ♦ end or identify (<END>) ♦ both of the above (<NL><END>).

In the examples of this guide, there is an assumed message terminator at the end of each message.

NOTE: All RS-232 response data sent by the electronic load is terminated by the ASCII character

pair <carriage return><newline>. This differs from GPIB response data which is terminated by the single character <newline> with EOI asserted.

SCPI Data Formats

All data programmed to or returned from the electronic load is ASCII. The data may be numerical or character string.

Numerical Data Formats

Symbol Data Form

Talking Formats <NR1> Digits with an implied decimal point assumed at the right of the least-significant digit.

Examples: 273 <NR2> <NR3>

Listening Formats <Nrf> <Nrf+>

<Bool>

Digits with an explicit decimal point. Example: .0273

Digits with an explicit decimal point and an exponent. Example: 2.73E+2

Extended format that includes <NR1>, <NR2> and <NR3>. Examples: 273 273. 2.73E2

Expanded decimal format that includes <NRf> and MIN MAX. Examples: 273 273.

2.73E2 MAX. MIN and MAX are the minimum and maximum limit values that are

implicit in the range specification for the parameter.

Boolean Data. Example: 0 | 1 or ON | OFF

Introduction to Programming - 2

Suffixes and Multipliers

Class Suffix Unit Unit with Multiplier

Amplitude V volt MV (millivolt)

Current A ampere MA (milliampere)

Power W watt MW (milliwatt)

Resistance OHM ohm MOHM (megohm)

Slew Rate A/s

R/s V/s

Time s second MS (millisecond)

1E3 K kilo 1E-3 M milli 1E-6 U micro

amps/second ohms/second

volts/second

Common Multipliers

Response Data Types

Character strings returned by query statements may take either of the following forms, depending on the length of the returned string:

<CRD>

<AARD>

<SRD>

Character Response Data. Permits the return of character strings.

Arbitrary ASCII Response Data. Permits the return of undelimited 7-bit ASCII. This data type has an implied message terminator.

String Response Data. Returns string parameters enclosed in double quotes.

SCPI Command Completion

SCPI commands sent to the electronic load are processed either sequentially or in parallel. Sequential commands finish execution before a subsequent command begins. Parallel commands allow other commands to begin executing while the parallel command is still executing. Commands that affect trigger actions are among the parallel commands.

The *WAI, *OPC, and *OPC? common commands provide different ways of indicating when all transmitted commands, including any parallel ones, have completed their operations. The syntax and parameters for these commands are described in chapter 4. Some practical considerations for using these commands are as follows:

*WAI

*OPC?

*OPC

This prevents the electronic load from processing subsequent commands until all pending operations are completed.

This places a 1 in the Output Queue when all pending operations have completed. Because it requires your program to read the returned value before executing the next program statement, *OPC? can be used to cause the controller to wait for commands to complete before proceeding with its program.

This sets the OPC status bit when all pending operations have completed. Since your program can read this status bit on an interrupt basis, *OPC allows subsequent commands to be executed.

NOTE: The trigger system must be in the Idle state in order for the status OPC bit to be true.

Therefore, as far as triggers are concerned, OPC is false whenever the trigger system is in the Initiated state.

2 - Introduction to Programming

Using Device Clear

You can send a device clear at any time to abort a SCPI command that may be hanging up the GPIB interface. The status registers, the error queue, and all configuration states are left unchanged when a device clear message is received. Device clear performs the following actions:

♦ The input and output buffers of the electronic load are cleared.

♦ The electronic load is prepared to accept a new command string.

The following statement shows how to send a device clear over the GPIB interface using GW BASIC:

CLEAR 705 IEEE-488 Device Clear

The following statement shows how to send a device clear over the GPIB interface using the GPIB command library for C or QuickBASIC:

IOCLEAR (705)

NOTE: For RS-232 operation, sending a Break will perform the same operation as the IEEE-488

device clear message.

RS-232 Troubleshooting

If you are having trouble communicating over the RS-232 interface, check the following:

♦ The computer and the electronic load must be configured for the same baud rate, parity, number

of data bits, and flow control options. Note that the electronic load is configured for 1 start bit and 1 stop bit (these values are fixed).

♦ The correct interface cables or adapters must be used, as described under RS-232 Connector.

Note that even if the cable has the proper connectors for your system, the internal wiring may be incorrect.

♦ The interface cable must be connected to the correct serial port on your computer (COM1, COM2,

etc.).

Introduction to Programming - 2

SCPI Conformance Information

SCPI Conformed Commands

The Electronic Load conforms to SCPI Version 1995.0.

ABOR MEAS | FETC[:SCAL]:VOLT:MAX [SOUR]:RES[:LEV][:IMM][:AMP]

CAL:DATA MEAS | FETC[:SCAL]:VOLT:MIN [SOUR]:RES[:LEV]:TRIG[:AMP]

CAL:STAT SENS:CURR[:DC]:RANG[:UPP] [SOUR]:RES:MODE

INIT[:IMM]:SEQ SENS:SWE:OFFS [SOUR]:RES:RANG

INIT[:IMM]:NAME SENS:SWE:POIN [SOUR]:RES:SLEW

INIT:CONT:SEQ SENS:SWE:TINT [SOUR]:VOLT[:LEV][:IMM][:AMP]

INIT:CONT:NAME SENS:WIND[:TYPE] [SOUR]:VOLT[:LEV]:TRIG[:AMP]

INP | OUTP[:STAT] SENS:VOLT[:DC]:RANG[:UPP] [SOUR]:VOLT:MODE

INP | OUTP:PROT:CLE [SOUR]:CURR[:LEV][:IMM][:AMP] [SOUR]:VOLT:RANG

MEAS | FETC:ARR:CURR[:DC] [SOUR]:CURR[:LEV]:TRIG[:AMP] [SOUR]:VOLT:SLEW

MEAS | FETC:ARR:POW[:DC] [SOUR]:CURR:MODE STAT:OPER[:EVEN]

MEAS | FETC:ARR:VOLT[:DC] [SOUR]:CURR:PROT[:LEV] STAT:OPER:COND

MEAS | FETC[:SCAL]:CURR[:DC] [SOUR]:CURR:PROT:STAT STAT:OPER:ENAB

MEAS | FETC[:SCAL]:CURR:MAX [SOUR]:CURR:RANG STAT:OPER:NTR

MEAS | FETC[:SCAL]:CURR:MIN [SOUR]:CURR:SLEW STAT:OPER:PTR

MEAS | FETC[:SCAL]:POW[:DC] [SOUR]:LIST:COUN STAT:QUES[:EVEN]

MEAS | FETC[:SCAL]:POW:MAX [SOUR]:LIST:CURR STAT:QUES:COND

MEAS | FETC[:SCAL]:POW:MIN [SOUR]:LIST:DWEL STAT:QUES:ENAB

MEAS | FETC[:SCAL]:VOLT[:DC] [SOUR]:LIST:RES SYST:ERR

[SOUR]:LIST:VOLT SYST:VER

Non-SCPI Commands

CAL:IMON:LEV [SOUR]:LIST:CURR:TLEV [SOUR]:TRAN[:STAT]

CAL:IPR:LEV [SOUR]:LIST:FUNC | MODE [SOUR]:TRAN:DCYC

CAL:LEV [SOUR]:LIST:RES:RANG [SOUR]:TRAN:FREQ

CAL:PASS [SOUR]:LIST:RES:SLEW[:BOTH] [SOUR]:TRAN:MODE

CAL:SAVE [SOUR]:LIST:RES:SLEW:NEG [SOUR]:TRAN:LMOD

CHAN | INST[:LOAD] [SOUR]:LIST:RES:SLEW:POS [SOUR]:TRAN:TWID

INP | OUTP:SHOR[:STAT] [SOUR]:LIST:RES:TLEV [SOUR]:VOLT:SLEW:NEG

MEAS | FETC[:SCAL]:CURR:ACDC [SOUR]:LIST:STEP [SOUR]:VOLT:SLEW:POS

MEAS | FETC[:SCAL]:VOLT:ACDC [SOUR]:LIST:TRAN[:STAT] [SOUR]:VOLT:TLEV

PORT0[:STAT] [SOUR]:LIST:TRAN:DCYC STAT:CHAN[:EVEN]

PORT1[:LEV] [SOUR]:LIST:TRAN:FREQ STAT:CHAN:COND

[SOUR]:CURR:PROT:DEL [SOUR]:LIST:TRAN:MODE STAT:CHAN:ENAB

[SOUR]:CURR:SLEW:NEG [SOUR]:LIST:TRAN:TWID STAT:CSUM[:EVEN]

[SOUR]:CURR:SLEW:POS [SOUR]:LIST:VOLT:RANG STAT:CSUM:ENAB

[SOUR]:CURR:TLEV [SOUR]:LIST:VOLT:SLEW[:BOTH] SYST:LOC

[SOUR]:FUNC | MODE [SOUR]:LIST:VOLT:SLEW:NEG SYST:REM

[SOUR]:FUNC | MODE:MODE [SOUR]:LIST:VOLT:SLEW:POS SYST:RWL

[SOUR]:LIST:CURR:RANG [SOUR]:LIST:VOLT:TLEV TRIG[:IMM]

[SOUR]:LIST:CURR:SLEW[:BOTH] [SOUR]:RES:SLEW:NEG TRIG:DEL

[SOUR]:LIST:CURR:SLEW:NEG [SOUR]:RES:SLEW:POS TRIG:SOUR

[SOUR]:LIST:CURR:SLEW:POS [SOUR]:RES:TLEV TRIG:TIM

TRIG:SEQ2:COUN

Programming Examples

Introduction

This chapter contains examples on how to program your electronic load. Simple examples show you how to program:

 Input functions such as voltage, current, and resistance

 Transient functions, including lists

 Measurement functions

 The status and protection functions

NOTE: These examples in this chapter show which commands are used to perform a particular

function, but do not show the commands being used in any particular programming environment.

Programming the Input

Power-on Initialization

When the electronic load is first turned on, it wakes up with the input state set OFF. The following commands are given implicitly at power-on:

*RST *CLS *SRE 0 *ESE 0

*RST is a convenient way to program all parameters to a known state. Refer to the *RST command in chapter 4 to see how each programmable parameter is set by *RST. Refer to the *PSC command in chapter 4 for more information on the power-on initialization of the *ESE and the *SRE registers.

Enabling the Input

To enable the input, use the command:

INPut ON

Input Voltage

The input voltage is controlled with the VOLTage command. For example, to set the input voltage to 25 volts, use:

VOLTage 25

3 - Programming Examples

Maximum Voltage

The maximum input voltage that can be programmed can be queried with:

VOLTage? MAXimum

Input Current

All models have a programmable current function. The command to program the current is:

CURRent <n>

where <n> is the input current in amperes.

Maximum Current

The maximum input current that can be programmed can be queried with:

CURRent? MAXimum

Overcurrent Protection

The electronic load can also be programmed to turn off its input if the current protection level is reached. As explained in chapter 4, this protection feature is implemented the following command:

CURRent:PROTection:STATe ON | OFF

NOTE: Use CURRent:PROTection:DELay to prevent momentary current limit conditions caused

by programmed input changes from tripping the overcurrent protection.

Setting the Triggered Voltage or Current Levels

To program voltage or current triggered levels, you must specify the voltage or current level that the input will go to once a trigger signal is received. Use the following commands to set a triggered level:

VOLTage:TRIGgered <n> or

CURRent:TRIGgered <n>

NOTE: Until they are explicitly programmed, triggered levels will assume their corresponding

immediate levels. For example, if a electronic load is powered up and VOLTage:LEVel is programmed to 6, then VOLTage:LEVel:TRIGger will also be 6 until you program it to another value. Once you program VOLTage:LEVel:TRIGger to a value, it will remain at that regardless of how you subsequently reprogram VOLTage:LEVel. Then, when the trigger occurs, the VOLTage:LEVel is set to the VOLTage:LEVel:TRIGger value.

Generating Triggers

You can generate a single trigger by sending the following command over the GPIB:

TRIGger:IMMediate

Note that this command will always generate a trigger. Use the TRIGger:SOURce command to select other trigger sources such as the mainframe's external trigger input.

Programming Examples - 3

Programming Transients

Transient operation is used to synchronize input changes with internal or external trigger signals, and simulate loading conditions with precise control of timing, duration, and slew. The following transient modes can be generated:

Continuous

Pulse

Toggled

NOTE: Before turning on transient operation, set the desired mode of operation as well as all of

Generates a repetitive pulse stream that toggles between two load levels.

Generates an load change that returns to its original state after some time period.

Generates a repetitive pulse stream that toggles between two load levels. Similar to Continuous mode except that the transient points are controlled by explicit triggers instead of an internal transient generator.

the parameters associated with transient operation. At *RST all transient functions are set to OFF.

Continuous Transients

In continuous operation, a repetitive pulse train switches between two load levels, a main level (which can be either the immediate or triggered level) and a transient level. The rate at which the level changes is determined by the slew rate (see slew rate descriptions for CV, CR, or CV mode as applicable). In addition, the frequency and duty cycle of the continuous pulse train are programmable. Use the following commands to program continuous transients:

TRANsient:MODE CONTinuous

CURRent 5

CURRent:TLEVel 10

TRANsient:FREQuency 1000

TRANsient:DCYCle 40

TRANsient ON

This example assumes that the CC mode is active and the slew rate is at the default setting (maximum rate). The load module starts conduction at the main level (in this case 5 amps). When transient operation is turned on (no trigger is required in continuous mode), the module input current will slew to and remain at 10 amps for 40% of the period (400 µs). The input current will then slew to and remain at 5 amps for the remaining 60% (600 µs) of that cycle.

Pulse Transients

Pulsed transient operation generates a load change that returns to its original state after some time period. It is similar to continuous operation with the following exceptions:

a. To get a pulse, an explicit trigger is required. To specify the trigger source, use

TRIGger:SOURce. See "Triggering Transients".

b. One pulse results from each trigger. Therefore, frequency cannot be programmed.

Use the following commands to program pulsed transients:

3 - Programming Examples

TRIGger:SOURce EXTernal TRANsient:MODE PULSe CURRent 5 CURRent:TLEVel 10 TRANsient:TWIDth .01 TRANsient ON

This example assumes that the CC mode is active, the slew rate is at the factory default setting (maximum rate), and a trigger signal is connected to the mainframe's external trigger input. The load module starts conduction at the main current level setting (5 amps). When the transient mode is turned on and an external trigger signal is received, the input level starts increasing at a rate determined by the slew rate. When the value specified by the transient level setting (10 amps) is reached, it stays there for the remainder of the time determined by the pulse width setting (10 milliseconds). After this time has elapsed, the input level decreases to the main level again at the rate specified by the slew setting and remains there until another trigger is received. Any triggers that occur during the time the transient level is in effect will re-trigger the pulse, extending the pulse by another pulse-width value.

Toggled Transients

Toggled transient operation causes the module input to alternate between two pre-defined levels as in continuous operation except that the transient transitions are controlled by explicit triggers instead of the internal transient generator. See "Triggering Transients". Use the following commands to program toggled transients:

TRIGger:SOURce EXTernal TRANsient:MODE TOGGle CURRent 5 CURRent:TLEVel 10 TRANsient ON

This example assumes that the CC mode is active, the slew rate is at the factory default setting (maximum rate), and a trigger signal is connected to the mainframe's external trigger input. Toggled transient operation is similar to that described for continuous and pulse operation, except that each time a trigger is received the input alternates between the main and transient input current levels.

Programming Lists

List mode lets you generate complex sequences of input changes with rapid, precise timing, which may be synchronized with internal or external signals. This is useful when running test sequences with a minimum amount of programming overhead.

You can program up to 50 settings (or steps) in the list, the time interval (dwell) that each setting is maintained, the number of times that the list will be executed, and how the settings change in response to triggers. All list data is can be stored in nonvolatile memory when saved in locations 0, 7, 8, or 9 using the *SAV command. This means that the programmed data for any list will be retained when the electronic load is turned off. Use the *RCL command to recall the saved state. *RST clears the presently active list but will not clear the lists saved in locations 0, 7, 8, or 9.

List steps can be either individually triggered, or paced by a separate list of dwell times that define the duration of each step. Therefore, each of the up to 50 steps has an associated dwell time, which specifies the time (in seconds) that the input remains at that step before moving on to the next step. The following procedure shows how to generate a simple 9-step list of current and voltage changes.

Programming Examples - 3

Step 1

Step 2

Set the mode of each function that will participate in the sequence to LIST. For example:

CURRent:MODE LIST

Program the list of input values for each function. The list commands take a comma-separated list of arguments. The order in which the arguments are given determines the sequence in which the values will be input. For example, to vary the input current of the electronic load to simulate a 25%, 50%, and 100% load, a list may include the following values:

LIST:CURRent[:LEVel] 15, 30, 60, 15, 30, 60, 15, 30, 60

You must specify a list for all current functions, whether or not the functions will be used. For example, to synchronize the previous current list with another list that varies the slew rate from

0.01A/µs, to 0.1A/µs, to 1A/µs (programmed in A/s), the lists may include the following values:

LIST:CURRent[:LEVel] 15, 30, 60, 15, 30, 60, 15, 30, 60 LIST:CURRent:SLEW 1E+5, 1E+5, 1E+5, 1E+6, 1E+6, 1E+6, 1E+7, 1E+7, 1E+7 LIST:CURRent:RANGe 60 LIST:CURRent:TLEVel 0

All lists must have the same number of data values or points, or an error will occur when the list system that starts the sequence is initiated. The exception is when a list has only one item or point. In this case the single-item list is treated as if it had the same number of points as the other lists, with all values being equal to the one item. For example:

LIST:CURRent 15, 30, 45, 60;SLEW 1E+6

is the same as:

LIST:CURRent 15, 30, 45, 60

LIST:CURRent:SLEW 1E+6, 1E+6, 1E+6, 1E+6

Step 3

Step 4

Step 5

Determine the time interval that the input remains at each level or point in the list before it advances to the next point. The time is specified in seconds. For example, to specify five dwell intervals, use:

LIST:DWELl 1, 1.5, 2, 2.5, 3

The number of dwell points must equal the number of input points. If a dwell list has only one value, that value will be applied to all points in the input list.

Determine the number of times the list is repeated before it completes. For example, to repeat a list 10 times use:

LIST:COUNt 10

Entering INFinity makes the list repeat indefinitely. At *RST, the count is set to 1.

Determines how the list sequencing responds to triggers. For a closely controlled sequence of input levels, you can use a dwell-paced list. To cause the list to be paced by dwell time use:

LIST:STEP AUTO

As each dwell time elapses, the next point is immediately input. This is the *RST setting.

If you need the input to closely follow asynchronous events, then a trigger-paced list is more appropriate. In a trigger-paced list, the list advances one point for each trigger received. To enable trigger-paced lists use:

LIST:STEP ONCE

The dwell time of each point determines the minimum time that the input remains at that point. If a trigger is received before the previous dwell time completes, the trigger is ignored. Therefore, to ensure that no triggers are lost, program the dwell time to "MIN".

Step 6

Use the list trigger system to trigger the list. See "Triggering Transients and Lists".

3 - Programming Examples

Programming Lists for Multiple Channels

You can program separate lists for individual channels on a load mainframe. Once lists have been programmed for each channel, they can all be triggered at the same time using the list trigger system.

NOTE: All lists must have the same number of data values or points, or an error will occur when

the list system that starts the sequence is initiated.

Step 1

Step 2

Step 3

Step 4

Select the channel for which you want to program the list. All subsequent list commands will be sent to this channel until another channel is selected.

CHANnel 1

Program the list of values for each function for that channel. The list commands take a commaseparated list of arguments. For example:

LIST:CURRent 15, 30, 60, 15, 30, 60, 15, 30, 60 LIST:CURRent:SLEW 1E+5, 1E+5, 1E+5, 1E+6, 1E+6, 1E+6, 1E+7, 1E+7, 1E+7

. . .

Add other list functions.

Select the next channel for which you want to program a list. All subsequent list commands will now be sent to this channel.

CHANnel 2

Program the list of values for each function for that channel. You can program different functions for each channel, however all functions must have the same number of steps

LIST:VOLTage 30, 60, 30, 30, 60, 30, 30, 60, 30

LIST:VOLTage:SLEW 1E+5, 1E+5, 1E+5, 1E+6, 1E+6, 1E+6, 1E+7, 1E+7, 1E+7 . . .

Add other list functions. You do not have to program the same number of functions for each

channel.

Step 5

Step 6

Repeat steps 3 and 4 for any other channel that you wish to program.

Use the list trigger system to trigger the list. This is described under "Triggering Transients and

Lists".

Programming Examples - 3

Triggering Transients and Lists

Continuous, pulse, and toggled transient modes respond to triggers as soon as the trigger is received. This is not the case for lists. Lists have an independent trigger system that is similar to the measurement trigger system. This section describes the list trigger system. The measurement trigger system is described under "Triggering Measurements".

SCPI Triggering Nomenclature

In SCPI terms, trigger systems are called sequences. When more than one trigger system exists, they are differentiated by naming them SEQuence1 and SEQuence2. SEQuence1 is the list trigger system and SEQuence2 is the measurement trigger system. The electronic load uses aliases with more descriptive names for these sequences. These aliases can be used instead of the sequence forms.

Sequence Form Alias

SEQuence1 LIST SEQuence2 ACQuire

List Trigger Model

Figure 3-3 is a model of the list trigger system. The rectangles represent states. The arrows show the transitions between states. These are labeled with the input or event that causes the transition to occur.

INITiate:CONTinuous OFF

INITiate:CONTinuous ON

List not complete and

LIST:STEP ONCE

INITIATED STATE

DELAYING STATE

LIST STEP CHANGE

WAIT FOR DWELL

TO COMPLETE

IDLE STATE

LIST:STEP

AUTO?

YES

ABORt *RST *RCL

INITiate[:IMMediate]

TRIGGER RECEIVED

DELAY COMPLETED

Figure 3-3. Model of List Triggers

3 - Programming Examples

Initiating List Triggers

When the electronic load is turned on, the list trigger system is in the idle state. In this state, the list system ignores all triggers. Sending the following commands at any time returns the list system to the Idle state:

ABORt *RST *RCL

The INITiate commands move the list system from the Idle state to the Initiated state. This enables the list system to receive triggers. INITiate commands are not channel-specific, they affect all installed load modules. To initiate the list system for a single triggered action, use:

INITiate:SEQuence1 or

INITiate:NAME LIST

NOTE: Whenever a list is initiated or triggered, the φ1 annunciator is lit on the front panel.

After a trigger is received and the action completes, the list system will return to the Idle state. Thus it will be necessary to initiate the list system each time a triggered action is desired.

To keep the list system initiated for multiple actions without having to send an Initiate command for each trigger, use:

INITiate:CONTinuous:SEQuence1 ON or

INITiate:CONTinuous:NAME LIST, ON

Specifying a Trigger Delay

A time delay can be programmed betweent he receipt of the trigger system and the start of the triggered action. This delay applies to both list and measurement triggers. At *RST the trigger delay is set to 0, which mens there is no trigger delay. To program a trigger delay use:

TRIGger:DELay <n>

Generating Transient and List Triggers

Use one of the following triggering methods to generate transients and lists:

TRIGger:SOURce BUS | EXTernal | HOLD | LINE | TIMer

After you have specified the appropriate trigger source, you can generate triggers as follows:

Single triggers over the bus

Continuous triggers synchronized with the ac line frequency

Continuous triggers synchronized with the internal timer

Send one of the following commands over the GPIB:

TRIGger:IMMediate

*TRG

a group execute trigger

Send the following command over the GPIB:

TRIGger:SOURce LINE

Send the following commands over the GPIB:

TRIGger:TIMer <time>

TRIGger:SOURce TIMer

External trigger

Apply a low to high signal to the external trigger input at the back of the mainframe.

Programming Examples - 3

Making Measurements

The electronic load has the ability to make several types of voltage or current measurements. The measurement capabilities of the electronic load are particularly useful with applications that draw current in pulses.

All measurements are performed by digitizing the instantaneous input voltage or current for a defined number of samples and sample interval, storing the results in a buffer, and then calculating the measured result. Many parameters of the measurement are programmable. These include the number of samples, the time interval between samples, and the method of triggering. Note that there is a tradeoff between these parameters and the speed, accuracy, and stability of the measurement in the presence of noise.

There are two ways to make measurements:

♦ Use the MEASure commands to immediately start acquiring new voltage or current data, and

return measurement calculations from this data as soon as the buffer is full. This is the easiest way to make measurements, since it requires no explicit trigger programming.

♦ Use an acquisition trigger to acquire the data. Then use the FETCh commands to return

calculations from the data that was retrieved by the acquisition trigger. This method gives you the flexibility to synchronize the data acquisition with a trigger. FETCh commands do not trigger the acquisition of new measurement data, but they can be used to return many different calculations from the data that was retrieved by the acquisition trigger.

Making triggered measurements with the acquisition trigger system is discussed under "Triggering Measurements".

NOTE: For each MEASure form of the query, there is a corresponding query that begins with the

header FETCh. FETCh queries perform the same calculation as their MEASure counterparts, but do not cause new data to be acquired. Data acquired by an explicit trigger or a previously programmed MEASure command are used.

Voltage and Current Measurements

The SCPI language provides a number of MEASure and FETCh queries, which return various measurement parameters of voltage and current waveforms.

DC Measurements

To measure the dc input voltage or current, use:

MEASure:VOLTage? or

MEASure:CURRent?

DC voltage and current is measured by acquiring a number of readings at the selected time interval, optionally applying a Hanning window function to the readings, and averaging the readings. Windowing is a signal conditioning process that reduces the error in dc measurements made in the presence of periodic signals such as line ripple. At power-on and after a *RST command, the following parameters are set:

SENSe:SWEep:TINTerval 10E-6

SENSe:SWEep:POINts 1000

This results in a data acquisition time of 10 milliseconds. Adding a command processing overhead of about 20 milliseconds results in a total measurement time of about 30 milliseconds per measurement sample.

3 - Programming Examples

Ripple rejection is a function of the number of cycles of the ripple frequency contained in the acquisition window. More cycles in the acquisition window results in better ripple rejection. If you increase the time interval for each measurement to 45 microseconds for example, this results in 5.53 cycles in the acquisition window at 60 Hz, for a ripple rejection of about 70 dB.

Note that the processing overhead time will vary, depending on the number of measurement samples. If you reduce the number of sample points, you will also reduce the command processing overhead. If you increase the number of sample point (up to a maximum of 4096) you increase the command processing overhead.

RMS Measurements

To read the rms content of a voltage or current waveform, use:

MEASure:VOLTage:ACDC? or

MEASure:CURRent:ACDC?

This returns the total rms measurement, including the dc portion.

Minimum and Maximum Measurements

To measure the maximum or minimum voltage or current of a pulse or ac waveform, use:

MEASure:VOLTage:MAXimum?

MEASure:VOLTage:MINimum?

MEASure:CURRent:MAXimum?

MEASure:CURRent:MINimum?

Measurement Ranges

The electronic load has two current and two voltage measurement ranges. The commands that control the measurement ranges are:

SENSe:CURRent:RANGe MIN | MAX

SENSe:VOLTage:RANGe MIN | MAX

When the range is set to MAX, the maximum current or voltage that can be measured is a function of the current and voltage rating of the load module that is being programmed (see Table 4-1).

Returning Measurement Data From the Data Buffer

The MEASure and FETCh queries can also return all data values of the instantaneous voltage or current buffer. The commands are:

FETCh:ARRay:CURRent?

FETCh:ARRay:VOLTage?

This is a useful feature if, for example, you have entered multiple measurements into the buffer as a result of measuring the response to a triggered list. Data is returned from the buffer in the same order in which it was entered into the buffer. Refer to "Synchronizing Transients and Measurements" for more information.

Programming Examples - 3

Triggering Measurements

You can use the data acquisition trigger system to synchronize the timing of the voltage and current data acquisition with a trigger source. Then use the FETCh commands to return different calculations from the data acquired by the measurement trigger.

SCPI Triggering Nomenclature

Sequence Form Alias

SEQuence2 ACQuire

Measurement Trigger Model

Figure 3-1 is a model of the measurement trigger system. The rectangular boxes represent states. The arrows show the transitions between states. These are labeled with the input or event that causes the transition to occur.

IDLE STATE

INITIATED STATE

DELAYING STATE

SENSe:SWEep:POINts

ACQUIRED

TRIGger:COUNt

COMPLETE?

YES

ABORt *RST *RCL

INITiate[:IMMediate]

TRIGGER RECEIVED

DELAY COMPLETED

Figure 3-1. Model of Measurement Triggers

3 - Programming Examples

Initiating the Measurement Trigger System

When the electronic load is turned on, the trigger system is in the idle state. In this state, the trigger system ignores all triggers. Sending the following commands at any time returns the trigger system to the Idle state:

ABORt *RST *RCL

The INITiate commands move the trigger system from the Idle state to the Initiated state. This enables the electronic load to receive triggers. INITiate commands are not channel-specific, they affect all installed load modules. To initiate a measurement trigger, use:

INITiate:SEQuence2 or INITiate:NAME ACQuire

After a trigger is received and the data acquisition completes, the trigger system will return to the Idle state unless multiple measurements are programmed using the TRIGger:SEQuence2:COUNt command. Thus it will be necessary to initiate the system each time a triggered acquisition is desired.

NOTE: You cannot initiate measurement triggers continuously. Otherwise, the measurement data

in the data buffer would continuously be overwritten.

Generating Measurement Triggers

Use one of the following triggering methods to generate measurements:

TRIGger:SOURce BUS | EXTernal | HOLD | LINE | TIMer

After you have specified the appropriate source, you can generate measurement triggers as follows:

Single triggers over the bus

Continuous triggers synchronized with the ac line frequency

Continuous triggers synchronized with the internal timer

External trigger

When the acquisition finishes, any of the FETCh queries can be used to return the results. Once the measurement trigger is initiated, if a FETCh query is sent before the data acquisition is triggered or before it is finished, the response data will be delayed until the trigger occurs and the acquisition completes. This may tie up the controller if the trigger condition does not occur immediately.

Send one of the following commands over the GPIB:

TRIGger:IMMediate (this overrides TRIG:SOUR HOLD)

*TRG

a group execute trigger

Send the following command over the GPIB:

TRIGger:SOURce LINE

Send the following commands over the GPIB:

TRIGger:TIMer <time>

TRIGger:SOURce TIMer

Apply a low to high signal to the external trigger input at the back of the mainframe.

One way to wait for results without tying up the controller is to use the SCPI command completion commands. For example, you can send the *OPC command after INITialize, then occasionally poll the OPC status bit in the standard event status register for status completion while doing other tasks. You can also set up an SRQ condition on the OPC status bit going true, and do other tasks until an SRQ interrupt occurs.

Programming Examples - 3

Controlling Measurement Samples

Varying the Sampling Rate

You can vary both the number of data points in a measurement sample, as well as the time between samples. You can also specify a delay from the trigger to the start of the measurement. This is illustrated in the following figure.

SENS:SWE:POIN <value>

SENS:SWE:TINT <value>

SENS:SWE:OFFS <value>

Trigger1 Trigger2 Trigger4Trigger3

TRIG:SEQ2:COUN <value>

Figure 3-2. Sense Commands Used to Vary the Sampling Rate

At power-on, the input voltage and current sampling rate is 10 microseconds. This means that, not accounting for the command processing overhead, it takes about 41 milliseconds to fill up 4096 data points in the data buffer. You can vary this data sampling rate with:

SENSe:SWEep:TINTerval <sample_period> SENSe:SWEep:POINts <points>

For example, to set the time interval to 50 microseconds per sample with 500 samples, use:

SENSe:SWEep:TINTerval 50E-6;POINts 500.

Measurement Delay

You can delay the start of a measurement in relation to the trigger. This is useful if you do not want to start taking measurements at the beginning of an input transient or list step during the time that the input voltage or current is still slewing or settling into its programmed value. To offset the measurement from the beginning of the input transient or list step, use:

SENSe:SWEep:OFFSet 10E-3

In this example, the measurement occurs 10 milliseconds after the start of the trigger. The offset can be set to a negative value, but this number cannot exceed the TRIGger:DELay value.

Multiple Measurements

The electronic load also has the ability to set up several acquisition triggers in succession and concatenate the results from each acquisition in the measurement buffer. This is useful for making measurements from lists. To set up the trigger system for a number of sequential acquisitions use:

TRIGger:SEQuence2:COUNt <number>

3 - Programming Examples

With this setup, the instrument performs each acquisition sequentially, storing the digitized readings in the internal measurement buffer. A trigger signal is required to make each measurement. It is only necessary to initialize the measurement once at the start; after each completed acquisition the instrument will wait for the next valid trigger condition to start another. The results returned by MEASure or FETCh will be the average of the total data acquired.

If you do not want the instrument to average the acquisition data, use the FETCh:ARRay commands to return the raw data from the voltage or current measurement buffer.

NOTE: The total number of data points cannot exceed 4096. This means that the trigger count

multiplied by the number of points cannot exceed 4096; otherwise an error will occur.

Synchronizing Transients and Measurements

The transient and measurement systems are independent of each other. However, it possible to synchronize the two systems through the use of triggers. This is because when both transient and measurement systems have been initialized, the same trigger signal will affect both systems. For example, you may have an application where you need to measure the effects of a list step.

Measuring Triggered Transients or Lists

Measuring triggered transients or lists is generally a straightforward process because you are using the same trigger to generate the output transient and simultaneously take the measurement. The following example illustrates how to make measurements from a simple 3-step trigger paced list. Each list step has a duration of two seconds. Each step-measurement consists of three data points with an offset of 100 milliseconds.

Step 1

Step 2

Step 3

Step 4

Set the mode of each function that will participate in the sequence to LIST. For example:

CURRent:MODE LIST

Program the list of input values for each function.

LIST:CURRent 15, 30, 60 LIST:CURRent:SLEW 1E+6, 1E+6, 1E+6 LIST:CURRent:RANGe 60 LIST:CURRent:TLEVel 0

Specify the number of triggered measurements that will be taken.

TRIGger:SEQuence2:COUNt 3

The number of measurements should match the number of steps in the list.

Specify the time interval and the number of points in each triggered measurement.

SENSe:SWEep:TINTerval 100E-3

SENSe:SWEep:POINts 3

In this example, three measurements or data points are taken at each list step, separated by 100ms intervals. Make sure that all of the measurement samples complete within the step time interval. If another trigger occurs while a measurement is in progress, the measurement system will ignore the trigger. Also note that the number of data points specified in this step multiplied by the measurement count specified in step 3 cannot exceed 4096.

Step 5

Specify a delay time from the start of the trigger until the measurement is taken.

SENSe:SWEep:OFFset 100E-6

This specifies the offset in seconds, in this case, 100 microseconds

Programming Examples - 3

Step 6

Step 7

Step 8

NOTE: Each load module retains its measurement data. If multiple lists have been executed, you

Initiate both the transient (list) and the measurement trigger systems.

INITiate:SEQuence1

INITiate:SEQuence2

Specify the trigger source and the timing that will control the list steps and the measurements.

TRIGger:TIMer 2

TRIGger:SOURce TIMer

In this example the trigger source is the internal trigger. Because the internal timer starts running as soon as the TRIGger:SOURce:TIMer command is executed, the trigger that starts the list and measurement will not occur until the end of the two-second timer window within which the trigger is received. After the initial trigger occurs, the list will remain at each step for two seconds before the next trigger occurs.

Return the current measurements from the data array. In this case, a total of nine measurements were taken, three at each list step. To return the measurement data you must first dimension an array, then fetch the data.

Dimension an array here

FETch:CURRent:ARRay ARRAY1

must select each channel in turn, and fetch the measurement data from that channel.

Measuring Dwell-Paced Lists

The main difference between a trigger-paced list and a dwell-paced list is that no triggers occur between steps in a dwell-paced list. Only one measurement will be taken during the time the list is executed. Therefore, to capture measurement data for the entire time the list is executed, the total measurement time of a dwell paced list (time interval X number of points) must equal the total dwell time of the list.

Step 1

Step 2

Step 3

Step 4

Step 5

Program the list as previously described under "Measuring Triggered Transients or Lists."

Specify a dwell time for each list step. For example:

LIST:DWELl 1, 1.5, 2, 2.5, 3

Add up the total number of dwell times to determine the time of the entire list. For the previous example, the total dwell time adds up to 10 seconds. This is the time it takes to execute the list.

Specify the time interval and the number of points for the measurement.

SENSe:SWEep:TINTerval 100E-3

SENSe:SWEep:POINts 100

In this example, the measurement interval is set to take 100 measurement points at 100ms intervals. The total time of the measurement therefore equals the total dwell time of the list.

Return the measurements from the data array.

Dimension an array here

FETch:CURRent:ARRay ARRAY1

When you read back the measurement from the array, you must determine at what point during the list that the measurement occurred. One way to do this is to multiply the measurement number by the measurement interval. For example, multiply measurement #5 by 100ms, and you get 500ms, which is the time that the measurement was made.

3 - Programming Examples

Programming the Status Registers

You can use status register programming to determine the operating condition of the electronic load at any time. For example, you may program the electronic load to generate an interrupt (assert SRQ) when an event such as a current protection occurs. When the interrupt occurs, your program can then act on the event in the appropriate fashion.

Table 3-1 defines the status bits. Figure 3-4 shows the status register structure of the electronic load. The Standard Event, Status Byte, and Service Request Enable registers and the Output Queue perform standard GPIB functions as defined in the IEEE 488.2 Standard Digital Interface for Programmable Instrumentation. The Operation Status and Questionable Status registers implement functions that are specific to the electronic load.

Table 3-1. Bit Configurations of Status Registers

Bit Signal Meaning

0 5

10 11

CAL WTG

EPU

RRV

UNR LRV

Operation Status Group

Calibrating Waiting

Channel Status Group

Voltage Fault

the active state of the FLT pin on the back of the unit. The bit remains set until the condition is removed and INP:PROT:CLE is programmed.

Overcurrent

102% of the rated current or if it exceeds the user-programmed current protection level. Removing the overcurrent condition clears the bit. If the condition persists beyond the user programmable delay time, bit 13 is also set and the input is turned off. Both bits remain set until the condition is removed and INP:PROT:CLE is programmed.

Overpowe

rated power of the input. Removing the overpower condition clears the bit. If the condition persists for more than 3 seconds, bit 13 is also set and the input is turned off. Both bits remain set until the condition is removed and INP:PROT:CLE is programmed.

Overtemperature

set and the input is turned off. Both bits remain set until the unit is cooled down and INP:PROT:CLE is programmed.

Extended Power Unavailable

persists for more than 3 seconds will cause the input to be shut off and bit 13 to be set. When EPU satus is false, an overpower condition will be reported in bit 3, but this will not cause the input to be turned off. The state of the EPU bit is dependent on the internal temperature of the load.

Remote Reverse Voltage

terminals. Both this bit and bit 0 are set. Removing the reverse voltage clears this bit but does not clear bit 0. Bit 0 remains set until INP:PROT:CLE is programmed.

Unregulated Local Reverse Voltage

Both this bit and bit 0 are set. Removing the reverse voltage clears this bit but does not clear bit 0. Bit 0 remains set until INP:PROT:CLE is programmed.

Overvoltage

FETs are turned on as hard as possible to lower the voltage. Both bits remain set until the condition is removed and INP:PROT:CLE is programmed.

Protection Shutdown

overcurrent, overpower, or overtemperature condition. The bit remains set until INP:PROT:CLE is programmed.

. The electronic load is computing new calibration constants

. The electronic load is waiting for a trigger

. Either an overvoltage or a reverse voltage has occurred. This bit reflects

. An overcurrent condition has occurred. This occurs if the current exceeds

r. An overpower condition has occurred. This occurs if the unit exceeds the

. An overtemperature condition has occurred. Both this bit and bit 13 are

. When EPU status is true, an overpower condition that

. A reverse voltage condition has occurred on the sense

. The input is unregulated. When the input is regulated the bit is cleared.

. A reverse voltage condition has occurred on the input terminals.

. An overvoltage condition has occurred. Both this bit and bit 0 are set and the

. The protection shutdown circuit has tripped because of an

OPC

QYE

DDE

EXE

CME

PON

Programming Examples - 3

Table 3-1. Bit Configurations of Status Registers (continued)

Questionable Status Group

Same as Channel Status Group

Standard Event Status Group

Operation Complete

programmed for this bit to be set when pending operations are complete.

Query Error

in the range of −499 through −400 can set this bit.

Device-Dependent Error

through −300 can set this bit.

Execution Error

load's operation, or prevented from executing because of an operating condition. Errors in the range of −299 through −200 can set this bit.

Command Error

within a program message. Errors in the range of −199 through −100 can set this bit.

Power-On

. The output queue was read with no data present or the data was lost. Errors

. The unit has been turned off and then on since this bit was last read.

. The load has completed all pending operations. *OPC must be

. Memory was lost or self test failed. Errors in the range of −399

. A command parameter was outside its legal range, inconsistent with the

. A syntax or semantic error has occurred or the load received a <get>

CSUM

QUES

MAV

ESB

MSS

RQS

OPER

Status Byte and Service Request Enable Registers

Channel Summary

Questionable Status Summary

Message Available Summary

Event Status Summary

Master Status Summary

Request Service

Operation Status Summary

. Indicates if an enabled channel event has occurred.

. Indicates if an enabled questionable event has occurred.

. Indicates if the Output Queue contains data.

. Indicates if an enabled standard event has occurred.

. For an *STB? query, MSS is returned without being cleared.

. During a serial poll, RQS is returned and cleared.

. Indicates if an operation event has occurred.

3 - Programming Examples

CONDITION

256

512

1024

2048

4096

8192

CHANNEL STATUS

EVENT ENABLE

256

512

1024

2048

4096

8192

1024

2048

4096

8192

CHANNEL SUMMARY

EVENT ENABLE

256

512

LOGICAL OR

SAME

CHAN 1

CHAN 2

CHAN 3

CHAN 4

CHAN 5

CHAN 6

N.U.

LOGICAL OR

(IDENTICAL REGISTERS FOR EACH CHANNEL)

N.U.

5-7

N.U.

RRV

EPU

UNR

LRV

5-9

N.U.

QUESTIONABLE STATUS

SAME

CHAN 1

CHAN 2

CHAN 3

CHAN 4

CHAN 5

CHAN 6

LOGICAL OR

N.U.

UNR

LRV

OV PS

N.U.

RRV

EPU

CONDITION

5-7

256

512

1024

2048

4096

8192

5-9

EVENT ENABLE

1024

2048

4096

8192

256

512

256

1024

2048

4096

8192

512

LOGICAL OR

OPC

N.U.

QYE

DDE

EXE

CME

N.U.

PON

CAL

N.U.

WTG

N.U.

1-4

6-15

STANDARD EVENT

STATUS

EVENT ENABLE

128

LOGICAL OR

OPERATION STATUS

CONDITION

PTR/NTR EVENT ENABLE

11 1

32 32 32

Figure 3-4. Electronic Load Status Model

OUTPUT QUEUE

DATA

QUEUE

NOT

EMPTY

LOGICAL OR

N.U.

CSUM

QUES

MAV

ESB

RQS

OPER

STATUS BYTE

0,1

128

RQS

SERVICE

REQUEST

GENERATION

SERVICE

REQUEST

ENABLE

128

LOGICAL OR

Programming Examples - 3

Power-On Conditions

Refer to the *RST command description in chapter 4 for the power-on conditions of the status registers.

Channel Status Group

The Channel Status registers record signals that indicate abnormal operation of a specific channel of the electronic load. As shown below, the group consists of a Condition, Event, and Enable register. The outputs of the Channel Status registers are logically-ORed into the Channel Summary Registers.

Condition

Event

Enable

STAT:CHAN:COND?

STAT:CHAN:EVEN?

STAT:CHAN:ENAB <n>

A read-only register that holds real-time status of the channel being monitored. A read-only register that latches any condition. It is cleared when read. A read/write register that functions as a mask for enabling specific bits in the Event register.

Channel Summary Group

The Channel Summary registers summarize the abnormal operation of all channels of the electronic load. As shown below, the group consists of an Event and Enable register. The outputs of the Channel Summary registers are logically-ORed into the Channel SUMmary bit (2) of the Status Byte register.

Event

Enable

STAT:CSUM:EVEN?

STAT:CSUM:ENAB <n>

A read-only register that latches any condition from all channels. It is cleared when read. A read/write register that functions as a mask for enabling specific bits in the Enable register.

Questionable Status Group

The Questionable Status registers record signals that indicate abnormal operation of the electronic load from all of the channels. The group consists of the same type of registers as the Channel Status group. The outputs of the Questionable Status group are logically-ORed into the QUEStionable summary bit (3) of the Status Byte register.

Condition

Event

Enable

STAT:QUES:COND?

STAT:QUES:EVEN?

STAT:QUES:ENAB <n>

A read-only register that holds real-time logically ORed status of all channels of the mainframe. A read-only register that latches any condition. It is cleared when read. A read/write register that functions as a mask for enabling specific bits in the Enable register.

Standard Event Status Group

This group consists of an Event register and an Enable register that are programmed by Common commands. The Standard Event event register latches events relating to instrument communication status (see figure 3-4). It is a read-only register that is cleared when read. The Standard Event enable register functions similarly to the enable registers of the Operation and Questionable status groups.

3 - Programming Examples

Command Action

*ESE *PSC ON *ESR?

The PON (Power On) Bit

The PON bit in the Standard Event event register is set whenever the electronic load is turned on. The most common use for PON is to generate an SRQ at power-on following an unexpected loss of power. To do this, bit 7 of the Standard Event enable register must be set so that a power-on event registers in the ESB (Standard Event Summary Bit), bit 5 of the Service Request Enable register must be set to permit an SRQ to be generated, and *PSC OFF must be sent. The commands to accomplish these conditions are:

*PSC OFF *ESE 128 *SRE 32

programs specific bits in the Standard Event enable register. clears the Standard Event enable register at power-on. reads and clears the Standard Event event register.

Operation Status Group

The Operation Status registers record signals that occur during normal operation. As shown below, the group consists of a Condition, PTR/NTR, Event, and Enable register. The outputs of the Operation Status register group are logically-ORed into the OPER(ation) summary bit (7) of the Status Byte register.

Condition

PTR Filter

NTR Filter

Event

Enable

STAT:OPER:COND?

STAT:OPER:PTR <n>

STAT:OPER:NTR <n>

STAT:OPER:EVEN?

STAT:OPER:ENAB <n>

A read-only register that holds real-time status of the circuits being monitored. A read/write positive transition filter that functions as described in chapter 4 under STAT:OPER:NTR|PTR.

A read/write negative transition filter that functions as described in chapter 4 under STAT:OPER:NTR|PTR.

A read-only register that latches any condition that is passed through the PTR or NTR filters. It is cleared when read. A read/write register that functions as a mask for enabling specific bits from the Event register.

Status Byte Register

This register summarizes the information from all other status groups as defined in the IEEE 488.2 Standard Digital Interface for Programmable Instrumentation. The bit configuration is shown in Table 3-1.

Command Action

*STB? reads the data in the register but does not clear it (returns MSS in bit 6) serial poll clears RQS inside the register and returns it in bit position 6 of the response.

The MSS Bit

This is a real-time (unlatched) summary of all Status Byte register bits that are enabled by the Service Request Enable register. MSS is set whenever the electronic load has one or more reasons for requesting service. *STB? reads the MSS in bit position 6 of the response but does not clear any of the bits in the Status Byte register.

The RQS Bit

The RQS bit is a latched version of the MSS bit. Whenever the electronic load requests service, it sets the SRQ interrupt line true and latches RQS into bit 6 of the Status Byte register. When the controller does a serial poll, RQS is cleared inside the register and returned in bit position 6 of the response. The remaining bits of the Status Byte register are not disturbed.

Programming Examples - 3

The MAV Bit and Output Queue

The Output Queue is a first-in, first-out (FIFO) data register that stores electronic load-to-controller messages until the controller reads them. Whenever the queue holds one or more bytes, it sets the MAV bit (4) of the Status Byte register.

Determining the Cause of a Service Interrupt

You can determine the reason for an SRQ by the following actions:

Step 1 Determine which summary bits are active. Use:

*STB? or serial poll

Step 2 Read the corresponding Event register for each summary bit to determine which events

caused the summary bit to be set. Use:

STATus:QUEStionable:EVENt?

STATus:OPERation:EVENt?

ESR?

When an Event register is read, it is cleared. This also clears the corresponding summary

bit.

Step 3 Remove the specific condition that caused the event. If this is not possible, the event may

be disabled by programming the corresponding bit of the status group Enable register or

NTR|PTR filter if there is one. A faster way to prevent the interrupt is to disable the service

request by programming the appropriate bit of the Service Request Enable register

Servicing Standard Event Status and Questionable Status Events

This example assumes you want a service request generated whenever the electronic load experiences a command execution error, or whenever the electronic load's overcurrent, overpower, or overtemperature circuits have tripped. From figure 3-4, note the required path for a condition at bit 4 (EXE) of the Standard Event Status register to set bit 6 (RQS) of the Status Byte register. Also note the required path for Questionable Status conditions at bits 1, 3, and 4 to generate a service request (RQS) at the Status Byte register. The required register programming is as follows:

Step 1 Program the Standard Event Status register to enable an event at bit 4. This allows the

event to be summed into the ESB bit of the Status Byte Register. Use:

*ESE 4

Step 2

Step 3

Step 4

Program the Questionable Status register to allow an event at bits 1, 3, or 4 to be

summed into the Questionable summary bit. Use:

STATus:QUEStionable:ENABle 26 (2 + 8 + 16 = 26)

Program the Service Request Enable register to allow both the Standard Event Status

and the Questionable summary bits from the Status Byte register to generate RQS. Use:

*SRE 40 (8 + 32 = 40)

When you service the request, read the event registers to determine which Operation

Status and Questionable Status Event register bits are set, and clear the registers for the

next event. Use:

STATus:OPERation:EVENt;QUEStionable:EVENt?

3 - Programming Examples

Programming Examples

NOTE: Because of the wide variety of input ratings between load modules, not all of the values

used in the following programming examples will work with every module.

CC Mode Example

This example selects channel 1, sets the current level to 1.25 A and reads back the actual current value.

10 OUTPUT 705; "CHAN 1" 20 OUTPUT 705;"INPUT OFF" 30 OUTPUT 705;"FUNC CURR" 40 OUTPUT 705;"CURR:RANG MIN" 50 OUTPUT 705;"CURR 1.25" 60 OUTPUT 705;"INPUT ON" 70 OUTPUT 705;"MEAS:CURR?" 80 ENTER 705;A 90 DISP A 100 END

Line 10: Selects the channel 1 module. Line 20: Turns off the input. Line 30: Selects the CC mode. Line 40: Selects the low current range. Line 50: Sets the current level to 1.25 amps. Line 60: Turns on the input. Line 70: Measures the actual input current and stores it in a buffer inside the electronic load. Line 80: Reads the input current value into variable A in the computer. Line 90: Displays the measured current value on the computer's display.

CV Mode Example

This example selects channel 2, presets the voltage level to 10 volts, and selects the external trigger source. When the external trigger signal is received, the channel 2 CV level will be set to 10 volts.

10 OUTPUT 705; "CHAN 2;:INPUT OFF" 20 OUTPUT 705;"FUNC VOLT" 30 OUTPUT 705;"VOLT 0" 40 OUTPUT 705;"VOLT:TRIG 10" 50 OUTPUT 705;"TRIG:SOUR EXT" 60 OUTPUT 705;"INPUT ON" 70 END

Line 10: Selects channel 2 and turns off the input. Line 20: Selects the CV mode. Line 30: Sets the initial voltage level to 0 volts. Line 40: Sets the triggered voltage level to 10 volts. Line 50: Selects the external input as the trigger source. Line 60: Turns on the channel 2 input.

Programming Examples - 3

CR Mode Example

This example selects channel 1, sets the current protection limit to 2 amps, programs the resistance level to 100 ohms, and reads back the computed power.

10 OUTPUT 705;"CHAN 1;:INPUT OFF" 20 OUTPUT 705;"FUNC RES" 30 OUTPUT 705;"CURR:PROT:LEV 2;DEL 0.5" 40 OUTPUT 705;"CURR:PROT:STAT ON" 50 OUTPUT 705;"RES:RANG MAX" 60 OUTPUT 705;"RES 1000" 70 OUTPUT 705;”INPUT ON" 80 OUTPUT 705;”MEAS:POW?" 90 ENTER 705;A 100 DISP A 110 END

Line 10: Selects channel 1 and turns off the input. Line 20: Selects the CR mode. Line 30: Sets the current protection limit to 2 amps with a trip delay of 5 seconds. Line 40: Enables the current protection feature. Line 50: Selects the high resistance range. Line 60: Sets the resistance level to 1000 ohms. Line 70: Turns on the input. Line 80: Reads the computed input power value and stores it in a buffer inside the electronic load. Line 90: Reads the computed input power level into variable A in the computer. Line 100: Displays the computed input power level on the computer's display.

Continuous Transient Operation Example

This example selects channel 2, sets the CC levels and programs the slew, frequency, and duty cycle parameters for continuous transient operation.

10 OUTPUT 705;"CHAN 2;:INPUT OFF" 20 OUTPUT 705;"FUNC CURR" 30 OUTPUT 705;"CURR 1" 40 OUTPUT 705;"CURR:TLEV 2;SLEW MAX" 50 OUTPUT 705;"TRAN:MODE CONT;FREQ 5000;DCYC 40" 60 OUTPUT 705;"TRAN ON;:INPUT ON" 70 END

Line 10: Selects channel 2 and turns the input off Line 20: Selects the CC mode. Line 30: Sets the main current level to 1 ampere. Line 40: Sets the transient current level to 2 amps and the slew rate to maximum. Line 50: Selects continuous transient operation, sets the transient generator frequency to 5 kHz, and sets the duty cycle to 40%. Line 60: Turns on the transient generator and the input.

3 - Programming Examples

Pulsed Transient Operation Example

This example selects channel 1, sets the CR levels, selects the bus as the trigger source, sets the fastest slew rate, programs a pulse width of 1 millisecond, and turns on transient operation. W hen the *TRG command is received, a 1 millisecond pulse is generated at the channel 1 input.

10 OUTPUT 705;"CHAN 1;:INPUT OFF" 20 OUTPUT 705;"FUNC RES" 30 OUTPUT 705;"RES:RANG MAX; LEV 1000" 40 OUTPUT 705;"RES:TLEV 2000" 50 OUTPUT 705;"TRIG:SOUR BUS" 60 OUTPUT 705;"RES:SLEW MAX" 70 OUTPUT 705;"TRAN:MODE PULS;TWID .001" 80 OUTPUT 705;"TRAN ON;:INPUT ON"

200 OUTPUT 705;"*TRG" 210 END

Line 10: Selects channel 1 and turns the input off. Line 20: Selects the CR mode. Line 30: Selects the high resistance range and sets the main resistance level to 100 ohms. Line 40: Sets the transient resistance level to 50 ohms. Line 50: Selects the HP-IB as the trigger source. Line 60: Sets the CR slew rate to the maximum value. Line 70: Selects pulsed transient operation and sets the pulse width to 1 millisecond. Line 80: Turns on the transient generator and the input.

Other commands are executed

Line 200: The *TRG command generates a 1 millisecond pulse at the channel 1 input.

Synchronous Toggled Transient Operation Example

This example programs channels 1 and 2 to generate synchronous transient waveforms. The channels can then be paralleled for increased current input. Each channel is set up to operate in the CC mode with toggled transient operation turned on. The electronic load's internal trigger oscillator is set up to produce trigger pulses at a frequency of 2 kHz in order to generate synchronous waveforms at the channel 1 and channel 2 inputs.

10 OUTPUT 705;"CHAN 1;:INPUT OFF" 20 OUTPUT 705;"FUNC CURR" 30 OUTPUT 705;"CURR 25" 40 OUTPUT 705;"CURR:TLEV 50; SLEW MAX" 50 OUTPUT 705;"TRAN:MODE TOGG" 60 OUTPUT 705;"TRAN ON;:INPUT ON" 70 OUTPUT 705; "CHAN 2;:INPUT OFF" 80 OUTPUT 705;"FUNC CURR" 90 OUTPUT 705; "CURR 25" 100 OUTPUT 705; "CURR:TLEV 50; SLEW MAX" 110 OUTPUT 705;"TRAN:MODE TOGG" 120 OUTPUT 705;"TRAN ON;:INPUT ON" 130 OUTPUT 705;"TRIG:TIM .0005" 140 OUTPUT 705; "TRIG:SOUR TIM" 150 END

Programming Examples - 3

Line 10: Selects channel 1 and turns the input off. Line 20: Selects the CC mode. Line 30: Sets the main current level to 25 A. Line 40: Sets the transient current level to 50 A and the slew rate to maximum. Line 50: Selects toggled transient operation. Line 60: Enables transient operation and turns on the channel 1 input. Line 70: Selects channel 2 and turns the input off. Line 80: Selects the CC mode. Line 90: Sets the main current level to 25 A. Line 100: Sets the transient current level to 50 A and the slew to maximum. Line 110: Selects toggled transient operation. Line 120: Enables transient operation and turns on the channel 2 input. Line 130: Sets the internal trigger oscillator frequency to 2 kHz (period of pulses = 0.0005). line 140: Selects the electronic load's internal oscillator as the trigger source. The oscillator starts running as soon as this line is executed.

Battery Testing Example

The principal measurement of a battery's performance is its rated capacity. The capacity of a fully charged battery, at a fixed temperature, is defined as the product of the rated discharge current in amperes and the discharge time in hours, to a specified minimum termination voltage in volts (see figure 3-5). A battery is considered completely discharged when it reaches the specified minimum voltage called the "end of discharge voltage" (EODV).

Figure 3-5. Typical Discharge Curve

In this example, the electronic load discharges three nickel-cadmium batteries to determine their discharge rates at a fixed temperature (see Figure 3-6). The batteries are connected in series so that when the EODV is reached, it is still above the minimum operating voltage of the electronic load. The EODV for nickel-cadmium batteries is typically 1.0 volts.

3 - Programming Examples

Figure 3-6. Batteries in Series

Battery Test Example Program

l0 ! Battery Test Example Program 20 ! 30 Eodv=l.0 ! End of discharge voltage for single cell 40 Number_of_cells=3 ! Number of cells to be discharged in series 50 Discharge_at=.05 ! Constant current discharge rate in amperes 60 ! 70 OUTPUT 705; 80 OUTPUT 705;"FUNCTION CURRENT" ! Sets CC mode 90 OUTPUT 705;"CURRENT:LEVEL";Discharge_at ! Sets the CC level l00 OUTPUT 705;"INPUT ON" ! Enables the input 110 ! 120 Start_time=TIMEDATE ! Records test start time 130 ! 140 Start_test: ! Starts test routine that 150 OUTPUT 705;"MEASURE:VOLTAGE?" ! continuously measures and reads 160 ENTER 705;Sum_of_volts ! back the voltage and current 170 OUTPUT 705;"MEASURE:CURRENT?" ! until batteries are completely 180 ENTER 705;Actual_current ! discharged 190 ! 200 PRINT "Total cell voltage: ";Sum_of_volts 210 PRINT "Actual current: ";Actual_current 220 PRINT "Elapsed time in seconds: ";TIMEDATE-Start_time 230 ! 240 IF Sum_of_volts>(Number_of_cells*Eodv) THEN GOTO Start_test 250 ! Checks if the total voltage is less than the 260 ! sum of the minimum cell voltages of all cells 270 ! 280 OUTPUT 705;"INPUT OFF" ! Disables the input 290 ! 300 END

"CHAN 1;:INPUT OFF" ! Selects Chan 1; Disables input

Programming Examples - 3

Power Supply Testing Example

A typical use for electronic loads when testing power supplies involves power supply burn-in. One of the problems associated with burn-in is what to do if the power supply fails before the test is over. One solution involves continuously monitoring the supply and removing the load if the supply fails during the test (see figure 3-7).

In this example, the electronic load is used to burn-in a power supply at its rated output current. Because the electronic load is operating in CC mode, if the power supply's output current drops below the rated output current during the test, the UNR (unregulated) condition will be set on the electronic load. This can be used to indicate that a failure has occurred on the power supply. If the unregulated condition persists for a specified time, the inputs of the electronic load are turned off.

The purpose of this example is not to illustrate power supply testing, but to explain how to program and use the status registers on the electronic load. The part of the program that runs the test simply monitors the supply at the rated output current for one hour and stops the test. You can replace this portion of the program with your own routine to test the power supply. Although SRQ (service request) is enabled to interrupt only on the UNR bit in this example, you can modify the program to interrupt on other conditions.

Figure 3-7. Typical Burn-In Test

Power Supply Test Example Program

l0 ! Power Supply Test Example Program 20 ! 30 Current=10 ! Load current in amperes 40 Burn_in_time=36000 ! One hour burn-in time 50 ! 60 ON INTR 7 GOSUB Srq_service ! Set up interrupt linkage 70 ENABLE INTR 7;2 ! Enable interrupts for SRQs 80 ! 90 OUTPUT 705; l00 OUTPUT 705;"*SRE 4" ! Enable SRQ (SRQ enable for CSUM) 110 OUTPUT 705;"STAT:CSUM:ENAB 2" ! Enable Chan 1 (channel summary) 120 OUTPUT 705;"STAT:CHAN:ENAB l024" ! Enable UNR bit (channel status) 130 OUTPUT 705;"FUNCTION CURRENT" ! Sets CC mode 140 OUTPUT 705;"CURRENT:LEVEL";Current ! Sets the CC level l50 OUTPUT 705;"INPUT ON" ! Enables the input 160 ! 170 PRINT "Burn-in test started at ";TIME$(TIMEDATE) 180 ! 190 FOR I=1 TO Burn_in_time ! Loop on wait You can write your 200 WAIT .1 ! own power supply test routine and 210 NEXT I ! insert it in this section 220 !

"CHAN 1;:INPUT OFF" ! Selects Chan 1; Disables input

3 - Programming Examples

230 OUTPUT 705;"INPUT OFF" ! Disables the input at end of test 240 PRINT "Burn-in test complete at ";TIME$(TIMEDATE) 250 STOP 260 ! 270 Srq_service ! Service request subroutine 280 Load_status=SPOLL(705) ! Conduct serial poll 290 IF BIT(Load_status, 6) THEN ! Check if SRQ bit is set 300 GOSUB Check_unr 310 ELSE 320 PRINT "A condition other than UNR generated SRQ at ";TIME$(TIMEDATE) 330 END IF ! You can also check the other bits 340 ENABLE INTR 7 ! Re-enable interrupts before return 350 RETURN 360 ! 370 Check_unr ! Check if UNR bit still set 380 WAIT 1 ! Wait 1 s before reading UNR bit 390 OUTPUT 705;"STAT:CHAN:COND?" ! Read channel condition register 400 ENTER 705;Value 410 IF Bit(Value, l0)=0 THEN ! Return value for UNR bit only 420 OUTPUT 705;"*CLS" ! If 0, clear channel event register 430 PRINT "UNR was momentarily asserted at ";TIME$(TIMEDATE) 440 ELSE 450 OUTPUT 705;"INPUT OFF" ! Disables the inputs 460 PRINT "UNR is asserted at ";TIME$(TIMEDATE);" Input is turned off" 470 STOP 480 END IF 490 RETURN 500 END

C++ Programming Example

This program demonstrates the use of lists and triggered measurements in an Agilent N3300A Electronic Load. The load is programmed to step through three values of current at 1 second intervals. At each current step, the load measures its own current by sampling it 50 times at 10 microsecong intervals. The program reads back all of the data, averages the 50 samples for each of the three current steps, and outputs the results. After each current step, the measurement is delayed by 100us to allow the current to settle.

#include <stdio.h> #include <stdlib.h> #include "sicl.h"

#define MEAS_BUF_SIZE 4096 /* Size of measurement buffer in load. */

/* SICL error handler */ void ErrorHandler(INST id, int error) { printf("SICL error %d\n", error); exit(1); }

/* Each triggered measurement consists of nPoints samples. If multiple * triggered measurements are taken, all of the samples (nPoints times the * number of measurements) are placed in the load's measurement buffer. * This function averages the samples in the buffer that are associated * with one triggered measurement. When nIndex is 0, the first set of * nPoints samples are averaged; when nIndex is 1, the 2nd set of nPoints * samples are averaged; etc. */

Programming Examples - 3

double Average(double *pData, int nPoints, int nIndex) { int nStart, nEnd, i; double dSum = 0.0;

nStart = nIndex * nPoints; nEnd = nStart + nPoints; for (i = nStart; i < nEnd; ++i) dSum += pData[i]; return dSum / nPoints; }

void main(int argc, char **argv) { INST Load; int i, nListSteps, nTotalPoints; double aMeasData[MEAS_BUF_SIZE];

/* This array contains the load current values, in Amps. */ double aListData[] = {0.5, 1.0, 1.5};

/* The current steps occur at 1 sec intervals. */ double dListPeriod = 1.0;

/* 50 measurement samples are taken at each current step. */ int nMeasPoints = 50;

/* The measurement samples are taken at 10us intervals. */ double dMeasPeriod = 10e-6;

/* The measurements are delayed by 100us after each current step. */ double dMeasDelay = 100e-6;

/* The total number of measurement samples may not exceed the size of * the load's measurement buffer. */ nListSteps = sizeof(aListData) / sizeof(aListData[0]); nTotalPoints = nMeasPoints * nListSteps; if (nTotalPoints > MEAS_BUF_SIZE) { printf("Total number of measurement points exceeds buffer size.\n"); exit(1); }

/* Set up the SICL error handler. */ ionerror(ErrorHandler);

/* Assume the load is set to the address shown here. */ Load = iopen("hpib7,5"); itimeout(Load, 10000);

/* Put the load current into List mode. */ iprintf(Load, "curr:mode list\n");

/* Send the list of currents to the load. */ iprintf(Load, "list:curr %.4,*lf\n", nListSteps, aListData);

/* Since current is in List mode, all parameters associated with current * must also have lists programmed. All lists must be of the same * length, or they may have a single value as shown below. */ iprintf(Load, "list:curr:slew max\n"); iprintf(Load, "list:curr:range max\n"); iprintf(Load, "list:curr:tlevel 0\n");

3 - Programming Examples

/* We are using trigger-paced lists, so set the list of dwell times to * minimum so no triggers are lost. */ iprintf(Load, "list:dwell min\n");

/* Set trigger-paced lists. */ iprintf(Load, "list:step once\n");

/* Set up the parameters for each triggered measurement. */ iprintf(Load, "sense:sweep:points %d\n", nMeasPoints); iprintf(Load, "sense:sweep:tinterval %lf\n", dMeasPeriod); iprintf(Load, "sense:sweep:offset %lf\n", dMeasDelay);

/* Make sure the load's trigger timer is off by setting the trigger * source to something else. */ iprintf(Load, "trig:source bus\n");

/* Set the period of the trigger timer. */ iprintf(Load, "trig:timer %lf\n", dListPeriod);

/* Set the measurement trigger count, so the measurement system can * be triggered multiple times (by the timer) after being initiated * only once. */ iprintf(Load, "trig:seq2:count %d\n", nListSteps);

/* Initiate the list system and the measurement system. */ iprintf(Load, "init:name list\n"); iprintf(Load, "init:name acq\n");

/* Set the trigger source to Timer. This also starts the timer, so * execution of the load current list and measurements will start here. */ iprintf(Load, "trig:source timer\n");

/* Fetch the array of data. The iscanf() call will not return until * all measurements are complete and the data is available. */ iprintf(Load, "fetch:array:curr?\n"); iflush(Load, I_BUF_READ); iscanf(Load, "%,#lf", &nTotalPoints, &aMeasData);

/* For each list step, average the measurement samples and output the * results. */ for (i = 0; i < nListSteps; ++i) printf("%8.3lf\n", Average(aMeasData, nMeasPoints, i));

/* To output all the measurement samples, uncomment this loop. */ /* for (i = 0; i < nTotalPoints; ++i) * printf("%8.3lf\n", aMeasData[i]); */

}

Language Dictionary

Introduction

This section gives the syntax and parameters for all the IEEE 488.2 SCPI subsystem and common commands used by the electronic loads. It is assumed that you are familiar with the material in chapter 2 "Introduction to Programming". Because the SCPI syntax remains the same for all programming languages, the examples given for each command are generic.

Syntax Forms

Parameters

Channel

Related Commands

Order of Presentation

Syntax definitions use the long form, but only short form headers (or "keywords") appear in the examples. Use the long form to help make your program selfdocumenting.

Most commands require a parameter and all queries will return a parameter. The range for a parameter may vary according to the model of electronic load. Parameters for all models are listed in the Specifications table in the User’s Guide.

If a command only applies to individual channels of a mainframe, the entry Channel Selectable will appear in the command description.

Where appropriate, related commands or queries are included. These are listed because they are either directly related by function, or because reading about them will clarify or enhance your understanding of the original command or query.

The dictionary is organized as follows:

 Subsystem commands, arranged by subsystem  IEEE 488.2 common commands

Subsystem Commands

Subsystem commands are specific to functions. They can be a single command or a group of commands. The groups are comprised of commands that extend one or more levels below the root. The description of common commands follows the description of the subsystem commands.

The subsystem command groups are arranged according to function: Calibration, Channel, Input, List, Measurement, Port, Status, System, Transient, and Trigger. Commands under each function are grouped alphabetically under the subsystem. Commands followed by a question mark (?) take only the query form. When commands take both the command and query form, this is noted in the syntax descriptions.

Appendix A lists all subsystem commands in alphabetical order.

4 - Language Dictionary

Common Commands

Common commands begin with an * and consist of three letters (command) or three letters and a ? (query). They are defined by the IEEE 488.2 standard to perform common interface functions. Common commands and queries are categorized under System, Status, or Trigger functions and are listed at the end of this chapter.

Programming Parameters

The following table lists the electronic load programming parameters. Refer to Appendix A of the User's Guide for programming accuracy and resolution.

Table 4-1. Programming Parameters

Parameter Code1 Model and Value N3302A N3303A N3304A N3305A N3306A N3307A CURR <Nrf+>

CURR:TLEV <Nrf+>

CURR:TRIG <Nrf+> CURR:RANG <Nrf+>

CURR:SLEW <Nrf+>

(amperes/second)

RES <Nrf+> RES:TLEV <Nrf+> RES:TRIG <Nrf+>

1 2 3 4

RES:RANG <Nrf+>

1 2 3 4

RES:SLEW <Nrf+>

(ohms/second)

VOLT <Nrf+> VOLT:TLEV <Nrf+>

VOLT:TRIG <Nrf+> VOLT:RANG <Nrf+>

VOLT:SLEW <Nrf+>

(volts/second)

CURR:PROT <Nrf+> CURR:PROT:DEL <Nrf+> TRAN:FREQ <Nrf+> TRAN:DCYC <Nrf+> TRAN:TWID <Nrf+> TRIG:TIM <Nrf+> TRIG:DEL <Nrf+>

Code: L = Low range 1 = Resistance range 1

H = High range 2 = Resistance range 2 B = Both ranges 3 = Resistance range 3 4 = Resistance range 4

0 - 3A

0 - 30A

≥0 & ≤3A

>3 & ≤30A

500 - 25kA/s 50k - 2.5MA/s

0.067 - 4Ω

3.6 - 40Ω 36 - 400Ω 360 - 2kΩ

≥0 & ≤4Ω

>4& ≤40Ω

>40 & ≤400Ω >400 & ≤2kΩ

44 - 1125Ω/s 2250 - 34kΩ/s

440-11.25kΩ/s

22.5k-340kΩ/s

4.4k-112.5kΩ/s 225k- 3.4MΩ/s 44k-1.125MΩ/s

2.25M-34MΩ/s

0 - 6V

0 - 60V

≥0 & ≤6V

>6 & ≤60V

1k - 50kV/s 100k - 500kV/s

0 - 1A

0 - 10A

≥0 & ≤1A

>1 & ≤10A

167 - 8330A/s

16.7k - 833kA/s

0.2 - 48Ω

44 - 480Ω

440 - 4.8kΩ

4.4k - 12kΩ

≥0 & ≤48Ω

>48&≤480Ω

>480&≤4.8kΩ >4.8k&≤12kΩ

540 - 13.5kΩ/s 27k - 408kΩ/s

5.4k - 135kΩ/s 270k-4.08MΩ/s 54k - 1.35MΩ/s

2.7M- 40.8MΩ/s 540k- 13.5MΩ/s 27M - 408MΩ/s

0 - 24V

0 - 240V

≥0 & ≤24V

>24 & ≤240V

4k - 200kV/s 400k - 2MV/s

0 - 6A

0 - 60A

≥0 & ≤6A

>6 & ≤60A

1k - 50kA/s 100k - 5MA/s

0.033 - 2Ω

1.8 - 20Ω

18 - 200Ω

180 - 2kΩ

≥0 & ≤2Ω >2&≤20Ω

>20&≤200Ω

>200& ≤2kΩ

22 - 560Ω/s 1120 - 17kΩ/s

220 - 5600Ω/s

11.2k-170kΩ/s

2.2k - 56kΩ/s 112k-1.7MΩ/s 22k - 560kΩ/s

1.12M- 17MΩ/s

0 - 6V

0 - 60V

≥0 & ≤6V

>6 & ≤60V

1k - 50kV/s 100k - 500kV/s

0 - 6A

0 - 60A

≥0 & ≤6A

>6 & ≤60A

1k - 50kA/s 100k - 5MA/s

0.033 - 5Ω

4.5 - 50Ω

45 - 500Ω

450 - 2.5kΩ

≥0 & ≤5Ω

>5 & ≤50Ω

>50 & ≤500Ω

>500&≤2.5kΩ

55 - 1400Ω/s 2800 -42.5kΩ/s

550 - 14kΩ/s 28k - 425kΩ/s

5.5k - 140kΩ/s 280k-4.25MΩ/s 55k - 1.4MΩ/s

2.8M-42.5MΩ/s

0 - 15V

0 - 150V

≥0 & ≤15V

>15& ≤150V

2.5k - 125kV/s 250k -1.25MV/s

0 - 12A

0 - 120A

≥0 & ≤12A

>12 & ≤120A

2k - 100kA/s 200k - 10MA/s

0.017 - 1Ω

0.9 - 10Ω 9 - 100Ω 90 - 1kΩ

≥0 & ≤1Ω

>1 & ≤10Ω

>10 & ≤100Ω >100 & ≤1kΩ

11 - 280Ω/s 560 - 8.5kΩ/s

110 - 2800Ω/s 5600 - 85kΩ/s

1.1k - 28kΩ/s 56k - 850kΩ/s 11k - 280kΩ/s 560k - 8.5MΩ/s

0 - 6V

0 - 60V

≥0 & ≤6V

>6 & ≤60V

1k - 50kV/s 100k - 500kV/s

0 - 3A

0 - 30A

≥0 & ≤3A

>3 & ≤30A

500 - 25kA/s 50k - 2.5MA/s

0.067 - 10Ω 9 - 100Ω 90 - 1kΩ

900 - 2.5kΩ

≥0 & ≤10Ω

>10 & ≤100Ω

>100 & ≤1kΩ

>1k & ≤2.5kΩ

110 - 2800Ω/s 5600 - 85kΩ/s

1.1k - 28kΩ/s 56k - 850kΩ/s 11k - 280kΩ/s 560k - 8.5MΩ/s 110k - 2.8MΩ/s

5.6M - 85MΩ/s

0 - 15V

0 - 150V

≥0 & ≤15V

>15& ≤150V

2.5k - 125kV/s 250k -1.25MV/s

0 - 30.6A 0 - 10.2A 0 - 61.2A 0 - 61.2A 0 - 122.4A 0 - 30.6A

0 - 60s

0.25Hz - 10kHz

1.8% - 98.2% 50µs - 4s

8µs - 4s

0 - 0.032s

Language Dictionary - 4

Calibration Commands

Calibration commands let you:

 Enable and disable the calibration mode  Change the calibration password  Calibrate the input functions, current monitor offset and gain, and store new calibration constants

in nonvolatile memory.

CALibrate:DATA

This command is only used in calibration mode. It enters a calibration value that you obtain by reading an external meter. You must first select a calibration level (with CALibrate:LEVel) for the value being entered. These constants are not stored in nonvolatile memory until they are saved with CALibrate:SAVE. If CALibrate:STATE OFF is programmed without a CALibrate:SAVE, the previous calibration constants are restored.

Command Syntax

Parameters

Examples

Related Commands

CALibrate:DATA <NRf> {,<NRf>,<NRf>} <external reading>

CAL:DATA 3222.3 CAL:DATA 5.000

CAL:STAT CAL:SAV

CALibrate:IMON:LEVel

This command can only be used in calibration mode. It is used to set the two calibration points of the analog current monitor signal.

Command Syntax

Parameters

Examples

Related Commands

CALibrate:IMON:LEVel <level> P1 | P2

CAL:LEV P2

CAL:STAT CAL:SAV

CALibrate:IPR:LEVel

This command can only be used in calibration mode. It is used to set the four calibration points for calibrating the gains of the analog current monitor signal and the analog current programming signal.

Command Syntax

Parameters

Examples

Related Commands

CALibrate:IPRog:LEVel <level> P1 | P2 | P3 | P4

CAL:LEV P2

CAL:STAT CAL:SAV

CALibrate:LEVel

This command can only be used in calibration mode. It is used to set the two calibration points of the presently selected FUNCtion and RANGe.

Command Syntax

Parameters

Examples

Related Commands

CALibrate:LEVel <level> P1 | P2

CAL:LEV P2

CAL:STAT CAL:SAV

4 - Language Dictionary

CALibrate:PASSword

This command can only be used in calibration mode. It allows you to change the calibration password. The new password is not saved until you send the CALibrate:SAVE command. If the password is set to 0, password protection is removed and the ability to enter the calibration mode is unrestricted.

Command Syntax

Parameters

Examples

Related Commands

CALibrate:PASSword <NRf> 0 (default)

CAL:PASS N3301A CAL:PASS 02.1997

CAL:STAT

CALibrate:SAVE

This command can only be used in calibration mode. It saves any new calibration constants (after a current or voltage calibration procedure has been completed) in nonvolatile memory.

Command Syntax

Parameters

Examples

Related Commands

CALibrate:SAVE None

CAL:SAVE

CAL:STAT

CALibrate:STATe

This command enables and disables calibration mode. The calibration mode must be enabled before the load will accept any other calibration commands. The first parameter specifies the enabled or disabled state. The second parameter is the password. It is required if the calibration mode is being enabled and the existing password is not 0. If the password is not entered or is incorrect, an error is generated and the calibration mode remains disabled. The query statement returns only the state, not the password.

Whenever the calibration state is changed from enabled to disabled, any new calibration constants are lost unless they have been stored with CALibrate:SAVE.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

CALibrate:STATe <bool> [,<NRf>] 0 | 1 | OFF | ON [,<password>] OFF

CAL:STAT 1, N3301A CAL:STAT OFF

CALibrate:STATe? <NR1> CAL:PASS CAL:SAVE

Language Dictionary - 4

Channel Commands

These commands program the channel selection capability of the electronic load. The CHANnel and INSTrument commands are equivalent.

CHANnel INSTrument

These commands select the multiple electronic load channel to which all subsequent channel-specific commands will be directed. If the specified channel number does not exist or is outside the MIN/MAX range, an error code is generated (see appendix C). Refer to the installation section of the User's Guide for more information about channel number assignments.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

CHANnel[:LOAD] <NRf+> INSTrument[:LOAD] <NRf+> 1 - 6 1

CHAN:LOAD 3 INST 2

CHANnel? (NOTE: Use CHAN? MAX to return the number of channels installed in a load mainframe) <NR1>

4 - Language Dictionary

Input Commands

These commands control the input of the electronic load. The INPut and OUTput commands are equivalent. The CURRent, RESistance and VOLTage commands program the actual input current, resistance, and voltage.

[SOURce:]INPut [SOURce:]OUTPut

Channel Specific

These commands enable or disable the electronic load inputs. The state of a disabled input is a high impedance condition.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]INPut[:STATe] <bool> [SOURce:]OUTPut[:STATe] <bool> 0 | 1 | OFF | ON ON

INP 1 OUTP:STAT ON

INPut[:STATe]? OUTPut[:STATe]? 0 | 1 *RCL *SAV

[SOURce:]INPut:PROTection:CLEar [SOURce:]OUTput:PROTection:CLEar

Channel Specific

These commands clear the latch that disables the input when a protection condition such as overvoltage (OV) or overcurrent (OC) is detected. All conditions that generated the fault must be removed before the latch can be cleared. The input is then restored to the state it was in before the fault condition occurred.

Command Syntax

Parameters

Examples

Related Commands

[SOURce:]INPut:PROTection:CLEar [SOURce:]OUTPut:PROTection:CLEar None

OUTP:PROT:CLE

OUTP:PROT:DEL *SAV *RCL

[SOURce:]INPut:SHORt [SOURce:]OUTPut:SHORt

Channel Specific

This command programs the specified electronic load module to the maximum current that it can sink in the present operating range.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]INPut:SHORt <bool> [SOURce:]OUTPut:SHORt <bool> 0 | 1 | OFF | ON OFF

INP:SHOR 1 OUTP:SHOR ON

INPut:SHORt? 0 | 1 INP OUTP

Language Dictionary - 4

[SOURce:]CURRent

Channel Specific

This command sets the current that the load will regulate when operating in constant current mode. Refer to Table 4-1 for model-specific programming ranges.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]CURRent[:LEVel][:IMMediate][:AMPLitude] <NRf+> 0 through MAX | MINimum | MAXimum A (amperes) MINimum

CURR 5 CURR:LEV .5

[SOURce:]CURRent[:LEVel][:IMMediate][:AMPLitude]? <NR3> CURR:TLEV CURR:MODE

[SOURce:]CURRent:MODE

Channel Specific

This command determines whether the current settings are controlled by values in a list or by the CURRent command setting.

FIXed LIST

Returned Parameters

The current settings are determined by the CURRent command. The current settings are determined by the active list.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Related Commands

[SOURce:]CURRent:MODE <mode> FIXed | LIST FIXed

CURR:MODE FIX

[SOURce:]CURRent:MODE? <CRD> CURR: CURR:TRIG

[SOURce:]CURRent:PROTection

Channel Specific

This command sets the soft current protection level. If the input current exceeds the soft current protection level for the time specified by CURR:PROT:DEL, the input is turned off. Refer to Table 4-1 for modelspecific programming ranges.

NOTE: Use CURR:PROT:DEL to prevent momentary current limit conditions caused by

programmed changes from tripping the overcurrent protection.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]CURRent:PROTection[:LEVel] <NRf+> 0 through MAX | MINimum | MAXimum A (amperes) MAXimum

CURR:PROT 2

[SOURce:]CURRent:PROTection? 0 | 1 CURR:PROT:DEL CURR:PROT:STAT

4 - Language Dictionary

[SOURce:]CURRent:PROTection:DELay

Channel Specific

This command specifies the time that the input current can exceed the protection level before the input is turned off.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]CURRent:PROTection:DELay <NRf+> 0 to 60 seconds seconds 0

CURR:PROT:DEL .5

[SOURce:]CURRent:PROTection:DELay? <NR3> CURR:PROT CURR:PROT:STAT

[SOURce:]CURRent:PROTection:STATe

Channel Specific

This command enables or disables the over-current protection feature.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]CURRent:PROTection:STATe <Bool> 0 | 1 | OFF | ON OFF

CURR:PROT:STAT 1 CURR:PROT:STAT ON

[SOURce:]CURRent:PROTection:STATe? <NR3> CURR:PROT

[SOURce:]CURRent:RANGe

Channel Specific

This command sets the current range of the electronic load module. There are two current ranges.

High Range: model dependent, see Table 4-1 Low Range: model dependent, see Table 4-1

When you program a range value, the load automatically selects the range that corresponds to the value that you program. If the value falls in a region where ranges overlap, the load selects the range with the highest resolution.

NOTE: When this command is executed, the IMMediate, TRANsient, TRIGgered, and SLEW

current settings are adjusted as follows:

If the existing settings are within the new range: No adjustment is made. If the existing settings are outside the new range: The levels are set to the

maximum value of the new range.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]CURRent:RANGe <NRf+> 0 through MAX | MINimum | MAXimum A (amperes)

Unit

MAXimum (high range)

SOUR:CURR:RANGE MIN

[SOURce:]CURRent:RANGe? <NR3> CURR CURR:SLEW

Language Dictionary - 4

[SOURce:]CURRent:SLEW

Channel Specific

This command sets the slew rate for all programmed changes in the input current level of the electronic load. This command programs both positive and negative going slew rates. Although any slew rate value may be entered, the electronic load selects a slew rate that is closest to the programmed value. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rates greater than the maximum value are set to MAXimum.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]CURRent:SLEW[:BOTH] <NRf+> 0 to 9.9E37 | MAXimum | MINimum A (amps per second) MAXimum

CURR:SLEW 50 CURR:SLEW MAX

[SOURce:]CURRent:SLEW[:BOTH]? <NR3> CURR:SLEW:NEG CURR:SLEW:POS

[SOURce:]CURRent:SLEW:NEGative

Channel Specific

This command sets the slew rate of the current for negative going transitions. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]CURRent:SLEW:NEGative <NRf+> 0 to 9.9E37 | MAXimum | MINimum A (amps per second) MAXimum

CURR:SLEW:NEG 50 CURR:SLEW:NEG MAX

[SOURce:]CURRent:SLEW:NEGative? <NR3> CURR:SLEW

[SOURce:]CURRent:SLEW:POSitive

Channel Specific

This command sets the slew rate of the current for positive going transitions. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]CURRent:SLEW:POSitive <NRf+> 0 to 9.9E37 | MAXimum | MINimum A (amps per second) MAXimum

CURR:SLEW:POS 50 CURR:SLEW:POS MAX

[SOURce:]CURRent:SLEW:POSitive? <NR3> CURR:SLEW

4 - Language Dictionary

[SOURce:]CURRent:TLEVel

Channel Specific

This command specifies the transient level of the input current. The transient function switches between the immediate setting and the transient level. Refer to Table 4-1 for model-specific programming ranges.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]CURRent:TLEVel <NRf+> 0 through MAX | MINimum | MAXimum A (amperes) MAXimum

CURR:TLEV 5 CURR:TLEV .5

[SOURce:]CURRent:TLEVel? <NR3> CURR:

[SOURce:]CURRent:TRIGgered

Channel Specific

This command sets the current level that will become active when the next trigger occurs.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]CURRent[:LEVel]:TRIGgered[:AMPLitude] <NRf+> refer to Specifications Table in User’s Guide A (amperes) MINimum

CURR:TRIG 15

[SOURce:]CURRent:TRIG? <NR3> (if the trigger level is not programmed, the immediate level is returned) CURR: CURR:MODE

[SOURce:]FUNCtion [SOURce:]MODE

Channel Specific

These equivalent commands select the input regulation mode of the electronic load.

CURRent RESistance VOLTage

Returned Parameters

Equivalent Commands

constant current mode constant resistance mode constant voltage mode

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Related Commands

[SOURce:]FUNCtion <function> [SOURce:]MODE <function> CURRent | RESistance | VOLTage CURRent

FUNC RES MODE VOLT

[SOURce:]FUNCtion? [SOURce:]MODE? <CRD> FUNC MODE FUNC TRIG VOLT MODE:CURR MODE:RES MODE:VOLT

Language Dictionary - 4

[SOURce:]FUNCtion:MODE

Channel Specific

This command determines whether the input regulation mode is controlled by values in a list or by the FUNCtion command setting.

FIXed LIST

Returned Parameters

The regulation mode is determined by the FUNCtion or MODE command. The regulation mode is determined by the active list.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Related Commands

[SOURce:]FUNCtion:MODE <mode> FIXed | LIST FIXed

FUNC:MODE FIX

[SOURce:]FUNCtion:MODE? <CRD> FUNC MODE

[SOURce:]RESistance

Channel Specific

This command sets the resistance of the load when operating in constant resistance mode. Refer to Table 4-1 for model-specific programming ranges.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]RESistance[:LEVel][:IMMediate][:AMPLitude] <NRf+> 0 through MAX | MINimum | MAXimum Ω (ohms) MAXimum

RES 5 RES:LEV .5

[SOURce:]RESistance[:LEVel][:IMMediate][:AMPLitude]? <NR3> RES:TLEV RES:MODE

[SOURce:]RESistance:MODE

Channel Specific

This command determines whether the resistance setting is controlled by values in a list or by the RESistance command setting.

FIXed LIST

Returned Parameters

The resistance setting is determined by the RESistance command. The resistance setting is determined by the active list.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Related Commands

[SOURce:]RESistance:MODE <mode> FIXed | LIST FIXed

RES:MODE FIX

[SOURce:]RESistance:MODE? <CRD> RES: RES:TRIG

4 - Language Dictionary

[SOURce:]RESistance:RANGe

Channel Specific

This command sets the resistance range of the electronic load module. There are four resistance ranges, the values of which are model dependent. Refer to Table 4-1 for the resistance ranges of each electronic load model.

NOTE: When this command is executed, the IMMediate, TRANsient, TRIGgered, and SLEW

resistance settings are adjusted as follows:

If the existing settings are within the new range: No adjustment is made. If the existing settings are outside the new range: The levels are set to either the

maximum or minimum value of the new range, depending on which they are closest to.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]RESistance:RANGe <NRf+> 0 through MAX | MINimum | MAXimum Ω (ohms) MAXimum (high range)

RES:RANG 15 SOUR:RES:RANGE MIN

[SOURce:]RESistance:RANGe? <NR3> RES RES:SLEW

[SOURce:]RESistance:SLEW

Channel Specific

This command sets the slew rate for all programmed changes in the resistance level of the electronic load. This command programs both positive and negative going slew rates. Although any slew rate value may be entered, the electronic load selects a slew rate that is closest to the programmed value. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rates greater than the maximum value are set to MAXimum.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]RESistance:SLEW[:BOTH] <NRf+> 0 to 9.9E37 | MAXimum | MINimum Ω (ohms/second) MAXimum

RES:SLEW 50 RES:SLEW MAX

[SOURce:]RESistance:SLEW[:BOTH]? <NR3> RES:SLEW:POS RES:SLEW :NEG

[SOURce:]RESistance:SLEW:NEGative

Channel Specific

This command sets the slew rate of the resistance for negative going transitions. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate.

Language Dictionary - 4

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]RESistance:SLEW:NEGative <NRf+> 0 to 9.9E37 | MAXimum | MINimum Ω (ohms/second) MAXimum

RES:SLEW:NEG 50 RES:SLEW:NEG MAX

[SOURce:]RESistance:SLEW:NEGative? <NR3> RES:SLEW

[SOURce:]RESistance:SLEW:POSitive

Channel Specific

This command sets the slew rate of the resistance for positive going transitions. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]RESistance:SLEW:POSitive <NRf+> 0 to 9.9E37 | MAXimum | MINimum Ω (ohms/second) MAXimum

RES:SLEW:POS 50 RES:SLEW:POS MAX

[SOURce:]RESistance:SLEW:POSitive? <NR3> RES:SLEW

[SOURce:]RESistance:TLEVel

Channel Specific

This command specifies the transient level of the resistance. The transient function switches between the immediate setting and the transient level. Refer to Table 4-1 for model-specific programming ranges.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]RESistance:TLEVel <NRf+> 0 through MAX | MINimum | MAXimum Ω (ohms) MAXimum

RES:TLEV 5 RES:TLEV .5

[SOURce:]RESistance:TLEVel? <NR3> RES:

[SOURce:]RESistance:TRIGgered

Channel Specific

This command sets the resistance level that will become active when the next trigger occurs.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]RESistance[:LEVel]:TRIGgered[:AMPLitude] <NRf+> refer to Specifications Table in User’s Guide Ω (ohms) MAXimum

RES:TRIG 120 RES:LEV:TRIG 150

[SOURce:]RESistance[:LEVel]:TRIGgered[:AMPLitude]? <NR3> (if the trigger level is not programmed, the immediate level is returned) RES RES:MODE

4 - Language Dictionary

[SOURce:]VOLTage

Channel Specific

This command sets the voltage that the load will regulate when operating in constant voltage mode. Refer to Table 4-1 for model-specific programming ranges.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]VOLTage[:LEVel][:IMMediate][:AMPLitude] <NRf+> 0 through MAX | MINimum | MAXimum V (volts) MAXimum

VOLT 5 VOLT:LEV .5

[SOURce:]VOLTage[:LEVel][:IMMediate][:AMPLitude]? <NR3> VOLT:TLEV VOLT:MODE

[SOURce:]VOLTage:MODE

Channel Specific

This command determines whether the voltage setting is controlled by values in a list or by the VOLTage command setting.

FIXed LIST

Returned Parameters

The voltage setting is determined by the VOLTage command. The voltage setting is determined by the active list.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Related Commands

[SOURce:]VOLTage:MODE <mode> FIXed | LIST FIXed

VOLT:MODE FIX

[SOURce:]VOLTage:MODE? <CRD> VOLT: VOLT:TRIG

[SOURce:]VOLTage:RANGe

Channel Specific

This command sets the voltage range of the electronic load module. There are two voltage ranges.

High Range: model dependent, see Table 4-1 Low Range: model dependent, see Table 4-1

NOTE: When this command is executed, the IMMediate, TRANsient, TRIGgered, and SLEW

voltage settings are adjusted as follows:

If the existing settings are within the new range: No adjustment is made. If the existing settings are outside the new range: The levels are set to the

maximum value of the new range.

Language Dictionary - 4

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]VOLTage:RANGe <NRf+> 0 through MAX | MINimum | MAXimum V (volts) MAXimum (high range)

VOLT:RANG 15 SOUR:VOLT:RANGE MIN

[SOURce:]VOLTage:RANGe? <NR3> VOLT VOLT:SLEW

[SOURce:]VOLTage:SLEW

Channel Specific

This command sets the slew rate for all programmed changes in the input voltage level of the electronic load. This command programs both positive and negative going slew rates. Although any slew rate value may be entered, the electronic load selects a slew rate that is closest to the programmed value. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rates greater than the maximum value are set to MAXimum.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]VOLTage:SLEW[:BOTH] <NRf+> 0 to 9.9E37 | MAXimum | MINimum V (volts per second) MAXimum

VOLT:SLEW 50 VOLT:SLEW MAX

[SOURce:]VOLTage:SLEW[:BOTH]? <NR3> VOLT:SLEW:POS VOLT:SLEW:NEG

[SOURce:]VOLTage:SLEW:NEGative

Channel Specific

This command sets the slew rate of the voltage for negative going transitions. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]VOLTage:SLEW:NEGative <NRf+> 0 to 9.9E37 | MAXimum | MINimum V (volts per second) MAXimum

VOLT:SLEW:NEG 50 VOLT:SLEW:NEG MAX

[SOURce:]VOLTage:SLEW:NEGative? <NR3> VOLT:SLEW

4 - Language Dictionary

[SOURce:]VOLTage:SLEW:POSitive

Channel Specific

This command sets the slew rate of the voltage for positive going transitions. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]VOLTage:SLEW:POSitive <NRf+> 0 to 9.9E37 | MAXimum | MINimum V (volts per second) MAXimum

VOLT:SLEW:POS 50 VOLT:SLEW:POS MAX

[SOURce:]VOLTage:SLEW:POSitive? <NR3> VOLT:SLEW

[SOURce:]VOLTage:TLEVel

Channel Specific

This command specifies the transient level of the input voltage. The transient function switches between the immediate setting and the transient level. Refer to Table 4-1 for model-specific programming ranges.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]VOLTage:TLEVel <NRf+> 0 through MAX | MINimum | MAXimum V (volts) MAXimum

VOLT:TLEV 5 VOLT:TLEV .5

[SOURce:]VOLTage:TLEVel? <NR3> VOLT:

[SOURce:]VOLTage:TRIGgered

Channel Specific

This command sets the voltage level that will become active when the next trigger occurs.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]VOLTage[:LEVel]:TRIGgered[:AMPLitude] <NRf+> refer to Specifications Table in User’s Guide V (volts) MAXimum

VOLT:TRIG 120 VOLT:LEV:TRIG 150

[SOURce:]VOLTage[:LEVel]:TRIGgered[:AMPLitude]? <NR3> (if the trigger level is not programmed, the immediate level is returned) VOLT VOLT:MODE

Language Dictionary - 4

Measurement Commands

Measurement commands consist of measurement and sense commands.

Two measurement commands are available: MEASure and FETCh. MEASure triggers the acquisition of new data before returning the readings from the array. FETCh returns previously acquired data from the array. Only input current and voltage are actually measured. Power is calculated from the stored voltage and current data. The input voltage and current are digitized whenever a measure command is given or whenever an acquire trigger occurs. The time interval of the measurement is set by SENSe:SWEep:TINTerval, and the position of the trigger relative to the beginning of the data buffer is determined by SENSe:SWEep:OFFSet.

Sense commands control the measurement range, the acquisition sequence, and the measurement window of the electronic load.

ABORt

This command resets the measurement and list trigger systems to the Idle state. Any measurement or list that is in progress is immediately aborted. ABORt also resets the WTG bit in the Operation Condition Status register (see chapter 3 under “Programming the Status Registers”). ABORt is executed at power turn-on and upon execution of *RCL, RST, or any implied abort command (see List Commands).

NOTE: If INITiate:CONTinuous ON has been programmed, the trigger system initiates itself

immediately after ABORt, thereby setting the WTG bit.

Command Syntax

Parameters

Examples

Related Commands

ABORt None

ABOR

INIT *RST *TRG TRIG

MEASure:ARRay:CURRent? FETCh:ARRay:CURRent?

Channel Specific

These queries return an array containing the instantaneous input current.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:ARRay:CURRent[:DC]? FETCh:ARRay:CURRent[:DC]? None

MEAS:ARR:CURR? FETC:ARR:CURR?

4096 NR3 values MEAS:ARR:VOLT?

MEASure:ARRay:POWer? FETCh:ARRay:POWer?

Channel Specific

These queries return an array containing the instantaneous input power. The power is calculated from the instantaneous voltage and current data points.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:ARRay:POWer[:DC]? FETCh:ARRay:POWer[:DC]? None

MEAS:ARR:POW? FETC:ARR:POW?

4096 NR3 values MEAS:ARR:VOLT?

4 - Language Dictionary

MEASure:ARRay:VOLTage? FETCh:ARRay:VOLTage?

Channel Specific

These queries return an array containing the instantaneous input voltage.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:ARRay:VOLTage[:DC]? FETCh:ARRay:VOLTage[:DC]? None

MEAS:ARR:VOLT? FETC:ARR:VOLT?

4096 NR3 values MEAS:ARR:CURR?

MEASure:CURRent? FETCh:CURRent?

Channel Specific

These queries return the average value of the input current.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:CURRent[:DC]? FETCh:[SCALar]:CURRent[:DC]? None

MEAS:CURR? FETC:CURR?

<NR3> MEAS:VOLT?

MEASure:CURRent:ACDC? FETCh:CURRent:ACDC?

Channel Specific

These queries return the total rms measurement, including the dc portion.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:CURRent:ACDC? FETCh:[SCALar]:CURRent:ACDC? None

MEAS:CURR:ACDC? FETC:CURR:ACDC?

<NR3> MEAS:VOLT:ACDC? MEAS:CURR:AMPL:MAX?

MEASure:CURRent:MAXimum? FETCh:CURRent:MAXimum?

Channel Specific

These queries return the value of the maximum data point in the input current measurement.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:CURRent:MAXimum? FETCh:[SCALar]:CURRent:MAXimum? None

MEAS:CURR:MAX? FETC:CURR:MAX?

<NR3> MEAS:CURR:ACDC?

Language Dictionary - 4

MEASure:CURRent:MINimum? FETCh:CURRent:MINimum?

Channel Specific

These queries return the value of the minimum data point in the input current measurement.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:CURRent:MINimum? FETCh:[SCALar]:CURRent:MINimum? None

MEAS:CURR:MIN? FETC:CURR:MIN?

<NR3> MEAS:CURR:ACDC?

MEASure:POWer? FETCh:POWer?

Channel Specific

These queries return the average value of the input power in watts.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:POWer[:DC]? FETCh:[SCALar]:POWer[:DC]? None

MEAS:POW? FETC:POW?

<NR3> MEAS:POW:MAX?

MEASure:POWer:MAXimum? FETCh:POWer:MAXimum?

Channel Specific

These queries return the value of the maximum data point in the input power measurement.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:POWer:MAXimum? FETCh:[SCALar]:POWer:MAXimum? None

MEAS:POW:MAX? FETC:POW:MAX?

<NR3> MEAS:POW? MEAS:POW:MIN?

MEASure:POWer:MINimum? FETCh:POWer:MINimum?

Channel Specific

These queries return the value of the minimum data point in the input power measurement.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:POWer:MINimum? FETCh:[SCALar]:POWer:MINimum? None

MEAS:POW:MIN? FETC:POW:MIN?

<NR3> MEAS:POW? MEAS:POW:MAX?

4 - Language Dictionary

MEASure:VOLTage? FETCh:VOLTage?

Channel Specific

These queries return the average value of the input voltage.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:VOLTage[:DC]? FETCh:[SCALar]:VOLTage[:DC]? None

MEAS:VOLT? FETC:VOLT?

<NR3> MEAS:CURR? MEAS:VOLT:ACDC?

MEASure:VOLTage:ACDC? FETCh:VOLTage:ACDC?

Channel Specific

These queries return the rms value of the input voltage. This returns the total rms measurement, including the dc portion.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:VOLTage:ACDC? FETCh:[SCALar]:VOLTage:ACDC? None

MEAS:VOLT:ACDC? FETC:VOLT:ACDC?

<NR3> MEAS:CURR:ACDC? MEAS:VOLT?

MEASure:VOLTage:MAXimum? FETCh:VOLTage:MAXimum?

Channel Specific

These queries return the maximum value of the input voltage.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:VOLTage:MAXimum? FETCh:[SCALar]:VOLTage:MAXimum? None

MEAS:VOLT:MAX? FETC:VOLT:MAX?

<NR3> MEAS:VOLT:ACDC? MEAS:VOLT?

MEASure:VOLTage:MINimum? FETCh:VOLTage:MINimum?

Channel Specific

These queries return the minimum value of the input voltage.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

MEASure:[SCALar]:VOLTage:MINimum? FETCh:[SCALar]:VOLTage:MINimum? None

MEAS:VOLT:MIN? FETC:VOLT:MIN?

<NR3> MEAS:VOLT:ACDC? MEAS:VOLT?

Language Dictionary - 4

SENSe:CURRent:RANGe

Channel Specific

This command sets the current measurement range. There are two current measurement ranges:

High Range: model dependent, see Table 4-1 Low Range: model dependent, see Table 4-1

A value of infinity is returned if the measured value is outside the specified current measurement range.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

SENSe:CURRent:RANGe <NRf+> 0 through MAX | MINimum | MAXimum A (amperes)

Unit

MAX (high range)

SENS:CURR:RANGE MIN

SENSe:CURRent:RANGe? <NR3>

SENSe:SWEep:POINts

Channel Specific

This command specifies how many data points are taken in any measurement. Applies to both voltage and current measurements. The number of points can be specified, from 1 to 4096.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

SENSe:SWEep:POINts <NRf+> 1 through 4096 | MINimum | MAXimum 1000

SENS:SWE:POIN 2048

SENSe:SWEep:POINts? <NR3> SENS:SWE:TINT MEAS:ARR

SENSe:SWEep:OFFSet

Channel Specific

This command specifies a delay time after the trigger, but before the measurement is taken. The delay is specified in seconds. The measurement offset can be either positive or negative with respect to the trigger.

NOTE: Negative measurement offsets can only be programmed in conjunction with delayed

triggers. The negative measurement offset cannot exceed the trigger delay value.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

SENSe:SWEep:OFFSet <NRf+> 0 through 0.032 | MINimum | MAXimum seconds 0 (zero)

SENS:SWE:OFFS 0.01

SENSe:SWEep:OFFSet? <NR3> SENS:SWE:TINT MEAS:ARR

4 - Language Dictionary

SENSe:SWEep:TINTerval

Channel Specific

This command defines the time period between measurement points. The time interval can be programmed from 0.00001 to 0.032 seconds in 10 microsecond increments.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

SENSe:SWEep:TINTerval <NRf+>

0.00001 - 0.032 | MAXimum | MINimum seconds 10 µs

SENS:SWE:TINT 100E-6

SENSe:SWEep:TINTerval? <NR3> SENS:SWE:OFFS:POIN MEAS:ARR

SENSe:WINDow

Channel Specific

This command sets the window function that is used in dc and ac+dc rms measurement calculations. The following functions can be selected:

HANNing

RECTangular

A signal conditioning window that reduces errors in dc and rms measurement calculations in the presence of periodic signals such as line ripple. It also reduces jitter when measuring successive pulses. The Hanning window multiplies each point in the measurement sample by the function cosine when measuring single-shot pulses. A window that returns measurement calculations without any signal conditioning.

. Do not use the Hanning window

NOTE: Neither window function alters the voltage or current data in the measurement array.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

SENSe:WINDow[:TYPE] <type> RECTangular | HANNing RECTangular

SENS:WIND HANN

SENSe:WINDow? <CRD>

SENSe:VOLTage:RANGe

Channel Specific

This command sets the voltage measurement range. There are two voltage measurement ranges:

High Range: model dependent, see Table 4-1 Low Range: model dependent, see Table 4-1

A value of infinity is returned if the measured value is outside the specified voltage measurement range.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

SENSe:VOLTage:RANGe[:UPPer] <NRf+> 0 through MAX | MINimum | MAXimum V (voltage)

Unit

MAX (high range)

SENS:VOLT:RANGE MIN

SENSe:VOLTage:RANGe? <NR3> SENS:SWE:TINT MEAS:ARR

Language Dictionary - 4

Port Commands

These commands control the general purpose digital port on the electronic load modules.

PORT0

Channel Specific

This command sets the state of the general purpose digital port on the specified electronic load module. A value of 1 sets the state high, a 0 sets the state low.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

PORT1

PORT0[:STATe] <bool> 0 | 1 | OFF | ON OFF

PORT0 1 PORT0 0N

PORT0[:STATe]? 0 | 1 PORT1

This command sets the state of the two general purpose digital ports on the mainframe. The value that you send is the equivalent of a 2-bit binary word. Use the following values to set the individual bits. Note that the digital port on the mainframe can also be programmed using lists.

value Dig 2 Dig 1

0 Lo Lo 1 Lo Hi 2 Hi Lo 3 Hi Hi

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

PORT1[:LEVel] <NR1> 0 | 1 | 2 | 3 0

PORT1 1 PORT1 3

PORT1? <NR3> PORT0

4 - Language Dictionary

List Commands

List commands let you program complex sequences of input changes with rapid, precise timing, and synchronized with trigger signals. Each function for which lists can be generated has a list of values that specify the input at each list step. MODE commands such as VOLTage:MODE LIST are used to activate specific functions. LIST:COUNt determines how many times the unit sequences through a list before that list is completed. LIST:DWELl specifies the time interval that each value (step) of a list is to remain in effect. LIST:STEP determines if a trigger causes a list to advance only to its next step or to sequence through all of its steps.

NOTE: The LIST:DWELl command is active whenever any function is set to list mode. Therefore,

a LIST:DWELl time must always be specified whenever any list function is programmed.

The list data is given in the list command parameters, which are separated by commas. The order in which the data is entered determines the sequence in which the data is programmed when a list is triggered. Changing list data while a list is running generates an implied ABORt.

All functions that are set to LIST mode must have the same number of steps (up to 50), or an error is generated when the INITiate command is sent. The only exception is a list consisting of only one step. Such a list is treated as if it had the same number of steps as the other lists, with all of the implied step having the same value as the one specified step. All list point data can be stored in nonvolatile memory.

[SOURce:]LIST:COUNt

This command sets the number of times that the list is executed before it is completed. The command accepts parameters in the range 1 through 9.9E37, but any number greater than 2E9 is interpreted as infinity. Use INFinity to execute a list indefinitely. This command is not channel specific, it applies to the entire mainframe.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:COUNt <NRf+> | INFinity 1 to 9.9E37 | MINimum | MAXimum | INFinity 1

LIST:COUN 3 LIST:COUN INF

[SOURce:]LIST:COUNt? <NR3> LIST:CURR LIST:FREQ LIST:TTLT LIST:VOLT

[SOURce:]LIST:CURRent [SOURce:]LIST:CURRent:POINts?

Channel Specific

This command specifies the current setting for each list step. Refer to Table 4-1 for model-specific programming ranges. LIST:CURRent:POINts returns the number of points programmed.

Command Syntax

Parameters

Unit

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:CURRent[:LEVel] <NRf+> {,<NRf+>} 0 through MAX | MINimum | MAXimum A (amperes)

LIST:CURR 2.5,3.0,3.5 LIST:CURR MAX,3.5,2.5,MIN

[SOURce:]LIST:CURRent[:LEVel]? [SOURce:]LIST:CURRent:POINts? <NR3> {,<NR3>} CURR

Language Dictionary - 4

[SOURce:]LIST:CURRent:RANGe [SOURce:]LIST:CURRent:RANGe:POINts?

Channel Specific

This command sets the current range for each list step. There are two current ranges.

High Range: model dependent, see Table 4-1 Low Range: model dependent, see Table 4-1

NOTE: If the existing IMMediate, TRANsient, and TRIGgered current list settings are outside the

new range, a list error is generated when the list is initiated and the list does not execute.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:CURRent:RANGe <NRf+> {,<NRf+>} 0 through MAX | MINimum | MAXimum A (amperes)

Unit

MAXimum (high range)

LIST:CURR:RANGE MIN

[SOURce:]LIST:CURRent:RANGe? [SOURce:]LIST:CURRent:RANGe:POINts? <NR3> {,<NR3>} CURR:RANG

[SOURce:]LIST:CURRent:SLEW [SOURce:]LIST:CURRent:SLEW:POINts?

Channel Specific

This command sets the current slew rate for each step. This command programs both positive and negative going slew rates. MAXimum sets the slew to its fastest possible rate. MINimum sets the slew to its slowest rate. LIST:CURRent:SLEW:POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:CURRent:SLEW[:BOTH] <NRf+> {,<NRf+>} 0 to 9.9E37 | MAXimum | MINimum A (amperes per second) MAXimum

LIST:CURR:SLEW 50 LIST:CURR:SLEW MAX

[SOURce:]LIST:CURRent:SLEW[:BOTH]? [SOURce:]LIST:CURRent:SLEW:POINts? <NR3> {,<NR3>} CURR:SLEW

4 - Language Dictionary

[SOURce:]LIST:CURRent:SLEW:NEGative

Channel Specific

This command sets the negative current slew rate for each step. MAXimum sets the slew to its fastest possible rate. MINimum sets the slew to its slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:CURRent:SLEW:NEGative <NRf+> {,<NRf+>} 0 to 9.9E37 | MAXimum | MINimum A (amperes per second) MAXimum

LIST:CURR:SLEW:NEG 50 LIST:CURR:SLEW:NEG MAX

[SOURce:]LIST:CURRent:SLEW:NEGative? <NR3> {,<NR3>} CURR:SLEW:NEG

[SOURce:]LIST:CURRent:SLEW:POSitive

Channel Specific

This command sets the positive current slew rate for each step. MAXimum sets the slew to its fastest possible rate. MINimum sets the slew to its slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:CURRent:SLEW:POSitive <NRf+> {,<NRf+>} 0 to 9.9E37 | MAXimum | MINimum A (amperes per second) MAXimum

LIST:CURR:SLEW:POS 50 LIST:CURR:SLEW:POS MAX

[SOURce:]LIST:CURRent:SLEW:POSitive? <NR3> {,<NR3>} CURR:SLEW:POS

[SOURce:]LIST:CURRent:TLEVel [SOURce:]LIST:CURRent:TLEVel:POINts?

Channel Specific

This command specifies the transient current level for each step. The transient function switches between the immediate setting and the transient level. LIST:CURRent:TLEVel:POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:CURRent:TLEVel <NRf+> {,<NRf+>} refer to Specifications Table in User’s Guide A (amperes) MAXimum

LIST:CURR:TLEV 5 LIST:CURR:TLEV .5

[SOURce:]LIST:CURRent:TLEVel? [SOURce:]LIST:CURRent:TLEVel:POINts? <NR3> {,<NR3>} CURR:TLEV

Language Dictionary - 4

[SOURce:]LIST:FUNCtion [SOURce:]LIST:MODE [SOURce:]LIST:FUNCtion:POINTs?

Channel Specific

These equivalent commands specify the regulation mode for each list step. LIST:FUNCtion:POINts? returns the number of points programmed.

CURR RES VOLT

Returned Parameters

constant current mode constant resistance mode constant voltage mode

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Related Commands

[SOURce:]LIST:FUNCtion <function> {,<function>} [SOURce:]LIST:MODE <function> {,<function>} CURRent | RESistance | VOLTage CURRent

LIST:FUNC RES, RES, RES, VOLT

[SOURce:]LIST:FUNCtion? [SOURce:]LIST:FUNCtion:POINts? <CRD> {,<CRD>} MODE FUNC

[SOURce:]LIST:DWELl [SOURce:]LIST:DWELl:POINts?

This command sets the sequence of list dwell times. Each value represents the time in seconds that the input will remain at the particular list step point before completing the step. At the end of the dwell time, the input of the electronic load depends upon the following conditions:

 If LIST:STEP AUTO has been programmed, the input automatically changes to the next

point in the list.

 If LIST:STEP ONCE has been programmed, the input remains at the present level until a

trigger sequences the next point in the list.

The order in which the points are entered determines the sequence in which they are executed when a list is triggered. Changing list data while a subsystem is in list mode generates an implied ABORt. This command is not channel specific, it applies to the entire mainframe. LIST:DWELl:POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

Examples

Query Syntax

Returned Parameters

[SOURce:]LIST:DWELl <NRf+> {,<NRf+>} 0 - 10s | MINimum | MAXimum s (seconds)

LIST:DWEL 2.5,1.5,.5

[SOURce:]LIST:DWELl? [SOURce:]LIST:DWELl:POINts? <NR3> {,<NR3>}

4 - Language Dictionary

[SOURce:]LIST:RESistance [SOURce:]LIST:RESistance:POINts?

Channel Specific

This command specifies the resistance setting for each list step. Refer to Table 4-1 for model-specific programming ranges. LIST:RESistance:POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:RESistance[:LEVel] <NRf+> {,<NRf+>} 0 through MAX | MINimum | MAXimum Ω (ohms)

LIST:RES 2.5,3.0,3.5 LIST:RES MAX,3.5,2.5,MIN

[SOURce:]LIST:RESistance[:LEVel]? [SOURce:]LIST:RESistance:POINts? <NR3> {,<NR3>} RES

[SOURce:]LIST:RESistance:RANGe [SOURce:]LIST:RESistance:RANGe:POINts?

Channel Specific

This command sets the resistance range for each list step. There are four resistance ranges, the values of which are model dependent. Refer to Table 4-1 for the resistance ranges of each Electronic Load model.

NOTE: If the existing IMMediate, TRANsient, and TRIGgered resistance list settings are outside

the new range, a list error is generated when the list is initiated and the list does not execute.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:RESistance:RANGe <NRf+> {,<NRf+>} 0 through MAX | MINimum | MAXimum

Unit

Ω (ohms) MAXimum (high range)

LIST:RES:RANGE MIN

[SOURce:]LIST:RESistance:RANGe? [SOURce:]LIST:RESistance:RANG:POINts? <NR3> {,<NR3>} RES:RANG

Language Dictionary - 4

[SOURce:]LIST:RESistance:SLEW [SOURce:]LIST:RESistance:SLEW:POINts?

Channel Specific

This command sets the resistance slew rate for each step. This command programs both positive and negative going slew rates. MAXimum sets the slew to its fastest possible rate. MINimum sets the slew to its slowest rate. LIST:RESistance:SLEW:POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:RESistance:SLEW[:BOTH] <NRf+> {,<NRf+>} 0 to 9.9E37 | MAXimum | MINimum Ω (ohms per second) MAXimum

LIST:RES:SLEW 50 LIST:RES:SLEW MAX

[SOURce:]LIST:RESistance:SLEW[:BOTH]? [SOURce:]LIST:RESistance:SLEW:POINts? <NR3> {,<NR3>} RES:SLEW

[SOURce:]LIST:RESistance:SLEW:NEGative

Channel Specific

This command sets the negative resistance slew rate for each step. MAXimum sets the slew to its fastest possible rate. MINimum sets the slew to its slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:RESistance:SLEW:NEGative <NRf+> {,<NRf+>} 0 to 9.9E37 | MAXimum | MINimum Ω (ohms per second) MAXimum

LIST:RES:SLEW:NEG 50 LIST:RES:SLEW:NEG MAX

[SOURce:]LIST:RESistance:SLEW:NEGative? <NR3> {,<NR3>} RES:SLEW:NEG

[SOURce:]LIST:RESistance:SLEW:POSitive

Channel Specific

This command sets the positive resistance slew rate for each step. MAXimum sets the slew to its fastest possible rate. MINimum sets the slew to its slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:RESistance:SLEW:POSitive <NRf+> {,<NRf+>} 0 to 9.9E37 | MAXimum | MINimum Ω (ohms per second) MAXimum

LIST:RES:SLEW:POS 50 LIST:RES:SLEW:POS MAX

[SOURce:]LIST:RESistance:SLEW:POSitive? <NR3> {,<NR3>} RES:SLEW:POS

4 - Language Dictionary

[SOURce:]LIST:RESistance:TLEVel [SOURce:]LIST:RESistance:TLEVel:POINTs?

Channel Specific

This command specifies the transient resistance level for each step. The transient function switches between the immediate setting and the transient level. LIST:RESistance:TLEVel:POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:RESistance:TLEVel <NRf+> {,<NRf+>} refer to Table 4-1 Ω (ohms) MAXimum

LIST:RES:TLEV 5 LIST:RES:TLEV .5

[SOURce:]LIST:RESistance:TLEVel? [SOURce:]LIST:RESistance:TLEVel:POINts? <NR3> {,<NR3>} RES:TLEV

[SOURce:]LIST:STEP

This command specifies how the list sequencing responds to triggers. The following parameters may be specified. This command is not channel specific, it applies to the entire mainframe.

ONCE

AUTO

Returned Parameters

Causes the list to advance only one point after each trigger. Triggers that arrive during a dwell delay are ignored Causes the entire list to be executed sequentially after the starting trigger, paced by its dwell delays. As each dwell delay elapses, the next point is immediately executed.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Related Commands

[SOURce:]LIST:STEP <step> ONCE | AUTO AUTO

LIST:STEP ONCE

[SOURce:]LIST:STEP? <CRD> LIST:COUN LIST:DWEL

[SOURce:]LIST:TRANsient [SOURce:]LIST:TRANsient:POINts?

Channel Specific

This command turns the transient generator on or off for each step. LIST:TRANsient:POINts? returns the number of points programmed.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:TRANsient[:STATe] <bool> {,<bool>} 0 | 1 | OFF | ON OFF

LIST:TRAN 1 LIST:TRAN 0

[SOURce:]LIST:TRANsient[:STATe]? [SOURce:]LIST:TRANsient:POINts? <NR3> {,<NR3>} TRAN

Language Dictionary - 4

[SOURce:]LIST:TRANsient:DCYCle [SOURce:]LIST:TRANsient:DCYCle:POINts?

Channel Specific

This command sets the transient duty cycle for each step when the generator is in CONTinuous mode. LIST:TRANsient:DCYCle:POINts? returns the number of points programmed.

Command Syntax

Parameters

Units

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:TRANsient:DCYCle <NRf+> {,<NRf+>}

1.8% - 98.2% | MAXimum | MINimum

percent

50%

LIST:TRAN:DCYC 10.5 LIST:TRAN:DCYC 50

[SOURce:]LIST:TRANsient:DCYCle? [SOURce:]LIST:TRANsient:DCYCle:POINts? <NR3> {,<NR3>} TRAN:DCYC

[SOURce:]LIST:TRANsient:FREQuency [SOURce:]LIST:TRANsient:FREQuency:POINts?

Channel Specific

This command sets the transient frequency for each step when the generator is in CONTinuous mode. LIST:TRANsient:FREQuency:POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:TRANsient:FREQuency <NRf+> {,<NRf+>}

0.25Hz - 10kHz | MAXimum | MINimum

Hertz

MAXimum

LIST:TRAN:FREQ 50 LIST:TRAN:FREQ 5

[SOURce:]LIST:TRANsient:FREQuency? [SOURce:]LIST:TRANsient:FREQuency:POINts? <NR3> {,<NR3>} TRAN:FREQ

[SOURce:]LIST:TRANsient:MODE [SOURce:]LIST:TRANsient:MODE:POINts?

Channel Specific

This command selects the transient operating mode for each step. LIST:TRANsient:MODE:POINts? returns the number of points programmed.

CONTinuous PULSe

Returned Parameters

The transient generator puts out a continuous pulse stream. The transient generator puts out a single pulse upon receipt of a trigger.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Related Commands

[SOURce:]LIST:TRANsient:MODE <mode> {,<mode>} CONTinuous | PULSe CONTinuous

LIST:TRAN:MODE PULS

[SOURce:]LIST:TRANsient:MODE? [SOURce:]LIST:TRANsient:MODE:POINTs? <CRD> {,<CRD>} TRAN:MODE

4 - Language Dictionary

[SOURce:]LIST:TRANsient:TWIDth [SOURce:]LIST:TRANsient:TWIDth:POINts?

Channel Specific

This command sets the transient pulse width for each step when the generator is in PULSe mode. LIST:TRANsient:TWIDth:POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:] LIST:TRANsient:TWIDth <NRf+> {,<NRf+>}

0.00005s - 4s | MAXimum | MINimum

seconds

0.0005s

LIST:TRAN:TWID .005 LIST:TRAN:TWID 5E-4

[SOURce:]LIST:TRANsient:TWIDth? [SOURce:]LIST:TRANsient:TWIDth:POINts? <NR3> {,<NR3>} TRAN:TWID

[SOURce:]LIST:VOLTage [SOURce:]LIST:VOLTage:POINts?

Channel Specific

This command specifies the voltage setting for each list step. Refer to Table 4-1 for model-specific programming ranges. LIST:VOLTage:POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:VOLTage[:LEVel] <NRf+> {,<NRf+>} 0 through MAX | MINimum | MAXimum V (volts)

LIST:VOLT 2.5,3.0,3.5 LIST:VOLT MAX,3.5,2.5,MIN

[SOURce:]LIST:VOLTage[:LEVel]? [SOURce:]LIST:VOLTage:POINts? <NR3> {,<NR3>} VOLT

[SOURce:]LIST:VOLTage:RANGe [SOURce:]LIST:VOLTage:RANGe:POINTs?

Channel Specific

This command sets the voltage range for each list step. There are two voltage ranges.

High Range: model dependent, see Table 4-1 Low Range: model dependent, see Table 4-1

NOTE: If the existing IMMediate, TRANsient, and TRIGgered voltage list settings are outside the

new range, a list error is generated when the list is initiated and the list does not execute.

Language Dictionary - 4

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:VOLTage:RANGe <NRf+> {,<NRf+>} 0 through MAX | MINimum | MAXimum V (volts)

Unit

MAX (high range)

LIST:VOLT:RANGE MIN

[SOURce:]LIST:VOLTage:RANGe? [SOURce:]LIST:VOLTage:RANGe:POINTs? <NR3> {,<NR3>} VOLT:RANG

[SOURce:]LIST:VOLTage:SLEW [SOURce:]LIST:VOLTage:SLEW:POINts?

Channel Specific

This command sets the voltage slew rate for each step. This command programs both positive and negative going slew rates. MAXimum sets the slew to its fastest possible rate. MINimum sets the slew to its slowest rate. LIST:VOLTage:SLEW :POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:VOLTage:SLEW [:BOTH] <NRf+> {,<NRf+>} 0 to 9.9E37 | MAXimum | MINimum V (volts per second) MAXimum

LIST:VOLT:SLEW 50 LIST:VOLT:SLEW MAX

[SOURce:]LIST:VOLTage:SLEW[:BOTH]? [SOURce:]LIST:VOLTage:SLEW:POINts? <NR3> {,<NR3>} VOLT:SLEW

[SOURce:]LIST:VOLTage:SLEW:NEGative

Channel Specific

This command sets the negative voltage slew rate for each step. MAXimum sets the slew to its fastest possible rate. MINimum sets the slew to its slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:VOLTage:SLEW :NEGative <NRf+> {,<NRf+>} 0 to 9.9E37 | MAXimum | MINimum V (volts per second) MAXimum

LIST:VOLT:SLEW:NEG 50 LIST:VOLT:SLEW:NEG MAX

[SOURce:]LIST:VOLTage:SLEW :NEGative? <NR3> {,<NR3>} VOLT:SLEW:NEG

4 - Language Dictionary

[SOURce:]LIST:VOLTage:SLEW:POSitive

Channel Specific

This command sets the positive voltage slew rate for each step. MAXimum sets the slew to its fastest possible rate. MINimum sets the slew to its slowest rate.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:VOLTage:SLEW :POSitive <NRf+> {,<NRf+>} 0 to 9.9E37 | MAXimum | MINimum V (volts per second) MAXimum

LIST:VOLT:SLEW:POS 50 LIST:VOLT:SLEW:POS MAX

[SOURce:]LIST:VOLTage:SLEW :POSitive? <NR3> {,<NR3>} VOLT:SLEW:POS

[SOURce:]LIST:VOLTage:TLEVel [SOURce:]LIST:VOLTage:TLEVel:POINts?

Channel Specific

This command specifies the transient voltage level for each step. The transient function switches between the immediate setting and the transient level. LIST:VOLTage:TLEVel:POINts? returns the number of points programmed.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]LIST:VOLTage:TLEVel <NRf+> {,<NRf+>} refer to Table 4-1 V (volts) MAXimum

LIST:VOLT:TLEV 5 LIST:VOLT:TLEV .5

[SOURce:]LIST:VOLTage:TLEVel? [SOURce:]LIST:VOLTage:TLEVel:POINts? <NR3> {,<NR3>} VOLT:TLEV

Language Dictionary - 4

Transient Commands

These commands program the transient generator of the electronic load. The transient generator programs a second (transient) level at which the electronic load can operate without changing the original programmed settings.

See also [SOURce:]CURRent:TLEVel, [SOURce:]RESistance:TLEVel, and [SOURce:]VOLTage:TLEVel in the Input Commands section.

[SOURce:]TRANsient

Channel Specific

This command turns the transient generator on or off.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]TRANsient[:STATe] <bool> 0 | 1 | OFF | ON OFF

TRAN 1 TRAN 0

[SOURce:]TRANsient[:STATe]? <NR3> TRAN:MODE TRAN:FREQ

[SOURce:]TRANsient:DCYCle

Channel Specific

This command sets the duty cycle of each of the transients when the generator is in CONTinuous mode.

Command Syntax

Parameters

*RST Value

Unit

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]TRANsient:DCYCle <NRf+>

1.8% - 98.2% | MAXimum | MINimum 50%

percent

TRAN:DCYC 10.5 TRAN:DCYC 50

[SOURce:]TRANsient:DCYCle? <NR3> TRAN:MODE TRAN:FREQ

[SOURce:]TRANsient:FREQuency

Channel Specific

This command sets the frequency of the transients when the generator is in CONTinuous mode.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]TRANsient:FREQuency <NRf+>

0.25Hz - 10kHz | MAXimum | MINimum

Hertz

MAXimum

TRAN:FREQ 50 TRAN:FREQ 5

[SOURce:]TRANsient:FREQuency? <NR3> TRAN:DCYC TRAN

4 - Language Dictionary

[SOURce:]TRANsient:MODE

Channel Specific

This command selects the operating mode of the transient generator as follows.

CONTinuous PULSe TOGGle

Returned Parameters

The transient generator puts out a continuous pulse stream. The transient generator puts out a single pulse upon receipt of a trigger. The transient generator toggles between two levels upon receipt of a trigger.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Related Commands

[SOURce:]TRANsient:MODE <mode> CONTinuous | PULSe | TOGGle CONTinuous

TRAN:MODE FIX

[SOURce:]TRANsient:MODE? <CRD> TRAN:DCYC TRAN

[SOURce:]TRANsient:LMODE

Channel Specific

This command selects whether the transient generator uses immediate or list values for the transient settings.

FIXed

LIST

Returned Parameters

The transient generator uses the fixed or immediate values (set by the TRANsient function commands) The transient generator uses the transient values programmed by the list.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Related Commands

[SOURce:]TRANsient:LMODE <mode> FIXed | LIST FIXed

TRAN:LMODE FIX

[SOURce:]TRANsient:LMODE? <CRD> TRAN:MODE TRAN

[SOURce:]TRANsient:TWIDth

Channel Specific

This command sets the pulse width of the transients when the generator is in PULSe mode.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

[SOURce:]TRANsient:TWIDth <NRf+>

0.00005s - 4s | MAXimum | MINimum

seconds

0.0005s

TRAN:TWID .005 TRAN:TWID 5E-4

[SOURce:]TRANsient:TWIDth? <NR3> TRAN:DCYC TRAN

Language Dictionary - 4

Status Commands

These commands program the electronic load status registers. The electronic load has five groups of status registers; Channel Status, Channel Summary, Questionable Status, Standard Event Status, and Operation Status. Refer to chapter 3 under “Programming the Status Registers” for more information.

Bit Configuration of Channel Status Registers

Bit Position 15-14 13 12 11 10 9 8 7–5 4 3 2 1 0

Bit Name N.U. PS OV LRV UNR EPU RRV N.U. OT OP N.U. OC VF

Bit Weight 8192 4096 2048 1024 512 256 16 8 4 2 1

VF voltage fault has occurred OC over-current condition has occurred OP over-power condition has occurred OT over-temperature condition has occurred RRV reverse voltage on the sense terminals

STATus:CHANnel?

Channel Specific

This query returns the value of the Channel Event register. The Event register is a read-only register which holds (latches) all events that are passed into it. Reading the Channel Event register clears it.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

STATus:CHANnel[:EVENt]? None

STAT:CHAN:EVEN?

<NR1> (register value) *CLS

EPU extended power unavailable UNR input is unregulated LRV reverse voltage on the input terminals OV over-voltage condition has occurred PS protection shutdown circuit has tripped

STATus:CHANnel:CONDition?

Channel Specific

This query returns the value of the Channel Condition register. The particular channel must first be selected by the CHAN command.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

STATus:CHANnel:CONDition? None

STAT:CHAN:COND?

<NR1> (register value) STAT:CHAN?

STATus:CHANnel:ENABle

Channel Specific

This command sets or reads the value of the Channel Enable register for a specific channel. The particular channel must first be selected by the CHAN command.

Command Syntax

Parameters

Examples

Query Syntax

Returned Parameters

Related Commands

STATus:CHANnel:ENABle <NRf+> channel number

STAT:CHAN:ENAB 3

STATus:CHANnel:ENABle? <NR1> (register value) *CLS

4 - Language Dictionary

STATus:CSUM?

This query returns the value of the Channel Event summary register. The bits in this register correspond to a summary of the channel register for each input channel. Reading the Channel Event summary register clears it. This command is not channel specific, it applies to the entire mainframe.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

STATus:CSUMmary[:EVENt]? None

STAT:CSUM:EVEN?

<NR1> (register value) *CLS

STATus:CSUMmary:ENABle

This command sets or reads the value of the Channel Enable summary register. This command is not channel specific, it applies to the entire mainframe.

Command Syntax

Parameters

Examples

Query Syntax

Returned Parameters

Related Commands

STATus:CSUMmary:ENABle <NRf+> channel number

STAT:CSUM:ENAB 3

STATus:CSUMmary:ENABle? <NR1> (register value) *CLS

Bit Configuration of Operation Status Registers

Bit Position 15–5 5 4–1 0 Bit Name not used WTG not used CAL Bit Weight 32 1 CAL = Interface is computing new calibration constants WTG = Interface is waiting for a trigger.

STATus:OPERation?

This query returns the value of the Operation Event register. The Event register is a read-only register that holds (latches) all events that are passed by the Operation NTR and/or PTR filter. Reading the Operation Event register clears it. This command is not channel specific, it applies to the entire mainframe.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

STATus:OPERation[:EVENt]? None

STAT:OPER:EVEN?

<NR1> (register value) *CLS STAT:OPER:NTR STAT:OPER:PTR

STATus:OPERation:CONDition?

This query returns the value of the Operation Condition register. That is a read-only register that holds the real-time (unlatched) operational status of the electronic load. This command is not channel specific, it applies to the entire mainframe.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

STATus:OPERation:CONDition? None

STAT:OPER:COND?

<NR1> (register value) STAT:QUES:COND?

Language Dictionary - 4

STATus:OPERation:ENABle

This command and its query set and read the value of the Operation Enable register. This register is a mask for enabling specific bits from the Operation Event register to set the operation summary bit (OPER) of the Status Byte register. The operation summary bit is the logical OR of all enabled Operation Event register bits. This command is not channel specific, it applies to the entire mainframe.

Command Syntax

Parameters

Default Value

Examples

Query Syntax

Returned Parameters

Related Commands

STATus:OPERation:ENABle <NRf+> 0 to 32767 | MAXimum | MINimum 0

STAT:OPER:ENAB 32 STAT:OPER:ENAB 1

STATus:OPERation:ENABle? <NR1> (register value) STAT:OPER?

STATus:OPERation:NTRansition STATus:OPERation:PTRansition

These commands set or read the value of the Operation NTR (Negative-Transition) and PTR (PositiveTransition) registers. These registers serve as polarity filters between the Operation Enable and Operation Event registers to cause the following actions. This command is not channel specific, it applies to the entire mainframe.

 When a bit in the Operation NTR register is set to 1, then a 1-to-0 transition of the corresponding

bit in the Operation Condition register causes that bit in the Operation Event register to be set.

 When a bit of the Operation PTR register is set to 1, then a 0-to-1 transition of the corresponding

bit in the Operation Condition register causes that bit in the Operation Event register to be set.

 If the same bits in both NTR and PTR registers are set to 1, then any transition of that bit at the

Operation Condition register sets the corresponding bit in the Operation Event register.

 If the same bits in both NTR and PTR registers are set to 0, then no transition of that bit at the

Operation Condition register can set the corresponding bit in the Operation Event register.

NOTE: Setting a bit in the PTR or NTR filter can of itself generate positive or negative events in

the corresponding Operation Event register.

Command Syntax

Parameters

Default Value

Examples

Query Syntax

Returned Parameters

Related Commands

STATus:OPERation:NTRansition <NRf+> STATus:OPERation:PTRansition <NRf+> 0 to 32767 | MAXimum | MINimum 0

STAT:OPER:NTR 32 STAT:OPER:PTR 1

STATus:OPERation:NTRansition? STATus:OPERation:PTRansition? <NR1> (register value) STAT:OPER:ENAB

4 - Language Dictionary

Bit Configuration of Questionable Status Registers

Bit Position 15-14 13 12 11 10 9 8 7–5 4 3 2 1 0

Bit Name N.U. PS OV LRV UNR EPU RRV N.U. OT OP N.U. OC VF

Bit Weight 8192 4096 2048 1024 512 256 16 8 4 2 1

VF voltage fault has occurred OC over-current condition has occurred OP over-power condition has occurred OT over-temperature condition has occurred RRV reverse voltage on the sense terminals

EPU extended power unavailable UNR input is unregulated LRV reverse voltage on the input terminals OV over-voltage condition has occurred PS protection shutdown circuit has tripped

STATus:QUEStionable?

This query returns the value of the Questionable Event register. The Event register is a read-only register that holds (latches) all events that pass into it. Reading the Questionable Event register clears it. This command is not channel specific, it applies to the entire mainframe.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

STATus:QUEStionable[:EVENt]? None

STAT:QUES:EVEN?

<NR1> (register value) *CLS

STATus:QUEStionable:CONDition?

This query returns the value of the Questionable Condition register. That is a read-only register that holds the real-time (unlatched) questionable status of the electronic load. This command is not channel specific, it applies to the entire mainframe.

Query Syntax

Parameters

Examples

Returned Parameters

Related Commands

STATus:QUEStionable:CONDition? None

STAT:QUES:COND?

<NR1> (register value) STAT:OPER:COND?

STATus:QUEStionable:ENABle

This command sets or reads the value of the Questionable Enable register. This register is a mask for enabling specific bits from the Questionable Event register to set the questionable summary (QUES) bit of the Status Byte register. This bit (bit 3) is the logical OR of all the Questionable Event register bits that are enabled by the Questionable Status Enable register. This command is not channel specific, it applies to the entire mainframe.

Command Syntax

Parameters

Default Value

Examples

Query Syntax

Returned Parameters

Related Commands

STATus:QUEStionable:ENABle <NRf+> 0 to 32767 | MAXimum | MINimum 0

STAT:QUES:ENAB 32 STAT:QUES:ENAB 1

STATus:QUEStionable:ENABle? <NR1> (register value) STAT:QUES?

Language Dictionary - 4

System Commands

System commands control the system-level functions of the electronic load that are not directly related to input control or measurement functions.

SYSTem:ERRor?

This query returns the next error number followed by its corresponding error message string from the remote programming error queue. The queue is a FIFO (first-in, first-out) buffer that stores errors as they occur. As it is read, each error is removed from the queue. When all errors have been read, the query returns “0, No Error”. If more errors are accumulated than the queue can hold, the last error in the queue is “-350, Too Many Errors”.

Query Syntax

Parameters

Returned Parameters

Examples

SYSTem:ERRor? None <NR1>, <SRD>

SYST:ERR?

SYSTem:LOCal

This command places the electronic load in local mode during RS-232 operation. The front panel keys are functional.

Command Syntax

Parameters

Example

Related Commands

SYSTem:LOCal None

SYST:LOC

SYST:REM SYST:RWL

SYSTem:REMote

This command places the electronic load in remote mode during RS-232 operation. This disables all front panel keys except the Local key. Pressing the Local key while in the remote state returns the front panel to the local state.

Command Syntax

Parameters

Example

Related Commands

SYSTem:REMote None

SYST:REM

SYST:LOC SYST:RWL

SYSTem:RWLock

This command places the electronic load in remote mode during RS-232 operation. All front panel keys including the Local key are disabled. Use SYSTem:LOCal to return the front panel to the local state.

Command Syntax

Parameters

Example

Related Commands

SYSTem:RWLock None

SYST:RWL

SYST:REM SYST:LOC

SYSTem:VERSion?

This query returns the SCPI version number to which the electronic load complies. The value is of the form YYYY.V, where YYYY is the year and V is the revision number for that year.

Query Syntax

Parameters

Examples

Returned Parameters

SYSTem:VERSion? None

SYST:VERS?

<NR2>

4 - Language Dictionary

Trigger Commands

Trigger commands controls the triggering of the electronic load. Chapter 3 under "Triggering Changes" provides an explanation of the Trigger System.

See also [SOURce:]CURRent:TRIGgered, [SOURce:]RESistance:TRIGgered, and [SOURce:]VOLTage:TRIGgered in the Input Commands section.

NOTE: The list and measurement commands must first be enabled using the INITiate commands

or no action due to triggering will occur. This does not apply to transient triggers.

ABORt

This command resets the list and measurement trigger systems to the Idle state. Any list or measurement that is in progress is immediately aborted. ABORt also resets the WTG bit in the Operation Condition Status register (see chapter 3 under “Programming the Status Registers”). ABORt is executed at power turn-on and upon execution of *RCL, RST, or any implied abort command (see List Commands).

NOTE: If INITiate:CONTinuous ON has been programmed, the trigger system initiates itself

immediately after ABORt, thereby setting the WTG bit.

Command Syntax

Parameters

Examples

Related Commands

ABORt None

ABOR

INIT *RST *TRG TRIG

INITiate:SEQuence INITiate:NAME

These equivalent commands prepare the list for the execution of the next trigger. These commands are not channel specific, they apply to the entire mainframe. If the trigger system is not in the Idle state, they are ignored. INITiate:SEQuence references the list sequence by a number, while INITiate:NAME references the list sequence by the name LIST.

Sequence Number Sequence Name Description

1 (the default) LIST List trigger sequence

Command Syntax

Parameters

Examples

Related Commands

INITiate[:IMMediate]:SEQuence[ 1 ] INITiate[:IMMediate]:NAME LIST For INIT:NAME: LIST

INIT:SEQ1 INIT:NAME LIST

ABOR INIT:CONT TRIG *TRG

INITiate:SEQuence2 INITiate:NAME

These equivalent commands prepare the measurement system to take a measurement on the next trigger. These commands are not channel specific, they apply to the entire mainframe. If the trigger system is not in the Idle state, they are ignored. INITiate:SEQuence references the measurement sequence by a number, while INITiate:NAME references the measurement sequence by the name ACQuire.

Sequence Number Sequence Name Description

2 ACQuire Measurement acquire trigger sequence

Language Dictionary - 4

Command Syntax

Parameters

Examples

Related Commands

INITiate[:IMMediate]:SEQuence2 INITiate[:IMMediate]:NAME ACQuire For INIT:NAME: ACQuire

INIT:SEQ2 INIT:NAME ACQ

ABOR INIT:CONT TRIG *TRG

INITiate:CONTinuous:SEQuence INITiate:CONTinuous:NAME

These equivalent commands prepare the list to respond to trigger commands. ON or 1 continuously initiates the list. OFF or 0 turns off continuous initiation. Upon the receipt of a trigger with continuous initiation on, one of the following actions occur:

 If LIST:STEP is set to ONCe, the list will progress to the next step in the sequence.

 If LIST:STEP is AUTO, each trigger will start the list again.

These commands are not channel specific, they apply to the entire mainframe. If the trigger system is not in the Idle state and therefore already initiated, the initiate commands are ignored.

Command Syntax

Parameters

Examples

Related Commands

INITiate:CONTinuous:SEQuence[1] <bool> INITiate:CONTinuous:NAME LIST, <bool> 0 | 1 | OFF | ON

INIT:CONT:SEQ1 ON INIT:CONT:NAME LIST, 1

ABOR INIT:CONT TRIG *TRG

TRIGger

When the trigger system has been initiated, this command generates a trigger signal regardless of the selected trigger source. This command is not channel specific, it applies to the entire mainframe.

Command Syntax

Parameters

Examples

Related Commands

TRIGger[:IMMediate] None

TRIG

ABOR TRIG:SOUR TRIG:DEL TRIG:TIM

TRIGger:DELay

Channel Specific

This command sets the time delay between the detection of a trigger signal and the start of any corresponding trigger action. After the time delay has elapsed, the trigger is implemented. This command only applies to the selected channel.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

TRIGger:DELay <NRf+> 0 - 0.032s | MINimum | MAXimum

seconds

TRIG:DEL .025 TRIG:DEL MAX

TRIGger:DELay? <NR3> ABOR TRIG TRIG:SOUR TRIG:TIM

4 - Language Dictionary

TRIGger:SEQuence2:COUNt

This command sets up a successive number of triggers for measuring data. With this command, the trigger system needs to be initialized only once at the start of the acquisition period. After each completed measurement, the instrument waits for the next valid trigger condition to start another measurement. This continues until the count has completed.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

TRIGger:SEQuence2:COUNt<NRf+> 1 to 100 1

TRIG:SEQ2:COUN 5

TRIGger:SEQuence2:COUNt? <NR3> TRIG INIT:SEQ

TRIGger:SOURce

This command selects the trigger source. This command is not channel specific, it applies to the entire mainframe.

BUS

EXTernal

HOLD

LINE

TIMer

Accepts a GPIB <GET> signal or a *TRG command as the trigger source. This selection guarantees that all previous commands are complete before the trigger occurs.

Selects the electronic load’s trigger input as the trigger source. This trigger is processed as soon as it is received.

Only the TRIG:IMM command will generate a trigger in HOLD mode. All other trigger commands are ignored.

This generates triggers that are in synchronization with the ac line frequency.

This generates triggers that are in synchronization with the electronic load's internal oscillator as the trigger source. The internal oscillator begins running as soon as this command is executed. Use TRIG:TIM to program the oscillator period.

Command Syntax

Parameters

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

TRIGger:SOURce <CRD> BUS | EXTernal | HOLD | LINE | TIMer HOLD

TRIG:SOUR BUS TRIG:SOUR EXT

TRIGger:SOURce? <CRD> ABOR TRIG TRIG:DEL TRIG:SYNC

TRIGger:TIMer

This command specifies the period of the triggers generated by the internal trigger generator. This command is not channel specific, it applies to the entire mainframe.

Command Syntax

Parameters

Unit

*RST Value

Examples

Query Syntax

Returned Parameters

Related Commands

TRIGger:TIMer <NRf+> 8µs to 4s | MINimum | MAXimum

seconds

0.001

TRIG:TIM .25 TRIG:TIM MAX

TRIGger:TIMer? <NR3> ABOR TRIG TRIG:SOUR TRIG:DEL

Language Dictionary - 4

Common Commands

Common commands begin with an * and consist of three letters (command) IEEE 488.2 standard to perform some common interface functions. The electronic loads respond to the required common commands that control status reporting, synchronization, and internal operations. The electronic loads also respond to optional common commands that control triggers, power-on conditions, and stored operating parameters.

Common commands and queries are listed alphabetically. If a command has a corresponding query that simply returns the data or status specified by the command, then both command and query are included under the explanation for the command. If a query does not have a corresponding command or is functionally different from the command, then the query is listed separately. The description for each common command or query specifies any status registers affected. Refer to chapter 3 under “Programming the Status Registers”, which explains how to read specific register bits and use the information that they return.

*CLS

This command clears the following registers (see chapter 3 under “Programming the Status Registers” for descriptions of all registers):

 Standard Event Status

 Operation Status Event

 Questionable Status Event

 Status Byte

 Error Queue

Command Syntax

Parameters

*CLS None

*ESE

This command programs the Standard Event Status Enable register bits. The programming determines which events of the Standard Event Status Event register (see *ESR?) are allowed to set the ESB (Event Summary Bit) of the Status Byte register. A "1" in the bit position enables the corresponding event. All of the enabled events of the Standard Event Status Event Register are logically ORed to cause the Event Summary Bit (ESB) of the Status Byte Register to be set. See chapter 3 under “Programming the Status Registers” for descriptions of the Standard Event Status registers.

The query reads the Standard Event Status Enable register.

Command Syntax

Parameters

Power-On Value

Examples

Query Syntax

Returned Parameters

Related Commands

*ESE <NRf> 0 to 255 see *PSC

*ESE 129

*ESE? <NR1> *ESR? *PSC *STB?

4 - Language Dictionary

Bit Configuration of Standard Event Status Enable Register

Bit Position 7 6 5 4 3 2 1 0 Bit Name PON not used CME EXE DDE QYE not used OPC Bit Weight 128 32 16 8 4 1 PON Power-on CME Command error EXE Execution error

DDE Device-dependent error QYE Query error OPC Operation complete

*ESR?

This query reads the Standard Event Status Event register. Reading the register clears it. The bit configuration of this register is the same as the Standard Event Status Enable register (see *ESE). See chapter 3 under “Programming the Status Registers” for a detailed explanation of this register.

Query Syntax

Parameters

Returned Parameters

Related Commands

*ESR? None <NR1> (register value) *CLS *ESE *ESE? *OPC

*IDN?

This query requests the electronic load to identify itself. It returns the data in four fields separated by commas.

Query Syntax

Parameters

Returned Parameters <AARD> Field Information

Example

*IDN? None

Agilent Technologies manufacturer xxxxA model number nnnnA-nnnnn serial number or 0 <R>.xx.xx firmware revision

Agilent Technologies, N3300A, 0, A.00.01

*OPC

This command causes the interface to set the OPC bit (bit 0) of the Standard Event Status register when the electronic load has completed all pending operations. (See *ESE for the bit configuration of the Standard Event Status registers.) Pending operations are complete when:

 All commands sent before *OPC have been executed. This includes overlapped commands. Most

commands are sequential and are completed before the next command is executed. Overlapped commands are executed in parallel with other commands. Commands that affect trigger actions are overlapped with subsequent commands sent to the electronic load. The *OPC command provides notification that all overlapped commands have been completed.

 All triggered actions are completed and the trigger system returns to the Idle state.

*OPC does not prevent processing of subsequent commands but Bit 0 will not be set until all pending operations are completed. The query causes the interface to place an ASCII "1" in the Output Queue when all pending operations are completed.

Command Syntax

Parameters

Query Syntax

Returned Parameters

Related Commands

*OPC None *OPC? <NR1> *TRIG *WAI

Language Dictionary - 4

*OPT?

This query requests the electronic load to identify any options that are installed. Options are identified by number. A 0 indicates no options are installed.

Query Syntax

Returned Parameters

*OPT? <AARD>

*PSC

This command controls the automatic clearing at power-on of the Service Request Enable and the Standard Event Status enable registers as follows (see chapter 3 under “Programming the Status Registers” for register details):

1 or ON

0 or OFF

The query returns the current state of *PSC.

Returned Parameters

Prevents the register contents from being saved, causing them to be cleared at power-on. This prevents a PON event from clearing SRQ at power-on. Saves the contents of the Service Request Enable and the Standard Event Status enable registers in non-volatile memory and recalls them at power-on. This allows a PON event to generate SRQ at power-on.

Command Syntax

Parameters

Example

Query Syntax

Related Commands

*PSC <Bool> 0 | 1 | OFF | ON

*PSC 0 *PSC 1

*PSC? 0 | 1 *ESE *SRE

*RCL

This command restores the electronic load to a state that was previously stored in memory with a *SAV command to the specified location. All states are recalled with the following exceptions:

 CAL:STATe is set to OFF

 The trigger system is set to the Idle state by an implied ABORt command (this cancels any

uncompleted trigger actions)

NOTE: The device state stored in location 0 is automatically recalled at power turn-on. Lists are

only restored if they have been saved in non-volatile memory locations 0, 7, 8, and 9.

Command Syntax

Parameters

Example

Related Commands

*RCL <NRf> 0 to 9

*RCL 3

*PSC *RST *SAV

4 - Language Dictionary

*RDT?

This query reads the model numbers of the modules installed in the mainframe. It returns the data in comma-separated fields.

Query Syntax

Parameters

Returned Parameters

Example

*RDT? None model numbers separated by commas CHAN1:N3302A; CHAN2:N3302A; CHAN3:N3304A

*RST

This command resets ALL channels of the electronic load to the following factory-defined states:

CAL:STAT OFF [SOUR:]RES MAX CHAN 1 [SOUR:]RES:MODE FIX INP ON [SOUR:]RES:RANG MAX INP:SHOR OFF [SOUR:]RES:SLEW MAX PORT0 OFF [SOUR:]RES:SLEW:NEG MAX PORT1 0 [SOUR:]RES:SLEW:POS MAX SENS:CURR:RANG MAX [SOUR:]RES:TLEV MAX SENS:SWE:POIN 1 [SOUR:]RES:TRIG MAX SENS:SWE:OFFS 0 [SOUR:]TRAN OFF SENS:SWE:TINT 0.00001 [SOUR:]TRAN:DCYC 50% SENS:VOLT:RANG MAX [SOUR:]TRAN:FREQ 10000 SENS:WIND RECT [SOUR:]TRAN:MODE CONT [SOUR:]CURR MIN [SOUR:]TRAN:TWID 0.0005 [SOUR:]CURR:MODE FIX [SOUR:]VOLT MAX [SOUR:]CURR:PROT MAX [SOUR:]VOLT:MODE FIX [SOUR:]CURR:PROT:DEL 15 s [SOUR:]VOLT:RANG MAX [SOUR:]CURR:PROT:STAT OFF [SOUR:]VOLT:SLEW MAX [SOUR:]CURR:RANG MAX [SOUR:]VOLT:SLEW :NEG MAX [SOUR:]CURR:SLEW MAX [SOUR:]VOLT:SLEW:POS MAX [SOUR:]CURR:SLEW:NEG MAX [SOUR:]VOLT:TLEV MAX [SOUR:]CURR:SLEW:POS MAX [SOUR:]VOLT:TRIG MAX [SOUR:]CURR:TLEV MIN TRIG:DEL 0 [SOUR:]CURR:TRIG MIN TRIG:SOUR HOLD [SOUR:]FUNC CURR TRIG:SEQ2:COUN 1 [SOUR:]LIST:COUN 1 TRIG:TIM 0.001 [SOUR:]LIST:STEP AUTO

NOTE:  *RST does not clear any of the status registers or the error queue, and does not

affect any interface error conditions.

 *RST sets the trigger system to the Idle state.  *RST clears the presently active list.

Command Syntax

Parameters

Related Commands

*RST None *PSC *SAV

100

Agilent N3300A Programming Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Safety Summary

Printing History

Table of Contents

General Information

About this Guide

Documentation Summary

External References

SCPI References

GPIB References

VXIplug&play Power Products Instrument Drivers

Supported Applications

System Requirements

Downloading and Installing the Driver

Accessing Online Help

Introduction to Programming

GPIB Capabilities of the Electronic Load

GPIB Address

RS-232 Capabilities of the Electronic Load

RS-232 Data Format

RS-232 Flow Control

Introduction to SCPI

Conventions Used in This Guide

Types of SCPI Commands

Multiple Commands in a Message

Moving Among Subsystems

Including Common Commands

Using Queries

Types of SCPI Messages

Headers

The Message Unit

Query Indicator

Message Unit Separator

Root Specifier

Message Terminator

SCPI Data Formats

Numerical Data Formats

Suffixes and Multipliers

Response Data Types

SCPI Command Completion

Using Device Clear

RS-232 Troubleshooting

SCPI Conformance Information

SCPI Conformed Commands

Non-SCPI Commands

Programming Examples

Introduction

Programming the Input

Power-on Initialization

Enabling the Input

Input Voltage

Input Current

Setting the Triggered Voltage or Current Levels

Programming Transients

Continuous Transients

Pulse Transients

Toggled Transients

Programming Lists

Programming Lists for Multiple Channels

Triggering Transients and Lists

SCPI Triggering Nomenclature

List Trigger Model

Initiating List Triggers

Specifying a Trigger Delay

Generating Transient and List Triggers

Making Measurements

Voltage and Current Measurements

Triggering Measurements

SCPI Triggering Nomenclature

Measurement Trigger Model

Initiating the Measurement Trigger System

Generating Measurement Triggers

Controlling Measurement Samples

Varying the Sampling Rate

Measurement Delay

Multiple Measurements

Synchronizing Transients and Measurements