Agilent Technologies 34401A User manual

Agilent 34401A

6 ½ Digit Multimeter

User’s Guide

Agilent Technologies

ii

Notices

© Agilent Technologies, Inc. 1991 - 2012

No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Agilent

Technologies, Inc. as governed by United

States and international copyright laws.

Manual Part Number

34401-90004

Edition

Eighth Edition. May 2012

Printed in Malaysia

Agilent Technologies, Inc.

3501 Stevens Creek Blvd.

Santa Clara, CA 95052 USA

Microsoft® and Windows® are U.S. registered trademarks of Microsoft Corporation.

Software Revision

This guide is valid for the firmware that was installed in the instrument at the time of manufacture. However, upgrading the firmware may add or change product features.

For the latest firmware and documentation, go to the product page at:

www.agilent.com/find/34401A

Warranty

The material contained in this document is provided “as is,” and is subject to being changed, without notice, in future editions. Further, to the maximum extent permitted by applicable law, Agilent disclaims all warranties, either express or implied, with regard to this manual and any information contained herein, including but not limited to the implied warranties of merchantability and fitness for a particular purpose. Agilent shall not be liable for errors or for incidental or consequential damages in connection with the furnishing, use, or performance of this document or of any information contained herein. Should

Agilent and the user have a separate written agreement with warranty terms covering the material in this document that conflict with these terms, the warranty terms in the separate agreement shall control.

Technology Licenses

The hardware and/or software described in this document are furnished under a license and may be used or copied only in accordance with the terms of such license.

Restricted Rights Legend

U.S. Government Restricted Rights. Software and technical data rights granted to the federal government include only those rights customarily provided to end user customers. Agilent provides this customary commercial license in Software and technical data pursuant to FAR 12.211 (Technical

Data) and 12.212 (Computer Software) and, for the Department of Defense, DFARS

252.227-7015 (Technical Data - Commercial

Items) and DFARS 227.7202-3 (Rights in

Commercial Computer Software or Computer Software Documentation).

Safety Notices

CAU T ION

A CAUTION notice denotes a hazard. It calls attention to an operating procedure, practice, or the like that, if not correctly performed or adhered to, could result in damage to the product or loss of important data. Do not proceed beyond a

CAUTION notice until the indicated conditions are fully understood and met.

WARN IN G

A WARNING notice denotes a hazard. It calls attention to an operating procedure, practice, or the like that, if not correctly performed or adhered to, could result in personal injury or death. Do not proceed beyond a WARNING notice until the indicated conditions are fully understood and met.

34401A User’s Guide

Safety Information

General

Do not use this product in any manner not specified by the manufacturer. The protective features of this product may be impaired if it is used in a manner not specified in the operation instructions.

Do not install substitute parts or perform any unauthorized modification to the product. Return the product to an Agilent Technologies Sales and Service Office for service and repair to ensure that safety features are maintained.

Ground the Instrument

If your product is provided with a grounding-type power plug, the instrument chassis and cover must be connected to an electrical ground to minimize shock hazard. The ground pin must be firmly connected to an electrical ground (safety ground) terminal at the power outlet. Any interruption of the protective (grounding) conductor or disconnection of the protective earth terminal will cause a potential shock hazard that could result in personal injury.

Cleaning

Clean the outside of the instrument with a soft, lint-free, slightly dampened cloth. Do not use detergent or chemical solvents.

Safety Symbols

Earth Ground

Chassis Ground

Risk of electric shock

WARN IN G

Main Power and Test Input Disconnect: Unplug instrument from wall outlet, remove power cord, and remove all probes from all terminals before servicing. Only qualified, service-trained personnel should remove the cover from the instrument.

Refer to manual for additional safety information

Alternating Current

On supply

Off supply

WARN IN G

Line and Current Protection

Fuses: For continued protection against fire, replace the line fuse and the current-protection fuse only with fuses of the specified type and rating.

‘In’ position of bi-stable push switch

‘Out’ position of bi-stable push switch

CAT II (300V)

IEC Measurement Category II.

Inputs may be connected to mains (up to 300 VAC) under

Category II overvoltage conditions.

WARN IN G

Front/Rear Switch: Do not change the position of the

Front/Rear switch on the front panel while signals are present on either the front or rear set of terminals. The switch is not intended as an active multiplexer. Switching while high voltages or currents are present may cause instrument damage and lead to the risk of electric shock.

34401A User’s Guide iii

WARN IN G

IEC Measurement Category II. The

HI and LO input terminals may be connected to mains in IEC Category II installations for line voltages up to 300 VAC. To avoid the danger of electric shock, do not connect the inputs to mains for line voltages above 300 VAC. See

"IEC Measurement Category II

Overvoltage Protection" on the following page for further information.

WARN IN G

Protection Limits: To avoid instrument damage and the risk of electric shock, do not exceed any of the Protection Limits defined in the following section.

Protection Limits

The Agilent 34401A Digital Multimeter provides protection circuitry to prevent damage to the instrument and to protect against the danger of electric shock, provided the Protection Limits are not exceeded. To ensure safe operation of the instrument, do not exceed the Protection Limits shown on the front and rear panel, and defined as follows:

Note: The front-panel terminals are shown above. The rear-panel terminals are identical. The Front/Rear switch selects the terminal set to be used. Do not operate this

switch while signals are present on the

front or rear terminals. The current-protection fuse is on the rear panel.

Input Terminal Protection

Limits

Protection Limits are defined for the input terminals:

Main Input (HI and LO) Terminals. The HI and LO input terminals are used for voltage, resistance, frequency (period), and diode test measurements. Two Protection Limits are defined for these terminals:

HI to LO Protection Limit. The Protection

Limit from HI to LO (Input terminals) is

1000 VDC or 750 VAC, which is also the maximum voltage measurement. This limit can also be expressed as 1000 Vpk maximum.

LO to Ground Protection Limit. The LO input terminal can safely "float" a maximum of 500 Vpk relative to ground.

As is implied by the above limits, the Protection Limit for the HI input terminal is a maximum of 1500 Vpk relative to ground.

Current Input Terminal. The current input

("I") terminal has a Protection Limit of 3A

(rms) maximum current flowing from the LO input terminal. Note that the current input terminal will be at approximately the same voltage as the LO terminal.

Note: The current-protection circuitry includes a fuse on the rear panel. To maintain protection, replace this fuse only with a fuse of the specified type and rating.

Sense Terminal Protection

Limits

The HI and LO sense terminals are used only for four-wire resistance and temperature measurements ("

Ω

4W"). The Protection Limit is 200 Vpk for all of the terminal pairings:

LO sense to LO input

HI sense to LO input

HI sense to LO sense

Note: The 200 Vpk limit on the sense terminals is the Protection Limit. Operational voltages in resistance measurements are much lower — less than 10 V in normal operation.

IEC Measurement Category II

Overvoltage Protection

To protect against the danger of electric shock, the Agilent 34401A Digital Multimeter provides overvoltage protection for line-voltage mains connections meeting

both of the following conditions:

The HI and LO input terminals are connected to the mains under Measurement

Category II conditions, defined below,

and

The mains are limited to a maximum line voltage of 300 VAC.

iv 34401A User’s Guide

IEC Measurement Category II includes electrical devices connected to mains at an outlet on a branch circuit. Such devices include most small appliances, test equipment, and other devices that plug into a branch outlet or socket. The 34401A may be used to make measurements with the HI and LO inputs connected to mains in such devices, or to the branch outlet itself (up to 300 VAC).

However, the 34401A may not be used with its HI and LO inputs connected to mains in permanently installed electrical devices such as the main circuit-breaker panel, sub-panel disconnect boxes, or permanently wired motors. Such devices and circuits are subject to overvoltages that may exceed the protection limits of the 34401A.

Note: Voltages above 300 VAC may be measured only in circuits that are isolated from mains. However, transient overvoltages are also present on circuits that are isolated from mains. The Agilent 34401A are designed to safely withstand occasional transient overvoltages up to 2500 Vpk. Do not use this equipment to measure circuits where transient overvoltages could exceed this level.

Additional Notices

Waste Electrical and

Electronic Equipment (WEEE)

Directive 2002/96/EC

This product complies with the WEEE Directive (2002/96/EC) marking requirement.

The affixed product label (see below) indicates that you must not discard this electrical/electronic product in domestic household waste.

Product Category: With reference to the equipment types in the WEEE directive

Annex 1, this product is classified as a

"Monitoring and Control instrumentation" product.

Do not dispose in domestic household waste.

To return unwanted products, contact your local Agilent office, or see www.agilent.com/environment/product for more information.

Agilent 34138A Test Lead Set

The Agilent 34401A is compatible with the

Agilent 34138A Test Lead Set described below.

Test Lead Ratings

Test Leads - 1000V, 15A

Fine Tip Probe Attachments - 300V, 3A

Mini Grabber Attachment - 300V, 3A

SMT Grabber Attachments - 300V, 3A

Operation

The Fine Tip, Mini Grabber, and SMT Grabber attachments plug onto the probe end of the Test Leads.

Maintenance

If any portion of the Test Lead Set is worn or damaged, do not use. Replace with a new

Agilent 34138A Test Lead Set.

WARN IN G

If the Test Lead Set is used in a manner not specified by Agilent

Technologies, the protection provided by the Test Lead Set may be impaired. Also, do not use a damaged or worn Test Lead Set.

Instrument damage or personal injury may result.

34401A User’s Guide v

DECLARATION OF CONFORMITY

According to ISO/IEC Guide 22 and CEN/CENELEC EN 45014

Manufacturer’s Name:

Manufacturer’s Address:

Agilent Technologies, Incorporated

815 – 14 th

St. SW

Loveland, Colorado 80537

USA

Declares, that the product

Product Name:

Model Number:

Product Options:

Multimeter

34401A

This declaration covers all options of the above product(s).

Conforms with the following European Directives:

The product herewith complies with the requirements of the Low Voltage Directive 73/23/EEC and the EMC Directive 89/336/EEC

(including 93/68/EEC) and carries the CE Marking accordingly.

Conforms with the following product standards:

EMC Standard

IEC 61326-1:1997+A1:1998 / EN 61326-1:1997+A1:1998

CISPR 11:1990 / EN 55011:1991

IEC 61000-4-2:1995+A1:1998 / EN 61000-4-2:1995

IEC 61000-4-3:1995 / EN 61000-4-3:1995

IEC 61000-4-4:1995 / EN 61000-4-4:1995

IEC 61000-4-5:1995 / EN 61000-4-5:1995

IEC 61000-4-6:1996 / EN 61000-4-6:1996

IEC 61000-4-11:1994 / EN 61000-4-11:1994

Canada: ICES-001:1998

Australia/New Zealand: AS/NZS 2064.1

Safety

Limit

Group 1 Class A

4kV CD, 8kV AD

3 V/m, 80-1000 MHz

0.5kV signal lines, 1kV power lines

0.5 kV line-line, 1 kV line-ground

3V, 0.15-80 MHz

Dips: 30% 10ms; 60% 100ms

Interrupt > 95%@5000ms

The product was tested in a typical configuration with Agilent Technologies test systems.

IEC 61010-1:1990+A1:1992+A2:1995 / EN 61010-1:1993+A2:1995

Canada: CSA C22.2 No. 1010.1:1992

UL 3111-1: 1994

18 July 2001

Date

Ray Corson

Product Regulations Program Manager

For further information, please contact your local Agilent Technologies sales office, agent or distributor.

Authorized EU-representative: Agilent Technologies Deutschland GmbH, Herrenberger Stra

βe 130, D 71034 Böblingen, Germany

Revision: B.01

Issue Date: 18 July 2001 Document 34401A.DOC

Note:

Unless otherwise indicated, this manual applies to all Serial Numbers.

The Agilent Technologies 34401A is a 6 1

⁄

2

-digit, high-performance digital multimeter. Its combination of bench-top and system features makes this multimeter a versatile solution for your measurement needs now and in the future.

Convenient Bench-Top Features

•

•

•

•

•

Highly visible vacuum-fluorescent display

Built-in math operations

Continuity and diode test functions

Hands-free, Reading Hold feature

Portable, ruggedized case with non-skid feet

Flexible System Features

•

•

•

•

•

•

GPIB (IEEE-488) interface and RS-232 interface

Standard programming languages: SCPI, Agilent 3478A, and

Fluke 8840

Reading rates up to 1000 readings per second

Storage for up to 512 readings

Limit testing with pass/fail signals

Optional 34812A BenchLink/Meter Software for Microsoft

®

Windows

TM

Agilent 34401A

Multimeter

Page 1 (User’s Guide)

The Front Panel at a Glance

1

Measurement Function keys

2

Math Operation keys

3

Single Trigger / Autotrigger / Reading Hold key

4

Shift / Local key

5

Front / Rear Input Terminal Switch

6

Range / Number of Digits Displayed keys

7

Menu Operation keys

2

The Front-Panel Menu at a Glance

The menu is organized in a top-down tree structure with three levels.

A: MEASurement MENU

1:

AC FILTER >

2:

CONTINUITY >

3:

INPUT R >

4:

RATIO FUNC >

5:

RESOLUTION

B: MATH MENU

1:

MIN-MAX >

2:

NULL VALUE >

3:

dB REL >

4:

dBm REF R >

5:

LIMIT TEST >

6:

HIGH LIMIT >

7:

LOW LIMIT

C: TRIGger MENU

1:

READ HOLD >

2:

TRIG DELAY >

3:

N SAMPLES

D: SYStem MENU

1:

RDGS STORE >

2:

SAVED RDGS >

3:

ERROR >

4:

TEST >

5:

DISPLAY >

6:

BEEP >

7:

COMMA >

8:

REVISION

E: Input / Output MENU

1:

GPIB ADDR >

2:

INTERFACE >

3:

BAUD RATE >

4:

PARITY >

5:

LANGUAGE

F: CALibration MENU

*

1:

SECURED > [

1:

UNSECURED ] > [

2:

CALIBRATE ] >

3:

CAL COUNT >

4:

MESSAGE

*

The commands enclosed in square brackets ( [ ] ) are “hidden” unless the multimeter

is UNSECURED for calibration.

3

Display Annunciators

∗

Adrs

Rmt

Man

Trig

Hold

Mem

Ratio

Math

ERROR

Rear

Shift

4W

Turns on during a measurement.

Multimeter is addressed to listen or talk over the GPIB interface.

Multimeter is in remote mode (remote interface).

Multimeter is using manual ranging (autorange is disabled).

Multimeter is waiting for a single trigger or external trigger.

Reading Hold is enabled.

Turns on when reading memory is enabled.

Multimeter is in dcv:dcv ratio function.

A math operation is enabled (null, min-max, dB, dBm, or limit test).

Hardware or remote interface command errors are detected.

Rear input terminals are selected.

“Shift” key has been pressed.

Press “Shift” again to turn off.

Multimeter is in 4-wire ohms function.

Multimeter is in continuity test function.

Multimeter is in diode test function.

To review the display annunciators, hold down the

Shift

key as you turn on the multimeter.

4

The Rear Panel at a Glance

1

Chassis Ground

2

Power-Line Fuse-Holder Assembly

3

Power-Line Voltage Setting

4

Front and Rear Current Input Fuse

5

Voltmeter Complete Output Terminal

6

External Trigger Input Terminal

7

GPIB (IEEE-488) Interface connector

8

RS-232 interface connector

Use the front-panel Input / Output Menu to:

•

Select the GPIB or RS-232 interface (see chapter 4).

•

Set the GPIB bus address (see chapter 4).

•

Set the RS-232 baud rate and parity (see chapter 4).

5

6

In This Book

Quick Start

Chapter 1 prepares the multimeter for use and helps you get familiar with a few of its front-panel features.

Front-Panel Menu Operation

Chapter 2 introduces you to the front-panel menu and describes some of the multimeter’s menu features.

Features and Functions

Chapter 3 gives a detailed description of the multimeter’s capabilities and operation. You will find this chapter useful whether you are operating the multimeter from the front panel or over the remote interface.

Remote Interface Reference

Chapter 4 contains reference information to help you program the multimeter over the remote interface.

Error Messages

Chapter 5 lists the error messages that may appear as you are working with the multimeter. Each listing contains enough information to help you diagnose and solve the problem.

Application Programs

Chapter 6 contains several remote interface application programs to help you develop programs for your measurement application.

Measurement Tutorial

Chapter 7 discusses measurement considerations and techniques to help you obtain the best accuracies and reduce sources of measurement error.

Specifications

Chapter 8 lists the multimeter’s specifications and describes how to interpret these specifications.

If you have questions relating to the operation of the Agilent 34401A, call 1-800-452-4844 in the United States, or contact your nearest

Agilent Sales Office.

If your 34401A fails within one year of purchase, Agilent will repair or replace it free of charge. Call 1-877-444-7278 (“Agilent Express”) in the

United States, or contact your nearest Agilent Sales Office.

Contents

Chapter 1 Quick Start

To Prepare the Multimeter for Use 13

If the Multimeter Does Not Turn On 14

To Adjust the Carrying Handle 16

To Measure Voltage 17

To Measure Resistance 17

To Measure Current 18

To Measure Frequency (or Period) 18

To Test Continuity 19

To Check Diodes 19

To Select a Range 20

To Set the Resolution 21

Front-Panel Display Formats 22

To Rack Mount the Multimeter 23

Chapter 2 Front-Panel Menu Operation

Front-Panel Menu Reference 27

A Front-Panel Menu Tutorial 29

To Turn Off the Comma Separator 37

To Make Null (Relative) Measurements 38

To Store Minimum and Maximum Readings 39

To Make dB Measurements 40

To Make dBm Measurements 41

To Trigger the Multimeter 42

To Use Reading Hold 43

To Make dcv:dcv Ratio Measurements 44

To Use Reading Memory 46

Chapter 3 Features and Functions

Measurement Configuration

AC Signal Filter 51

Continuity Threshold Resistance 52

DC Input Resistance 53

Resolution 54

Integration Time 57

Front / Rear Input Terminal Switching 58

Autozero 59

Ranging 60

7

Contents

Chapter 3 Features and Functions

(continued)

Math Operations

Min-Max Operation 64

Null (Relative) Operation 65

dB Measurements 67

dBm Measurements 68

Limit Testing 69

Triggering

Trigger Source Choices 73

The Wait-for-Trigger State 76

Halting a Measurement in Progress 76

Number of Samples 77

Number of Triggers 78

Trigger Delay 79

Automatic Trigger Delays 81

Reading Hold 82

Voltmeter Complete Terminal 83

External Trigger Terminal 83

System-Related Operations

Reading Memory 84

Error Conditions 85

Self-Test 86

Display Control 87

Beeper Control 88

Comma Separators 89

Firmware Revision Query 89

SCPI Language Version Query 90

Remote Interface Configuration

GPIB Address 91

Remote Interface Selection 92

Baud Rate Selection (RS-232) 93

Parity Selection (RS-232) 93

Programming Language Selection 94

Calibration

Calibration Security 95

Calibration Count 98

Calibration Message 99

Operator Maintenance

To Replace the Power-Line Fuse 100

To Replace the Current Input Fuses 100

Power-On and Reset State 101

8

Contents

Chapter 4 Remote Interface Reference

Command Summary 105

Simplified Programming Overview 112

The MEASure? and CONFigure Commands 117

Measurement Configuration Commands 121

Math Operation Commands 124

Triggering 127

Triggering Commands 130

System-Related Commands 132

The SCPI Status Model 134

Status Reporting Commands 144

Calibration Commands 146

RS-232 Interface Configuration 148

RS-232 Interface Commands 153

An Introduction to the SCPI Language 154

Output Data Formats 159

Using Device Clear to Halt Measurements 160

TALK ONLY for Printers 160

To Set the GPIB Address 161

To Select the Remote Interface 162

To Set the Baud Rate 163

To Set the Parity 164

To Select the Programming Language 165

Alternate Programming Language Compatibility 166

SCPI Compliance Information 168

IEEE-488 Compliance Information 169

Chapter 5 Error Messages

Execution Errors 173

Self-Test Errors 179

Calibration Errors 180

Chapter 6 Application Programs

Using MEASure? for a Single Measurement 185

Using CONFigure with a Math Operation 186

Using the Status Registers 188

RS-232 Operation Using QuickBASIC 192

RS-232 Operation Using Turbo C 193

9

Contents

Chapter 7 Measurement Tutorial

Thermal EMF Errors 199

Loading Errors (dc volts) 199

Leakage Current Errors 199

Rejecting Power-Line Noise Voltages 200

Common Mode Rejection (CMR) 201

Noise Caused by Magnetic Loops 201

Noise Caused by Ground Loops 202

Resistance Measurements 203

4-Wire Ohms Measurements 203

Removing Test Lead Resistance Errors 204

Power Dissipation Effects 204

Settling Time Effects 204

Errors in High Resistance Measurements 205

DC Current Measurement Errors 205

True RMS AC Measurements 206

Crest Factor Errors 207

Loading Errors (ac volts) 209

Measurements Below Full Scale 210

High-Voltage Self-Heating Errors 210

Temperature Coefficient and Overload Errors 210

Low-Level Measurement Errors 211

Common Mode Errors 212

AC Current Measurement Errors 212

Frequency and Period Measurement Errors 213

Making High-Speed DC and Resistance Measurements 213

Making High-Speed AC Measurements 214

Chapter 8 Specifications

DC Characteristics 216

AC Characteristics 218

Frequency and Period Characteristics 220

General Information 222

Product Dimensions 223

To Calculate Total Measurement Error 224

Interpreting Multimeter Specifications 226

Configuring for Highest Accuracy Measurements 229

Index

231

Declaration of Conformity

237

10

1

1

Quick Start

Quick Start

One of the first things you will want to do with your multimeter is to become acquainted with its front panel. We have written the exercises in this chapter to prepare the multimeter for use and help you get familiar with some of its front-panel operations.

The front panel has two rows of keys to select various functions and operations. Most keys have a shifted function printed in blue above the key. To perform a shifted function, press

Shift

(the

Shift

annunciator will turn on). Then, press the key that has the desired label above it. For example, to select the dc current function, press

Shift DC V

.

If you accidentally press

Shift

, just press it again to turn off the

Shift

annunciator.

The rear cover of this book is a fold-out Quick Reference Guide. On this cover you will find a quick summary of various multimeter features.

12

Chapter 1 Quick Start

To Prepare the Multimeter for Use

To Prepare the Multimeter for Use

The following steps help you verify that the multimeter is ready for use.

1 Check the list of supplied items.

Verify that you have received the following items with your multimeter.

If anything is missing, contact your nearest Agilent Sales Office.

One test lead kit.

One power cord.

This User’s Guide.

One Service Guide.

One folded Quick Reference card.

Certificate of Calibration.

2 Connect the power cord and turn on the multimeter.

The front-panel display will light up while the multimeter performs its power-on self-test. The

GPIB

bus address is displayed. Notice that the multimeter powers up in the dc voltage function with autoranging enabled.

To review the power-on display with all annunciators turned on, hold down

Shift

as you turn on the multimeter.

3 Perform a complete self-test.

The complete self-test performs a more extensive series of tests than those performed at power-on. Hold down

Shift as you press the

Power switch to turn on the multimeter; hold down the key for more

than 5 seconds. The self-test will begin when you release the key.

If the self-test is successful, “

PASS

” is displayed. If the self-test is not successful, “

FAIL

” is displayed and the

ERROR

annunciator turns on.

See the Service Guide for instructions on returning the multimeter to

Agilent for service.

1

13

Chapter 1 Quick Start

If the Multimeter Does Not Turn On

1

If the Multimeter Does Not Turn On

Use the following steps to help solve problems you might encounter when turning on the multimeter. If you need more help, see the

Service Guide for instructions on returning the multimeter to Agilent for service.

1 Verify that there is ac power to the multimeter.

First, verify that the multimeter’s Power switch is in the “On” position.

Also, make sure that the power cord is firmly plugged into the power module on the rear panel. You should also make sure that the power source you plugged the multimeter into is energized.

2 Verify the power-line voltage setting.

The line voltage is set to the proper value for your country when the multimeter is shipped from the factory. Change the voltage setting if it is not correct. The settings are: 100, 120, 220, or 240 Vac (for 230 Vac operation, use the 220 Vac setting).

See the next page if you need to change the line-voltage setting.

3 Verify that the power-line fuse is good.

The multimeter is shipped from the factory with a 250 mA fuse installed. This is the correct fuse for all line voltages.

See the next page if you need to replace the power-line fuse.

To replace the 250 mAT fuse, order Agilent part number 2110-0817.

14

Chapter 1 Quick Start

If the Multimeter Does Not Turn On

1

Remove the power cord. Remove the

fuse-holder assembly from the rear panel.

2

Remove the line-voltage selector from

the assembly.

1

See rear panel for proper fuse rating.

Agilent Part Number: 2110-0817 (250 mAT)

3

Rotate the line-voltage selector until the

correct voltage appears in the window.

4

Replace the fuse-holder assembly in

the rear panel.

100, 120, 220 (230) or 240 Vac

Verify that the correct line voltage is selected and the power-line fuse is good.

15

Chapter 1 Quick Start

To Adjust the Carrying Handle

To Adjust the Carrying Handle

To adjust the position, grasp the handle by the sides and pull outward.

Then, rotate the handle to the desired position.

Bench-top viewing positions Carrying position

16

Chapter 1 Quick Start

To Measure Voltage

To Measure Voltage

Ranges: 100 mV, 1 V, 10 V, 100 V, 1000 V (750 Vac)

Maximum resolution: 100 nV (on 100 mV range)

AC technique: true

RMS

, ac-coupled

1

To Measure Resistance

Ranges: 100

Ω,

1 k

Ω

, 10 k

Ω

, 100 k

Ω

, 1 M

Ω

, 10 M

Ω

, 100 M

Ω

Maximum resolution: 100

µΩ

(on 100 ohm range)

17

Chapter 1 Quick Start

To Measure Current

To Measure Current

Ranges: 10 mA (dc only), 100 mA (dc only), 1 A , 3 A

Maximum resolution: 10 nA (on 10 mA range)

AC technique: true

RMS

, ac-coupled

To Measure Frequency (or Period)

Measurement band: 3 Hz to 300 kHz (0.33 sec to 3.3

µ sec)

Input signal range: 100 mVac to 750 Vac

Technique: reciprocal counting

18

Chapter 1 Quick Start

To Test Continuity

To Test Continuity

Test current source: 1 mA

Maximum resolution: 0.1 Ω (range is fixed at 1 kohm)

Beeper threshold: 1

Ω

to 1000

Ω

(beeps below adjustable threshold)

1

To Check Diodes

Test current source: 1 mA

Maximum resolution: 100 µ V (range is fixed at 1 Vdc)

Beeper threshold: 0.3 volts ≤ V measured

≤ 0.8 volts (not adjustable)

19

Chapter 1 Quick Start

To Select a Range

To Select a Range

You can let the multimeter automatically select the range using

autoranging or you can select a fixed range using manual ranging.

Selects a lower range and disables autoranging.

Selects a higher range and disables autoranging.

Man

annunciator is on when manual range is enabled.

Toggles between autoranging and manual ranging.

•

•

•

•

•

Autoranging is selected at power-on and after a remote interface reset.

Autorange thresholds:

Down range at <10% of range

Up range at >120% of range

If the input signal is greater than the present range can measure, the multimeter will give an overload indication (“

OVLD

”).

For frequency and period measurements from the front panel, ranging applies to the signal’s input voltage, not its frequency.

The range is fixed for continuity (1 k Ω range) and diode (1 Vdc range).

Ranging is local to the selected function. This means that you can select the ranging method (auto or manual) for each function independently.

When manually ranging, the selected range is local to the function; the multimeter remembers the range when you switch between functions.

20

Chapter 1 Quick Start

To Set the Resolution

To Set the Resolution

You can set the display resolution to 4

1 ⁄

2

, 5

1 ⁄

2

, or 6

1 ⁄

2

digits either to optimize measurement speed or noise rejection. In this book, the most significant digit (leftmost on the display) is referred to as the “ 1

⁄

2

” digit, since it can only be a “0” or “1.”

1

Press the Shift key.

Selects 4

1

⁄

2

digits.

Selects 5

1 ⁄

2

digits.

Selects 6

1

⁄

2

digits (

most noise rejection

).

•

•

•

The resolution is set to 5 1

⁄

2

digits at power-on and after a remote interface reset.

The resolution is fixed at 5

1 ⁄

2

digits for continuity and diode tests.

You can also vary the number of digits displayed using the arrow keys

(however, the integration time is not changed).

Fewer More

Digits Digits

Resolution is local to the selected function. This means that you can select the resolution for each function independently. The multimeter remembers the resolution when you switch between functions.

21

Chapter 1 Quick Start

Front-Panel Display Formats

Front-Panel Display Formats

-

H.DDD,DDD EFFF

Front-panel display format.

–

Negative sign or blank (positive)

H

“

1

⁄

2

” digit (0 or 1)

D

Numeric digits

E

Exponent ( m, k, M )

F

Measurement units ( VDC, OHM, HZ, dB )

5 digits

“

1

⁄

2

” digit

“

1 ⁄

2

” digit

10.216,5 VDC

This is the 10 Vdc range, 5

1 ⁄

2

digits are displayed.

-

045.23 mVDC

This is the 100 mVdc range, 4

1 ⁄

2

digits are displayed.

113.325,6 OHM

This is the 100 ohm range, 6

1 ⁄

2

digits are displayed.

OVL.D mVDC

This is an overload indication on the 100 mVdc range.

22

Chapter 1 Quick Start

To Rack Mount the Multimeter

To Rack Mount the Multimeter

You can mount the multimeter in a standard 19-inch rack cabinet using one of three optional kits available. Instructions and mounting hardware are included with each rack-mounting kit. Any Agilent

System II

instrument of the same size can be rack-mounted beside the 34401A.

Remove the carrying handle, and the front and rear rubber bumpers, before rack-mounting the multimeter.

1

To remove the handle, rotate it to the vertical position and pull the ends outward.

Front Rear (bottom view)

To remove the rubber bumper, stretch a corner and then slide it off.

23

Chapter 1 Quick Start

To Rack Mount the Multimeter

To rack mount a single instrument, order adapter kit 5063-9240.

To rack mount two instruments side-by-side, order lock-link kit 5061-9694 and flange kit 5063-9212.

To install one or two instruments in a sliding support shelf, order shelf 5063-9255, and slide kit 1494-0015 (for a single instrument, also order filler panel 5002-3999).

24

2

2

Front-Panel

Menu Operation

Front-Panel Menu Operation

By now you should be familiar with the

FUNCTION

and

RANGE / DIGITS groups of front-panel keys. You should also understand how to make front-panel connections for the various types of measurements. If you are not familiar with this information, we recommend that you read chapter 1, “Quick Start,” starting on page 11.

This chapter introduces you to three new groups of front-panel keys:

MENU

,

MATH

, and

TRIG

. You will also learn how to use the comma separator and store readings in memory. This chapter does not give a detailed description of every front-panel key or menu operation. It does, however, give you a good overview of the front-panel menu and many front-panel operations. See chapter 3 “Features and Functions,” starting on page 49, for a complete discussion of the multimeter’s capabilities and operation.

26

Chapter 2 Front-Panel Menu Operation

Front-Panel Menu Reference

Front-Panel Menu Reference

A: MEASurement MENU

1:

AC FILTER >

2:

CONTINUITY >

3:

INPUT R >

4:

RATIO FUNC >

5:

RESOLUTION

1: AC FILTER

2: CONTINUITY

3: INPUT R

4: RATIO FUNC

5: RESOLUTION

Selects the slow, medium, or fast ac filter.

Sets the continuity beeper threshold (1

Ω

to 1000

Ω

).

Sets the input resistance for dc voltage measurements.

Enables the dcv:dcv ratio function.

Selects the measurement resolution.

B: MATH MENU

1:

MIN-MAX >

2:

NULL VALUE >

3:

dB REL >

4:

dBm REF R >

5:

LIMIT TEST >

6:

HIGH LIMIT >

7:

LOW LIMIT

1: MIN-MAX

2: NULL VALUE

3: dB REL

4: dBm REF R

5: LIMIT TEST

6: HIGH LIMIT

7: LOW LIMIT

Recalls the stored minimum, maximum, average, and reading count.

Recalls or sets the null value stored in the null register.

Recalls or sets the dBm value stored in the dB relative register.

Selects the dBm reference resistance value.

Enables or disables limit testing.

Sets the upper limit for limit testing.

Sets the lower limit for limit testing.

2

C: TRIGger MENU

1:

READ HOLD >

2:

TRIG DELAY >

3:

N SAMPLES

1: READ HOLD

2: TRIG DELAY

3: N SAMPLES

Sets the reading hold sensitivity band.

Specifies a time interval which is inserted before a measurement.

Sets the number of samples per trigger.

27

Chapter 2 Front-Panel Menu Operation

Front-Panel Menu Reference

D: SYStem MENU

1:

RDGS STORE >

2:

SAVED RDGS >

3:

ERROR >

4:

TEST >

5:

DISPLAY >

6:

BEEP >

7:

COMMA >

8:

REVISION

1: RDGS STORE

2: SAVED RDGS

3: ERROR

4: TEST

5: DISPLAY

6: BEEP

7: COMMA

8: REVISION

Enables or disables reading memory.

Recalls readings stored in memory (up to 512 readings).

Retrieves errors from the error queue (up to 20 errors).

Performs a complete self-test.

Enables or disables the front-panel display.

Enables or disables the beeper function.

Enables or disables a comma separator between digits on the display.

Displays the multimeter’s firmware revision codes.

E: Input / Output MENU

1:

GPIB ADDR >

2:

INTERFACE >

3:

BAUD RATE >

4:

PARITY >

5:

LANGUAGE

1: HP-IB ADDR

2: INTERFACE

3: BAUD RATE

4: PARITY

5: LANGUAGE

Sets the GPIB bus address (0 to 31).

Selects the GPIB or RS-232 interface.

Selects the baud rate for RS-232 operation.

Selects even, odd, or no parity for RS-232 operation.

Selects the interface language: SCPI, Agilent 3478, or Fluke

8840/42.

F: CALibration MENU

*

1:

SECURED > [

1:

UNSECURED ] > [

2:

CALIBRATE ] >

3:

CAL COUNT >

4:

MESSAGE

1: SECURED

1: UNSECURED

2: CALIBRATE

3: CAL COUNT

4: MESSAGE

The multimeter is secured against calibration; enter code to unsecure.

The multimeter is unsecured for calibration; enter code to secure.

Performs complete calibration of present function; must be UNSECURED.

Reads the total number of times the multimeter has been calibrated.

Reads the calibration string (up to 12 characters) entered from remote.

*

The commands enclosed in square brackets ( [ ] ) are “hidden” unless the multimeter is UNSECURED for calibration.

28

Chapter 2 Front-Panel Menu Operation

A Front-Panel Menu Tutorial

A Front-Panel Menu Tutorial

This section is a step-by-step tutorial which shows how to use the front-panel menu. We recommend that you spend a few minutes with this tutorial to get comfortable with the structure and operation of the menu.

The menu is organized in a top-down tree structure with three levels (menus, commands, and parameters). You move down

∨ or up

∧

the menu tree to get from one level to the next. Each of the three levels has several horizontal choices which you can view by moving left

<

or right

>

.

2

Menus

Commands

Parameters

•

To turn on the menu, press

Shift Menu On/Off

.

•

To turn off the menu, press

Shift Menu On/Off

, or press any of the function or math keys on the top row of front-panel keys.

•

To execute a menu command, press

Enter

.

•

To recall the last menu command that was executed, press

Shift Recall

.

29

Chapter 2 Front-Panel Menu Operation

A Front-Panel Menu Tutorial

MESSAGES DISPLAYED DURING MENU USE

TOP OF MENU

∧ the menu and you cannot go any higher.

To turn off the menu, press (Menu On/Off). To move across the choices

< >

Shift <

∨

MENUS

<

>

COMMANDS

command choices within the selected menu group.

<

>

PARAMETER

< the parameter for the selected command.

MENU BOTTOM

∨ level of the menu and you cannot go any lower.

>

To turn off the menu, press (Menu On/Off). To move up a level,

∧

Shift <

CHANGE SAVED

The change made on the “parameter” level is saved. This is

Auto/Man

MIN VALUE

The value you specified on the “parameter” level is too small for the selected command. The minimum value allowed is displayed for you to edit.

MAX VALUE

The value you specified on the “parameter” level is too large for the selected command. The maximum value allowed is displayed for you to edit.

EXITING MENU

You will see this message if you turn off the menu by pressing

Shift < on the “parameter” level and changes were NOT saved.

NOT ENTERED

You will see this message if you turn off the menu by pressing

Shift < parameters but the changes were NOT saved. Press (Menu Enter) to save changes made on the “parameter” level.

Auto/Man

NOT RELEVANT

The selected math operation is NOT valid for the function in use.

30

Chapter 2 Front-Panel Menu Operation

A Front-Panel Menu Tutorial

Menu Example 1

The following steps show you how to turn on the menu, move up or down between levels, move across the choices on each level, and turn off the menu. In this example, you will turn off the front-panel beeper.

On/Off

Shift <

1 Turn on the menu.

You enter the menu on the “menus” level. The

MEAS MENU

is your first choice on this level.

2

A: MEAS MENU

> > >

2 Move across to the

SYS MENU

choice on this level.

There are six menu group choices available on the “menus” level. Each choice has a letter prefix for easy identification (

A:

,

B:

, etc.).

D: SYS MENU

∨

3 Move down to the “commands” level within the

SYS MENU

.

The

RDGS STORE

command is your first choice on this level.

1: RDGS STORE

31

Chapter 2 Front-Panel Menu Operation

A Front-Panel Menu Tutorial

> > >

> >

∨

>

Auto/Man

ENTER

4 Move across to the

BEEP

command on the “commands” level.

There are eight command choices available in the

SYS MENU

. Each choice on this level has a number prefix for easy identification (

1:

,

2:

, etc.).

6: BEEP

5 Move down a level to the

BEEP

parameter choices.

The first parameter choice is “

ON

” for the

BEEP command (the beeper setting is stored in non-volatile memory and “

ON

” is the factory setting).

ON

6 Move across to the

“OFF”

choice.

There are two parameter choices for

BEEP

.

OFF

7 Save the change and turn off the menu.

The multimeter beeps and displays a message to show that the change is now in effect. You are then exited from the menu.

CHANGE SAVED

32

Chapter 2 Front-Panel Menu Operation

A Front-Panel Menu Tutorial

Menu Example 2

The following exercise demonstrates how to use the menu recall feature as a shortcut to set the

BEEP

command back to its original setting.

You must perform the steps in Example 1 before you start this example.

Recall

Shift >

1 Use menu recall to return to the

BEEP

command.

This returns you to the

BEEP

command, which was the last command used before you exited the menu in the Example 1.

6: BEEP

2

∨

2 Move down to the

BEEP

parameter choices.

The first parameter choice is “

OFF

” (the current setting from Example 1).

OFF

>

3 Move across to the

“ON”

choice.

Set the parameter back to its original value.

ON

Auto/Man

ENTER

4 Save the change and turn off the menu.

The multimeter beeps and displays a message to show that the change is now in effect. You are then exited from the menu.

CHANGE SAVED

33

Chapter 2 Front-Panel Menu Operation

A Front-Panel Menu Tutorial

Menu Example 3

Some commands in the menu require that you enter a numeric parameter value. The following steps show you how to enter a number in the menu. For this example, you will set the null value to –2.0 volts.

Make sure the multimeter is in the dc voltage function with 5

1

resolution displayed. Disconnect all inputs to the multimeter.

⁄

2

digits of

On/Off

Shift <

1 Turn on the menu.

You enter the menu on the “menus” level. The

MEAS MENU

is your first choice on this level.

A: MEAS MENU

>

2 Move across to the

MATH MENU

choice on this level.

There are six menu group choices available on this level.

B: MATH MENU

∨

3 Move down to the “commands” level within the

MATH MENU

.

The

MIN–MAX

command is your first choice on this level.

1: MIN-MAX

>

4 Move across to the

NULL VALUE

command on this level.

There are seven command choices available within the

MATH MENU

.

2: NULL VALUE

34

∨

∨ ∨

>

∧

∧

Chapter 2 Front-Panel Menu Operation

A Front-Panel Menu Tutorial

5 Move down to edit the

NULL VALUE

parameter.

The null value should be 0.0 Vdc when you come to this point in the menu for the first time. For this example, you will set the null value to –2.0 volts.

∧

000.000 mVDC

When you see the flashing “

∧

” on the left side of the display, you can abort the edit and return to the “commands” level by pressing

∧

.

6 Make the number negative.

The leftmost character on the display toggles between + and – .

-000.000 mVDC

7 Move the flashing cursor over to edit the first digit.

Notice that the leftmost digit is flashing.

-000.000 mVDC

8 Increment the first digit until “ 2 ” is displayed.

You decrement or increment each digit independently. Neighboring digits are not affected.

-200.000 mVDC

2

35

Chapter 2 Front-Panel Menu Operation

A Front-Panel Menu Tutorial

<

<

∧

Auto/Man

ENTER

9 Move the flashing cursor over to the “units” location.

Notice that the units are flashing on the right side of the display.

-200.000 mVDC

10 Increase the displayed number by a factor of 10.

Notice that the position of the decimal point changes and the displayed number increases by a factor of 10.

-2.000,00 VDC

11 Save the change and turn off the menu.

The multimeter beeps and displays a message to show that the change is now in effect. You are then exited from the menu.

CHANGE SAVED

Keep in mind that math null is turned on and –2.0 volts is used as

the null value for measurements. To clear the null value, press

Null

.

This is the end of the front-panel menu tutorial. The remainder of the chapter discusses several of the most common front-panel operations.

36

Chapter 2 Front-Panel Menu Operation

To Turn Off the Comma Separator

On/Off

Shift <

To Turn Off the Comma Separator

The multimeter can display readings on the front panel with or without a comma separator. The following steps show how to disable the comma.

2

08.241,53 VDC

08.24153 VDC

With comma separator

(factory setting)

Without comma separator

1 Turn on the menu.

A: MEAS MENU

> > >

2 Move across to the

SYS MENU

choice on the “menus” level.

D: SYS MENU

∨

< <

3 Move down a level and then across to the

COMMA

command.

7: COMMA

∨ >

4 Move down a level and then move across to the “

OFF

” choice.

OFF

Auto/Man

ENTER

5 Save the change and turn off the menu.

The comma separator setting is stored in non-volatile memory, and

does not change when power has been off or after a remote interface reset.

37

Chapter 2 Front-Panel Menu Operation

To Make Null (Relative) Measurements

To Make Null (Relative) Measurements

Each null measurement, also called relative, is the difference between a stored null value and the input signal.

Result

= reading – null value

To read / edit the null value, use the MATH menu.

Enables null operation;

Press again to disable.

Math

annunciator is on when null operation is enabled.

•

•

•

•

•

You can make null measurements with any function except continuity, diode, or ratio. The null operation is local to the selected function; when you change functions, null is disabled.

To null the test lead resistance for more accurate two-wire ohms measurements, short the ends of the test leads together and then press

Null

.

The first reading taken after you press

Null is stored as the null value in the Null Register. Any previously stored value is replaced with the new value.

After enabling null, you can edit the stored null value by pressing

Shift >

(Menu Recall). This takes you to the

“

NULL VALUE

” command in the

MATH MENU

(only if null is

enabled). Go down to the “parameter” level, and then edit the displayed value.

The null register is cleared when you change functions, turn null off, turn off the power, or perform a remote interface reset.

38

Chapter 2 Front-Panel Menu Operation

To Store Minimum and Maximum Readings

To Store Minimum and Maximum Readings

You can store the minimum and maximum readings during a series of measurements. The following discussion shows how to read the minimum, maximum, average, and reading count.

To read the minimum, maximum, average, and count, use the MATH menu.

2

Enables min-max operation;

Press again to disable.

Math

annunciator is on when min-max operation is enabled.

•

••

•

•

You can use min-max with any function except continuity or diode test.

The min-max operation is local to the selected function; when you change functions, min-max is disabled.

After enabling min-max, you can read the stored minimum, maximum, average, and count by pressing

Shift >

(Menu Recall).

This takes you to the “

MIN–MAX

” command in the

MATH MENU

(only if min-max is enabled). Go down to the “parameter” level, and then read the values by pressing

<

or

>

.

The stored values are cleared when you turn min-max off, turn off the power, or perform a remote interface reset.

The average is of all readings taken since min-max was enabled (not just the average of the stored minimum and maximum). The count is the total number of readings taken since min-max was enabled.

39

Chapter 2 Front-Panel Menu Operation

To Make dB Measurements

To Make dB Measurements

Each dB measurement is the difference between the input signal and a stored relative value, with both values converted to dBm.

dB

= reading in dBm – relative value in dBm

To read / edit the dB relative value, use the MATH menu.

Enables dB operation;

Press again to disable.

Math

annunciator is on when dB operation is enabled.

•

•

•

•

Select

DC V

or

AC V

.

The first reading taken after you enable dB measurements is converted to dBm and is stored as the relative value in the dB Relative Register. Any previously stored value is replaced with the new value.

After enabling dB operations, you can edit the relative value by pressing

Shift >

(Menu Recall). This takes you to the “ dB REL

” command in the

MATH MENU

(only if dB is enabled). Go down to the “parameter” level, and then edit the value displayed.

The register is cleared when you change functions, turn dB off, turn off the power, or perform a remote interface reset.

40

Chapter 2 Front-Panel Menu Operation

To Make dBm Measurements

To Make dBm Measurements

The dBm operation calculates the power delivered to a resistance referenced to 1 milliwatt.

dBm

= 10 × Log

10

( reading

2

/

reference resistance

/

1 mW )

To read / edit the dBm reference resistance, use the MATH menu.

2

Enables dBm operation;

Press again to disable.

Math

annunciator is on when dBm operation is enabled.

•

•

Select

DC V

or

AC V

.

The factory setting for the reference resistance is 600 Ω . To select a different value, press

Shift >

(Menu Recall) after enabling dBm operations. This takes you to the “ dBm REF R

” command in the

MATH MENU

(only if dBm is enabled).

•

Go down to the “parameter” level, and then select a value: 50, 75,

93, 110, 124, 125, 135, 150, 250, 300, 500, 600, 800, 900, 1000,

1200, or 8000 ohms.

The reference resistance is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

41

Chapter 2 Front-Panel Menu Operation

To Trigger the Multimeter

To Trigger the Multimeter

You can trigger the multimeter from the front panel using single trigger or auto trigger.

Enables single trigger and triggers the multimeter.

∗

(sample) annunciator is on during each measurement.

Toggles between auto trigger and reading hold.

Trig

annunciator is on when the multimeter is waiting for single trigger (auto trigger disabled).

•

•

Auto triggering is enabled when you turn on the multimeter. Notice that the ∗ (sample) annunciator turns on during each measurement.

Single triggering takes one reading each time you press

Single and then waits for the next trigger. Continue pressing this key to trigger the multimeter.

Using an External Trigger

Single the single trigger mode except that you apply a trigger pulse to the rear-panel

Ext Trig terminal. The multimeter is triggered on the negative edge of a

TTL pulse.

42

Chapter 2 Front-Panel Menu Operation

To Use Reading Hold

To Use Reading Hold

The reading hold feature allows you to capture and hold a stable reading on the display. When a stable reading is detected, the multimeter emits a beep and holds the value on the display.

To adjust the reading hold sensitivity band, use the TRIG menu.

2

Toggles between auto trigger and reading hold.

Hold

annunciator is on when reading hold is enabled.

•

•

Reading hold has an adjustable sensitivity band to allow you to select which readings are considered stable enough to be displayed.

The band is expressed as a percent of reading on the selected range.

The multimeter will capture and display a new value only after three consecutive readings are within the band.

The default band is 0.10% of reading. After enabling reading hold, you can choose a different band by pressing

Shift >

(Menu Recall). This takes you to the “

READ HOLD

” command in the

TRIG MENU

(only if reading hold is enabled).

•

Go down to the “parameter” level, and then select a value:

0.01%, 0.10%, 1.00%, or 10.00% of reading.

The sensitivity band is stored in volatile memory; the multimeter sets the band to 0.10% of reading when power has been off or after a remote interface reset.

43

Chapter 2 Front-Panel Menu Operation

To Make dcv:dcv Ratio Measurements

To Make dcv:dcv Ratio Measurements

To calculate a ratio, the multimeter measures a dc reference voltage applied to the

Sense

terminals and the voltage applied to the

Input

terminals.

Ratio

=

dc signal voltage

dc reference voltage

To enable ratio measurements, use the MEAS menu.

Ratio

annunciator is on when ratio measurements are enabled.

•

•

•

At the

Sense

terminals, the reference voltage measurement function is always dc voltage and has a maximum measurable input of

±

12 Vdc. Autoranging is automatically selected for reference voltage measurements on the

Sense

terminals.

The

Input LO

and

Sense LO

terminals must have a common reference and cannot have a voltage difference greater than

±

2 volts.

The specified measurement range applies only to the signal connected to the

Input

terminals. The signal on the

Input

terminals can be any dc voltage up to 1000 volts.

44

Chapter 2 Front-Panel Menu Operation

To Make dcv:dcv Ratio Measurements

On/Off

Shift <

The following steps show you how to select the ratio function using the front-panel menu.

1 Turn on the menu.

A: MEAS MENU

2

∨ < <

2 Move down a level and then across to the

RATIO FUNC

command.

4: RATIO FUNC

∨

3 Move down to the “parameter” level.

For this command, there is only one choice on this level.

DCV:DCV

Auto/Man

ENTER

4 Select the ratio function and turn off the menu.

Notice that the

Ratio

annunciator turns on.

CHANGE SAVED

To disable ratio measurements, select a different measurement function by pressing any front-panel function key.

45

Chapter 2 Front-Panel Menu Operation

To Use Reading Memory

Single

On/Off

Shift <

To Use Reading Memory

The multimeter can store up to 512 readings in internal memory.

The following steps demonstrate how to store readings and retrieve them.

1 Select the function.

Select any measurement function. You can also select Null, Min–Max, dB, dBm, or limit test. You can change the function at any time during reading memory.

2 Select the single trigger mode.

Notice that the

Trig

annunciator turns on. When reading memory is enabled, readings are stored when you trigger the multimeter.

For this example, single triggering is used to store readings. You can also use auto triggering or reading hold.

3 Turn on the menu.

A: MEAS MENU

> > >

∨

4 Move across to the

SYS MENU

choice on this level.

D: SYS MENU

5 Move down to a level to the

RDGS STORE command.

1: RDGS STORE

46

Chapter 2 Front-Panel Menu Operation

To Use Reading Memory

∨

>

Auto/Man

ENTER

Single

Single

Single

Recall

Shift >

6 Move down a level and then across to the “

ON

” choice.

ON

7 Save the change and exit the menu.

Notice that the

Mem

(memory) annunciator turns on to indicate that the multimeter is ready to store readings. Up to 512 readings can be stored in first-in-first-out (

FIFO

) order. When memory is full, the

Mem

annunciator will turn off.

Readings are preserved until you re-enable reading memory at another time, turn off the power, or perform a remote interface reset.

8 Trigger the multimeter three times.

This stores three readings in memory.

9 Use menu recall to retrieve the stored readings.

This takes you to the “

SAVED RDGS

” command in the

SYS MENU

.

2: SAVED RDGS

2

47

Chapter 2 Front-Panel Menu Operation

To Use Reading Memory

∨

10 Move down a level to view the first stored reading.

Reading memory is automatically turned off when you go to the

“parameter” level in the menu.

The first reading displayed is the first reading that was stored (FIFO).

If no readings are stored in memory, “

EMPTY

” is displayed. The stored readings are displayed with their units ( µ , m, k, etc.) when appropriate.

For example:

Reading number

10.31607K: 1

Exponent

> >

On/Off

Shift <

11 Move across to view the two remaining stored readings.

The readings are stored horizontally on the “parameter” level.

If you press

<

when you get to the “parameter” level, you will see the

last reading and you will know how many readings were stored.

12 Turn off the menu.

EXITING MENU

48

3

Features and

Functions

3

Features and Functions

You will find that this chapter makes it easy to look up all the details about a particular feature of the multimeter. Whether you are operating the multimeter from the front panel or from the remote interface, this chapter will be useful. This chapter is divided into the following sections:

•

•

•

•

•

•

•

•

Measurement Configuration, starting on page 51

Math Operations, starting on page 63

Triggering, starting on page 71

System-Related Operations, starting on page 84

Remote Interface Configuration, starting on page 91

Calibration Overview, starting on page 95

Operator Maintenance, starting on page 100

Power-On and Reset State, on page 101

Some knowledge of the front-panel menu will be helpful before you read this chapter. If you have not already read chapter 2, “Front-Panel Menu

Operation,” starting on page 25, you may want to read it now. Chapter 4,

“Remote Interface Reference,” starting on page 103, lists the syntax for the

SCPI

commands available to program the multimeter.

Throughout this manual, the following conventions are used for

SCPI

command syntax for remote interface programming.

•

•

•

•

Square brackets ( [ ] ) indicate optional keywords or parameters.

Braces ( { } ) enclose parameters within a command string.

Triangle brackets ( < > ) indicate that you must substitute a value for the enclosed parameter.

A vertical bar (

|

) separates multiple parameter choices.

50

Chapter 3 Features and Functions

Measurement Configuration

Measurement Configuration

This section contains information to help you configure the multimeter for making measurements. You may never have to change any of the measurement parameters discussed here, but they are provided to give you the flexibility you might need.

AC Signal Filter

The multimeter uses three different ac filters which enable you to either optimize low frequency accuracy or achieve faster ac settling times.

The multimeter selects the slow, medium, or fast filter based on the input frequency that you specify.

Applies to ac voltage and ac current measurements only.

3

Input Frequency

3 Hz to 300 kHz

20 Hz to 300 kHz

200 Hz to 300 kHz

AC Filter Selected

Slow filter

Medium filter (default)

Fast filter

Settling Time

7 seconds / reading

1 reading / second

10 readings / second

•

•

The ac filter selection is stored in volatile memory; the multimeter selects the medium filter (20 Hz) when power has been off or after a remote interface reset.

Front-Panel Operation: Select from the menu the slow filter (3 Hz), medium filter (20 Hz), or fast filter (200 Hz). The default is the

medium filter.

1: AC FILTER (MEAS MENU)

•

Remote Interface Operation: Specify the lowest frequency expected in the input signal. The multimeter selects the appropriate filter based on the frequency you specify (see table above). The

CONFigure

and

MEASure?

commands select the 20 Hz filter.

DETector:BANDwidth {3|20|200|MINimum|MAXimum}

51

Chapter 3 Features and Functions

Measurement Configuration

Continuity Threshold Resistance

When measuring continuity, the multimeter emits a continuous tone if the measured resistance is less than the threshold resistance. You can set the threshold to any value between 1

Ω

and 1000

Ω

.

The threshold resistance is adjustable only from the front panel.

•

•

•

The threshold resistance is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

The factory setting for the threshold resistance is 10

Ω

.

After enabling the continuity function, you can select a different threshold resistance by pressing

Shift >

(Menu Recall).

2: CONTINUITY (MEAS MENU)

∧

0010 OHM

See also “To Test Continuity,” on page 19.

52

Chapter 3 Features and Functions

Measurement Configuration

DC Input Resistance

Normally, the multimeter’s input resistance is fixed at 10 M

Ω

for all dc voltage ranges to minimize noise pickup. To reduce the effects of measurement loading errors, you can set the input resistance to greater than 10 G

Ω

for the 100 mVdc, 1 Vdc, and 10 Vdc ranges.

Applies to dc voltage measurements and is disabled for all other functions.

Input Resistance Input Resistance

100mV, 1V, 10V ranges 100V, 1000V ranges

Fixed Resistance ON

(default)

10 M

Ω

Fixed Resistance OFF

> 10 G

Ω

10 M

Ω

10 M

Ω

3

•

•

The input resistance setting is stored in volatile memory; the multimeter selects 10 M

Ω

(for all dc voltage ranges) when power has been off or after a remote interface reset.

Front-Panel Operation: Select from the menu the 10 M Ω

mode (fixed resistance for all dc voltage ranges) or the >10 G

Ω

mode. The default

is 10 M

Ω

.

3: INPUT R (MEAS MENU)

•

Remote Interface Operation: You can enable or disable the automatic input resistance mode. With

AUTO OFF

(default), the input resistance is fixed at 10 M

Ω

for all ranges. With

AUTO ON

, the input resistance is set to >10 G

Ω for the three lowest dc voltage ranges. The

CONFigure and

MEASure?

commands automatically turn

AUTO OFF

.

INPut:IMPedance:AUTO {OFF|ON}

53

Chapter 3 Features and Functions

Measurement Configuration

Resolution

Resolution is expressed in terms of number of digits the multimeter can measure or display. You can set the resolution to 4, 5, or 6 full digits, plus a “

1 ⁄

2

” digit which can only be a “0” or “1”. To increase measurement accuracy and improve noise rejection, select 6

1 ⁄

2

digits. To increase measurement speed, select 4 1

⁄

2

digits.

Applies to all measurement functions. The resolution for the math operations (null, min-max, dB, dBm, limit test) is the same as the resolution for the measurement function in use.

The correspondence between the number of digits selected and the resulting integration time (in power line cycles) is shown below.

The autozero mode is set indirectly when you set the resolution.

See also “Autozero,” on page 59.

Resolution Choices

Fast 4 Digit

*

Slow 4 Digit

Integration Time

0.02 PLC

1 PLC

Fast 5 Digit

*

Slow 5 Digit

(default)

0.2 PLC

10 PLC

*

Fast 6 Digit

Slow 6 Digit

10 PLC

100 PLC

*

These settings configure the multimeter just as if you had pressed

the corresponding “DIGITS” keys from the front panel.

Resolution is local to the selected function. This means that you can select the resolution for each function independently. The multimeter remembers the resolution when you switch between functions.

54

Chapter 3 Features and Functions

Measurement Configuration

5 digits

“

1

⁄

2

” digit

“

1 ⁄

2

” digit

10.216,5 VDC

This is the 10 Vdc range, 5

1

⁄

2

digits are displayed.

-

045.23 mVDC

This is the 100 mVdc range, 4

1

⁄

2

digits are displayed.

113.325,6 OHM

This is the 100 ohm range, 6

1 ⁄

2

digits are displayed.

•

•

•

•

•

The resolution is stored in volatile memory; the multimeter sets the resolution to 5 1

⁄

2

digits (for all functions) when power has been off or after a remote interface reset.

The resolution is fixed at 5 1

⁄

2

digits for continuity and diode tests.

For dc and resistance measurements, changing the number of digits does more than just change the resolution of the multimeter. It also changes the integration time, which is the period the multimeter’s analog-to-digital (A/D) converter samples the input signal for a measurement. See also “Integration Time,” on page 57.

For ac measurements, the resolution is actually fixed at 6 1

⁄

2

digits.

If you select 4

1 ⁄

2

digits or 5

1 ⁄

2

digits, the multimeter “masks” one or two digits. The only way to control the reading rate for ac measurements is by setting a trigger delay (see page 79).

For ratio measurements, the specified resolution applies to the signal connected to the

Input

terminals.

3

55

Chapter 3 Features and Functions

Measurement Configuration

Resolution

(continued)

•

Front-Panel Operation: Select either the slow or fast mode for each resolution setting. The default mode is 5 digits slow.

5: RESOLUTION (MEAS MENU)

See also “To Set the Resolution,” on page 21.

•

Remote Interface Operation: You can set the resolution using the following commands.

CONFigure:<

function

> {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

MEASure:<

function

>? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

<

function

>:RESolution {<

resolution

>|MIN|MAX}

Specify the resolution in the same units as the measurement function, not in number of digits. For example, for dc volts, specify the resolution in volts. For frequency, specify the resolution in hertz.

CONF:VOLT:DC 10,0.001

4

1

⁄

2

digits on the 10 Vdc range

MEAS:CURR:AC? 1,1E-6

6

1 ⁄

2

digits on the 1 A range

CONF:FREQ 1 KHZ,0.1 Hz

1000 Hz input, 0.1 Hz resolution

VOLT:AC:RES 0.05

50 mV resolution on the ac function

56

Chapter 3 Features and Functions

Measurement Configuration

Integration Time

Integration time is the period during which the multimeter’s analog-todigital (A/D) converter samples the input signal for a measurement.

Integration time affects the measurement resolution (for better resolution, use a longer integration time), and measurement speed (for faster measurements, use a shorter integration time).

Applies to all measurement functions except ac voltage, ac current, frequency, and period. The integration time for the math operations

(null, min-max, dB, dBm, limit test) is the same as the integration time for the measurement function in use.

•

•

•

•

•

Integration time is specified in number of power line cycles (

NPLC s).

The choices are 0.02, 0.2, 1, 10, or 100 power line cycles. The default

is 10 PLCs.

The integration time is stored in volatile memory; the multimeter selects 10 PLCs when power has been off or after a remote interface reset.

Only the integral number of power line cycles (1, 10, or 100

PLC s) provide normal mode (line frequency noise) rejection.

The only way to control the reading rate for ac measurements is by setting a trigger delay (see page 79).

The following table shows the relationship between integration time and measurement resolution.

Integration Time

0.02 NPLC

0.2 NPLC

1 NPLC

10 NPLC

100 NPLC

Resolution

0.0001 x Full-Scale

0.00001 x Full-Scale

0.000003 x Full-Scale

0.000001 x Full-Scale

0.0000003 x Full-Scale

3

57

Chapter 3 Features and Functions

Measurement Configuration

Integration Time

(continued)

•

•

Front-Panel Operation: Integration time is set indirectly when you select the number of digits. See the table for resolution on page 54.

Remote Interface Operation:

<

function

>:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}

For frequency and period measurements, aperture time (or gate time) is analogous to integration time. Specify 10 ms (4 1

⁄

2

digits), 100 ms

(default; 5 1

⁄

2

digits), or 1 second (6 1

⁄

2

digits).

FREQuency:APERture {0.01|0.1|1|MINimum|MAXimum}

PERiod:APERture {0.01|0.1|1|MINimum|MAXimum}

Front / Rear Input Terminal Switching

Any measurement made using the front terminals can also be made using the input terminals on the rear panel. See “The Front Panel at a Glance,” on page 2, for the location of the front / rear switch.

The input terminals can only be configured from the front panel.

You cannot select the terminals from the remote interface, but you can query the present setting.

•

•

The

Rear

annunciator turns on when you select the rear terminals.

Remote Interface Operation: You can query the multimeter to determine whether the front or rear input terminals are selected.

ROUTe:TERMinals?

returns “

FRON

” or “

REAR

”

58

Chapter 3 Features and Functions

Measurement Configuration

Autozero

When autozero is enabled (default), the multimeter internally disconnects the input signal following each measurement, and takes a

zero reading. It then subtracts the zero reading from the preceding reading. This prevents offset voltages present on the multimeter’s input circuitry from affecting measurement accuracy.

When autozero is disabled, the multimeter takes one zero reading and subtracts it from all subsequent measurements. It takes a new zero reading each time you change the function, range, or integration time.

Applies to dc voltage, dc current, and 2-wire ohms measurements only.

Autozero is enabled when you select 4-wire ohms or ratio measurements.

•

•

The autozero mode is stored in volatile memory; the multimeter automatically enables autozero when power has been off or after a remote interface reset.

Front-Panel Operation: The autozero mode is set indirectly when you set the resolution.

Resolution Choices

Fast 4 Digit

*

Slow 4 Digit

Fast 5 Digit

*

Slow 5 Digit

(default)

*

Fast 6 Digit

Slow 6 Digit

Integration Time

0.02 PLC

1 PLC

0.2 PLC

10 PLC

10 PLC

100 PLC

Autozero

Off

On

Off

On

On

On

*

These settings configure the multimeter just as if you had

pressed the corresponding “DIGITS” keys from the front panel.

3

•

Remote Interface Operation: The

OFF

and

ONCE

parameters have a similar effect. Autozero

OFF

does not issue a new zero measurement.

Autozero

ONCE

issues an immediate zero measurement.

ZERO:AUTO {OFF|ONCE|ON}

59

Chapter 3 Features and Functions

Measurement Configuration

Autozero

(continued)

The following table shows the relationship between integration time and autozero settings from the remote interface and the corresponding front-panel settings.

Remote Configuration

NPLC: 100

Autozero: On

Digits Displayed: 6

NPLC: 100

1

⁄

2

Autozero: Off

Digits Displayed: 6

1 ⁄

NPLC: 10

2

Autozero: On

Digits Displayed: 6

NPLC: 10

1

⁄

2

Autozero: Off

Digits Displayed: 6

NPLC: 1

1

⁄

2

Autozero: On

Digits Displayed: 5

NPLC: 1

1

⁄

2

Autozero: Off

Digits Displayed: 5

1 ⁄

NPLC: 0.2

2

Autozero: On

Digits Displayed: 5

NPLC: 0.2

1

⁄

2

Autozero: Off

Digits Displayed: 5

NPLC: 0.02

1

⁄

2

Autozero: On

Digits Displayed: 4

NPLC: 0.02

1

⁄

2

Autozero: Off

Digits Displayed: 4 1 ⁄

2

Front-Panel Equivalent

Slow 6 digits

N/A

Fast 6 digits

Slow 5 digits

N/A

Slow 4 digits

N/A

N/A

Fast 5 digits

N/A

Fast 4 digits

From 34401A Specifications:

1

Digits Displayed Readings/Sec

N/A

N/A

6 1

⁄

2

N/A

6 1 ⁄

2

N/A

5 1

⁄

2

N/A

5 1 ⁄

2

N/A

4 1

⁄

2

0.6

N/A

6

N/A

60

N/A

300

N/A

1000

1

See the Agilent 34401A specifications listed on page 217.

60

Chapter 3 Features and Functions

Measurement Configuration

Ranging

You can let the multimeter automatically select the range using

autoranging or you can select a fixed range using manual ranging.

Autoranging is convenient because the multimeter automatically selects the appropriate range for each measurement. However, you can use manual ranging for faster measurements since the multimeter does not have to determine which range to use for each measurement.

•

•

•

•

•

•

The selected mode (auto or manual range) is stored in volatile memory; the multimeter returns to autoranging when power has been off or after a remote interface reset.

Autorange thresholds:

Down range at <10% of range

Up range at >120% of range

If the input signal is greater than the present range can measure, the multimeter gives an overload indication: “

OVLD

” from the front panel or “9.90000000E+37” from the remote interface.

For frequency and period measurements, the multimeter uses one

“range” for all inputs between 3 Hz and 300 kHz. The multimeter determines an internal resolution based on a 3 Hz signal. If you query the range, the multimeter will respond with “3 Hz”. With no input signal applied, frequency and period measurements return “0”.

The range is fixed for continuity tests (1 k

Ω

range) and diode tests

(1 Vdc range with 1 mA current source output).

For ratio measurements, the specified range applies to the signal connected to the

Input

terminals. Autoranging is automatically selected for reference voltage measurements on the

Sense

terminals.

3

Ranging is local to the selected function. This means that you can select the ranging method (auto or manual) for each function independently.

When manually ranging, the selected range is local to the function; the multimeter remembers the range when you switch between functions.

61

Chapter 3 Features and Functions

Measurement Configuration

Ranging

(continued)

•

Front-Panel Operation: Use the front-panel

RANGE

keys to select autoranging or manual ranging. For frequency and period measurements from the front panel, ranging applies to the signal’s input voltage, not its frequency.

See also “To Select a Range,” on page 20.

•

Remote Interface Operation: You can set the range using any of the following commands.

CONFigure:<

function

> {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

MEASure:<

function

>? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

<

function

>:RANGe {<

range

>|MINimum|MAXimum}

<

function

>:RANGe:AUTO {OFF|ON}

62

Chapter 3 Features and Functions

Math Operations

Null

Min-Max dB dBm

Limit

Math Operations

There are five math operations available, only one of which can be enabled at a time. Each math operation performs a mathematical operation on each reading or stores data on a series of readings.

The selected math operation remains in effect until you disable it, change functions, turn off the power, or perform a remote interface reset. The math operations use one or more internal registers. You can preset the values in some of the registers, while others hold the results of the math operation.

The following table shows the math/measurement function combinations allowed. Each “

X

” indicates an allowable combination. If you choose a math operation that is not allowed with the present measurement function, math is turned off. If you select a valid math operation and then change to one that is invalid, a “Settings conflict” error is generated from the remote interface.

3

DC V

X

X

X

X

X

AC V

X

X

X

X

X

DC I

X

X

X

AC I

X

X

X

Ω

2W

X

X

X

Ω

4W

X

X

X

Freq

X

X

Per

X

X

X

X

Cont Diode Ratio

X

X

From the front panel, you enable a math operation by pressing the appropriate key. The exception is Limit Test which you enable using the

LIMIT TEST

command in the

MATH MENU

.

From the remote interface, the math operations and registers are controlled using commands within the

CALCulate

command subsystem. First, select the math operation you want to use (the default

function is null):

CALCulate:FUNCtion {NULL|DB|DBM|AVERage|LIMit}

Then, enable the selected math function by turning the math state on:

CALCulate:STATe ON

63

Chapter 3 Features and Functions

Math Operations

Min–Max Operation

The min-max operation stores the minimum and maximum readings during a series of measurements. The multimeter then calculates the average of all readings and records the number of readings taken since min-max was enabled.

Applies to all measurement functions, except continuity and diode.

•

•

•

•

After you enable min-max, the first reading that the multimeter takes is stored as both the minimum and maximum value.

The minimum is replaced with any subsequent value that is less.

The maximum is replaced with any subsequent value that is greater.

The multimeter displays “

MIN

” or “

MAX

” and beeps (if the front-panel beeper is enabled) whenever a new minimum or maximum is found.

It is possible that the multimeter will beep even if the displayed reading does not change; this is because the multimeter’s internal resolution may be greater than the displayed resolution. See also

“Beeper Control,” on page 88.

The minimum, maximum, average, and count are stored in volatile memory; the multimeter clears the values when min-max is turned on, when power has been off, or after a remote interface reset.

Front-Panel Operation: After enabling min-max, you can read the stored minimum, maximum, average, and count by pressing

Shift >

(Menu Recall). Turning on the menu does not disable the min-max operation; the multimeter will resume taking measurements when you turn off the menu.

1: MIN-MAX (MATH MENU)

See also “To Store Minimum and Maximum Readings,” on page 39.

64

Chapter 3 Features and Functions

Math Operations

•

Remote Interface Operation: You can use the following commands to make min-max measurements.

CALCulate:FUNCtion AVERage

CALCulate:STATe {OFF|ON}

CALCulate:AVERage:MINimum?

read the minimum value

CALCulate:AVERage:MAXimum?

read the maximum value

CALCulate:AVERage:AVERage?

read the average of all readings

CALCulate:AVERage:COUNt?

read the count

A new command is available starting with firmware Revision 2 which allows you to take readings using

INITiate

without storing them in internal memory. This command may be useful with the min-max operation since it allows you to determine the average of a series of readings without storing the individual values.

DATA:FEED RDG_STORE, ""

do not store readings

DATA:FEED RDG_STORE, "CALCulate"

store readings (default)

See page 126 for more information on using the

DATA:FEED

command.

3

Null (Relative) Operation

When making null measurements, also called relative, each reading is the difference between a stored null value and the input signal.

One possible application is in making more accurate two-wire ohms measurements by nulling the test lead resistance.

Result

= reading – null value

Applies to all measurement functions, except continuity, diode, and ratio.

•

•

The null value is adjustable and you can set it to any value between

0 and ± 120% of the highest range, for the present function.

The null value is stored in volatile memory; the value is cleared when power has been off, after a remote interface reset, or after a function change.

65

Chapter 3 Features and Functions

Math Operations

Null (Relative)

(continued)

•

The null value is stored in the multimeter’s Null Register. There are two ways you can specify the null value. First, you can enter a specific number into the register from the front-panel menu or from the remote interface. Any previously stored value is replaced with the new value. If you are operating the multimeter from the front panel,

entering a null value also turns on the null function.

•

The second way to enter the null value is to let the multimeter store the first reading in the register. After you enable null, the first

reading displayed will be zero (if you have not changed the value

stored in the register). If you entered a number into the register, as described in the paragraph above, the first reading does not overwrite the stored value.

Front-Panel Operation: After enabling null, you can edit the stored null value by pressing

Shift >

(Menu Recall). Any previously stored value is replaced with the new value. Turning on the menu does not disable the null operation; the multimeter will resume taking measurements when you turn off the menu.

2: NULL VALUE (MATH MENU)

See also “To Make Null (Relative) Measurements,” on page 38.

•

Remote Interface Operation: You can use the following commands to make null measurements. Math must be enabled before you can store

a value in the Null Register.

CALCulate:FUNCtion NULL

CALCulate:STATe {OFF|ON}

CALCulate:NULL:OFFSet {<

value

>|MINimum|MAXimum}

The following program segment shows the proper order that you should execute the commands to enable null and set an offset value.

CALC:FUNC NULL

CALC:STAT ON

CALC:NULL:OFFS -2.0

66

Chapter 3 Features and Functions

Math Operations

dB Measurements

Each dB measurement is the difference between the input signal and a stored relative value, with both values converted to dBm.

dB

= reading in dBm – relative value in dBm

Applies to dc voltage and ac voltage measurements only.

•

•

•

The relative value is adjustable and you can set it to any value between 0 dBm and ± 200.00 dBm.

The relative value is stored in volatile memory; the value is cleared when power has been off, after a remote interface reset, or after a function change.

The relative value is stored in the multimeter’s dB Relative Register.

There are two ways you can specify the relative value. First, you can enter a specific number into the register from the front-panel menu or from the remote interface. Any previously stored value is replaced with the new value. If you are operating the multimeter from the front

panel, entering a relative value also turns on the dB function.

•

The second way to enter the relative value is to let the multimeter take the first reading, convert it to dBm, and store that value in the register. Changing the dBm reference resistance (see page 68) does not change the stored relative value. After you enable dB, the first

reading taken will be 0 dB (if you have not changed the value stored in

the register). If you entered a number into the register, as described in the paragraph above, the first reading does not overwrite the stored value.

Front-Panel Operation: After enabling dB, you can edit the stored relative value by pressing

Shift >

(Menu Recall). Any previously stored value is replaced with the new value. Turning on the menu does not disable the dB operation; the multimeter will resume taking measurements when you turn off the menu.

3: dB REL (MATH MENU)

See also “To Make dB Measurements,” on page 40.

3

67

Chapter 3 Features and Functions

Math Operations

•

Remote Interface Operation: You can use the following commands to make dB measurements. Math must be enabled before you can store a

value to the Relative Register.

CALCulate:FUNCtion DB

CALCulate:STATe {OFF|ON}

CALCulate:DB:REFerence {<

value

>|MINimum|MAXimum}

dBm Measurements

The dBm operation calculates the power delivered to a resistance referenced to 1 milliwatt.

dBm

= 10 × Log

10

( reading

2

/

reference resistance

/

1 mW )

Applies to dc voltage and ac voltage measurements only.

•

You can choose from 17 different reference resistance values.

The factory setting for the reference resistance is 600

Ω

.

•

•

The choices are: 50, 75, 93, 110, 124, 125, 135, 150, 250, 300, 500,

600

, 800, 900, 1000, 1200, or 8000 ohms.

The reference resistance is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

Front-Panel Operation: After enabling dBm, you can select a new reference resistance by pressing

Shift >

(Menu Recall). Turning on the menu does not disable the dBm operation; the multimeter will resume taking measurements when you turn off the menu.

4: dBm REF R (MATH MENU)

See also “To Make dBm Measurements,” on page 41.

•

Remote Interface Operation: You can use the following commands to make dBm measurements.

CALCulate:FUNCtion DBM

CALCulate:STATe {OFF|ON}

CALCulate:DBM:REFerence {<

value

>|MINimum|MAXimum}

68

Chapter 3 Features and Functions

Math Operations

Limit Testing

The limit test operation enables you to perform pass/fail testing to upper and lower limits that you specify.

Applies to all measurement functions, except continuity and diode tests.

•

•

•

•

You can set the upper and lower limits to any value between 0 and

± 120% of the highest range, for the present function. The upper limit selected should always be a more positive number than the lower limit. The default upper and lower limits are both “0”.

The upper and lower limits are stored in volatile memory; the multimeter sets both limits to “0” when power has been off, after a remote interface reset, or after a function change.

You can configure the multimeter to generate a service request (

SRQ

) on the first occurrence of a failed reading. See “The SCPI Status

Model,” starting on page 134 for more information.

Front-Panel Operation: The multimeter displays “

OK

” for each reading that is within the specified limits. It displays “

HI

” or “

LO

” for each reading that exceeds the upper or lower limit. The multimeter beeps once (if the front-panel beeper is enabled) on the first occurrence of a failed reading after a good reading. See also “Beeper

Control,” on page 88.

5: LIMIT TEST (MATH MENU)

enable or disable limit test

6: HIGH LIMIT (MATH MENU)

set the upper limit

7: LOW LIMIT (MATH MENU)

set the lower limit

You can also turn off limit test by selecting a different math operation from the front panel (only one math operation can be enabled at a time).

3

69

Chapter 3 Features and Functions

Math Operations

Limit Testing

(continued)

•

Remote Interface Operation: You can use the following commands for limit testing.

CALCulate:FUNCtion LIMit

CALCulate:STATe {OFF|ON}

CALCulate:LIMit:LOWer {<

value

>|MINimum|MAXimum}

CALCulate:LIMit:UPPer {<

value

>|MINimum|MAXimum}

•

There are two unused pins on the

RS-232

interface connector which are available to indicate the pass/fail status of readings taken with limit testing. To configure these pins for limit testing, you must install two jumpers inside the multimeter. See the Service Guide for

more information.

A low-going pulse is output to pin 1 for each reading that is within the specified limits. A low-going pulse is output to pin 9 for each reading that exceeds the upper or lower limit.

1

5 V

0 V

9

Pin 1: Pass Output

Pin 9: Fail Output

2 ms minimum

C a u t i o n

Do not use the RS-232 interface if you have configured the multimeter to output pass/fail signals on pins 1 and 9. Internal components on the

RS-232 interface circuitry may be damaged.

70

Chapter 3 Features and Functions

Triggering

Triggering

The multimeter’s triggering system allows you to generate triggers either manually or automatically, take multiple readings per trigger, and insert a delay before each reading. Normally, the multimeter will take one reading each time it receives a trigger, but you can specify multiple readings (up to 50,000) per trigger.

You can trigger the multimeter from the front panel using a single trigger, an external trigger, or auto triggering. Single triggering takes one reading each time you press the

Single key. External triggering is like single triggering, but the multimeter waits for a pulse on the rear-panel Ext Trig (external trigger) terminal before taking a reading. Auto triggering takes continuous readings at the fastest rate possible for the present configuration. See also “To Trigger

the Multimeter,” on page 42.

Triggering the multimeter from the remote interface is a multi-step process that offers triggering flexibility.

•

•

•

First, you must configure the multimeter for the measurement by selecting the function, range, resolution, etc.

Then, you must specify the source from which the multimeter will accept the trigger. The multimeter will accept a software (bus) trigger from the remote interface, a hardware trigger from the Ext Trig terminal, or an immediate internal trigger.

Then, you must make sure that the multimeter is ready to accept a trigger from the specified trigger source (this is called the

wait-for-trigger state).

The diagram on the next page shows the multimeter’s triggering system.

3

71

Chapter 3 Features and Functions

Triggering

Agilent 34401A Triggering System

Initiate Triggering

MEASure?

READ?

INITiate

Idle

State

Trigger Source

TRIGger:SOURce IMMediate

TRIGger:SOURce EXTernal

TRIGger:SOURce BUS

Front-panel “Single” key

Wait-for-

Trigger

State

Trigger Delay

TRIGger:DELay

Delay

Sample (

∗

)

Annunciator

Measurement

Sample

Sample

Count ≠ 1

Trigger

Count ≠ 1

72

Chapter 3 Features and Functions

Triggering

Trigger Source Choices

You must specify the source from which the multimeter will accept a trigger. From the front panel, the multimeter will accept a single trigger, a hardware trigger from the Ext Trig terminal, or continuously take readings using auto trigger. At power-on, auto triggering is used.

From the remote interface, the multimeter will accept a software (bus) trigger, a hardware trigger from the Ext Trig terminal, or an immediate internal trigger. The

Q

(sample) annunciator turns on during each measurement.

•

•

The trigger source is stored in volatile memory; the source is set to auto trigger (front panel) or immediate (remote interface) when power has been off or after a remote interface reset.

To select the trigger source from the remote interface, use the following command. The

CONFigure

and

MEASure?

commands automatically set the trigger source to

IMMediate

.

TRIGger:SOURce {BUS|IMMediate|EXTernal}

3

Auto Triggering

In the auto trigger mode (front panel only), the multimeter continuously takes readings at the fastest rate possible for the present configuration. This is the power-on trigger source for front-panel operation.

Single Triggering

In the single trigger mode (front panel only), you can manually trigger the multimeter by pressing

Single

.

The multimeter takes one reading, or the specified number of readings (sample count), each time you press the key. The

Trig

annunciator turns on when the multimeter is waiting for a trigger.

The front-panel

Single

key is disabled when in remote.

73

Chapter 3 Features and Functions

Triggering

External Triggering

In the external trigger mode, the multimeter will accept a hardware trigger applied to the Ext Trig terminal.

The multimeter takes one reading, or the specified number of readings

(sample count), each time Ext Trig receives a low-true pulse.

See also “External Trigger Terminal,” on page 83.

•

•

The multimeter buffers one external trigger. This means that if the multimeter is taking a reading and another external trigger occurs, that trigger is accepted (a “Trigger ignored” error is not reported).

After the reading in progress is complete, the stored trigger satisfies the trigger source and then the trigger is issued.

Front-Panel Operation: The external trigger mode is like the single trigger mode except that you apply the trigger to the Ext Trig terminal. Pressing

Single to enable the single trigger mode also enables the external trigger mode. The

Trig

annunciator turns on when the multimeter is waiting for an external trigger.

The front-panel

Single

key is disabled when in remote.

•

Remote Interface Operation:

TRIGger:SOURce EXTernal

74

Chapter 3 Features and Functions

Triggering

Internal Triggering

In the internal trigger mode (remote interface only), the trigger signal is always present. When you place the multimeter in the wait-for-trigger state, the trigger is issued immediately. This is the power-on trigger source for remote interface operation.

To select the internal trigger source, send the following command.

The

CONFigure

and

MEASure?

commands automatically set the trigger source to

IMMediate

.

TRIGger:SOURce IMMediate

Software (Bus) Triggering

The bus trigger mode is available only from the remote interface. This mode is similar to the single trigger mode from the front panel, but you trigger the multimeter by sending a bus trigger command.

•

To select the bus trigger source, send the following command.

TRIGger:SOURce BUS

•

•

To trigger the multimeter from the remote interface (

GPIB or

RS-232

), send the

*TRG

(trigger) command. The

*TRG

command will not be accepted unless the multimeter is in the wait-for-trigger state.

You can also trigger the multimeter from the

GPIB

interface by sending the

IEEE-488

Group Execute Trigger (

GET

) message.

The multimeter must be in the wait-for-trigger state. The following statement shows how to send a

GET

using BASIC.

TRIGGER 722

Group Execute Trigger

3

75

Chapter 3 Features and Functions

Triggering

The Wait-for-Trigger State

After you have configured the multimeter and selected a trigger source, you must place the multimeter in the wait-for-trigger state. A trigger will not be accepted until the multimeter is in this state. If a trigger signal is present, and if multimeter is in the “wait-for-trigger” state, the measurement sequence begins and readings are taken.

The “wait-for-trigger” state is a term used primarily for remote interface operation. From the front panel, the multimeter is always in the

“wait-for- trigger” state and will accept triggers at any time, unless a measurement is already in progress.

You can place the multimeter in the “wait-for-trigger” state by executing any of the following commands from the remote interface.

MEASure?

READ?

INITiate

The multimeter requires approximately 20 ms of set-up time after you send a command to change to the “wait-for-trigger” state. Any external triggers that occur during this set-up time are ignored.

Halting a Measurement in Progress

You can send a device clear at any time to halt a measurement in progress and place the multimeter in the “idle state.” The following statement shows how to send a device clear over the

GPIB

interface using BASIC.

CLEAR 722

IEEE-488 Device Clear

A device clear does not affect the configuration of the triggering system.

The trigger source, sample count, trigger delay, and number of triggers

are not changed.

76

Chapter 3 Features and Functions

Triggering

Number of Samples

Normally, the multimeter takes one reading (or sample) each time it receives a trigger from the selected trigger source (if the multimeter is in the wait-for-trigger state). You can, however, instruct the multimeter to take multiple readings for each trigger received.

•

•

•

Number of samples: 1 to 50,000. The default is 1 sample per trigger.

The selected number of samples is stored in volatile memory; the multimeter sets the sample count to 1 when power has been off or after a remote interface reset. The

CONFigure

and

MEASure?

commands automatically set the sample count to 1.

Front-Panel Operation:

3: N SAMPLES (TRIG MENU)

3

•

Remote Interface Operation:

SAMPle:COUNt {<

value

>|MINimum|MAXimum}

77

Chapter 3 Features and Functions

Triggering

Number of Triggers

Normally, the multimeter will accept only one trigger before returning to the “idle” trigger state. You can, however, instruct the multimeter to accept multiple triggers.

This feature is available only from the remote interface. If you set the trigger count and then go to local (front panel), the multimeter ignores the trigger count setting; when you return to remote, the trigger count returns to the value you selected.

•

•

•

Number of triggers: 1 to 50,000. The default is 1 trigger.

The selected number of triggers is stored in volatile memory; the multimeter sets the trigger count to 1 when power has been off or after a remote interface reset. The

CONFigure

and

MEASure?

commands automatically set the trigger count to 1.

Remote Interface Operation:

TRIGger:COUNt {<

value

>|MINimum|MAXimum|INFinite}

78

Chapter 3 Features and Functions

Triggering

Trigger Delay

You can insert a delay between the trigger signal and each sample that follows. This may be useful in applications where you want to allow the input to settle before taking a reading, or for pacing a burst of readings.

If you do not specify a trigger delay, the multimeter automatically selects a delay for you.

•

•

•

•

•

Delay range: 0 to 3600 seconds. The default trigger delay is

automatic; the delay is determined by function, range, integration time, and ac filter setting (see also “Automatic Trigger Delays,” on page 81).

The trigger delay is stored in volatile memory; the multimeter selects an automatic trigger delay when power has been off or after a remote interface reset. The

CONFigure

and

MEASure?

commands automatically set the trigger delay to automatic.

If you specify a delay other than automatic, that same delay is used for all functions and ranges.

If you have configured the multimeter to take more than one reading per trigger (sample count > 1), the specified trigger delay is inserted between the trigger and each reading.

Front-Panel Operation: You can use an automatic trigger delay or you can specify a delay in seconds.

2: TRIG DELAY (TRIG MENU)

If an automatic trigger delay is enabled, “

AUTO

” is displayed momentarily before the actual number of seconds is displayed.

3

--- AUTO ---

79

Chapter 3 Features and Functions

Triggering

Trigger Delay

(continued)

•

Front-Panel Operation (continued)

To set the delay to 0 seconds, select the “parameter” level of the

TRIG

DELAY

command. Move the flashing cursor to the “units” location on the right side of the display. Press

∨ until

ZERO DELAY

is reached, then press Menu Enter.

ZERO DELAY

To select the automatic trigger delay, select the “parameter” level of the

TRIG DELAY

command. Move the flashing cursor to the

“units” location on the right side of the display. Press

∨ until

AUTO DELAY

is reached, then press Menu Enter.

AUTO DELAY

•

Remote Interface Operation:

You can use the following command to set the trigger delay.

TRIGger:DELay {<

seconds

>|MINimum|MAXimum}

You can use the following command to set an automatic trigger delay.

TRIGger:DELay:AUTO {OFF|ON}

80

Chapter 3 Features and Functions

Triggering

Automatic Trigger Delays

If you do not specify a trigger delay, the multimeter selects an automatic delay for you. The delay is determined by function, range, integration time, and ac filter setting.

•

DC Voltage and DC Current (for all ranges):

Integration Time

NPLC ≥ 1

NPLC < 1

Trigger Delay

1.5 ms

1.0 ms

•

Resistance (2-wire and 4-wire):

Range

100 Ω

1 k Ω

10 k

Ω

100 k Ω

1 M Ω

10 M

Ω

100 M Ω

Trigger Delay

(For NPLC

≥

1)

1.5 ms

1.5 ms

1.5 ms

1.5 ms

15 ms

100 ms

100 ms

Range

100 Ω

1 k Ω

10 k

Ω

100 k Ω

1 M Ω

10 M

Ω

100 M Ω

Trigger Delay

(For NPLC < 1)

1.0 ms

1.0 ms

1.0 ms

1.0 ms

10 ms

100 ms

100 ms

3

•

AC Voltage and AC Current (for all ranges):

Remote or single/external trigger

Front panel with auto trigger ON

AC Filter Trigger Delay AC Filter Trigger Delay

Slow

Medium

Fast

7.0 sec

1.0 sec

600 ms

Slow

Medium

Fast

1.5 sec

200 ms

100 ms

•

Frequency and Period:

Remote or single/external trigger

Trigger Delay

1.0 sec

Front panel with auto trigger ON

Trigger Delay

0 sec

81

Chapter 3 Features and Functions

Triggering

Reading Hold

The reading hold feature allows you to capture and hold a stable reading on the front-panel display. This is especially useful in situations where you want to take a reading, remove the test probes, and have the reading remain on the display. When a stable reading is detected, the multimeter emits a beep (if the front-panel beeper is enabled) and holds the reading on the display. See also “Beeper Control,” on page 88.

The reading hold feature is available only from the front panel. If you go to remote when reading hold is enabled, the multimeter ignores it; when you return to local (front panel), reading hold is enabled again.

•

Reading hold has an adjustable sensitivity band (adjustable only from the front panel) to allow you to select which readings are considered stable enough to be displayed. The band is expressed as a percent of reading, on the selected range. The multimeter will capture and display a new value only after three consecutive readings are within the band.

•

•

•

•

•

Select one of these values: 0.01%, 0.10% (default), 1.00%, or 10.00% of reading. For example, assume that the 1.00% band is selected and a 5 volt signal is applied to the multimeter. If three consecutive readings are between 4.975 volts and 5.025 volts, the display will show a new reading.

The sensitivity band is stored in volatile memory; the multimeter sets the band to 0.10% when power has been off or after an interface reset.

If the multimeter is in autorange when you enable reading hold, it will autorange to the correct range. If the multimeter is in the

manual range mode, the same fixed range will be used for reading hold.

When reading hold is enabled, the input resistance is automatically set to 10 M

Ω

(

AUTO OFF

) for all dc voltage ranges. This helps to minimize noise pickup when the test leads are open-circuit.

For certain applications, it may be useful to use reading hold with reading memory. See also “Reading Memory,” on page 84.

Front-Panel Operation: After enabling reading hold, you can select a different sensitivity band by pressing

Shift >

(Menu Recall).

1: READ HOLD (TRIG MENU)

See also “To Use Reading Hold,” on page 43.

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Chapter 3 Features and Functions

Triggering

Voltmeter Complete Terminal

The rear-panel VM Comp (voltmeter complete) terminal provides a low-true pulse after the completion of each measurement. Voltmeter complete and external trigger (see below) implement a standard hardware handshake sequence between measurement and switching devices.

Output

5 V

0 V

Approximately

2

µ s

External Trigger Terminal

You can trigger the multimeter by applying a low-true pulse to the rear-panel Ext Trig (external trigger) terminal. To use this terminal from the remote interface, you must select the external trigger source

(

TRIGger:SOURce EXTernal

).

Input

5 V

0 V

3

>1

µ s

You can use a simple switch to generate an external trigger using the

Ext Trig input as shown below.

Ext Trig

83

Chapter 3 Features and Functions

System-Related Operations

System-Related Operations

This section gives information on topics such as reading memory, errors, self-test, and front-panel display control. This information is not directly related to making measurements but is an important part of operating the multimeter.

Reading Memory

The multimeter can store up to 512 readings in internal memory.

Readings are stored in first-in-first-out (

FIFO

) order. The first reading returned is the first reading stored. The reading memory feature is

available only from the front panel.

•

•

•

•

You can use reading memory with all functions, math operations, and also reading hold. After you have enabled reading memory, you can change the function. Be aware, however, that the function labels

(

VDC

,

OHM

, etc.) are not stored with the reading.

Readings taken while reading memory is enabled are stored in

volatile memory; the multimeter clears the stored readings when reading memory is turned on again, when power has been off, after a self-test, or after a remote interface reset.

You can use reading memory with auto trigger, single trigger, external trigger, and reading hold. If you configure the multimeter for multiple readings per trigger, the specified number of readings are stored in memory each time a trigger is received.

Front-Panel Operation:

1: RDGS STORE (SYS MENU)

store readings in memory

2: SAVED RDGS (SYS MENU)

read the stored readings

•

Reading memory is automatically turned off when you go to the

“parameter” level in the menu to recall the readings. See also “To Use

Reading Memory,” on page 46.

Remote Interface Operation: The

INITiate

command uses reading memory to store readings prior to a

FETCh?

command. You can query the number of stored readings in memory by sending the

DATA:POINts?

command from the remote interface.

84

Chapter 3 Features and Functions

System-Related Operations

Error Conditions

When the front-panel

ERROR

annunciator turns on, one or more command syntax or hardware errors have been detected. A record of up to 20 errors is stored in the multimeter’s error queue. See chapter 5,

“Error Messages,” for a complete listing of the errors.

•

•

•

•

Errors are retrieved in first-in-first-out (

FIFO

) order. The first error returned is the first error that was stored. When you have read all errors from the queue, the

ERROR

annunciator turns off.

The multimeter beeps once each time an error is generated.

If more than 20 errors have occurred, the last error stored in the queue (the most recent error) is replaced with -350, “Too many errors”.

No additional errors are stored until you remove errors from the queue. If no errors have occurred when you read the error queue, the multimeter responds with +0, “No error”.

The error queue is cleared when power has been off or after a

*CLS

(clear status) command has been executed. The

*RST

(reset) command does not clear the error queue.

Front-Panel Operation:

3: ERROR (SYS MENU)

If the

ERROR

annunciator is on, press

Shift <

(Recall Menu) to read the errors stored in the queue. The errors are listed

horizontally on the “parameter” level. All errors are cleared when you go to the “parameter” level and then turn off the menu.

3

ERR 1: -113

First error in queue Error code

•

Remote Interface Operation:

SYSTem:ERRor?

Reads one error from the error queue

Errors have the following format (the error string may contain

up to 80 characters):

-113,"Undefined header"

85

Chapter 3 Features and Functions

System-Related Operations

Self-Test

A power-on self-test occurs automatically when you turn on the multimeter. This limited test assures you that the multimeter is operational. This self-test does not perform the extensive set of analog tests that are included as part of the complete self-test described below.

A complete self-test runs a series of tests and takes approximately

15 seconds to execute. If all tests pass, you can have a high confidence that the multimeter is operational.

•

•

•

The results of the complete self-test are stored in internal reading memory (see page 84). Memory is cleared as the self-test stores this information. Other than clearing memory, the complete self-test

does not alter the state of the multimeter.

If the complete self-test is successful, “

PASS

” is displayed on the front panel. If the self-test fails, “

FAIL

” is displayed and the

ERROR

annunciator turns on. See the Service Guide for instructions on returning the multimeter to Agilent for service.

Front-Panel Operation: You can perform some of the tests (complete self-test) individually or you can perform all tests together at once.

4: TEST (SYS MENU)

•

Another way to perform the complete front-panel self-test is as follows:

Hold down

Shift as you press the Power switch to turn on the multimeter; hold down the key for more than 5 seconds. The selftest will begin when you release the key.

Remote Interface Operation:

*TST?

Returns “0” if the self-test is successful, or “1” if it fails.

86

Chapter 3 Features and Functions

System-Related Operations

Display Control

To speed up your measurement rate, or for security reasons, you may want to turn off the front-panel display. From the remote interface, you can also display a 12-character message on the front panel.

•

•

•

•

•

When the display is turned off, readings are not sent to the display and all display annunciators except

ERROR

and

Shift

are disabled.

Front-panel operation is otherwise unaffected by turning off the display.

The display state is stored in volatile memory; the display is enabled when power has been off or after a remote interface reset.

You can display a message on the front panel by sending a command from the remote interface. The multimeter can display up to 12 characters of the message on the front panel; any additional characters are truncated. Commas, periods, and semicolons share a display space with the preceding character, and are not considered individual characters. When a message is displayed, readings are not sent to the display.

Sending a message to the display from the remote interface overrides the display state; this means that you can display a message even if the display is turned off.

Front-Panel Operation:

5: DISPLAY (SYS MENU)

•

The display always turns on for menu operation; this means that even when the display is turned off, you can still operate the menu.

Remote Interface Operation:

DISPlay {OFF|ON}

disable/enable the display

DISPlay:TEXT <

quoted string

>

display the string enclosed in quotes

DISPlay:TEXT:CLEar

clear the displayed message

The following command string shows how to display a message on the front panel.

"DISP:TEXT ’HELLO’"

3

87

Chapter 3 Features and Functions

System-Related Operations

Beeper Control

Normally, the multimeter will emit a tone whenever certain conditions are met from the front panel. For example, the multimeter will beep when a stable reading is captured in reading hold. You may want to disable the front-panel beeper for certain applications.

•

•

When you disable the beeper, the multimeter will not emit a tone when:

1) a new minimum or maximum is found in a min–max test.

2) a stable reading is captured in reading hold.

3) a limit is exceeded in a limit test.

4) a forward-biased diode is measured in the diode test function.

Disabling the beeper has no effect on the tone generated when:

1) an error is generated.

2) the continuity threshold is exceeded.

3) you turn off the front-panel menu.

•

•

Turning off the beeper does not disable the key click generated when you press a front-panel key.

The beeper state is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

The beeper is enabled when the multimeter is shipped from the factory.

Front-Panel Operation:

6: BEEP (SYS MENU)

•

Remote Interface Operation:

SYSTem:BEEPer

issue a single beep immediately

SYSTem:BEEPer:STATe {OFF|ON}

disable/enable beeper state

88

Chapter 3 Features and Functions

System-Related Operations

Comma Separators

The multimeter can display readings on the front panel with or without a comma separator. This feature is available only from the front panel.

08.241,53 VDC 08.24153 VDC

With comma separator

(factory setting)

Without comma separator

•

•

The display format is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

The comma separator is enabled when the multimeter is shipped from the factory.

Front-Panel Operation:

7: COMMA (SYS MENU)

See also “To Turn Off the Comma Separator,” on page 37.

Firmware Revision Query

The multimeter has three microprocessors for control of various internal systems. You can query the multimeter to determine which revision of firmware is installed for each microprocessor.

•

•

The multimeter returns three numbers. The first number is the firmware revision number for the measurement processor; the second is for the input/output processor; and the third is for the front-panel processor.

Front-Panel Operation:

8: REVISION (SYS MENU) REV XX-XX-XX

•

Remote Interface Operation:

*IDN?

returns

“HEWLETT-PACKARD,34401A,0,XX-XX-XX”

Be sure to dimension a string variable with at least 35 characters.

3

89

Chapter 3 Features and Functions

System-Related Operations

SCPI Language Version Query

The multimeter complies with the rules and regulations of the present version of

SCPI

(Standard Commands for Programmable Instruments).

You can determine the

SCPI

version with which the multimeter is in compliance by sending a command from the remote interface.

You cannot query the

SCPI

version from the front panel.

•

The following command returns the

SCPI

version.

SYSTem:VERSion?

Returns a string in the form “YYYY.V” where the “Y’s” represent the year of the version, and the “V” represents a version number for that year (for example, 1991.0).

90

Chapter 3 Features and Functions

Remote Interface Configuration

Remote Interface Configuration

This section gives information on configuring the remote interface.

For additional information, see chapter 4, “Remote Interface Reference,” starting on page 103.

GPIB Address

Each device on the

GPIB

(

IEEE-488

) interface must have a unique address. You can set the multimeter’s address to any value between

0 and 31. The address is set to “22” when the multimeter is shipped from the factory. The

GPIB address is displayed at power-on.

The GPIB address can be set only from the front-panel.

•

•

The address is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

You can set the address to “31” which is the talk only mode. In this mode, the multimeter can output readings directly to a printer without being addressed by a bus controller (over either

GPIB

or

RS-232

). For proper operation, make sure your printer is configured in the listen always mode. Address 31 is not a valid address if you are operating the multimeter from the

GPIB

interface with a bus controller.

•

•

•

If you select the

RS-232

interface and then set the

GPIB

address to the talk only address (31), the multimeter will send readings over the

RS-232

interface when in the local mode.

If you select the

RS-232

interface and then set the

GPIB

address to the talk only address (31), the multimeter will send readings over the

RS-232

interface when in the local mode.

Your

GPIB

bus controller has its own address. Be sure to avoid using the bus controller’s address for any instrument on the interface bus.

Agilent controllers generally use address “21”.

Front-Panel Operation:

1: GPIB ADDR (I/O MENU)

See also “To Set the

GPIB

Address,” on page 161.

3

91

Chapter 3 Features and Functions

Remote Interface Configuration

Remote Interface Selection

The multimeter is shipped with both an

GPIB

(

IEEE-488

) interface and an

RS-232

interface. Only one interface can be enabled at a time.

The

GPIB

interface is selected when the multimeter is shipped from the factory.

The remote interface can be set only from the front-panel.

•

•

•

•

•

The interface selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

If you select the

GPIB

interface, you must select a unique address for the multimeter. The

GPIB address is displayed when you turn on the multimeter.

If you select the

RS-232 interface, you must set the baud rate and parity for the multimeter. “

RS-232

” is displayed when you turn on the multimeter.

If you select the

RS-232

interface and then set the

GPIB

address to the talk only address (31), the multimeter will send readings over the

RS-232

interface when in the local mode.

There are certain restrictions to be aware of when you are selecting the remote interface (see also “Programming Language Selection,” on page 94). The only programming language supported on

RS-232

is

SCPI

.

SCPI Language

3478A Language

Fluke 8840A Language

GPIB / 488

X

X

X

RS-232

X

Not allowed

Not allowed

•

Front-Panel Operation:

2: INTERFACE (I/O MENU)

See also “To Select the Remote Interface,” on page 162.

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Chapter 3 Features and Functions

Remote Interface Configuration

Baud Rate Selection (

RS-232

)

You can select one of six baud rates for

RS-232

operation. The rate is set to 9600 baud when the multimeter is shipped from the factory.

The baud rate can be set only from the front-panel.

•

•

•

Select one of the following: 300, 600, 1200, 2400, 4800, or 9600 baud

(factory setting).

The baud rate selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

Front-Panel Operation:

3: BAUD RATE (I/O MENU)

See also “To Set the Baud Rate,” on page 163.

3

Parity Selection (

RS-232

)

You can select the parity for

RS-232

operation. The multimeter is configured for even parity with 7 data bits when shipped from the factory.

The parity can be set only from the front-panel.

•

•

•

Select one of the following: None (8 data bits), Even (7 data bits), or

Odd (7 data bits). When you set the parity, you are indirectly setting the number of data bits.

The parity selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

Front-Panel Operation:

4: PARITY (I/O MENU)

See also “To Set the Parity,” on page 164.

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Chapter 3 Features and Functions

Remote Interface Configuration

Programming Language Selection

You can select one of three languages to program the multimeter from the selected remote interface. The language is

SCPI

when the multimeter is shipped from the factory.

•

•

•

Select one of the following: SCPI, Agilent 3478A, or Fluke 8840A.

The language selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

There are certain restrictions to be aware of when you are selecting the interface language (see also “Remote Interface Selection,” on page 92). The Agilent 3478A and Fluke 8840A/8842A languages

are not supported on the

RS-232

interface.

SCPI Language

3478A Language

Fluke 8840A Language

GPIB / 488

X

X

X

RS-232

X

Not allowed

Not allowed

•

Front-Panel Operation:

5: LANGUAGE (I/O MENU)

See also “To Select the Programming Language,” on page 165.

•

Remote Interface Operation:

L1

select SCPI language

L2

select Agilent 3478A language

L3

select Fluke 8840A language

94

Chapter 3 Features and Functions

Calibration Overview

Calibration Overview

This section gives a brief introduction to the calibration features of the multimeter. For a more detailed discussion of the calibration procedures, see chapter 4 in the Service Guide.

Calibration Security

This feature allows you to enter a security code to prevent accidental or unauthorized calibrations of the multimeter. When you first receive your multimeter, it is secured. Before you can calibrate the multimeter, you must unsecure it by entering the correct security code.

•

•

The security code is set to “

HP034401

” when the multimeter is shipped from the factory. The security code is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

To secure the multimeter from the remote interface, the security code may contain up to 12 alphanumeric characters as shown below.

The first character must be a letter, but the remaining characters can be letters or numbers. You do not have to use all 12 characters but the first character must always be a letter.

A _ _ _ _ _ _ _ _ _ _ _

(12 characters)

3

•

To secure the multimeter from the remote interface so that it can be unsecured from the front panel, use the eight-character format shown below. The first two characters must be “HP” and the remaining characters must be numbers. Only the last six characters are recognized from the front panel, but all eight characters are required.

(To unsecure the multimeter from the front panel, omit the “HP” and enter the remaining numbers as shown on the following pages.)

H P _ _ _ _ _ _

(8 characters)

If you forget your security code, you can disable the security feature by adding a jumper inside the multimeter, and then entering a new code.

See the Service Guide for more information.

95

Chapter 3 Features and Functions

Calibration Overview

Calibration

Security

(continued)

To Unsecure for Calibration

You can unsecure the multimeter for calibration either from the front panel or remote interface.

The multimeter is secured when shipped from the factory, and the security code is set to “

HP034401

”.

•

Front-Panel Operation:

1: SECURED (CAL MENU)

If the multimeter is secured, you will see the above command when you go into the

CAL MENU

. (If you move across the “commands” level in the menu, you will notice that the “

2: CALIBRATE

” command is

“hidden” if the multimeter is secured.) To unsecure the multimeter, select the “parameter” level of the

SECURED

command, enter the security code, then press Menu Enter.

∧

000000 CODE

When you go to the “commands” level in the

CAL MENU

again, you will notice that the multimeter is unsecured. Notice also that the

“

2: CALIBRATE

” command is no longer hidden and you can perform a calibration.

1: UNSECURED

•

Remote Interface Operation:

CALibration:SECure:STATe {OFF|ON},<

code

>

To unsecure the multimeter, send the above command with the same code used to secure. For example,

"CAL:SEC:STAT OFF,HP034401"

96

Chapter 3 Features and Functions

Calibration Overview

To Secure Against Calibration

You can secure the multimeter against calibration either from the front panel or remote interface.

The multimeter is secured when shipped from the factory, and the security code is set to “

HP034401

”.

Make sure you have read the security code rules on page 95 before attempting to secure the multimeter.

•

Front-Panel Operation:

1: UNSECURED (CAL MENU)

If the multimeter is unsecured, you will see the above command when you go into the

CAL MENU

. To secure the multimeter, select the

“parameter” level of the

UNSECURED

command, enter the security code, then press Menu Enter.

∧

000000 CODE

3

When you go to the “commands” level in the

CAL MENU

again, you will notice that the multimeter is secured. Notice also that the

“

2: CALIBRATE

” command is now hidden and you cannot perform a calibration.

1: SECURED

•

Remote Interface Operation:

CALibration:SECure:STATe {OFF|ON},<

code

>

To secure the multimeter, send the above command with the same code as used to unsecure. For example,

"CAL:SEC:STAT ON,HP034401"

97

Chapter 3 Features and Functions

Calibration Overview

Calibration

Security

(continued)

To Change the Security Code

To change the security code, you must first unsecure the multimeter, and then enter a new code. Make sure you have read the security code rules on page 95 before attempting to secure the multimeter.

•

•

Front-Panel Operation: To change the security code, first make sure that the multimeter is unsecured. Select the “parameter” level of the

UNSECURED

command, enter the new security code, then press

Menu Enter. Changing the code from the front panel also changes the code as seen from the remote interface.

Remote Interface Operation:

CALibration:SECure:CODE <

new code

>

To change the security code, first unsecure the multimeter using the old security code. Then, enter the new code. For example,

CAL:SEC:STAT OFF, HP034401

unsecure with old code

CAL:SEC:CODE ZZ010443

enter new code

Calibration Count

You can determine the number of times that your multimeter has been calibrated. Your multimeter was calibrated before it left the factory.

When you receive your multimeter, read the count to determine its initial value.

•

•

•

The calibration count is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

The calibration count increments up to a maximum of 32,767 after which it wraps-around to 0. Since the value increments by one for each calibration point, a complete calibration increases the value by several counts.

Front-Panel Operation:

3: CAL COUNT (CAL MENU)

•

Remote Interface Operation:

CALibration:COUNt?

98

Chapter 3 Features and Functions

Calibration Overview

Calibration Message

You can use the calibration message feature to record calibration information about your multimeter. For example, you can store such information as the last calibration date, the next calibration due date, the multimeter’s serial number, or even the name and phone number of the person to contact for a new calibration.

You can record information in the calibration message only from the remote interface. However, you can read the message from either the front-panel menu or the remote interface.

•

•

•

The calibration message may contain up to 40 characters. However, the multimeter can display only 12 characters of the message on the front panel (additional characters are truncated).

The calibration message is stored in non-volatile memory, and

does not change when power has been off or after a remote interface reset.

Front-Panel Operation:

4: MESSAGE (CAL MENU)

read the cal message

•

Remote Interface Operation:

CALibration:STRing <

quoted string

>

store the cal message

The following command string shows how to store a calibration message.

"CAL:STR ’CAL 2-1-96’"

3

99

Chapter 3 Features and Functions

Operator Maintenance

Operator Maintenance

This section describes how to replace the power-line and current fuses.

If you need additional information about replacing parts or repairing the multimeter, see the Service Guide.

To Replace the Power-Line Fuse

The power-line fuse is located within the multimeter’s fuse-holder assembly on the rear panel (see also page 15). See the rear panel of the multimeter for the proper fuse rating. To replace the 250 mAT fuse, order Agilent part number 2110-0817.

To Replace the Current Input Fuses

The front and rear current input terminals are protected by two series fuses. The first fuse is a 3A, 250 Vac, fast-blow fuse and is located on the rear panel. To replace this fuse, order Agilent part number 2110-0780.

With a small flatblade screwdriver, push in on the fuse cap and rotate it counterclockwise. Remove the fuse cap and fuse.

A second fuse is located inside the multimeter to provide an additional level of current protection. This fuse is a 7A, 250 Vac, high-interrupt rated fuse (Agilent part number 2110-0614). To replace this fuse, you must remove the multimeter’s case by loosening three screws. See the

Service Guide for more information on disassembling the multimeter.

100

Chapter 3 Features and Functions

Power-On and Reset State

Power-On and Reset State

For your convenience, this table is duplicated on the rear cover of this manual and on the

Quick Reference Card.

The parameters marked with a bullet ( • ) are stored in

non-volatile

memory.

The factory settings are shown.

Measurement Configuration

AC Filter

Autozero

•

Continuity Threshold

Function

Input Resistance

Integration Time

Range

Resolution

Math Operations

Math State, Function

Math Registers

•

dBm Reference Resistance

Triggering Operations

Reading Hold Threshold

Samples Per Trigger

Trigger Delay

Trigger Source

System-Related Operations

•

Beeper Mode

•

Comma Separators

Display Mode

Reading Memory

Input/Output Configuration

•

•

Baud Rate

GPIB Address

•

Interface

•

•

Language

Parity

Calibration

•

Calibration State

Power-On/Reset State

20 Hz (medium filter)

On

•

10 Ω

DC volts

10 M Ω

(fixed for all dcv ranges)

10 PLCs

Autorange

5 1 ⁄

2

digits, slow mode

Power-On/Reset State

Off, Null

All registers are cleared

• 600 Ω

Power-On/Reset State

0.10% of range

1 sample

Automatic Delay

Auto Trigger

Power-On/Reset State

•

On

•

On

On

Off (cleared)

Power-On/Reset State

•

•

9600 baud

22

•

GPIB (IEEE-488)

•

•

SCPI

Even (7 data bits)

Power-On/Reset State

•

Secured

3

101

102

4

Remote Interface

Reference

4

Remote Interface Reference

>

•

Command Summary, starting on page 105

• Simplified Programming Overview, starting on page 112

•

The MEASure? and CONFigure Commands, starting on page 117

• Measurement Configuration Commands, starting on page 121

•

Math Operation Commands, starting on page 124

• Triggering, starting on page 127

•

Triggering Commands, starting on page 130

• System-Related Commands, starting on page 132

•

The SCPI Status Model, starting on page 134

• Status Reporting Commands, starting on page 144

•

Calibration Commands, on page 146

>

• RS-232 Interface Configuration, starting on page 148

•

RS-232 Interface Commands, on page 153

• An Introduction to the SCPI Language, starting on page 154

•

Output Data Formats, on page 159

• Using Device Clear to Halt Measurements, on page 160

•

TALK ONLY for Printers, on page 160

• To Set the GPIB Address, on page 161

•

To Select the Remote Interface, on page 162

• To Set the Baud Rate, on page 163

•

To Set the Parity, on page 164

• To Select the Programming Language, on page 165

•

Alternate Programming Language Compatibility, starting on page 166

• SCPI Compliance Information, on page 168

•

IEEE-488 Compliance Information, on page 169

If you are a first-time user of the SCPI language, you may want to refer to these sections to become familiar with the language before attempting to program the multimeter.

104

Chapter 4 Remote Interface Reference

Command Summary

First-time

SCPI users, see page 154.

Command Summary

This section summarizes the

SCPI

(Standard Commands for

Programmable Instruments) commands available to program the multimeter. Refer to the later sections in this chapter for more complete details on each command.

Throughout this manual, the following conventions are used for

SCPI

command syntax. Square brackets ( [ ] ) indicate optional

keywords or parameters. Braces ( { } ) enclose parameters within a

command string. Triangle brackets ( < > ) indicate that you must

substitute a value for the enclosed parameter.

The MEASure? and CONFigure Commands

(see page 117 for more information)

MEASure

:VOLTage:DC? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:VOLTage:DC:RATio? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:VOLTage:AC? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:CURRent:DC? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:CURRent:AC? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:RESistance? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:FRESistance? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:FREQuency? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:PERiod? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:CONTinuity?

:DIODe?

CONFigure

:VOLTage:DC {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:VOLTage:DC:RATio {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:VOLTage:AC {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:CURRent:DC {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:CURRent:AC {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:RESistance {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:FRESistance {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:FREQuency {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:PERiod {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

:CONTinuity

:DIODe

CONFigure?

4

105

Chapter 4 Remote Interface Reference

Command Summary

Measurement Configuration Commands

(see page 121 for more information)

[SENSe:]

FUNCtion "VOLTage:DC"

FUNCtion "VOLTage:DC:RATio"

FUNCtion "VOLTage:AC"

FUNCtion "CURRent:DC"

FUNCtion "CURRent:AC"

FUNCtion "RESistance"

(2-wire ohms)

FUNCtion "FRESistance"

(4-wire ohms)

FUNCtion "FREQuency"

FUNCtion "PERiod"

FUNCtion "CONTinuity"

FUNCtion "DIODe"

FUNCtion?

[SENSe:]

VOLTage:DC:RANGe {<

range

>|MINimum|MAXimum}

VOLTage:DC:RANGe? [MINimum|MAXimum]

VOLTage:AC:RANGe {<

range

>|MINimum|MAXimum}

VOLTage:AC:RANGe? [MINimum|MAXimum]

CURRent:DC:RANGe {<

range

>|MINimum|MAXimum}

CURRent:DC:RANGe? [MINimum|MAXimum]

CURRent:AC:RANGe {<

range

>|MINimum|MAXimum}

CURRent:AC:RANGe? [MINimum|MAXimum]

RESistance:RANGe {<

range

>|MINimum|MAXimum}

RESistance:RANGe? [MINimum|MAXimum]

FRESistance:RANGe {<

range

>|MINimum|MAXimum}

FRESistance:RANGe? [MINimum|MAXimum]

FREQuency:VOLTage:RANGe {<

range

>|MINimum|MAXimum}

FREQuency:VOLTage:RANGe? [MINimum|MAXimum]

PERiod:VOLTage:RANGe {<

range

>|MINimum|MAXimum}

PERiod:VOLTage:RANGe? [MINimum|MAXimum]

[SENSe:]

VOLTage:DC:RANGe:AUTO {OFF|

ON

}

VOLTage:DC:RANGe:AUTO?

VOLTage:AC:RANGe:AUTO {OFF|

ON

}

VOLTage:AC:RANGe:AUTO?

CURRent:DC:RANGe:AUTO {OFF|

ON

}

CURRent:DC:RANGe:AUTO?

CURRent:AC:RANGe:AUTO {OFF|

ON

}

CURRent:AC:RANGe:AUTO?

RESistance:RANGe:AUTO {OFF|

ON

}

RESistance:RANGe:AUTO?

FRESistance:RANGe:AUTO {OFF|

ON

}

FRESistance:RANGe:AUTO?

FREQuency:VOLTage:RANGe:AUTO {OFF|

ON

}

FREQuency:VOLTage:RANGe:AUTO?

PERiod:VOLTage:RANGe:AUTO {OFF|

ON

}

PERiod:VOLTage:RANGe:AUTO?

Default parameters are shown in

bold

.

106

Chapter 4 Remote Interface Reference

Command Summary

Measurement Configuration Commands

(continued)

[SENSe:]

VOLTage:DC:RESolution {<

resolution

>|MINimum|MAXimum}

VOLTage:DC:RESolution? [MINimum|MAXimum]

VOLTage:AC:RESolution {<

resolution

>|MINimum|MAXimum}

VOLTage:AC:RESolution? [MINimum|MAXimum]

CURRent:DC:RESolution {<

resolution

>|MINimum|MAXimum}

CURRent:DC:RESolution? [MINimum|MAXimum]

CURRent:AC:RESolution {<

resolution

>|MINimum|MAXimum}

CURRent:AC:RESolution? [MINimum|MAXimum]

RESistance:RESolution {<

resolution

>|MINimum|MAXimum}

RESistance:RESolution? [MINimum|MAXimum]

FRESistance:RESolution {<

resolution

>|MINimum|MAXimum}

FRESistance:RESolution? [MINimum|MAXimum]

[SENSe:]

VOLTage:DC:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}

VOLTage:DC:NPLCycles? [MINimum|MAXimum]

CURRent:DC:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}

CURRent:DC:NPLCycles? [MINimum|MAXimum]

RESistance:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}

RESistance:NPLCycles? [MINimum|MAXimum]

FRESistance:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}

FRESistance:NPLCycles? [MINimum|MAXimum]

[SENSe:]

FREQuency:APERture {0.01|0.1 |1|MINimum|MAXimum}

FREQuency:APERture? [MINimum|MAXimum]

PERiod:APERture {0.01|0.1 |1|MINimum|MAXimum}

PERiod:APERture? [MINimum|MAXimum]

[SENSe:]

DETector:BANDwidth {3|20|200|MINimum|MAXimum}

DETector:BANDwidth? [MINimum|MAXimum]

[SENSe:]

ZERO:AUTO {OFF|ONCE|ON}

ZERO:AUTO?

INPut

:IMPedance:AUTO {

OFF

|ON}

:IMPedance:AUTO?

ROUTe:TERMinals?

4

Default parameters are shown in

bold

.

107

Chapter 4 Remote Interface Reference

Command Summary

Math Operation Commands

(see page 124 for more information)

CALCulate

:FUNCtion {NULL|DB|DBM|AVERage|LIMit}

:FUNCtion?

:STATe {OFF|ON}

:STATe?

CALCulate

:AVERage:MINimum?

:AVERage:MAXimum?

:AVERage:AVERage?

:AVERage:COUNt?

CALCulate

:NULL:OFFSet {<

value

>|MINimum|MAXimum}

:NULL:OFFSet? [MINimum|MAXimum]

CALCulate

:DB:REFerence {<

value

>|MINimum|MAXimum}

:DB:REFerence? [MINimum|MAXimum]

CALCulate

:DBM:REFerence {<

value

>|MINimum|MAXimum}

:DBM:REFerence? [MINimum|MAXimum]

CALCulate

:LIMit:LOWer {<

value

>|MINimum|MAXimum}

:LIMit:LOWer? [MINimum|MAXimum]

:LIMit:UPPer {<

value

>|MINimum|MAXimum}

:LIMit:UPPer? [MINimum|MAXimum]

DATA:FEED RDG_STORE, {"CALCulate"|""}

DATA:FEED?

108

Chapter 4 Remote Interface Reference

Command Summary

Triggering Commands

(see page 127 for more information)

INITiate

READ?

TRIGger

:SOURce {BUS|IMMediate |EXTernal}

:SOURce?

TRIGger

:DELay {<

seconds

>|MINimum|MAXimum}

:DELay? [MINimum|MAXimum]

TRIGger

:DELay:AUTO {OFF|ON}

:DELay:AUTO?

SAMPle

:COUNt {<

value

>|MINimum|MAXimum}

:COUNt? [MINimum|MAXimum]

TRIGger

:COUNt {<

value

>|MINimum|MAXimum|INFinite}

:COUNt? [MINimum|MAXimum]

System-Related Commands

(see page 132 for more information)

FETCh?

READ?

DISPlay {OFF|

ON

}

DISPlay?

DISPlay

:TEXT <

quoted string

>

:TEXT?

:TEXT:CLEar

SYSTem

:BEEPer

:BEEPer:STATe {OFF|ON}

:BEEPer:STATe?

SYSTem:ERRor?

SYSTem:VERSion?

DATA:POINts?

*RST

*TST?

*IDN?

L1

L2

L3

Default parameters are shown in

bold

.

109

4

Chapter 4 Remote Interface Reference

Command Summary

Status Reporting Commands

(see page 144 for more information)

SYSTem:ERRor?

STATus

:QUEStionable:ENABle <

enable value

>

:QUEStionable:ENABle?

:QUEStionable:EVENt?

STATus:PRESet

*CLS

*ESE <

enable value

>

*ESE?

*ESR?

*OPC

*OPC?

*PSC {0|1}

*PSC?

*SRE <

enable value

>

*SRE?

*STB?

Calibration Commands

(see page 146 for more information)

CALibration?

CALibration:COUNt?

CALibration

:SECure:CODE <

new code

>

:SECure:STATe {OFF|ON},<

code

>

:SECure:STATe?

CALibration

:STRing <

quoted string

>

:STRing?

CALibration

:VALue <

value

>

Default parameters are shown in

bold

.

110

Chapter 4 Remote Interface Reference

Command Summary

RS-232 Interface Commands

(see page 148 for more information)

SYSTem:LOCal

SYSTem:REMote

SYSTem:RWLock

IEEE-488.2 Common Commands

(see page 169 for more information)

*CLS

*ESE <

enable value

>

*ESE?

*ESR?

*IDN?

*OPC

*OPC?

*PSC {0|1}

*PSC?

*RST

*SRE <

enable value

>

*SRE?

*STB?

*TRG

*TST?

Default parameters are shown in

bold

.

111

4

Chapter 4 Remote Interface Reference

Simplified Programming Overview

First-time

SCPI users, see page 154.

Simplified Programming Overview

You can program the multimeter to take measurements from the remote interface using the following simple seven-step sequence.

1. Place the multimeter in a known state (often the reset state).

2. Change the multimeter’s settings to achieve the desired configuration.

3. Set-up the triggering conditions.

4. Initiate or arm the multimeter for a measurement.

5. Trigger the multimeter to make a measurement.

6. Retrieve the readings from the output buffer or internal memory.

7. Read the measured data into your bus controller.

The

MEASure?

and

CONFigure

commands provide the most straightforward method to program the multimeter for measurements. You can select the measurement function, range, and resolution all in one command. The multimeter automatically presets other measurement parameters (ac filter, autozero, trigger count, etc.) to default values as shown below.

MEASure? and CONFigure Preset States

Command

AC Filter (DET:BAND)

Autozero (ZERO:AUTO)

Input Resistance (INP:IMP:AUTO)

Samples per Trigger (SAMP:COUN)

Trigger Count (TRIG:COUN)

Trigger Delay (TRIG:DEL)

Trigger Source (TRIG:SOUR)

Math Function (CALCulate subsystem)

MEASure? and CONFigure Setting

20 Hz (medium filter)

OFF if resolution setting results in NPLC < 1;

ON if resolution setting results in NPLC ≥ 1

OFF (fixed at 10 M Ω for all dc voltage ranges)

1 sample

1 trigger

Automatic delay

Immediate

OFF

112

Chapter 4 Remote Interface Reference

Simplified Programming Overview

Using the

MEASure?

Command

The easiest way to program the multimeter for measurements is by using the

MEASure?

command. However, this command does not offer much flexibility. When you execute the command, the multimeter

presets the best settings for the requested configuration and immediately performs the measurement. You cannot change any settings (other than function, range, and resolution) before the measurement is taken. The results are sent to the output buffer.

Sending the MEASure? command is the same as sending a CONFigure command followed immediately by a READ? command.

Using the

CONFigure

Command

For a little more programming flexibility, use the

CONFigure

command.

When you execute the command, the multimeter presets the best settings for the requested configuration (like the

MEASure?

command).

However, the measurement is not automatically started and you can change measurement parameters before making measurements. This allows you to “incrementally” change the multimeter’s configuration from the preset conditions. The multimeter offers a variety of low-level commands in the

INPut

,

SENSe

,

CALCulate

, and

TRIGger subsystems. (You can use the

SENSe:FUNCtion

command to change the measurement function without using

MEASure?

or

CONFigure

.)

Use the INITiate or READ? command to initiate the measurement.

4

113

Chapter 4 Remote Interface Reference

Simplified Programming Overview

Using the

range

and

resolution

Parameters

With the

MEASure?

and

CONFigure

commands, you can select the measurement function, range, and resolution all in one command.

Use the range parameter to specify the expected value of the input signal. The multimeter then selects the correct measurement range.

For frequency and period measurements, the multimeter uses one

“range” for all inputs between 3 Hz and 300 kHz. The range parameter is required only to specify the resolution. Therefore, it is not necessary to send a new command for each new frequency to be measured.

Use the resolution parameter to specify the desired resolution for the measurement. Specify the resolution in the same units as the measurement function, not in number of digits. For example, for dc volts, specify the resolution in volts. For frequency, specify the resolution in hertz.

You must specify a range to use the resolution parameter.

Using the READ? Command

The

READ?

command changes the state of the trigger system from the

“idle” state to the “wait-for-trigger” state. Measurements will begin when the specified trigger conditions are satisfied following the receipt of the

READ?

command. Readings are sent immediately to the output buffer. You must enter the reading data into your bus controller or the multimeter will stop making measurements when the output buffer fills. Readings are not stored in the multimeter’s internal memory when using the

READ?

command.

Sending the READ? command is like sending the INITiate command followed immediately by the FETCh? command, except readings are not buffered internally.

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C a u t i o n

MEASure?

Example

If you send two query commands without reading the response from the first, and then attempt to read the second response, you may receive some data from the first response followed by the complete second response.

To avoid this, do not send a query command without reading the response. When you cannot avoid this situation, send a device clear before sending the second query command.

Using the INITiate and FETCh? Commands

The

INITiate

and

FETCh?

commands provide the lowest level of control (with the most flexibility) of measurement triggering and reading retrieval. Use the

INITiate

command after you have configured the multimeter for the measurement. This changes the state of the triggering system from the “idle” state to the “wait-for-trigger” state. Measurements will begin when the specified trigger conditions are satisfied after the

INITiate

command is received. The readings are placed in the multimeter’s internal memory (up to 512 readings can be stored). Readings are stored in memory until you are able to retrieve them.

Use the

FETCh?

command to transfer the readings from the multimeter’s internal memory to the multimeter’s output buffer where you can read them into your bus controller.

4

The following program segment shows how to use the

MEASure?

command to make a measurement. This example configures the multimeter for dc voltage measurements, automatically places the multimeter in the “wait-for-trigger” state, internally triggers the multimeter to take one reading, and then sends the reading to the output buffer.

MEAS:VOLT:DC? 10,0.003

bus enter statement

This is the simplest way to take a reading. However, you do not have any flexibility with

MEASure?

to set the trigger count, sample count, trigger delay, etc. All measurement parameters except function, range, and resolution are preset for you automatically (see the table on page 112).

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CONFigure

Example

CONFigure

Example

The following program segment shows how to use the

READ?

command with

CONFigure

to make an externally-triggered measurement.

The program configures the multimeter for dc voltage measurements.

CONFigure

does not place the multimeter in the “wait-for-trigger” state.

The

READ?

command places the multimeter in the “wait-for-trigger” state, takes a reading when the Ext Trig terminal is pulsed, and sends the reading to the output buffer.

CONF:VOLT:DC 10, 0.003

TRIG:SOUR EXT

READ?

bus enter statement

The following program segment is similar to the program above but it uses

INITiate

to place the multimeter in the “wait-for-trigger” state.

The

INITiate

command places the multimeter in the “wait-for-trigger” state, takes a reading when the Ext Trig terminal is pulsed, and sends the reading to the multimeter’s internal memory. The

FETCh?

command transfers the reading from internal memory to the output buffer.

CONF:VOLT:DC 10, 0.003

TRIG:SOUR EXT

INIT

FETC?

bus enter statement

Storing readings in memory using the

INITiate

command is faster than sending readings to the output buffer using the

READ?

command.

The multimeter can store up to 512 readings in internal memory. If you configure the multimeter to take more than 512 readings (using the sample count and trigger count), and then send

INITiate

, a memory error is generated.

After you execute an

INITiate

command, no further commands are accepted until the measurement sequence is completed. However, if you select

TRIGger:SOURce BUS

, the multimeter will accept the

*TRG command (bus trigger) or an

IEEE-488

Group Execute Trigger message.

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The MEASure? and CONFigure Commands

The MEASure? and CONFigure Commands

See also “Measurement Configuration,” starting on page 51 in chapter 3.

•

•

For the range parameter,

MIN selects the lowest range for the selected function;

MAX

selects the highest range;

DEF

selects autoranging.

For the resolution parameter, specify the resolution in the same units as the measurement function, not in number of digits.

MIN

selects the smallest value accepted, which gives the best resolution;

MAX

selects the largest value accepted, which gives the least resolution;

DEF

selects the default resolution which is 5 1

⁄

2

digits slow (10

PLC

).

Note

: You must specify a

range

to use the

resolution

parameter.

MEASure:VOLTage:DC? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and make a dc voltage measurement with the specified range and resolution. The reading is sent to the output buffer.

MEASure:VOLTage:DC:RATio? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and make a dc:dc ratio measurement with the specified range and resolution. The reading is sent to the output buffer. For ratio measurements, the specified range applies to the signal connected to the

Input

terminals. Autoranging is automatically selected for reference voltage measurements on the

Sense

terminals.

MEASure:VOLTage:AC? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and make an ac voltage measurement with the specified range and resolution. The reading is sent to the output buffer. For ac measurements, resolution is actually fixed at 6 1

⁄

2

digits. The resolution parameter only affects the front-panel display.

MEASure:CURRent:DC? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and make a dc current measurement with the specified range and resolution. The reading is sent to the output buffer.

4

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MEASure:CURRent:AC? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and make an ac current measurement with the specified range and resolution. The reading is sent to the output buffer. For ac measurements, resolution is actually fixed at 6

1 ⁄

2

digits. The resolution parameter only affects the front-panel display.

MEASure:RESistance? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and make a 2-wire ohms measurement with the specified range and resolution. The reading is sent to the output buffer.

MEASure:FRESistance? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and make a 4-wire ohms measurement with the specified range and resolution. The reading is sent to the output buffer.

MEASure:FREQuency? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and make a frequency measurement with the specified range and resolution. The reading is sent to the output buffer. For frequency measurements, the multimeter uses one “range” for all inputs between

3 Hz and 300 kHz. With no input signal applied, frequency measurements return “0”.

MEASure:PERiod? {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and make a period measurement with the specified range and resolution. The reading is sent to the output buffer. For period measurements, the multimeter uses one “range” for all inputs between

0.33 seconds and 3.3

µ sec. With no input signal applied, period measurements return “0”.

MEASure:CONTinuity?

Preset and make a continuity measurement. The reading is sent to the output buffer. The range and resolution are fixed for continuity tests

(1 k

Ω

range and 5 1

⁄

2

digits).

MEASure:DIODe?

Preset and make a diode measurement. The reading is sent to the output buffer. The range and resolution are fixed for diode tests

(1 Vdc range with 1 mA current source output and 5

1 ⁄

2

digits).

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CONFigure:VOLTage:DC {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and configure the multimeter for dc voltage measurements with the specified range and resolution. This command does not initiate the measurement.

CONFigure:VOLTage:DC:RATio {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and configure the multimeter for dc:dc ratio measurements with the specified range and resolution. This command does not initiate the measurement. For ratio measurements, the specified range applies to the signal connected to the

Input

terminals. Autoranging is automatically selected for reference voltage measurements on the

Sense

terminals.

CONFigure:VOLTage:AC {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and configure the multimeter for ac voltage measurements with the specified range and resolution. This command does not initiate the measurement. For ac measurements, resolution is actually fixed at

6 1

⁄

2

digits. The resolution parameter only affects the front-panel display.

CONFigure:CURRent:DC {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and configure the multimeter for dc current measurements with the specified range and resolution. This command does not initiate the measurement.

CONFigure:CURRent:AC {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and configure the multimeter for ac current measurements with the specified range and resolution. This command does not initiate the measurement. For ac measurements, resolution is actually fixed at

6

1 ⁄

2

digits. The resolution parameter only affects the front-panel display.

CONFigure:RESistance {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and configure the multimeter for 2-wire ohms measurements with the specified range and resolution. This command does not initiate the measurement.

CONFigure:FRESistance {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and configure the multimeter for 4-wire ohms measurements with the specified range and resolution. This command does not initiate the measurement.

4

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CONFigure:FREQuency {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and configure a frequency measurement with the specified range and resolution. This command does not initiate the measurement.

For frequency measurements, the multimeter uses one “range” for all inputs between 3 Hz and 300 kHz. With no input signal applied, frequency measurements return “0”.

CONFigure:PERiod {<

range

>|MIN|MAX|DEF},{<

resolution

>|MIN|MAX|DEF}

Preset and configure a period measurement with the specified range and resolution. This command does not initiate the measurement.

For period measurements, the multimeter uses one “range” for all inputs between 0.33 seconds and 3.3

µ sec. With no input signal applied, period measurements return “0”.

CONFigure:CONTinuity

Preset and configure the multimeter for continuity measurements.

This command does not initiate the measurement. The range and resolution are fixed for continuity tests (1 k

Ω

range and 5 1

⁄

2

digits).

CONFigure:DIODe

Preset and configure the multimeter for diode measurements.

This command does not initiate the measurement. The range and resolution are fixed for diode tests (1 Vdc range with 1 mA current source output and 5

1 ⁄

2

digits).

CONFigure?

Query the multimeter’s present configuration and return a quoted string.

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Measurement Configuration Commands

See also “Measurement Configuration,” starting on page 51 in chapter 3.

FUNCtion "<

function

>"

Select a measurement function. The function must be enclosed in quotes in the command string (

FUNC "VOLT:DC"

). Specify one of the following strings.

VOLTage:DC

VOLTage:DC:RATio

VOLTage:AC

CURRent:DC

CURRent:AC

RESistance (

2-wire ohms

)

FRESistance (

4-wire ohms

)

FREQuency

PERiod

CONTinuity

DIODe

FUNCtion?

Query the measurement function and return a quoted string.

<

function

>:RANGe {<

range

>|MINimum|MAXimum}

Select the range for the selected function. For frequency and period measurements, ranging applies to the signal’s input voltage, not its frequency (use

FREQuency:VOLTage

or

PERiod:VOLTage

).

MIN

selects the lowest range for the selected function.

MAX

selects the highest range. [Stored in volatile memory]

<

function

>:RANGe? [MINimum|MAXimum]

Query the range for the selected function.

<

function

>:RANGe:AUTO {OFF|ON}

Disable or enable autoranging for the selected function. For frequency and period, use

FREQuency:VOLTage or

PERiod:VOLTage

.

Autorange thresholds: Down range at <10% of range; Up range at >120% of range. [Stored in volatile memory]

<

function

>:RANGe:AUTO?

Query the autorange setting. Returns “0” (

OFF

) or “1” (

ON

).

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<

function

>:RESolution {<

resolution

>|MINimum|MAXimum}

Select the resolution for the specified function (not valid for frequency, period, or ratio). Specify the resolution in the same units as the measurement function, not in number of digits.

MIN

selects the smallest value accepted, which gives the most resolution.

MAX

selects the largest value accepted which gives the least resolution. [Stored in volatile memory]

<

function

>:RESolution? [MINimum|MAXimum]

Query the resolution for the selected function. For frequency or period measurements, the multimeter returns a resolution setting based upon a 3 Hz input frequency.

<

function

>:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum}

Select the integration time in number of power line cycles for the present function (the default is 10

PLC

). This command is valid only for dc volts, ratio, dc current, 2-wire ohms, and 4-wire ohms.

MIN

= 0.02.

MAX

= 100. [Stored in volatile memory]

<

function

>:NPLCycles? [MINimum|MAXimum]

Query the integration time for the selected function.

FREQuency:APERture {0.01|0.1|1|MINimum|MAXimum}

Select the aperture time (or gate time) for frequency measurements

(the default is 0.1 seconds). Specify 10 ms (4

1 ⁄

2

digits), 100 ms (default;

5 1

⁄

2

digits), or 1 second (6 1

⁄

2

[Stored in volatile memory]

digits).

MIN

= 0.01 seconds.

MAX

= 1 second.

FREQuency:APERture? [MINimum|MAXimum]

Query the aperture time for frequency measurements.

PERiod:APERture {0.01|0.1|1|MINimum|MAXimum}

Select the aperture time (or gate time) for period measurements

(the default is 0.1 seconds). Specify 10 ms (4 1

⁄

2

digits), 100 ms (default;

5 1

⁄

2

digits), or 1 second (6 1

⁄

2

digits).

[Stored in volatile memory]

MIN

= 0.01 seconds.

MAX

= 1 second.

PERiod:APERture? [MINimum|MAXimum]

Query the aperture time for period measurements.

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[SENSe:]DETector:BANDwidth {3|20|200|MINimum|MAXimum}

Specify the lowest frequency expected in the input signal. The multimeter selects the slow, medium (default), or fast ac filter based on the frequency you specify.

MIN

= 3 Hz.

MAX

= 200 Hz. [Stored in volatile memory]

[SENSe:]DETector:BANDwidth? [MINimum|MAXimum]

Query the ac filter. Returns “+3.000000E+00”, “+2.000000E+01”, or

“+2.000000E+02”.

[SENSe:]ZERO:AUTO {OFF|ONCE|ON}

Disable or enable (default) the autozero mode. The

OFF

and

ONCE parameters have a similar effect. Autozero

OFF

does not issue a new zero measurement until the next time the multimeter goes to the

“wait-for-trigger” state. Autozero

ONCE

issues an immediate zero measurement. [Stored in volatile memory]

[SENSe:]ZERO:AUTO?

Query the autozero mode. Returns “0” (

OFF

or

ONCE

) or “1” (

ON

).

INPut:IMPedance:AUTO {OFF|ON}

Disable or enable the automatic input resistance mode for dc voltage measurements. With

AUTO OFF

(default), the input resistance is fixed at 10 M

Ω

for all ranges. With

AUTO ON

, the input resistance is set to

>10 G

Ω for the 100 mV, 1 V, and 10 V ranges. [Stored in volatile memory]

INPut:IMPedance:AUTO?

Query the input resistance mode. Returns “0” (

OFF

) or “1” (

ON

).

ROUTe:TERMinals?

Query the multimeter to determine if the front or rear input terminals are selected. Returns “

FRON

” or “

REAR

”.

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Math Operation Commands

Math Operation Commands

See also “Math Operations,” starting on page 63 in chapter 3.

There are five math operations available, only one of which can be enabled at a time. Each math operation performs a mathematical operation on each reading or stores data on a series of readings.

The selected math operation remains in effect until you disable it, change functions, turn off the power, or perform a remote interface reset. The math operations use one or more internal registers. You can preset the values in some of the registers, while others hold the results of the math operation.

The following table shows the math/measurement function combinations allowed. Each “

X

” indicates an allowable combination. If you choose a math operation that is not allowed with the present measurement function, math is turned off. If you select a valid math operation and then change to one that is invalid, a “Settings conflict” error is generated over the remote interface. For null and dB measurements, you must turn

on the math operation before writing to their math registers.

Null

Min-Max dB dBm

Limit

DC V

X

X

X

X

X

AC V

X

X

X

X

X

X

DC I

X

X

X

AC I

X

X

Ω

2W

X

X

X

Ω

4W

X

X

X

Freq

X

X

Per

X

X

Cont Diode Ratio

X

X

X

X

CALCulate:FUNCtion {NULL|DB|DBM|AVERage|LIMit}

Select the math function. Only one function can be enabled at a time.

The default function is null. [Stored in volatile memory]

CALCulate:FUNCtion?

Query the present math function. Returns

NULL

,

DB

,

DBM

,

AVER

, or

LIM

.

CALCulate:STATe {OFF|ON}

Disable or enable the selected math function. [Stored in volatile memory]

CALCulate:STATe?

Query the state of the math function. Returns “0” (

OFF

) or “1” (

ON

).

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CALCulate:AVERage:MINimum?

Read the minimum value found during a min-max operation. The multimeter clears the value when min-max is turned on, when power has been off, or after a remote interface reset. [Stored in volatile memory]

CALCulate:AVERage:MAXimum?

Read the maximum value found during a min-max operation. The multimeter clears the value when min-max is turned on, when power has been off, or after a remote interface reset. [Stored in volatile memory]

CALCulate:AVERage:AVERage?

Read the average of all readings taken since min-max was enabled.

The multimeter clears the value when min-max is turned on, when power has been off, or after a remote interface reset. [Stored in volatile

memory]

CALCulate:AVERage:COUNt?

Read the number of readings taken since min-max was enabled. The multimeter clears the value when min-max is turned on, when power has been off, or after a remote interface reset. [Stored in volatile

memory]

CALCulate:NULL:OFFSet {<

value

>|MINimum|MAXimum}

Store a null value in the multimeter’s Null Register. You must turn on

the math operation before writing to the math register. You can set the null value to any number between 0 and

±

120% of the highest range, for the present function.

MIN

= –120% of the highest range.

MAX

= 120% of the highest range. [Stored in volatile memory]

CALCulate:NULL:OFFSet? [MINimum|MAXimum]

Query the null value.

CALCulate:DB:REFerence {<

value

>|MINimum|MAXimum}

Store a relative value in the dB Relative Register. You must turn on the

math operation before writing to the math register. You can set the relative value to any number between 0 dBm and

±

200 dBm.

MIN

= –200.00 dBm.

MAX

= 200.00 dBm. [Stored in volatile memory]

CALCulate:DB:REFerence? [MINimum|MAXimum]

Query the dB relative value.

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CALCulate:DBM:REFerence {<

value

>|MINimum|MAXimum}

Select the dBm reference value. Choose from: 50, 75, 93, 110, 124, 125,

135, 150, 250, 300, 500, 600, 800, 900, 1000, 1200, or 8000 ohms.

MIN

= 50 Ω .

MAX

= 8000 Ω . [Stored in non-volatile memory]

CALCulate:DBM:REFerence? [MINimum|MAXimum]

Query the dBm reference resistance.

CALCulate:LIMit:LOWer {<

value

>|MINimum|MAXimum}

Set the lower limit for limit testing. You can set the value to any number between 0 and

±

120% of the highest range, for the present function.

MIN

= –120% of the highest range.

[Stored in volatile memory]

MAX

= 120% of the highest range.

CALCulate:LIMit:LOWer? [MINimum|MAXimum]

Query the lower limit.

CALCulate:LIMit:UPPer {<

value

>|MINimum|MAXimum}

Set the lower limit for limit testing. You can set the value to any number between 0 and

±

120% of the highest range, for the present function.

MIN

= –120% of the highest range.

[Stored in volatile memory]

MAX

= 120% of the highest range.

CALCulate:LIMit:UPPer? [MINimum|MAXimum]

Query the upper limit.

DATA:FEED RDG_STORE, {"CALCulate"|""}

Selects whether readings taken using the

INITiate

command are stored in the multimeter’s internal memory (default) or not stored at all.

In the default state (

DATA:FEED RDG_STORE, "CALC"

), up to

512 readings are stored in memory when

INITiate

is executed.

The

MEASure?

and

CONFigure

commands automatically select

"CALC"

.

With memory disabled (

DATA:FEED RDG_STORE, ""

), readings taken using

INITiate

are not stored. This may be useful with the min-max operation since it allows you to determine an average of the readings without storing the individual values. An error will be generated if you attempt to transfer readings to the output buffer using the

FETCh?

command.

DATA:FEED?

Query the reading memory state. Returns

"CALC"

or

""

.

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Triggering

First-time

SCPI users, see page 154.

Triggering

See also “Triggering,” starting on page 71 in chapter 3.

The multimeter’s triggering system allows you to generate triggers either manually or automatically, take multiple readings per trigger, and insert a delay before each reading. Normally, the multimeter will take one reading each time it receives a trigger, but you can specify multiple readings (up to 50,000) per trigger.

Triggering the multimeter from the remote interface is a multi-step process that offers triggering flexibility.

•

•

•

First, you must configure the multimeter for the measurement by selecting the function, range, resolution, etc.

Then, you must specify the source from which the multimeter will accept the trigger. The multimeter will accept a software (bus) trigger from the remote interface, a hardware trigger from the rear-panel

Ext Trig (external trigger) terminal, or an immediate internal trigger.

Then, you must make sure that the multimeter is ready to accept a trigger from the specified trigger source (this is called the wait-for-

trigger state).

The diagram on the next page shows the multimeter’s triggering system.

4

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Triggering

Agilent 34401A Triggering System

Initiate Triggering

MEASure?

READ?

INITiate

Idle

State

Trigger Source

TRIGger:SOURce IMMediate

TRIGger:SOURce EXTernal

TRIGger:SOURce BUS

Front-panel “Single” key

Wait-for-

Trigger

State

Trigger Delay

TRIGger:DELay

Delay

Sample (

∗

)

Annunciator

Measurement

Sample

Sample

Count ≠ 1

Trigger

Count ≠ 1

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Triggering

The Wait-for-Trigger State

After you have configured the multimeter and selected a trigger source, you must place the multimeter in the wait-for-trigger state. A trigger will not be accepted until the multimeter is in this state. If a trigger signal is present, and if multimeter is in the “wait-for-trigger” state, the measurement sequence begins and readings are taken.

The “wait-for-trigger” state is a term used primarily for remote interface operation. From the front panel, the multimeter is always in the “waitfor-trigger” state and will accept triggers at any time, unless a measurement is already in progress.

You can place the multimeter in the “wait-for-trigger” state by executing any of the following commands from the remote interface.

MEASure?

READ?

INITiate

4

The multimeter requires approximately 20 ms of set-up time after you send a command to change to the “wait-for-trigger” state. Any external triggers that occur during this set-up time are ignored.

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Triggering Commands

See also “Triggering,” starting on page 71 in chapter 3.

INITiate

Change the state of the triggering system from the “idle” state to the

“wait-for-trigger” state. Measurements will begin when the specified trigger conditions are satisfied after the

INITiate

command is received. The readings are placed in the multimeter’s internal memory

(up to 512 readings can be stored). Readings are stored in memory until you are able to retrieve them. Use the

FETCh?

command to retrieve reading results.

A new command is available starting with firmware Revision 2 which allows you to take readings using

INITiate

without storing them in internal memory. This command may be useful with the min-max operation since it allows you to determine the average of a series of readings without storing the individual values.

DATA:FEED RDG_STORE, ""

do not store readings

DATA:FEED RDG_STORE, "CALCulate"

store readings (default)

See page 126 for more information on using the

DATA:FEED

command.

READ?

Change the state of the trigger system from the “idle” state to the

“wait-for-trigger” state. Measurements will begin when the specified trigger conditions are satisfied following the receipt of the

READ?

command. Readings are sent immediately to the output buffer.

TRIGger:SOURce {BUS|IMMediate|EXTernal}

Select the source from which the multimeter will accept a trigger.

The multimeter will accept a software (bus) trigger, an immediate internal trigger (this is the default source), or a hardware trigger from the rear-panel Ext Trig (external trigger) terminal. [Stored in volatile memory]

TRIGger:SOURce?

Query the present trigger source. Returns “

BUS

”, “

IMM

”, or “

EXT

”.

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TRIGger:DELay {<

seconds

>|MINimum|MAXimum}

Insert a trigger delay between the trigger signal and each sample that follows. If you do not specify a trigger delay, the multimeter automatically selects a delay for you. Select from 0 to 3600 seconds.

MIN

= 0 seconds.

MAX

= 3600 seconds. [Stored in volatile memory]

TRIGger:DELay? [MINimum|MAXimum]

Query the trigger delay.

TRIGger:DELay:AUTO {OFF|ON}

Disable or enable an automatic trigger delay. The delay is determined by function, range, integration time, and ac filter setting. Selecting a specific trigger delay value automatically turns off the automatic trigger delay. [Stored in volatile memory]

TRIGger:DELay:AUTO?

Query the automatic trigger delay setting. Returns “0” (

OFF

) or “1” (

ON

).

SAMPle:COUNt {<

value

>|MINimum|MAXimum}

Set the number of readings (samples) the multimeter takes per trigger.

Select from 1 to 50,000 readings per trigger.

MIN

= 1.

MAX

= 50,000.

[Stored in volatile memory]

SAMPle:COUNt? [MINimum|MAXimum]

Query the sample count.

TRIGger:COUNt {<

value

>|MINimum|MAXimum|INFinite}

Set the number of triggers the multimeter will accept before returning to the “idle” state. Select from 1 to 50,000 triggers. The

INFinite parameter instructs the multimeter to continuously accept triggers

(you must send a device clear to return to the “idle” state). Trigger count is ignored while in local operation.

MIN

= 1.

MAX

= 50,000.

[Stored in volatile memory]

TRIGger:COUNt? [MINimum|MAXimum]

Query the trigger count. If you specify an infinite trigger count, the query command returns “9.90000000E+37”.

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System-Related Commands

System-Related Commands

See also “System-Related Operations,” starting on page 84 in chapter 3.

FETCh?

Transfer readings stored in the multimeter’s internal memory by the

INITiate

command to the multimeter’s output buffer where you can read them into your bus controller.

READ?

Change the state of the trigger system from the “idle” state to the

“wait-for-trigger” state. Measurements will begin when the specified trigger conditions are satisfied following the receipt of the

READ?

command. Readings are sent immediately to the output buffer.

DISPlay {OFF|ON}

Turn the front-panel display off or on. [Stored in volatile memory]

DISPlay?

Query the front-panel display setting. Returns “0” (

OFF

) or “1” (

ON

).

DISPlay:TEXT <

quoted string

>

Display a message on the front panel. The multimeter will display up to

12 characters in a message; any additional characters are truncated.

[Stored in volatile memory]

DISPlay:TEXT?

Query the message sent to the front panel and return a quoted string.

DISPlay:TEXT:CLEar

Clear the message displayed on the front panel.

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System-Related Commands

SYSTem:BEEPer

Issue a single beep immediately.

SYSTem:BEEPer:STATe {OFF|ON}

Disable or enable the front-panel beeper. [Stored in non-volatile memory]

When you disable the beeper, the multimeter will not emit a tone when:

1) a new minimum or maximum is found in a min–max test.

2) a stable reading is captured in reading hold.

3) a limit is exceeded in a limit test.

4) a forward-biased diode is measured in the diode test function.

SYSTem:BEEPer:STATe?

Query the state of the front-panel beeper. Returns “0” (

OFF

) or “1” (

ON

).

SYSTem:ERRor?

Query the multimeter’s error queue. Up to 20 errors can be stored in the queue. Errors are retrieved in first-in-first out (

FIFO

) order. Each error string may contain up to 80 characters.

SYSTem:VERSion?

Query the multimeter to determine the present

SCPI

version.

DATA:POINts?

Query the number of readings stored in the multimeter’s internal memory.

*RST

Reset the multimeter to its power-on configuration.

*TST?

Perform a complete self-test of the multimeter. Returns “0” if the self-test is successful, or “1” if it test fails.

*IDN?

Read the multimeter’s identification string (be sure to dimension a string variable with at least 35 characters).

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The SCPI Status Model

The SCPI Status Model

All

SCPI

instruments implement status registers in the same way.

The status system records various instrument conditions in three register groups: the Status Byte register, the Standard Event register, and the Questionable Data register. The status byte register records high-level summary information reported in the other register groups.

The diagram on the next page illustrates the

SCPI

status system.

Chapter 6, “Application Programs,” contains an example program showing the use of the status registers. You may find it useful to refer to the program after reading the following section in this chapter.

What is an Event Register?

The standard event and questionable data registers have event registers.

An event register is a read-only register that reports defined conditions within the multimeter. Bits in the event registers are latched. Once an event bit is set, subsequent state changes are ignored. Bits in an event register are automatically cleared by a query of that register (such as

*ESR?

or

STAT:QUES:EVEN?

) or by sending the

*CLS

(clear status) command. A reset (

*RST

) or device clear will not clear bits in event registers. Querying an event register returns a decimal value which corresponds to the binary-weighted sum of all bits set in the register.

What is an Enable Register?

An enable register defines which bits in the corresponding event register are logically

OR ed together to form a single summary bit. Enable registers are both readable and writable. Querying an enable register

will not clear it. The

*CLS

(clear status) command does not clear enable registers but it does clear the bits in the event registers.

The

STATus:PRESet

command will clear the questionable data enable register. To enable bits in an enable register, you must write a decimal value which corresponds to the binary-weighted sum of the bits you wish to enable in the register.

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SCPI Status System

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The Status Byte

The status byte summary register reports conditions from other status registers. Query data that is waiting in the multimeter’s output buffer is immediately reported through the “message available” bit (bit 4). Bits in the summary registers are not latched. Clearing an event register will clear the corresponding bits in the status byte summary register.

Reading all messages in the output buffer, including any pending queries, will clear the message available bit.

Bit Definitions – Status Byte Register

Bit

0 Not Used

1 Not Used

2 Not Used

3 Questionable Data

4 Message Available

5 Standard Event

6 Request Service

7 Not Used

Decimal

Value

1

2

4

8

16

32

64

128

Definition

Always set to 0.

Always set to 0.

Always set to 0.

One or more bits are set in the Questionable Data

register (bits must be “enabled” in enable register).

Data is available in the multimeter’s output buffer.

One or more bits are set in the Standard Event

register (bits must be “enabled” in enable register).

The multimeter is requesting service (serial poll).

Always set to 0.

The status byte summary register is cleared when:

•

•

You execute a

*CLS

(clear status) command.

Querying the standard event and questionable data registers will clear only the respective bits in the summary register.

The status byte enable register (request service) is cleared when:

•

•

You turn on the power and you have previously configured the multimeter using the

*PSC 1

command.

You execute a

*SRE 0

command.

The status byte enable register will not be cleared at power-on if you have previously configured the multimeter using

*PSC 0.

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The SCPI Status Model

Using Service Request (

SRQ

) and Serial

POLL

You must configure your bus controller to respond to the

IEEE-488 service request (

SRQ

) interrupt to use this capability. Use the status byte enable register (

SRE

) to select which summary bits will set the low-level

IEEE-488 SRQ

signal. When the status byte “request service” bit (bit 6) is set, an

IEEE-488 SRQ

interrupt message is automatically sent to the bus controller. The bus controller may then poll the instruments on the bus to identify which one requested service (the one with bit 6 set in its status byte). The request service bit is only cleared by reading the status byte using an

IEEE-488

serial poll or by reading the event register whose summary bit is causing the service request.

To read the status byte summary register, send the

IEEE-488

serial poll message. Querying the summary register will return a decimal value which corresponds to the binary-weighted sum of the bits set in the register. Serial poll will automatically clear the “request service” bit in the status byte summary register. No other bits are affected. Performing a serial poll will not affect instrument throughput.

4

The IEEE-488.2 standard does not ensure synchronization between your bus controller program and the instrument. Use the *OPC? command to guarantee that commands previously sent to the instrument have completed. Executing a serial poll before a *RST, *CLS, or other commands have completed can cause previous conditions to be reported.

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Using

*STB?

to Read the Status Byte

The

*STB?

(status byte query) command is similar to a serial poll except it is processed like any other instrument command. The

*STB?

command returns the same result as an

IEEE-488

serial poll except that the

“request service” bit (bit 6) is not cleared if a serial poll has occurred.

The

*STB?

command is not handled automatically by the

IEEE-488

bus interface hardware and the command will be executed only after previous commands have completed. Polling is not possible using the

*STB?

command. Using the

*STB?

command does not clear the status byte summary register.

•

•

•

•

•

To Interrupt Your Bus Controller Using SRQ

Send a bus device clear message.

Clear the event registers with the

*CLS

(clear status) command.

Set the

*ESE

(standard event register) and

*SRE

(status byte register) enable masks.

Send the

*OPC?

(operation complete query) command and enter the result to assure synchronization.

Enable your bus controller’s

IEEE-488 SRQ

interrupt.

•

•

•

•

•

•

To Determine When a Command Sequence is Completed

Send a device clear message to clear the multimeter’s output buffer.

Clear the event registers with the

*CLS

(clear status) command.

Enable “operation complete” using the

*ESE 1

command (standard event register).

Send the

*OPC?

(operation complete query) command and enter the result to assure synchronization.

Send your programming command string, and place the

*OPC

(operation complete) command as the last command.

Use a serial poll to check to see when bit 5 (standard event) is set in the status byte summary register. You could also configure the multimeter for an

SRQ

interrupt by sending

*SRE 32

(status byte enable register, bit 5).

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How to Use the Message Available Bit (

MAV

)

You can use the status byte “message available” bit (bit 4) to determine when data becomes available to read into your bus controller. The multimeter sets bit 4 when the first reading trigger occurs (which can be

TRIGger:SOURce:IMMediate

). The multimeter subsequently clears bit 4 only after all messages have been read from the output buffer.

The message available (

MAV

) bit can only indicate when the first reading is available following a

READ?

command. This can be helpful if you do not know when a trigger event such as

BUS

or

EXTernal

will occur.

The

MAV

bit is set only after all specified measurements have completed when using the

INITiate

command followed by

FETCh?

. Readings are placed in the multimeter’s internal memory when using

INITiate

.

Sending the

FETCh?

command transfers readings (stored in internal memory by the

INITiate

command) to the multimeter’s output buffer.

Therefore, the

MAV

bit can only be set after all measurements have been completed.

4

Using

*OPC

to Signal When Data is in the Output Buffer

Generally, it is best to use the “operation complete” bit (bit 0) in the standard event register to signal when a command sequence is completed. This bit is set in the register after an

*OPC

command has been executed. If you send

*OPC after a command which loads a message in the multimeter’s output buffer (either reading data or query data), you can use the operation complete bit to determine when the message is available. However, if too many messages are generated before the

*OPC

command executes (sequentially), the output buffer will fill and the multimeter will stop taking readings.

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The Standard Event Register

The standard event register reports the following types of instrument events: power-on detected, command syntax errors, command execution errors, self-test or calibration errors, query errors, or when an

*OPC command is executed. Any or all of these conditions can be reported in the standard event summary bit through the enable register. You must write a decimal value using the

*ESE

(event status enable) command to set the enable register mask.

An error condition (standard event register bits 2, 3, 4, or 5) will always record one or more errors in the multimeter’s error queue, except for the following case. Read the error queue using SYSTem:ERRor?.

A reading overload condition is always reported in both the standard event register (bit 3) and the questionable data event register (bits 0, 1, or 9).

However, no error message is recorded in the multimeter’s error queue.

Bit Definitions – Standard Event Register

Bit

0 Operation Complete

1 Not Used

2 Query Error

3 Device Error

4 Execution Error

5 Command Error

6 Not Used

7 Power On

Decimal

Value

1

2

4

8

16

32

64

128

Definition

All comm ands pri or to and including an *OPC

command have been executed.

Always set to 0.

The multimeter tried to read the output buffer but

it was empty. Or, a new command line was

received before a previous query has been read.

Or, both the input and output buffers are full.

A self-test, calibration, or reading overload error

occurred (see error numbers 501 through 748 in

chapter 5).

An execution error occurred (see error numbers

-211 through -230 in chapter 5).

A command syntax error occurred (see error

numbers -101 through -158 in chapter 5).

Always set to 0.

Power has been turned off and on since the last

time the event register was read or cleared.

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The standard event register is cleared when:

•

•

You send a

*CLS

(clear status) command.

You query the event register using the

*ESR?

(event status register) command.

The standard event enable register is cleared when:

•

•

You turn on the power and you have previously configured the multimeter using the

*PSC 1 command.

You execute a

*ESE 0

command.

The standard event enable register will not be cleared at power-on if you have previously configured the multimeter using

*PSC 0.

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The Questionable Data Register

The questionable data register provides information about the quality of the multimeter’s measurement results. Overload conditions and high/low limit test results are reported. Any or all of these conditions can be reported in the questionable data summary bit through the enable register. You must write a decimal value using the

STATus:

QUEStionable:ENABle

command to set the enable register mask.

Note

: A reading overload condition is always reported in both the standard event register (bit 3) and the questionable data event register

(bits 0, 1, or 9). However, no error message is recorded in the multimeter’s error queue.

Bit Definitions – Questionable Data Register

Bit

0 Voltage Overload

1 Current Overload

2 Not Used

3 Not Used

4 Not Used

5 Not Used

6 Not Used

7 Not Used

8 Not Used

9 Ohms Overload

10 Not Used

11 Limit Fail LO

12 Limit Fail HI

13 Not Used

14 Not Used

15 Not Used

Decimal

Value

1

2

4

8

16

32

64

128

256

512

1024

2048

4096

8192

16384

32768

Definition

Range overload on dc volts, ac volts,

frequency, period, diode, or ratio function.

Range overload on dc or ac current function.

Always set to 0.

Always set to 0.

Always set to 0.

Always set to 0.

Always set to 0.

Always set to 0.

Always set to 0.

Range overload on 2-wire or 4-wire ohms.

Always set to 0.

Reading is less than lower limit in limit test.

Reading exceeds upper limit in limit test.

Always set to 0.

Always set to 0.

Always set to 0.

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The questionable data event register is cleared when:

•

•

You execute a

*CLS

(clear status) command.

You query the event register using

STATus:QUEStionable:EVENt?

.

The questionable data enable register is cleared when:

•

•

•

You turn on the power (

*PSC

does not apply).

You execute the

STATus:PRESet

command.

You execute the

STATus:QUEStionable:ENABle 0

command.

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Status Reporting Commands

Status Reporting Commands

SYSTem:ERRor?

Query the multimeter’s error queue. Up to 20 errors can be stored in the queue. Errors are retrieved in first-in-first out (

FIFO

) order. Each error string may contain up to 80 characters.

STATus:QUEStionable:ENABle <

enable value

>

Enable bits in the Questionable Data enable register. The selected bits are then reported to the Status Byte.

STATus:QUEStionable:ENABle?

Query the Questionable Data enable register. The multimeter returns a binary-weighted decimal representing the bits set in the enable register.

STATus:QUEStionable:EVENt?

Query the Questionable Data event register. The multimeter returns a decimal value which corresponds to the binary-weighted sum of all bits set in the register.

STATus:PRESet

Clear all bits in the Questionable Data enable register.

*CLS

Clear the Status Byte summary register and all event registers.

*ESE <

enable value

>

Enable bits in the Standard Event enable register. The selected bits are then reported to the Status Byte.

*ESE?

Query the Standard Event enable register. The multimeter returns a decimal value which corresponds to the binary-weighted sum of all bits set in the register.

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*ESR?

Query the Standard event register. The multimeter returns a decimal value which corresponds to the binary-weighted sum of all bits set in the register.

*OPC

Sets the “operation complete” bit (bit 0) in the Standard Event register after the command is executed.

*OPC?

Returns “1” to the output buffer after the command is executed.

*PSC {0|1}

Power-on status clear. Clear the Status Byte and Standard Event register enable masks when power is turned on (

*PSC 1

). When

*PSC 0 is in effect, the Status Byte and Standard Event register enable masks

are not cleared when power is turned on. [Stored in non-volatile memory]

*PSC?

Query the power-on status clear setting. Returns “0” (

*PSC 0

) or

“1” (

*PSC 1

).

*SRE <

enable value

>

Enable bits in the Status Byte enable register.

*SRE?

Query the Status Byte enable register. The multimeter returns a decimal value which corresponds to the binary-weighted sum of all bits set in the register.

*STB?

Query the Status Byte summary register. The

*STB?

command is similar to a serial poll but it is processed like any other instrument command. The

*STB?

command returns the same result as a serial poll but the “request service” bit (bit 6) is not cleared if a serial poll has occurred.

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Calibration Commands

Calibration Commands

See “Calibration Overview” starting on page 95 for an overview of the calibration features of the multimeter. For a more detailed discussion of the calibration procedures, see chapter 4 in the Service Guide.

CALibration?

Perform a calibration using the specified calibration value

(

CALibration:VALue

command). Before you can calibrate the multimeter, you must unsecure it by entering the correct security code.

CALibration:COUNt?

Query the multimeter to determine the number of times it has been calibrated. Your multimeter was calibrated before it left the factory.

When you receive your multimeter, read the count to determine its initial value. [Stored in non-volatile memory]

•

The calibration count increments up to a maximum of 32,767 after which it wraps-around to 0. Since the value increments by one for each calibration point, a complete calibration will increase the value by many counts.

CALibration:SECure:CODE <

new code

>

Enter a new security code. To change the security code, you must first unsecure the multimeter using the old security code, and then enter a new code. The calibration code may contain up to 12 characters.

[Stored in non-volatile memory]

CALibration:SECure:STATe {OFF|ON},<

code

>

Unsecure or secure the multimeter for calibration. The calibration code may contain up to 12 characters. [Stored in non-volatile memory]

CALibration:SECure:STATe?

Query the secured state of the multimeter. Returns “0” (

OFF

) or “1” (

ON

).

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Calibration Commands

CALibration:STRing <

quoted string

>

Record calibration information about your multimeter. For example, you can store such information as the last calibration date, the next calibration due date, the instrument serial number, or even the name and phone number of the person to contact for a new calibration.

[Stored in non-volatile memory]

•

•

You can record information in the calibration message only from the remote interface. However, you can read the message from either the front-panel menu or the remote interface.

The calibration message may contain up to 40 characters. However, the multimeter can display only 12 characters of the message on the front panel (additional characters are truncated).

CALibration:STRing?

Query the calibration message and return a quoted string.

CALibration:VALue <

value

>

Specify the value of the known calibration signal used by the calibration procedure.

CALibration:VALue?

Query the present calibration value.

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RS-232 Interface Configuration

RS-232 Interface Configuration

See also “Remote Interface Configuration,” on page 91 in chapter 3.

You connect the multimeter to the

RS

-232 interface using the 9-pin (

DB

-9) serial connector on the rear panel. The multimeter is configured as a

DTE

(Data Terminal Equipment) device. For all communications over the

RS

-232 interface, the multimeter uses two handshake lines:

DTR

(Data Terminal Ready) on pin 4 and

DSR

(Data Set Ready) on pin 6.

The following sections contain information to help you use the multimeter over the

RS

-232 interface. The programming commands for

RS

-232 are listed on page 153.

RS-232 Configuration Overview

Configure the

RS

-232 interface using the parameters shown below.

Use the front-panel

I/O MENU

to select the baud rate, parity, and number of data bits (see also pages 163 and 164 for more information).

•

•

•

•

Baud Rate: 300, 600, 1200, 2400, 4800, or

9600 baud

(factory setting)

Parity and Data Bits:

None / 8 data bits

Even / 7 data bits, (factory setting) or

Odd / 7 data bits

Number of Start Bits:

1 bit

(fixed)

Number of Stop Bits:

2 bits

(fixed)

C a u t i o n

Do not use the RS-232 interface if you have configured the multimeter to output pass/fail signals on pins 1 and 9. Internal components on the

RS-232 interface circuitry may be damaged.

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RS-232 Data Frame Format

A character frame consists of all the transmitted bits that make up a single character. The frame is defined as the characters from the start bit to the last stop bit, inclusively. Within the frame, you can select the baud rate, number of data bits, and parity type. The multimeter uses the following frame formats for seven and eight data bits.

Connection to a Computer or Terminal

To connect the multimeter to a computer or terminal, you must have the proper interface cable. Most computers and terminals are

DTE

(Data Terminal Equipment) devices. Since the multimeter is also a

DTE device, you must use a

DTE

-to-

DTE

interface cable. These cables are also called null-modem, modem-eliminator, or crossover cables.

The interface cable must also have the proper connector on each end and the internal wiring must be correct. Connectors typically have

9 pins (

DB

-9 connector) or 25 pins (

DB

-25 connector) with a “male” or “female” pin configuration. A male connector has pins inside the connector shell and a female connector has holes inside the connector shell.

If you cannot find the correct cable for your configuration, you may have to use a wiring adapter. If you are using a

DTE

-to-

DTE

cable, make sure the adapter is a “straight-through” type. Typical adapters include gender changers, null-modem adapters, and

DB

-9 to

DB

-25 adapters.

Refer to the cable and adapter diagrams on the following page to connect the multimeter to most computers or terminals. If your configuration is different than those described, order the Agilent 34399A

Adapter Kit. This kit contains adapters for connection to other computers, terminals, and modems. Instructions and pin diagrams are included with the adapter kit.

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DB-9 Serial Connection

If your computer or terminal has a 9-pin serial port with a male connector, use the null-modem cable included with the Agilent 34398A Cable Kit. This cable has a 9-pin female connector on each end. The cable pin diagram is shown below.

DB-25 Serial Connection

If your computer or terminal has a 25-pin serial port with a male connector, use the null-modem cable and 25-pin adapter included with the Agilent 34398A Cable Kit. The cable and adapter pin diagram is shown below.

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DTR / DSR Handshake Protocol

The multimeter is configured as a

DTE

(Data Terminal Equipment) device and uses the

DTR

(Data Terminal Ready) and

DSR

(Data Set Ready) lines of the

RS

-232 interface to handshake. The multimeter uses the

DTR

line to send a hold-off signal. The

DTR

line must be

TRUE

before the multimeter will accept data from the interface. When the multimeter sets the

DTR

line

FALSE

, the data must cease within 10 characters.

To disable the

DTR

/

DSR

handshake, do not connect the

DTR

line and tie the

DSR

line to logic

TRUE

. If you disable the

DTR

/

DSR

handshake, also select a slower baud rate (300, 600, or 1200 baud) to ensure that the data is transmitted correctly.

The multimeter sets the DTR line FALSE in the following cases:

1

When the multimeter’s input buffer is full (when approximately

100 characters have been received), it sets the

DTR

line

FALSE ( pin 4 on the

RS

-232 connector). When enough characters have been removed to make space in the input buffer, the multimeter sets the

DTR

line

TRUE

, unless the second case (see below) prevents this.

2

When the multimeter wants to “talk” over the interface (which means that it has processed a query) and has received a <new line> message terminator, it will set the

DTR

line

FALSE

. This implies that once a query has been sent to the multimeter, the controller should read the response before attempting to send more data. It also means that a

<new line> must terminate the command string. After the response has been output, the multimeter sets the

DTR

line

TRUE

again, unless the first case (see above) prevents this.

The multimeter monitors the

DSR

line to determine when the controller is ready to accept data over the interface. The multimeter monitors the

DSR

line (pin 6 on the

RS

-232 connector) before each character is sent.

The output is suspended if the

DSR

line is

FALSE

. When the

DSR

line goes

TRUE

, transmission will resume.

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The multimeter holds the

DTR

line

FALSE

while output is suspended.

A form of interface deadlock exists until the controller asserts the

DSR line

TRUE

to allow the multimeter to complete the transmission.

You can break the interface deadlock by sending the <Ctrl-C> character, which clears the operation in progress and discards pending output

(this is equivalent to the

IEEE

-488 device clear action). For the <Ctrl-C>

character to be recognized reliably by the multimeter while it holds DTR

FALSE, the controller must first set DSR FALSE.

In addition, you may have difficulty sending the <Ctrl-C> character if you are interrupting a query operation, in which case the multimeter hold the

DTR

line

FALSE

. This may prevent the controller from sending anything unless you first reprogram the interface to ignore

DTR

.

RS-232 Troubleshooting

Here are a few things to check if you are having problems communicating over the

RS

-232 interface. If you need additional help, refer to the documentation that came with your computer.

•

•

•

•

Verify that the multimeter and your computer are configured for the same baud rate, parity, and number of data bits. Make sure that your computer is set up for 1 start bit and 2 stop bits (these values are fixed on the multimeter).

Make sure to execute the

SYSTem:REMote

command to place the multimeter in the

REMOTE

mode.

Verify that you have connected the correct interface cable and adapters.

Even if the cable has the proper connectors for your system, the internal wiring may not be correct. The Agilent 34398A Cable Kit can be used to connect the multimeter to most computers or terminals.

Verify that you have connected the interface cable to the correct serial port on your computer (

COM

1,

COM

2, etc).

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RS-232 Interface Commands

RS-232 Interface Commands

Use the front-panel I/O MENU to select the baud rate, parity, and number of data bits (see pages 163 and 164 for more information).

SYSTem:LOCal

Place the multimeter in the local mode for

RS

-232 operation. All keys on the front panel are fully functional.

SYSTem:REMote

Place the multimeter in the remote mode for

RS

-232 operation.

All keys on the front panel, except the

LOCAL

key, are disabled.

It is very important that you send the

SYSTem:REMote

command to place the multimeter in the remote mode. Sending or receiving data over the RS-232 interface when not configured for remote operation can cause unpredictable results.

SYSTem:RWLock

Place the multimeter in the remote mode for

RS

-232 operation.

This command is the same as the

SYSTem:REMote

command except that all keys on the front panel are disabled, including the

LOCAL

key.

Ctrl-C

Clear the operation in progress over the

RS

-232 interface and discard any pending output data. This is equivalent to the IEEE-488 device clear

action over the GPIB interface.

4

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An Introduction to the SCPI Language

An Introduction to the SCPI Language

SCPI (Standard Commands for Programmable Instruments) is an

ASCII

-based instrument command language designed for test and measurement instruments. Refer to “Simplified Programming Overview,”

starting on page 112, for an introduction to the basic techniques used to program the multimeter over the remote interface.

SCPI commands are based on a hierarchical structure, also known as a

tree system. In this system, associated commands are grouped together under a common node or root, thus forming subsystems. A portion of the

SENSE

subsystem is shown below to illustrate the tree system.

SENSe:

VOLTage:

DC:RANGe {<

range

>|MINimum|MAXimum}

VOLTage:

DC:RANGe? [MINimum|MAXimum]

FREQuency:

VOLTage:RANGe {<

range

>|MINimum|MAXimum}

FREQuency:

VOLTage:RANGe? [MINimum|MAXimum]

DETector:

BANDwidth {3|20|200|MINimum|MAXimum}

DETector:

BANDwidth? [MINimum|MAXimum]

ZERO:

AUTO {OFF|ONCE|ON}

ZERO:

AUTO?

SENSe

is the root keyword of the command,

VOLTage

and

FREQuency are second-level keywords, and

DC

and

VOLTage

are third-level keywords. A colon ( : ) separates a command keyword from a lower-level keyword.

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An Introduction to the SCPI Language

Command Format Used in This Manual

The format used to show commands in this manual is shown below:

VOLTage:DC:RANGe {<

range

>|MINimum|MAXimum}

The command syntax shows most commands (and some parameters) as a mixture of upper- and lower-case letters. The upper-case letters indicate the abbreviated spelling for the command. For shorter program lines, send the abbreviated form. For better program readability, send the long form.

For example, in the above syntax statement,

VOLT

and

VOLTAGE are both acceptable forms. You can use upper- or lower-case letters.

Therefore,

VOLTAGE

, volt

, and

Volt

are all acceptable. Other forms, such as

VOL

and

VOLTAG

, will generate an error.

Braces ( { } ) enclose the parameter choices for a given command string.

The braces are not sent with the command string.

A vertical bar (

|

) separates multiple parameter choices for a given command string.

Triangle brackets ( < > ) indicate that you must specify a value for the enclosed parameter. For example, the above syntax statement shows the range parameter enclosed in triangle brackets. The brackets are not sent with the command string. You must specify a value for the parameter (such as

"VOLT:DC:RANG 10"

).

Some parameters are enclosed in square brackets ( [ ] ). The brackets indicate that the parameter is optional and can be omitted. The brackets are not sent with the command string. If you do not specify a value for an optional parameter, the multimeter chooses a default value.

4

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An Introduction to the SCPI Language

Command Separators

A colon ( : ) is used to separate a command keyword from a lower-level keyword. You must insert a blank space to separate a parameter from a command keyword. If a command requires more than one parameter, you must separate adjacent parameters using a comma as shown below:

"CONF:VOLT:DC 10, 0.003"

A semicolon ( ; ) is used to separate commands within the same subsystem, and can also minimize typing. For example, sending the following command string:

"TRIG:DELAY 1; COUNT 10"

... is the same as sending the following two commands:

"TRIG:DELAY 1"

"TRIG:COUNT 10"

Use a colon and a semicolon to link commands from different subsystems.

For example, in the following command string, an error is generated if you do not use both the colon and semicolon:

"SAMP:COUN 10;:TRIG:SOUR EXT"

Using the MIN and MAX Parameters

You can substitute

MINimum

or

MAXimum

in place of a parameter for many commands. For example, consider the following command:

VOLTage:DC:RANGe {<

range

>|MINimum|MAXimum}

Instead of selecting a specific voltage range, you can substitute

MIN to set the range to its minimum value or

MAX

to set the range to its maximum value.

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An Introduction to the SCPI Language

Querying Parameter Settings

You can query the current value of most parameters by adding a

question mark ( ? ) to the command. For example, the following command sets the sample count to 10 readings:

"SAMP:COUN 10"

You can query the sample count by executing:

"SAMP:COUN?"

You can also query the minimum or maximum count allowed as follows:

"SAMP:COUN? MIN"

"SAMP:COUN? MAX"

If you send two query commands without reading the response from the first, and then attempt to read the second response, you may receive some data from the first response followed by the complete second response.

To avoid this, do not send a query command without reading the response. When you cannot avoid this situation, send a device clear before sending the second query command.

4

SCPI Command Terminators

A command string sent to the multimeter must terminate with a

<new line> character. The

IEEE

-488 EOI (end-or-identify) message is interpreted as a <new line> character and can be used to terminate a command string in place of a <new line> character. A <carriage return> followed by a <new line> is also accepted. Command string termination will always reset the current

SCPI

command path to the root level.

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An Introduction to the SCPI Language

IEEE-488.2 Common Commands

The

IEEE

-488.2 standard defines a set of common commands that perform functions like reset, self-test, and status operations. Common commands always begin with an asterisk ( * ), are four to five characters in length, and may include one or more parameters. The command keyword is separated from the first parameter by a blank space.

Use a semicolon ( ; ) to separate multiple commands as shown below:

"*RST; *CLS; *ESE 32; *OPC?"

SCPI Parameter Types

The

SCPI

language defines several different data formats to be used in program messages and response messages.

Numeric Parameters

Commands that require numeric parameters will accept all commonly used decimal representations of numbers including optional signs, decimal points, and scientific notation.

Special values for numeric parameters like

MINimum

,

MAXimum

, and

DEFault

are also accepted. You can also send engineering unit suffixes with numeric parameters (e.g.,

M

,

K

, or u

). If only specific numeric values are accepted, the multimeter will automatically round the input numeric parameters. The following command uses a numeric parameter:

VOLTage:DC:RANGe {<

range

>|MINimum|MAXimum}

Discrete Parameters

Discrete parameters are used to program settings that have a limited number of values (like

BUS

,

IMMediate

,

EXTernal

). They have a short form and a long form just like command keywords. You can mix upper- and lower-case letters. Query responses will always return the short form in all upper-case letters. The following command uses discrete parameters:

TRIGger:SOURce {BUS|IMMediate|EXTernal}

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Output Data Formats

Boolean Parameters

Boolean parameters represent a single binary condition that is either true or false. For a false condition, the multimeter will accept “

OFF

” or “0”. For a true condition, the multimeter will accept

“

ON

” or “1”. When you query a boolean setting, the instrument will

always return “0” or “1”. The following command uses a boolean parameter:

INPut:IMPedance:AUTO {OFF|ON}

String Parameters

String parameters can contain virtually any set of

ASCII

characters. A string must begin and end with matching quotes; either with a single quote or with a double quote. You can include the quote delimiter as part of the string by typing it twice without any characters in between. The following command uses a string parameter:

DISPlay:TEXT <

quoted string

>

4

Output Data Formats

Output data will be in one of formats shown in the table below.

Type of Output Data

Non-reading queries

Single reading (IEEE-488)

Multiple readings (IEEE-488)

Single reading (RS-232)

Multiple readings (RS-232)

Output Data Format

< 80 ASCII character string

SD.DDDDDDDDESDD<nl>

SD.DDDDDDDDESDD,...,...,<nl>

SD.DDDDDDDDESDD<cr><nl>

SD.DDDDDDDDESDD,...,...,<cr><nl>

S

Negative sign or positive sign

D

Numeric digits

E

Exponent

<nl>

newline character

<cr>

carriage return character

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Using Device Clear to Halt Measurements

Using Device Clear to Halt Measurements

Device clear is an

IEEE-488

low-level bus message which can be used to halt measurements in progress. Different programming languages and

IEEE-488

interface cards provide access to this capability through their own unique commands. 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.

•

•

•

•

All measurements in progress are aborted.

The multimeter returns to the trigger “idle state.”

The multimeter’s input and output buffers are cleared.

The multimeter is prepared to accept a new command string.

For

RS-232

operation, sending the <Ctrl-C> character will perform the equivalent operations of the

IEEE-488

device clear message.

The multimeter’s

DTR

(data terminal ready) handshake line will be true following a device clear message. See “DTR/DSR Handshake Protocol,”

on page 151 for further details.

TALK ONLY for Printers

You can set the address to “31” which is the talk only mode. In this mode, the multimeter can output readings directly to a printer without being addressed by a bus controller (over either

GPIB

or

RS-232

).

For proper operation, make sure your printer is configured in the

listen always mode. Address 31 is not a valid address if you are operating the multimeter from the

GPIB

interface with a bus controller.

If you select the

RS-232

interface and then set the

GPIB

address to the talk only address (31), the multimeter will send readings over the

RS-232

interface when in the local mode.

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Chapter 4 Remote Interface Reference

To Set the GPIB Address

On/Off

Shift <

To Set the GPIB Address

Each device on the

GPIB

(

IEEE-488

) interface must have a unique address. You can set the multimeter’s address to any value between

0 and 31. The address is set to “

22

” when the multimeter is shipped from the factory. The address is displayed on the front panel when you turn on the multimeter. See also “

GPIB

Address,” on page 91.

1 Turn on the front-panel menu.

A: MEAS MENU

< <

∨

∨

Auto/Man

ENTER

2 Move across to the

I/O MENU

choice on this level.

E: I/O MENU

3 Move down a level to the

HP-IB ADDR

command.

1: HP-IB ADDR

4 Move down to the “parameter” level to set the address.

Use the left/right and down/up arrow keys to change the address.

∧

22 ADDR

5 Save the change and turn off the menu.

The address is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

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Chapter 4 Remote Interface Reference

To Select the Remote Interface

On/Off

Shift <

To Select the Remote Interface

The multimeter is shipped with both an

GPIB

(

IEEE-488

) interface and an

RS-232

interface. Only one interface can be enabled at a time.

The

GPIB

interface is selected when the multimeter is shipped from the factory. See also “Remote Interface Selection,” on page 92.

1 Turn on the front-panel menu.

A: MEAS MENU

< <

∨

>

∨

Auto/Man

ENTER

2 Move across to the

I/O MENU

choice on this level.

E: I/O MENU

3 Move down a level and then across to the

INTERFACE

command.

2: INTERFACE

4 Move down to the “parameter” level to select the interface.

Use the left/right arrow keys to see the interface choices. Choose from the following:

HP-IB / 488

or

RS-232

.

HP-IB / 488

5 Save the change and turn off the menu.

The interface selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

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Chapter 4 Remote Interface Reference

To Set the Baud Rate

On/Off

Shift <

To Set the Baud Rate

You can select one of six baud rates for

RS-232

operation. The rate is set to 9600 baud when the multimeter is shipped from the factory. See also

“Baud Rate Selection,” on page 93.

1 Turn on the front-panel menu.

A: MEAS MENU

< <

2 Move across to the

I/O MENU

choice on this level.

E: I/O MENU

∨

> >

3 Move down a level and then across to the

BAUD RATE

command.

3: BAUD RATE

4

∨

4 Move down to the “parameter” level to select the baud rate.

Use the left/right arrow keys to see the baud rate choices. Choose from one of the following: 300, 600, 1200, 2400, 4800, or 9600 baud.

9600 BAUD

Auto/Man

ENTER

5 Save the change and exit the menu.

The baud rate selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

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To Set the Parity

On/Off

Shift <

To Set the Parity

You can select the parity for

RS-232

operation. The multimeter is configured for even parity with 7 data bits when shipped from the factory. See also “Parity Selection,” on page 93.

1 Turn on the front-panel menu.

A: MEAS MENU

< <

2 Move across to the

I/O MENU

choice on this level.

E: I/O MENU

∨

< <

3 Move down a level and then across to the

PARITY

command.

4: PARITY

∨

4 Move down to the “parameter” level to select the parity.

Use the left/right arrow keys to see the parity choices. Choose from one of the following: None (8 data bits), Even (7 data bits), or Odd (7 data bits).

When you set parity, you are indirectly setting the number of data bits.

EVEN: 7 BITS

Auto/Man

ENTER

5 Save the change and turn off the menu.

The parity selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

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To Select the Programming Language

On/Off

Shift <

To Select the Programming Language

You can select one of three languages to program the multimeter from the selected remote interface. The language is

SCPI

when the multimeter is shipped from the factory. See also “Programming

Language Selection,” on page 94.

1 Turn on the front-panel menu.

A: MEAS MENU

< <

∨ <

2 Move across to the

I/O MENU

choice on this level.

E: I/O MENU

3 Move down a level and then across to the

LANGUAGE

command.

5: LANGUAGE

4

∨

4 Move down to the “parameter” level to select the language.

Choose from one of the following: SCPI, Agilent 3478A, or Fluke 8840A.

SCPI

Auto/Man

ENTER

5 Save the change and turn off the menu.

The language selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

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Alternate Programming Language Compatibility

Alternate Programming Language Compatibility

You can configure the Agilent 34401A to accept and execute the commands of either the Agilent 3478A multimeter or the Fluke

8840A/8842A multimeter. Remote operation will only allow you to access the functionality of the multimeter language selected. You can take advantage of the full functionality of the 34401A only through the

SCPI

programming language. For more information on selecting the alternate languages from the front panel menu, see “To Select the

Programming Language,” on the previous page. From the remote interface, use the following commands to select the alternate languages:

L1

L2

L3

select SCPI language select Agilent 3478A language select Fluke 8840A language

Virtually all of the commands available for the other two multimeters are implemented in the 34401A, with the exception of the self-test and calibration commands. You must always calibrate the 34401A using the

SCPI

language setting. The calibration commands from the other two multimeters will not be executed.

Be aware that measurement timing may be different in the alternate language compatibility modes.

Agilent 3478A Language Setting

All Agilent 3478A commands are accepted and executed by the 34401A with equivalent operations, with the exception of the commands shown below. Refer to your Agilent 3478A Operating Manual for further remote interface programming information.

3478A Command

C

Device Clear

Description

Perform a calibration.

Perform a self-test and reset.

Agilent 34401A Action

Command is accepted but is ignored.

Self-test is not executed.

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Alternate Programming Language Compatibility

Fluke 8840A/8842A Language Setting

All Fluke 8840A or 8842A commands are accepted and executed by the Agilent 34401A with equivalent operations, with the exception of the commands shown below. Refer to your Fluke 8840A or 8842A

Instruction Manual for further remote interface programming information.

Fluke 8840A

Command

G2

G4

G8

P2

P3

Z0

C0

C1

C2

C3

Description

GET calibration input prompt.

GET calibration status.

Return identification string.

PUT variable calibration value.

PUT user-defined message.

Perform self-test.

Store input as calibration value.

Begin A/D calibration.

Begin high-frequency AC calibration.

Enter ERASE mode.

Agilent 34401A Action

Generates Error 51 in 8840A/8842A.

Returns “1000”.

Returns “HEWLETT-PACKARD,

34401A,0,X-X-X”

Generates Error 51 in 8840A/8842A.

Generates Error 51 in 8840A/8842A.

Self-test is not executed and no

errors are recorded in the status byte.

Generates Error 51 in 8840A/8842A.

Generates Error 51 in 8840A/8842A.

Generates Error 51 in 8840A/8842A.

Generates Error 51 in 8840A/8842A.

4

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SCPI Compliance Information

SCPI Compliance Information

The following commands are device-specific to the Agilent 34401A. They are not included in the 1991.0 version of the

SCPI

standard. However, these commands are designed with the

SCPI

format in mind and they follow all of the syntax rules of the standard.

Many of the required SCPI commands are accepted by the multimeter but are not described in this manual for simplicity or clarity. Most of these non-documented commands duplicate the functionality of a command already described in this chapter.

CALCulate

:AVERage:MINimum?

:AVERage:MAXimum?

:AVERage:AVERage?

:AVERage:COUNt?

:DB:REFerence {<

value

>|MINimum|MAXimum}

:DB:REFerence? [MINimum|MAXimum]

:DBM:REFerence {<

value

>|MINimum|MAXimum}

:DBM:REFerence? [MINimum|MAXimum]

:FUNCtion {NULL|DB|DBM|AVERage|LIMit}

:FUNCtion?

:LIMit:LOWer {<

value

>|MINimum|MAXimum}

:LIMit:LOWer? [MINimum|MAXimum]

:LIMit:UPPer {<

value

>|MINimum|MAXimum}

:LIMit:UPPer? [MINimum|MAXimum]

:NULL:OFFSet {<

value

>|MINimum|MAXimum}

:NULL:OFFSet? [MINimum|MAXimum]

CALibration

:COUNt?

:SECure:CODE <

new code

>

:SECure:STATe {OFF|ON},<

code

>

:SECure:STATe?

:STRing <

quoted string

>

:STRing?

CONFigure

:CONTinuity

:DIODe

INPut

:IMPedance:AUTO {OFF|ON}

:IMPedance:AUTO?

MEASure

:CONTinuity?

:DIODe?

SAMPle

:COUNt {<

value

>|MINimum|MAXimum}

:COUNt? [MINimum|MAXimum]

[SENSe:]

FUNCtion "CONTinuity"

FUNCtion "DIODe"

FREQuency:VOLTage:RANGe {<

range

>|MINimum|MAXimum}

FREQuency:VOLTage:RANGe? [MINimum|MAXimum]

FREQuency:VOLTage:RANGe:AUTO {OFF|ON}

FREQuency:VOLTage:RANGe:AUTO?

PERiod:VOLTage:RANGe {<

range

>|MINimum|MAXimum}

PERiod:VOLTage:RANGe? [MINimum|MAXimum]

PERiod:VOLTage:RANGe:AUTO {OFF|ON}

PERiod:VOLTage:RANGe:AUTO?

ZERO:AUTO?

SYSTem

:LOCal

:REMote

:RWLock

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IEEE-488 Compliance Information

IEEE-488 Compliance Information

Dedicated Hardware Lines

ATN

IFC

REN

SRQ

Attention

Interface Clear

Remote Enable

Service Request Interrupt

Addressed Commands

DCL

EOI

GET

GTL

LLO

SDC

SPD

SPE

Device Clear

End or Identify Message Terminator

Group Execute Trigger

Go to Local

Local Lock-Out

Selected Device Clear

Serial Poll Disable

Serial Poll Enable

IEEE-488.2 Common Commands

*CLS

*ESE <

enable value

>

*ESE?

*ESR?

*IDN?

*OPC

*OPC?

*PSC {0|1}

*PSC?

*RST

*SRE <

enable value

>

*SRE?

*STB?

*TRG

*TST?

4

169

170

5

Error

Messages

5

Error Messages

•

•

•

•

Errors are retrieved in first-in-first-out (

FIFO

) order. The first error returned is the first error that was stored. When you have read all errors from the queue, the

ERROR

annunciator turns off.

The multimeter beeps once each time an error is generated.

If more than 20 errors have occurred, the last error stored in the queue (the most recent error) is replaced with -350, “Too many errors”.

No additional errors are stored until you remove errors from the queue. If no errors have occurred when you read the error queue, the multimeter responds with +0, “No error”.

The error queue is cleared when power has been off or after a

*CLS

(clear status) command has been executed. The

*RST

(reset) command does not clear the error queue.

Front-Panel Operation:

3: ERROR (SYS MENU)

If the

ERROR

annunciator is on, press

Shift >

(Recall Menu) to read the errors stored in the queue. The errors are listed

horizontally on the “parameter” level. All errors are cleared when you go to the “parameter” level and then turn off the menu.

ERR 1: -113

First error in queue Error code

•

Remote Interface Operation:

SYSTem:ERRor?

Reads one error from the error queue

Errors have the following format (the error string may contain

up to 80 characters):

-113,"Undefined header"

172

-101

-102

-103

-104

-105

-108

-109

Chapter 5 Error Messages

Execution Errors

Execution Errors

Invalid character

An invalid character was found in the command string. You may have inserted a character such as #, $, or % in the command header or within a parameter. Example:

CONF:VOLT#DC

Syntax error

Invalid syntax was found in the command string. You may have inserted a blank space before or after a colon in the command header, or before a comma. Example:

SAMP:COUN ,1

Invalid separator

An invalid separator was found in the command string. You may have used a comma instead of a colon, semicolon, or blank space – or you may have used a blank space instead of a comma. Example:

TRIG:COUN,1 or

CONF:FREQ 1000 0.1

Data type error

The wrong parameter type was found in the command string. You may have specified a number where a string was expected, or vice versa.

Example:

DISP:TEXT 5.0

GET not allowed

A Group Execute Trigger (

GET

) is not allowed within a command string.

Parameter not allowed

More parameters were received than expected for the command.

You may have entered an extra parameter, or you added a parameter to a command that does not accept a parameter. Example:

READ? 10

Missing parameter

Fewer parameters were received than expected for the command.

You omitted one or more parameters that are required for this command. Example:

SAMP:COUN

5

173

-112

-113

-121

-123

-124

-131

-138

-148

Chapter 5 Error Messages

Execution Errors

Program mnemonic too long

A command header was received which contained more than the maximum 12 characters allowed. Example:

CONFIGURATION:VOLT:DC

Undefined header

A command was received that is not valid for this multimeter. You may have misspelled the command or it may not be a valid command. If you are using the short form of the command, remember that it may contain up to four letters. Example:

TRIGG:COUN 3

Invalid character in number

An invalid character was found in the number specified for a parameter value. Example:

STAT:QUES:ENAB #B01010102

Numeric overflow

A numeric parameter was found whose exponent was larger than 32,000.

Example:

TRIG:COUN 1E34000

Too many digits

A numeric parameter was found whose mantissa contained more than

255 digits, excluding leading zeros.

Invalid suffix

A suffix was incorrectly specified for a numeric parameter. You may have misspelled the suffix. Example:

TRIG:DEL 0.5 SECS

Suffix not allowed

A suffix was received following a numeric parameter which does not accept a suffix. Example:

SAMP:COUN 1 SEC

(

SEC is not a valid suffix).

Character data not allowed

A discrete parameter was received but a character string or a numeric parameter was expected. Check the list of parameters to verify that you have used a valid parameter type. Example:

DISP:TEXT ON

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Chapter 5 Error Messages

Execution Errors

-151

-158

-160

to

-168

-170

to

-178

-211

-213

-214

Invalid string data

An invalid character string was received. Check to see if you have enclosed the character string in single or double quotes and that the string contains valid

ASCII

characters. Example:

DISP:TEXT ’ON

(the ending quote is missing).

String data not allowed

A character string was received but is not allowed for the command.

Check the list of parameters to verify that you have used a valid parameter type. Example:

CALC:STAT ’ON’

Block data errors

The multimeter does not accept block data.

Expression errors

The multimeter does not accept mathematical expressions.

Trigger ignored

A Group Execute Trigger (

GET

) or

*TRG

was received but the trigger was ignored. Make sure the multimeter is in the “wait-for-trigger” state before issuing a trigger, and make sure the correct trigger source is selected.

Init ignored

An

INITiate

command was received but could not be executed because a measurement was already in progress. Send a device clear to halt a measurement in progress and place the multimeter in the “idle” state.

Trigger deadlock

A trigger deadlock occurs when the trigger source is

BUS and a

READ?

command is received.

5

175

-222

-223

-224

-230

-330

-221

Chapter 5 Error Messages

Execution Errors

Settings conflict

This error can be generated in one of the following situations:

•

•

You sent a

CONFigure or

MEASure

command with autorange enabled and with a fixed resolution. Example:

CONF:VOLT:DC DEF,0.1

You turned math on (

CALC:STAT ON

) and then changed to a math operation that was not valid with the present measurement function.

For example, dB measurements are not allowed with 2-wire ohms.

The math state is turned off as a result of this condition.

Data out of range

A numeric parameter value is outside the valid range for the command.

Example:

TRIG:COUN -3

Too much data

A character string was received but could not be executed because the string length was more than 12 characters. This error can be generated by the

CALibration:STRing

and

DISPlay:TEXT

commands.

Illegal parameter value

A discrete parameter was received which was not a valid choice for the command. You may have used an invalid parameter choice.

Example:

CALC:FUNC SCALE

(

SCALE

is not a valid choice).

Data stale

A

FETCh?

command was received but internal reading memory was empty. The reading retrieved may be invalid.

Self-test failed

The multimeter’s complete self-test failed from the remote interface

(

*TST?

command). In addition to this error, more specific self-test errors are also reported. See also “Self-Test Errors,” starting on page 179.

176

-350

-410

-420

-430

-440

Chapter 5 Error Messages

Execution Errors

Too many errors

The error queue is full because more than 20 errors have occurred.

No additional errors are stored until you remove errors from the queue.

The error queue is cleared when power has been off, or after a

*CLS

(clear status) command has been executed.

Query

INTERRUPTED

A command was received which sends data to the output buffer, but the output buffer contained data from a previous command (the previous data is not overwritten). The output buffer is cleared when power has been off, or after a

*RST

(reset) command has been executed.

Query

UNTERMINATED

The multimeter was addressed to talk (i.e., to send data over the interface) but a command has not been received which sends data to the output buffer. For example, you may have executed a

CONFigure command (which does not generate data) and then attempted an

ENTER statement to read data from the remote interface.

Query

DEADLOCKED

A command was received which generates too much data to fit in the output buffer and the input buffer is also full. Command execution continues but all data is lost.

Query

UNTERMINATED

after indefinite response

The

*IDN?

command must be the last query command within a command string. Example:

*IDN?;:SYST:VERS?

5

177

532

540

550

501

502

511

512

513

514

521

522

531

Chapter 5 Error Messages

Execution Errors

Isolator UART framing error

Isolator UART overrun error

RS-232 framing error

RS-232 overrun error

RS-232 parity error

Command allowed only with RS-232

There are three commands which are only allowed with the

RS-232 interface:

SYSTem:LOCal

,

SYSTem:REMote

, and

SYSTem:RWLock

.

Input buffer overflow

Output buffer overflow

Insufficient memory

There is not enough memory to store the requested number of readings in internal memory using the

INITiate

command. The product of the sample count (

SAMPle:COUNt

) and the trigger count (

TRIGger:COUNt

) must not exceed 512 readings.

Cannot achieve requested resolution

The multimeter cannot achieve the requested measurement resolution.

You may have specified an invalid resolution in the

CONFigure

or

MEASure

command.

Cannot use overload as math reference

The multimeter cannot store an overload reading (9.90000000E+37) as the math reference for null or dB measurements. The math state is turned off as a result of this condition.

Command not allowed in local

The multimeter received a

READ?

or MEASure? command while in the local mode. During

RS-232

operation, you should always execute the

SYSTem:REMote

command before sending other commands over the interface.

178

608

609

610

611

612

613

614

615

601

602

603

604

605

606

607

Chapter 5 Error Messages

Self-Test Errors

Self-Test Errors

The following errors indicate failures that may occur during a self-test.

Refer to the Service Guide for more information.

Front panel does not respond

RAM read/write failed

A/D sync stuck

A/D slope convergence failed

Cannot calibrate rundown gain

Rundown gain out of range

Rundown too noisy

Serial configuration readback failed

DC gain x1 failed

DC gain x10 failed

DC gain x100 failed

Ohms 500 nA source failed

Ohms 5 uA source failed

DC 1000V zero failed

Ohms 10 uA source failed

5

179

622

623

624

625

626

616

617

618

619

620

621

701

702

Chapter 5 Error Messages

Calibration Errors

DC current sense failed

Ohms 100 uA source failed

DC high voltage attenuator failed

Ohms 1 mA source failed

AC rms zero failed

AC rms full scale failed

Frequency counter failed

Cannot calibrate precharge

Unable to sense line frequency

I/O processor does not respond

I/O processor failed self-test

Calibration Errors

The following errors indicate failures that may occur during a calibration. Refer to the Service Guide for more information.

Cal security disabled by jumper

The calibration security feature has been disabled with a jumper inside the multimeter. When applicable, this error will occur at power-on to warn you that the multimeter is unsecured.

Cal secured

The multimeter is secured against calibration.

180

703

704

705

706

707

708

709

710

720

721

722

723

724

Chapter 5 Error Messages

Calibration Errors

Invalid secure code

An invalid calibration security code was received when attempting to unsecure or secure the multimeter. You must use the same security code to unsecure the multimeter as was used to secure it, and vice versa. The security code may contain up to 12 alphanumeric characters. The first character must be a letter.

Secure code too long

A security code was received which contained more than 12 characters.

Cal aborted

A calibration in progress is aborted when you press any front-panel key, send a device clear, or change the local/remote state of the multimeter.

Cal value out of range

The specified calibration value (

CALibration:VALue

) is invalid for the present function and range.

Cal signal measurement out of range

The specified calibration value (

CALibration:VALue

) does not match the signal applied to the multimeter.

Cal signal frequency out of range

The input signal frequency for an ac calibration does not match the required input frequency for calibration.

No cal for this function or range

You cannot perform calibrations for ac current, period, continuity, diode, ratio, or on the 100 M

Ω

range.

Full scale correction out of range

Cal DCV offset out of range

Cal DCI offset out of range

Cal RES offset out of range

Cal FRES offset out of range

Extended resistance self cal failed

5

181

735

736

740

741

742

743

744

745

725

730

731

732

733

734

746

747

748

Chapter 5 Error Messages

Calibration Errors

500V DC correction out of range

Precharge DAC convergence failed

A/D turnover correction out of range

AC flatness DAC convergence failed

AC low frequency convergence failed

AC low frequency correction out of range

AC rms converter noise correction out of range

AC rms 100th scale linearity correction out of range

Cal checksum failed, secure state

Cal checksum failed, string data

Cal checksum failed, DCV corrections

Cal checksum failed, DCI corrections

Cal checksum failed, RES corrections

Cal checksum failed, FRES corrections

Cal checksum failed, AC corrections

Cal checksum failed, GPIB address

Cal checksum failed, internal data

182

6

Application

Programs

6

Application Programs

This chapter contains several remote interface application programs to help you develop programs for your measurement application.

Chapter 4, “Remote Interface Reference,” starting on page 103, lists the syntax for the

SCPI

(Standard Commands for Programmable

Instruments) commands available to program the multimeter.

The QuickBASIC example programs are written for the Agilent 82335A

GPIB

Interface Card and command library for IBM

â

PC compatibles.

The

GPIB

(IEEE-488) address is set to “22” when the multimeter is shipped from the factory. The examples in this chapter assume an

GPIB address of 22. When sending a remote interface command, you append this address to the

GPIB

interface’s select code (normally “7”). Therefore, with an address of “22” and a select code of “7”, the combination is “722”.

IBM is a U.S. registered trademark of International Business Machines Corporation.

184

Chapter 6 Application Programs

Using MEASure? for a Single Measurement

Using MEASure? for a Single Measurement

The following example uses the

MEASure?

command to make a single ac current measurement. This is the easiest way to program the multimeter for measurements. However,

MEASure?

does not offer much flexibility. The example is shown in BASIC and QuickBASIC.

GPIB Operation Using BASIC

10 REAL Rdg

20 ASSIGN @Dmm TO 722

30 CLEAR 7 ! Clear GPIB and dmm

40 OUTPUT @Dmm; "*RST" ! Reset dmm

50 OUTPUT @Dmm; "*CLS" ! Clear dmm status registers

60 OUTPUT @Dmm; "MEASURE:CURRENT:AC? 1A,0.001MA" ! Set to 1 amp ac range

70 ENTER @Dmm; Rdg

80 PRINT Rdg

90 END

GPIB Operation Using QuickBASIC

REM $Include "QBSetup"

DEV&=722

INFO1$="*RST"

LENGTH1%=LEN(INFO1$)

INFO2$="*CLS"

LENGTH2%=LEN(INFO2$)

INFO3$="MEASURE:CURRENT:AC? 1A,0.001MA"

LENGTH3%=LEN(INFO3$)

Call IOCLEAR(DEV&)

Call IOOUTPUTS(DEV&, INFO1$, LENGTH1%)

Call IOOUTPUTS(DEV&, INFO2$, LENGTH2%)

Call IOOUTPUTS(DEV&, INFO3$, LENGTH3%)

Call IOENTER(DEV&,Rdg)

Print Rdg

END

6

185

Chapter 6 Application Programs

Using CONFigure with a Math Operation

Using CONFigure with a Math Operation

The following example uses

CONFigure

with the dBm math operation.

The

CONFigure

command gives you a little more programming flexibility than the

MEASure?

command. This allows you to

“incrementally” change the multimeter’s configuration. The example is shown in BASIC and QuickBASIC (see next page).

GPIB Operation Using BASIC

10 DIM Rdgs(1:5)

20 ASSIGN @Dmm TO 722

30 CLEAR 7 ! Clear GPIB and dmm

40 OUTPUT @Dmm; "*RST" ! Reset dmm

50 OUTPUT @Dmm; "*CLS" ! Clear dmm status registers

60 OUTPUT @Dmm; "CALC:DBM:REF 50" ! 50 ohm reference resistance

70 OUTPUT @Dmm; "CONF:VOLT:AC 1,0.001" ! Set dmm to 1 amp ac range

80 OUTPUT @Dmm; "DET:BAND 200"

90 OUTPUT @Dmm; "TRIG:COUN 5"

100 OUTPUT @Dmm; "TRIG:SOUR IMM"

110 OUTPUT @Dmm; "CALC:FUNC DBM"

120 OUTPUT @Dmm; "CALC:STAT ON"

130 OUTPUT @Dmm; "READ?"

140 ENTER @Dmm; Rdgs(*)

150 PRINT USING "K,/"; Rdgs(*)

160 END

! Select 200 Hz (fast) ac filter

! Dmm will accept 5 triggers

! Trigger source is IMMediate

! Select dBm function

! Enable math

! Take readings; send to output buffer

186

Chapter 6 Application Programs

Using CONFigure with a Math Operation

GPIB Operation Using QuickBASIC

REM $Include "QBSetup"

DEV&=722

INFO1$="*RST"

LENGTH1%=LEN(INFO1$)

INFO2$="*CLS"

LENGTH2%=LEN(INFO2$)

INFO3$="CALC:DBM:REF 50"

LENGTH3%=LEN(INFO3$)

INFO4$="CONF:VOLT:AC 1,0.001"

LENGTH4%=LEN(INFO4$)

INFO5$="DET:BAND 200"

LENGTH5%=LEN(INFO5$)

INFO6$="TRIG:COUN 5"

LENGTH6%=LEN(INFO6$)

INFO7$="TRIG:SOUR IMM"

LENGTH7%=LEN(INFO7$)

INFO8$="CALC:FUNC DBM"

LENGTH8%=LEN(INFO8$)

INFO9$="CALC:STAT ON"

LENGTH9%=LEN(INFO9$)

INFO10$="READ?"

LENGTH10%=LEN(INFO10$)

DIM A(1:5)

Actual%=0

Call IOCLEAR(DEV&)

Call IOOUTPUTS(DEV&, INFO1$, LENGTH1%)

Call IOOUTPUTS(DEV&, INFO2$, LENGTH2%)

Call IOOUTPUTS(DEV&, INFO3$, LENGTH3%)

Call IOOUTPUTS(DEV&, INFO4$, LENGTH4%)

Call IOOUTPUTS(DEV&, INFO5$, LENGTH5%)

Call IOOUTPUTS(DEV&, INFO6$, LENGTH6%)

Call IOOUTPUTS(DEV&, INFO7$, LENGTH7%)

Call IOOUTPUTS(DEV&, INFO8$, LENGTH8%)

Call IOOUTPUTS(DEV&, INFO9$, LENGTH9%)

Call IOOUTPUTS(DEV&, INFO10$, LENGTH10%)

Call IOENTER(DEV&, Seg A(1),5,Actual%)

For I=1 to 5

Print A(I);

Next I

END

6

187

Chapter 6 Application Programs

Using the Status Registers

Using the Status Registers

The following example shows how you can use the multimeter’s status registers to determine when a command sequence is completed. For more information, see “The SCPI Status Model,” starting on page 134.

The example is shown in BASIC and QuickBASIC (see page 190).

GPIB Operation Using BASIC

10 REAL Aver,Min_rdg,Max_rdg

20 INTEGER Val,Hpib,Mask,Task

30 ASSIGN @Dmm TO 722

40 CLEAR 7 ! Clear GPIB and dmm

50 OUTPUT @Dmm; "*RST" ! Reset dmm

60 OUTPUT @Dmm; "*CLS" ! Clear dmm status registers

70 OUTPUT @Dmm; "*ESE 1" ! Enable "operation complete" bit to set

! "standard event" bit in status byte

80 OUTPUT @Dmm; "*SRE 32" ! Enable "standard event" bit in status byte

! to pull the IEEE-488 SRQ line

90 OUTPUT @Dmm; "*OPC?" ! Assure synchronization

100 ENTER @Dmm; Val

110 !

120 ! Configure the multimeter to make measurements

130 !

140 OUTPUT @Dmm; "CONF:VOLT:DC 10" ! Set dmm to 10 volt dc range

150 OUTPUT @Dmm; "VOLT:DC:NPLC 10" ! Set the integration time to 10 PLCs

160 OUTPUT @Dmm; "TRIG:COUN 100" ! Dmm will accept 100 triggers

170 OUTPUT @Dmm; "CALC:FUNC AVER;STAT ON" ! Select min-max and enable math

180 OUTPUT @Dmm; "INIT" ! Place dmm in "wait-for-trigger" state

190 OUTPUT @Dmm; "*OPC" ! Set "operation complete" bit in standard event

! registers when measurement is complete

200 !

210 Hpib=7

220 ON INTR Hpib GOSUB Read_data

230 Mask=2 ! Bit 1 is SRQ

240 ENABLE INTR Hpib;Mask ! Enable SRQ to interrupt the program

250 !

260 ! Execute other tasks while waiting for data

270 !

Continued on next page >

188

Chapter 6 Application Programs

Using the Status Registers

GPIB Operation Using BASIC

(continued)

280 Task=1

290 WHILE Task=1

300 DISP "Taking Readings"

310 WAIT .5

320 DISP ""

330 WAIT .5

340 END WHILE

350 DISP "AVE = ";Aver; " MIN = ";Min_rdg; " MAX = ";Max_rdg

360 STOP

370 !

380 Read_data: !

390 OUTPUT @Dmm; "CALC:AVER:AVER?;MIN?;MAX?" ! Read the average, min, and max

400 ENTER @Dmm; Aver, Min_rdg, Max_rdg

410 OUTPUT @Dmm; "*CLS" ! Clear dmm status registers

420 Task=0

430 RETURN

440 END

6

189

Chapter 6 Application Programs

Using the Status Registers

GPIB Operation Using QuickBASIC

REM $Include "QBSetup"

ISC&=7

DEV&=722

INFO1$="*RST"

LENGTH1%=LEN(INFO1$)

INFO2$="*CLS"

LENGTH2%=LEN(INFO2$)

INFO3$="*ESE 1"

LENGTH3%=LEN(INFO3$)

INFO4$="*SRE 32"

LENGTH4%=LEN(INFO4$)

INFO5$="*OPC?"

LENGTH5%=LEN(INFO5$)

INFO6$="CONF:VOLT:DC 10"

LENGTH6%=LEN(INFO6$)

INFO7$="VOLT:DC:NPLC 10"

LENGTH7%=LEN(INFO7$)

INFO8$="TRIG:COUN 100"

LENGTH8%=LEN(INFO8$)

INFO9$="CALC:FUNC AVER;STAT ON"

LENGTH9%=LEN(INFO9$)

INFO10$="INIT"

LENGTH10%=LEN(INFO10$)

INFO11$="*OPC"

LENGTH11%=LEN(INFO11$)

INFO12$="CALC:AVER:AVER?;MIN?;MAX?"

LENGTH12%=LEN(INFO12$)

INFO13$="*CLS"

LENGTH13%=LEN(INFO13$)

DIM A(1:3)

Actual%=0

Reading=0

Continued on next page >

190

Chapter 6 Application Programs

Using the Status Registers

GPIB Operation Using QuickBASIC

(continued)

Call IOCLEAR(DEV&)

Call IOOUTPUTS(DEV&, INFO1$, LENGTH1%)

Call IOOUTPUTS(DEV&, INFO2$, LENGTH2%)

ON PEN GOSUB RESULTS

PEN ON

Call IOPEN(ISC&,0)

Call IOOUTPUTS(DEV&, INFO3$, LENGTH3%)

Call IOOUTPUTS(DEV&, INFO4$, LENGTH4%)

Call IOOUTPUTS(DEV&, INFO5$, LENGTH5%)

Call IOENTER(DEV&,Reading)

Call IOOUTPUTS(DEV&, INFO6$, LENGTH6%)

Call IOOUTPUTS(DEV&, INFO7$, LENGTH7%)

Call IOOUTPUTS(DEV&, INFO8$, LENGTH8%)

Call IOOUTPUTS(DEV&, INFO9$, LENGTH9%)

BACK:GOTO BACK

RESULTS:

Call IOOUTPUTS(DEV&, INFO10$, LENGTH10%)

Call IOOUTPUTS(DEV&, INFO11$, LENGTH11%)

Call IOOUTPUTS(DEV&, INFO12$, LENGTH12%)

Call IOENTERA(DEV&, Seg A(1),3,Actual%)

For I=1 to 3

Print A(I);

Next I

Call IOOUTPUTS(DEV&, INFO13$, LENGTH13%)

END

191

6

Chapter 6 Application Programs

RS-232 Operation Using QuickBASIC

RS-232 Operation Using QuickBASIC

The following example shows how to send command instructions and receive command responses over the

RS-232

interface using QuickBASIC.

RS-232 Operation Using QuickBASIC

CLS

LOCATE 1, 1

DIM cmd$(100), resp$(1000)

’ Set up serial port for 9600 baud, even parity, 7 bits;

’ Ignore Request to Send and Carrier Detect; Send line feed,

’ enable parity check, reserve 1000 bytes for input buffer

’

OPEN "com1:9600,e,7,2,rs,cd,lf,pe" FOR RANDOM AS #1 LEN = 1000

’

’ Put the multimeter into the remote operation mode

PRINT #1, ":SYST:REM"

’

’ Query the multimeter’s id string

’

PRINT #1, "*IDN?"

LINE INPUT #1, resp$

PRINT "*IDN? returned: ", resp$

’

’ Ask what revision of SCPI the multimeter conforms to

PRINT #1, ":SYST:VERS?"

LINE INPUT #1, resp$

PRINT ":SYST:VERS? returned: ", resp$

’

’ Send a message to the multimeter’s display, and generate a beep

PRINT #1, ":SYST:BEEP;:DISP:TEXT ’34401A’"

’

’ Configure the multimeter for dc voltage readings,

’ 10 V range, 0.1 V resolution, 4 readings

PRINT #1, ":CONF:VOLT:DC 10,0.1;:SAMP:COUN 4"

’ Trigger the readings, and fetch the results

PRINT #1, ":READ?"

LINE INPUT #1, resp$

PRINT ":READ? returned: ", resp$

END

192

Chapter 6 Application Programs

RS-232 Operation Using Turbo C

RS-232 Operation Using Turbo C

The following example shows how to program an AT personal computer for interrupt-driven

COM

port communications. SCPI commands can be sent to the Agilent 34401A and responses received for commands that query information. The following program is written in Turbo C and can be easily modified for use with Microsoft

â

Quick C.

RS-232 Operation Using Turbo C

#include <bios.h>

#include <stdio.h>

#include <string.h>

#include <dos.h>

#include <conio.h>

#define EVEN_7 (0x18 | 0x02 | 0x04) /* Even parity, 7 data, 2 stop */

#define ODD_7 (0x08 | 0x02 | 0x04) /* Odd parity, 7 data, 2 stop */

#define NONE_8 (0x00 | 0x03 | 0x04)

#define BAUD300 0x40

/* None parity, 8 data, 2 stop */

#define BAUD600 0x60

#define BAUD1200 0x80

#define BAUD2400 0xA0

#define BAUD4800 0xC0

#define BAUD9600 0xE0

/* 8250 UART Registers */

#define COM 0x3F8 /* COM1 base port address */

#define THR COM+0 /* LCR bit 7 = 0 */

#define RDR COM+0 /* LCR bit 7 = 0 */

#define IER COM+1 /* LCR bit 7 = 0 */

#define IIR COM+2 /* The rest are don’t care for bit 7 */

#define LCR COM+3

#define MCR COM+4

#define LSR COM+5

#define MSR COM+6

Continued on next page >

6

Microsoft is a U.S. registered trademark of Microsoft Corporation.

193

Chapter 6 Application Programs

RS-232 Operation Using Turbo C

RS-232 Operation Using Turbo C

(continued)

#define IRQ4_int 0xC /* IRQ4 interrupt vector number */

#define IRQ4_enab 0xEF /* IRQ4 interrupt controller enable mask */

#define INT_controller 0x20 /* 8259 Interrupt controller address */

#define End_of_interrupt 0x20 /* Non-specific end of interrupt command */ void interrupt int_char_in(void); void send_ctlc(void);

#define INT_BUF_size 9000 char int_buf[INT_BUF_size], *int_buf_in = int_buf, *int_buf_out = int_buf; unsigned int int_buf_count = 0; unsigned char int_buf_ovfl = 0; int main(int argc, char *argv[])

{

void interrupt (*oldvect)();

char command[80], c;

int i;

oldvect = getvect(IRQ4_int); /* Save old interrupt vector */

setvect(IRQ4_int,int_char_in); /* Set up new interrupt handler */

bioscom(0,BAUD9600 | EVEN_7,0); /* Initialize settings for COM1 */

outportb(MCR,0x9); /* Enable IRQ buffer, DTR = 1 */

outportb(IER,0x1); /* Enable UART data receive interrupt */

/* Enable IRQ4 in 8259 interrupt controller register */

outportb(INT_controller+1,inportb(INT_controller+1) & IRQ4_enab);

do {

if(int_buf_ovfl) {

printf("\nBuffer Overflow!!!\n\n");

int_buf_in = int_buf_out = int_buf;

int_buf_count = int_buf_ovfl = 0;

}

Continued on next page >

194

Chapter 6 Application Programs

RS-232 Operation Using Turbo C

RS-232 Operation Using Turbo C

(continued)

printf("\nEnter command string:\n");

gets(command); strcat(command,"\n"); /* SCPI requires line feed */

if(command[0] == 0x19) send_ctlc(); /* If ^Y then send ^C */

else if(command[0] != ’q’) {

for(i=0; i<strlen(command); i++) {

}

}

/* Wait for DSR and transmitter hold register empty */

while(!(inportb(LSR) & inportb(MSR) & 0x20)) ;

outportb(THR,command[i]); /* Send character */

if(strpbrk(command,"?")) {

c = 0;

do {

/* If query then get response */

while(int_buf_count && !kbhit()) {

putch(c = *int_buf_out++); int_buf_count--;

if(int_buf_out >= int_buf + INT_BUF_size) int_buf_out = int_buf;

}

if(kbhit()) {

if(getch() == 0x19) send_ctlc(); /* if ^Y then send ^C */

c = 0xa;

}

}

while(c != 0xa);

} /* End if */

/* Terminate loop */

}

while(command[0] != ’q’); /* ’q’ to quit program */

outportb(IER,inportb(IER) & 0xfe);

outportb(MCR,0x1);

/* Disable UART interrupt */

/* Disable IRQ buffer, DTR = 1 */

/* Disable IRQ4 in 8259 interrupt controller register */

outportb(INT_controller+1,inportb(INT_controller+1) | ~IRQ4_enab);

setvect(IRQ4_int,oldvect); /* Restore old interrupt vector */

return(0);

}

Continued on next page >

6

195

Chapter 6 Application Programs

RS-232 Operation Using Turbo C

RS-232 Operation Using Turbo C

(continued)

void interrupt int_char_in(void)

{

enable(); /* Enable hardware interrupts */

if(int_buf_count < INT_BUF_size) {

*int_buf_in++ = inportb(RDR); /* Read byte from UART */

int_buf_count++;

if(int_buf_in >= int_buf + INT_BUF_size) int_buf_in = int_buf;

int_buf_ovfl = 0;

}

else {

inportb(RDR); /* Clear UART interrupt */

int_buf_ovfl = 1;

}

outportb(INT_controller,End_of_interrupt); /* Non-specific EOI */

} void send_ctlc(void)

{

outportb(MCR,0x8);

delay(10);

/* De-assert DTR */

/* Wait 10 mS for stray characters */

while(!(inportb(LSR) & 0x20)) ; /* Wait on transmitter register */

outportb(THR,0x3); /* Send ^C */

while(!(inportb(LSR) & 0x40)) ; /* Wait for ^C to be sent */

int_buf_in = int_buf_out = int_buf; /* Clear int_char_in buffer */

int_buf_count = int_buf_ovfl = 0;

delay(20); /* 20mS for 34401 to clean up */

outportb(MCR,0x9);

}

/* Assert DTR */

196

7

Measurement

Tutorial

7

Measurement Tutorial

The Agilent 34401A is capable of making highly accurate measurements. In order to achieve the greatest accuracy, you must take the necessary steps to eliminate potential measurement errors. This chapter describes common errors found in measurements and gives suggestions to help you avoid these errors.

Thermal

EMF

Errors

Thermoelectric voltages are the most common source of error in low-level dc voltage measurements. Thermoelectric voltages are generated when you make circuit connections using dissimilar metals at different temperatures. Each metal-to-metal junction forms a

thermocouple, which generates a voltage proportional to the junction temperature. You should take the necessary precautions to minimize thermocouple voltages and temperature variations in low-level voltage measurements. The best connections are formed using copper-to-copper crimped connections. The table below shows common thermoelectric voltages for connections between dissimilar metals.

Copper-to-

Copper

Gold

Silver

Brass

Beryllium Copper

Aluminum

Kovar or Alloy 42

Silicon

Copper-Oxide

Cadmium-Tin Solder

Tin-Lead Solder

Approx.

<0.3

0.5

0.5

3

5

5

40

500

1000

0.2

5

µ

V / °C

The Agilent 34401A’s input terminals are copper alloy.

198

Chapter 7 Measurement Tutorial

Loading Errors (dc volts)

V s

R s

Loading Errors (dc volts)

Measurement loading errors occur when the resistance of the deviceunder-test (

DUT

) is an appreciable percentage of the multimeter’s own input resistance. The diagram below shows this error source.

V s

R s

HI

LO

R i

Ideal

Meter

V s

= ideal DUT voltage

R s

= DUT source resistance

R i

= multimeter input resistance

( 10 M

Ω

or >10 G

Ω

)

Error

(

%

) =

100 x R s

R s

+

R i

To reduce the effects of loading errors, and to minimize noise pickup, you can set the multimeter’s input resistance to greater than 10 G

Ω

for the 100 mVdc, 1 Vdc, and 10 Vdc ranges. The input resistance is maintained at 10 M

Ω

for the 100 Vdc and 1000 Vdc ranges.

Leakage Current Errors

The multimeter’s input capacitance will “charge up” due to input bias currents when the terminals are open-circuited (if the input resistance is 10 G

Ω

). The multimeter’s measuring circuitry exhibits approximately

30 pA of input bias current for ambient temperatures from 0

°

C to 30

°

C.

Bias current will double (

×

2) for every 8

°

C change in ambient temperature above 30

°

C. This current generates small voltage offsets dependent upon the source resistance of the device-under-test. This effect becomes evident for a source resistance of greater than 100 k

Ω

, or when the multimeter’s operating temperature is significantly greater than 30

°

C.

HI

LO i b

R i

C i

Ideal

Meter i b

= multimeter bias current

R s

= DUT source resistance

C i

= multimeter input capacitance

For DCV ranges:

0.1V, 1V, 10V: C i

< 700 pF

100V, 1000V: C i

< 50 pF

For all ACV ranges: < 50 pF

Error (v) ≅ i b x

R s

7

199

Chapter 7 Measurement Tutorial

Rejecting Power-Line Noise Voltages

Rejecting Power-Line Noise Voltages

A desirable characteristic of integrating analog-to-digital (A/D) converters is their ability to reject spurious signals. Integrating techniques reject power-line related noise present with dc signals on the input. This is called normal mode rejection or

NMR

. Normal mode noise rejection is achieved when the multimeter measures the average of the input by

“integrating” it over a fixed period. If you set the integration time to a whole number of power line cycles (

PLC s) of the spurious input, these errors (and their harmonics) will average out to approximately zero.

The Agilent 34401A provides three A/D integration times to reject power-line frequency noise (and power-line frequency harmonics). When you apply power to the multimeter, it measures the power-line frequency (50 Hz or 60 Hz), and then determines the proper integration time. The table below shows the noise rejection achieved with various configurations. For better resolution and increased noise rejection, select a longer integration time.

Digits

4

5

6

6

4

5

1

⁄

2

1 ⁄

2

1

⁄

2

1 ⁄

2

1

⁄

2

1

⁄

2

Fast

Slow

Fast

Slow

Fast

Slow

NPLCs

0.02

1

0.2

10

10

100

Integration Time

60 Hz (50 Hz)

400 µ s (400 µ s)

16.7 ms (20 ms)

3 ms (3 ms)

167 ms (200 ms)

167 ms (200 ms)

1.67 sec (2 sec)

NMR

–

60 dB

–

60 dB

60 dB

60 dB

200

Chapter 7 Measurement Tutorial

Common Mode Rejection (CMR)

Common Mode Rejection (CMR)

Ideally, a multimeter is completely isolated from earth-referenced circuits.

However, there is finite resistance between the multimeter’s input LO terminal and earth ground as shown below. This can cause errors when measuring low voltages which are floating relative to earth ground.

HI

V test

V f

R s

LO

Ideal

Meter

C i

R i

>10 G

Ω

V f

= float voltage

R s

= DUT source resistance

imbalance

R i

= multimeter isolation

resistance (LO-Earth)

C i

= multimeter input

capacitance:

≈ 200 pF (LO-Earth)

Error

( v

) =

V f x

R s

+

R

R s i

Noise Caused by Magnetic Loops

If you are making measurements near magnetic fields, you should take the necessary precautions to avoid inducing voltages in the measurement connections. You should be especially careful when working near conductors carrying large currents. Use twisted-pair connections to the multimeter to reduce the noise pickup loop area, or dress the test leads as close together as possible. Loose or vibrating test leads will also induce error voltages. Make sure your test leads are tied down securely when operating near magnetic fields. Whenever possible, use magnetic shielding materials or physical separation to reduce problem magnetic field sources.

7

201

Chapter 7 Measurement Tutorial

Noise Caused by Ground Loops

Noise Caused by Ground Loops

When measuring voltages in circuits where the multimeter and the device-under-test are both referenced to a common earth ground, a “ground loop” is formed. As shown below, any voltage difference between the two ground reference points (V ground

) causes a current to flow through the measurement leads. This causes errors, such as noise and offset voltage (usually power-line related), which are added to the measured voltage.

The best way to eliminate ground loops is to maintain the multimeter’s isolation from earth; do not connect the input terminals to ground.

If the multimeter must be earth-referenced, be sure to connect it, and the device-under-test, to the same common ground point. This will reduce or eliminate any voltage difference between the devices.

Also make sure the multimeter and device-under-test are connected to the same electrical outlet whenever possible.

R

L

HI

V test

Ideal

Meter

R

L

LO

R i

>10 G Ω

V ground

R

L

= lead resistance

R i

= multimeter isolation resistance

Vground = voltage drop on ground bus

202

Chapter 7 Measurement Tutorial

Resistance Measurements

Resistance Measurements

The Agilent 34401A offers two methods for measuring resistance:

2-wire and 4-wire ohms. For both methods, the test current flows from the input HI terminal and then through the resistor being measured. For

2-wire ohms, the voltage drop across the resistor being measured is sensed internal to the multimeter. Therefore, test lead resistance is also measured. For 4-wire ohms, separate “sense” connections are required.

Since no current flows in the sense leads, the resistance in these leads does not give a measurement error.

The errors mentioned earlier in this chapter for dc voltage measurements also apply to resistance measurements. Additional error sources unique to resistance measurements are discussed on the following pages.

4-Wire Ohms Measurements

The 4-wire ohms method provides the most accurate way to measure small resistances. Test lead resistances and contact resistances are automatically reduced using this method. Four-wire ohms is often used in automated test applications where long cable lengths, numerous connections, or switches exist between the multimeter and the deviceunder-test. The recommended connections for 4-wire ohms measurements are shown below. See also “To Measure Resistance,”

on page 17.

HI

R

=

V meter

I test

HI-Sense

Ideal

Meter

LO-

Sense

I

test

7

LO

203

Chapter 7 Measurement Tutorial

Removing Test Lead Resistance Errors

Removing Test Lead Resistance Errors

To eliminate offset errors associated with the test lead resistance in

2-wire ohms measurements, follow the steps below.

1. Short the ends of the test leads together. The multimeter displays the

test lead resistance.

2. Press

Null from the front panel. The multimeter displays “0”

ohms with the leads shorted together.

Power Dissipation Effects

When measuring resistors designed for temperature measurements

(or other resistive devices with large temperature coefficients), be aware that the multimeter will dissipate some power in the device-under-test.

If power dissipation is a problem, you should select the multimeter’s next higher measurement range to reduce the errors to acceptable levels. The following table shows several examples.

Range

100 Ω

1 k Ω

10 k

Ω

100 k Ω

1 M Ω

10 M

Ω

Test Current

1 mA

1 mA

100

µ

A

10 µ A

5 µ A

500 nA

DUT

Power at Full Scale

100 µ W

1 mW

100 µ W

10

µ

W

30

µ

W

3

µ

W

Settling Time Effects

The 34401A has the ability to insert automatic measurement settling delays. These delays are adequate for resistance measurements with less than 200 pF of combined cable and device capacitance. This is particularly important if you are measuring resistances above 100 k

Ω

. Settling due to

RC time constant effects can be quite long. Some precision resistors and multi-function calibrators use large parallel capacitors (1000 pF to 0.1

µ

F) with high resistor values to filter out noise currents injected by their internal circuitry. Non-ideal capacitances in cables and other devices may have much longer settling times than expected just by RC time constants due to dielectric absorption (soak) effects. Errors will be measured when settling after the initial connection and after a range change.

204

Chapter 7 Measurement Tutorial

Errors in High Resistance Measurements

Errors in High Resistance Measurements

When you are measuring large resistances, significant errors can occur due to insulation resistance and surface cleanliness. You should take the necessary precautions to maintain a “clean” high-resistance system.

Test leads and fixtures are susceptible to leakage due to moisture absorption in insulating materials and “dirty” surface films. Nylon and

PVC

are relatively poor insulators (10

9

PTFE

â

insulators (10

13

ohms) when compared to

PTFE

ohms). Leakage from nylon or

PVC

insulators can easily contribute a 0.1% error when measuring a 1 M

Ω

resistance in humid conditions.

DC Current Measurement Errors

When you connect the multimeter in series with a test circuit to measure current, a measurement error is introduced. The error is caused by the multimeter’s series burden voltage. A voltage is developed across the wiring resistance and current shunt resistance of the multimeter as shown below.

R s

I

V s

V b

R

Ideal

Meter

LO

V s

= source voltage

R s

= DUT source resistance

V b

= multimeter burden voltage

R = multimeter current shunt

Error

(

%

)

=

−

100% x V b

V s

7

205

Chapter 7 Measurement Tutorial

True RMS AC Measurements

True RMS AC Measurements

True

RMS

responding multimeters, like the Agilent 34401A, measure the “heating” potential of an applied voltage. Unlike an “average responding” measurement, a true

RMS

measurement is used to determine the power dissipated in a resistor. The power is proportional to the square of the measured true

RMS

voltage, independent of waveshape. An average responding ac multimeter is calibrated to read the same as a true

RMS

meter for sinewave inputs only. For other waveform shapes, an average responding meter will exhibit substantial errors as shown below.

The multimeter’s ac voltage and ac current functions measure the ac-coupled true

RMS

value. This is in contrast to the ac+dc true

RMS value shown above. Only the “heating value” of the ac components of the input waveform are measured (dc is rejected). For sinewaves, triangle waves, and square waves, the ac and ac+dc values are equal since these waveforms do not contain a dc offset. Non-symmetrical waveforms, such as pulse trains, contain dc voltages which are rejected by ac-coupled true

RMS

measurements.

206

Chapter 7 Measurement Tutorial

Crest Factor Errors (non-sinusoidal inputs)

An ac-coupled true

RMS

measurement is desirable in situations where you are measuring small ac signals in the presence of large dc offsets.

For example, this situation is common when measuring ac ripple present on dc power supplies. There are situations, however, where you might want to know the ac+dc true

RMS

value. You can determine this value by combining results from dc and ac measurements as shown below. You should perform the dc measurement using at least 10 power line cycles of integration (6 digit mode) for best ac rejection.

√

2

+ dc

2

Crest Factor Errors (non-sinusoidal inputs)

A common misconception is that “since an ac multimeter is true

RMS

, its sinewave accuracy specifications apply to all waveforms.” Actually, the shape of the input signal can dramatically affect measurement accuracy. A common way to describe signal waveshapes is crest factor.

Crest factor is the ratio of the peak value to

RMS

value of a waveform.

For a pulse train, for example, the crest factor is approximately equal to the square root of the inverse of the duty cycle as shown in the table on the previous page. In general, the greater the crest factor, the greater the energy contained in higher frequency harmonics. All multimeters exhibit measurement errors that are crest factor dependent. Crest factor errors for the Agilent 34401A are shown in the specifications in chapter

8. Note that the crest factor errors do not apply for input signals below

100 Hz when using the slow ac filter.

207

7

Chapter 7 Measurement Tutorial

Crest Factor Errors (non-sinusoidal inputs)

Crest Factor

(continued)

You can estimate the measurement error due to signal crest factor as shown below:

Total Error = Error (sine) + Error (crest factor) + Error (bandwidth)

Error (sine): error for sinewave as shown in chapter 8.

Error (crest factor): crest factor additional error as shown in chapter 8.

Error (bandwidth): estimated bandwidth error as shown below.

Bandwidth Error

=

– C.F.

2

x F

4

π

x BW

C.F. = signal crest factor

F = input fundamental frequency

BW = multimeter’s

–

3 dB bandwidth

(1 MHz for the Agilent 34401A )

Example

Calculate the approximate measurement error for a pulse train input with a crest factor of 3 and a fundamental frequency of 20 kHz. For this example, assume the multimeter’s 90-day accuracy specifications:

±

(0.05% + 0.03%).

Total Error = 0.08% + 0.15% + 1.4% = 1.6%

208

Chapter 7 Measurement Tutorial

Loading Errors (ac volts)

Loading Errors (ac volts)

In the ac voltage function, the input of the Agilent 34401A appears as a

1 M

Ω

resistance in parallel with 100 pF of capacitance. The cabling that you use to connect signals to the multimeter will also add additional capacitance and loading. The table below shows the multimeter’s approximate input resistance at various frequencies.

Input Frequency

100 Hz

1 kHz

10 kHz

100 kHz

Input Resistance

1 M

Ω

850 k Ω

160 k Ω

16 k

Ω

For low frequencies:

Error (

%

) =

−

100 x R s

R s

+

1 M

Ω

Additional error for high frequencies:

√

1

Error

(

%

) =

100 x é

ê

ë

ê

ê

1 + (

2

π

x F x R s

x C in

)

2

−

1 ù

ú

ú

ú

û

R s

= source resistance

F = input frequency

C in

= input capacitance (100 pF) plus cable capacitance

7

209

Chapter 7 Measurement Tutorial

Measurements Below Full Scale

Measurements Below Full Scale

You can make the most accurate ac measurements when the multimeter is at full scale of the selected range. Autoranging occurs at 10% and

120% of full scale. This enables you to measure some inputs at full scale on one range and 10% of full scale on the next higher range. The accuracy will be significantly different for these two cases. For highest accuracy, you should use manual range to get to the lowest range possible for the measurement.

High-Voltage Self-Heating Errors

If you apply more than 300 Vrms, self-heating will occur in the multimeter’s internal signal-conditioning components. These errors are included in the multimeter’s specifications. Temperature changes inside the multimeter due to self-heating may cause additional error on other ac voltage ranges. The additional error will be less than 0.02% and will dissipate in a few minutes.

Temperature Coefficient and Overload Errors

The Agilent 34401A uses an ac measurement technique that measures and removes internal offset voltages when you select a different function or range. If you leave the multimeter in the same range for an extended period of time, and the ambient temperature changes significantly (or if the multimeter is not fully warmed up), the internal offsets may change.

This temperature coefficient is typically 0.002% of range per

°

C and is automatically removed when you change functions or ranges.

When manual ranging to a new range in an overload condition, the internal offset measurement may be degraded for the selected range.

Typically, an additional 0.01% of range error may be introduced.

This additional error is automatically removed when you remove the overload condition and then change functions or ranges.

210

Chapter 7 Measurement Tutorial

Low-Level Measurement Errors

Low-Level Measurement Errors

When measuring ac voltages less than 100 mV, be aware that these measurements are especially susceptible to errors introduced by extraneous noise sources. An exposed test lead will act as an antenna and a properly functioning multimeter will measure the signals received. The entire measurement path, including the power line, act as a loop antenna. Circulating currents in the loop will create error voltages across any impedances in series with the multimeter’s input.

For this reason, you should apply low-level ac voltages to the multimeter through shielded cables. You should connect the shield to the input LO terminal.

Make sure the multimeter and the ac source are connected to the same electrical outlet whenever possible. You should also minimize the area of any ground loops that cannot be avoided. A high-impedance source is more susceptible to noise pickup than a low-impedance source. You can reduce the high-frequency impedance of a source by placing a capacitor in parallel with the multimeter’s input terminals. You may have to experiment to determine the correct capacitor value for your application.

Most extraneous noise is not correlated with the input signal. You can determine the error as shown below.

√ in

2

+ Noise

2

Correlated noise, while rare, is especially detrimental. Correlated noise will always add directly to the input signal. Measuring a low-level signal with the same frequency as the local power line is a common situation that is prone to this error.

7

211

Chapter 7 Measurement Tutorial

Common Mode Errors

Common Mode Errors

Errors are generated when the multimeter’s input LO terminal is driven with an ac voltage relative to earth. The most common situation where unnecessary common mode voltages are created is when the output of an ac calibrator is connected to the multimeter “backwards.” Ideally, a multimeter reads the same regardless of how the source is connected.

Both source and multimeter effects can degrade this ideal situation.

Because of the capacitance between the input LO terminal and earth

(approximately 200 pF for the Agilent 34401A), the source will experience different loading depending on how the input is applied. The magnitude of the error is dependent upon the source’s response to this loading. The multimeter’s measurement circuitry, while extensively shielded, responds differently in the backward input case due to slight differences in stray capacitance to earth. The multimeter’s errors are greatest for high- voltage, high-frequency inputs. Typically, the multimeter will exhibit about 0.06% additional error for a 100 V, 100 kHz reverse input. You can use the grounding techniques described for dc common mode problems to minimize ac common mode voltages (see

page 201).

AC Current Measurement Errors

Burden voltage errors, which apply to dc current, also apply to ac current measurements. However, the burden voltage for ac current is larger due to the multimeter’s series inductance and your measurement connections. The burden voltage increases as the input frequency increases. Some circuits may oscillate when performing current measurements due to the multimeter’s series inductance and your measurement connections.

212

Chapter 7 Measurement Tutorial

Frequency and Period Measurement Errors

Frequency and Period Measurement Errors

The multimeter uses a reciprocal counting technique to measure frequency and period. This method generates constant measurement resolution for any input frequency. The multimeter’s ac voltage measurement section performs input signal conditioning. All frequency counters are susceptible to errors when measuring low-voltage, low-frequency signals. The effects of both internal noise and external noise pickup are critical when measuring “slow” signals. The error is inversely proportional to frequency. Measurement errors will also occur if you attempt to measure the frequency (or period) of an input following a dc offset voltage change. You must allow the multimeter’s input dc blocking capacitor to fully settle before making frequency measurements.

Making High-Speed DC and Resistance Measurements

The multimeter incorporates an automatic zero measurement procedure

(autozero) to eliminate internal thermal

EMF

and bias current errors.

Each measurement actually consists of a measurement of the input terminals followed by a measurement of the internal offset voltage.

The internal offset voltage error is subtracted from the input for improved accuracy. This compensates for offset voltage changes due to temperature.

For maximum reading speed, turn autozero off. This will more than double your reading speeds for dc voltage, resistance, and dc current functions.

Autozero does not apply to other measurement functions.

213

7

Chapter 7 Measurement Tutorial

Making High-Speed AC Measurements

Making High-Speed AC Measurements

The multimeter’s ac voltage and ac current functions implement three different low-frequency filters. These filters allow you to trade-off low frequency accuracy for faster reading speed. The fast filter settles in

0.1 seconds, and is useful for frequencies above 200 Hz. The medium

filter settles in 1 second, and is useful for measurements above 20 Hz.

The slow filter settles in 7 seconds, and is useful for frequencies above 3 Hz.

With a few precautions, you can perform ac measurements at speeds up to 50 readings per second. Use manual ranging to eliminate autoranging delays. By setting the preprogrammed settling (trigger) delays to 0, each filter will allow up to 50 readings per second. However, the measurement might not be very accurate since the filter is not fully settled. In applications where sample-to-sample levels vary widely, the medium filter will settle at 1 reading per second, and the fast filter will settle at 10 readings per second.

If the sample-to-sample levels are similar, little settling time is required for each new reading. Under this specialized condition, the medium filter will provide reduced accuracy results at 5 readings per second, and the fast filter will provide reduced accuracy results at 50 readings per second. Additional settling time may be required when the dc level varies from sample to sample. The multimeter’s dc blocking circuitry has a settling time constant of 0.2 seconds. This settling time only affects measurement accuracy when dc offset levels vary from sample to sample. If maximum measurement speed is desired in a scanning system, you may want to add an external dc blocking circuit to those channels with significant dc voltages present. This circuit can be as simple as a resistor and a capacitor.

214

8

Specifications

8

Chapter 8 Specifications

DC Characteristics

DC Characteristics

Function Range

[ 3 ]

DC Voltage

100.0000 mV

1.000000 V

10.00000 V

100.0000 V

1000.000 V

Resistance

[ 4 ]

100.0000 Ω

1.000000 k

Ω

10.00000 k

Ω

100.0000 k Ω

1.000000 M Ω

10.00000 M Ω

100.0000 M Ω

DC Current

10.00000 mA

100.0000 mA

1.000000 A

3.000000 A

Continuity

1000.0

Ω

Diode Test

[12]

1.0000 V

DC:DC

Ratio

100 mV

to

1000 V

Test Current or

Burden Voltage

1 mA

1 mA

100

µ

A

10 µ A

5 µ A

500 nA

500 nA

||

10 M

Ω

< 0.1 V

< 0.6 V

< 1 V

< 2 V

1 mA

1 mA

Accuracy Specifications

±

( % of reading + % of range ) [ 1 ]

24 Hour

[ 2 ]

23°C

±

1°C

0.0030 + 0.0030

0.0020 + 0.0006

0.0015 + 0.0004

0.0020 + 0.0006

0.0020 + 0.0006

90 Day

23°C

±

5°C

0.0040 + 0.0035

0.0030 + 0.0007

0.0020 + 0.0005

0.0035 + 0.0006

0.0035 + 0.0010

1 Year

5°C

0.0050 + 0.0035

0.0040 + 0.0007

0.0035 + 0.0005

0.0045 + 0.0006

0.0045 + 0.0010

Temperature

Coefficient /°C

0°C – 18°C

28°C – 55°C

0.0005 + 0.0005

0.0005 + 0.0001

0.0005 + 0.0001

0.0005 + 0.0001

0.0005 + 0.0001

0.0030 + 0.0030

0.0020 + 0.0005

0.0020 + 0.0005

0.0020 + 0.0005

0.002 + 0.001

0.015 + 0.001

0.300 + 0.010

0.008 + 0.004

0.008 + 0.001

0.008 + 0.001

0.008 + 0.001

0.008 + 0.001

0.020 + 0.001

0.800 + 0.010

0.010 + 0.004

0.010 + 0.001

0.010 + 0.001

0.010 + 0.001

0.010 + 0.001

0.040 + 0.001

0.800 + 0.010

0.0006 + 0.0005

0.0006 + 0.0001

0.0006 + 0.0001

0.0006 + 0.0001

0.0010 + 0.0002

0.0030 + 0.0004

0.1500 + 0.0002

0.005 + 0.010

0.01 + 0.004

0.05 + 0.006

0.10 + 0.020

0.030 + 0.020

0.030 + 0.005

0.080 + 0.010

0.120 + 0.020

0.050 + 0.020

0.050 + 0.005

0.100 + 0.010

0.120 + 0.020

0.002 + 0.030

0.008 + 0.030 0.010 + 0.030

0.002 + 0.0020

0.002 + 0.0005

0.005 + 0.0010

0.005 + 0.0020

0.001 + 0.002

0.002 + 0.010

0.008 + 0.020 0.010 + 0.020 0.001 + 0.002

( Input Accuracy ) + ( Reference Accuracy )

Input Accuracy

= accuracy specification for the HI-LO input signal.

Reference Accuracy

= accuracy specification for the HI-LO reference input signal.

Transfer Accuracy ( typical )

(

24 hour % of range error

)

2

Conditions:

Within 10 minutes and ± 0.5°C.

Within

±

10% of initial value.

Following a 2-hour warm-up.

Fixed range between 10% and 100% of full scale.

Using 6

1

⁄

2

digit slow resolution ( 100 PLC ).

Measurements are made using accepted metrology practices.

216

Chapter 8 Specifications

DC Characteristics

Measuring Characteristics

DC Voltage

Measurement Method:

A/D Linearity:

Input Resistance:

0.1 V, 1 V, 10 V ranges

100 V, 1000 V ranges

Input Bias Current:

Input Terminals:

Input Protection:

Continuously integrating, multi-slope III

A/D converter.

0.0002% of reading + 0.0001% of range

Selectable 10 M

Ω

or >10 G

Ω [11]

10 M

Ω ±

1%

< 30 pA at 25°C

Copper alloy

1000 V on all ranges

Resistance

Measurement Method:

Max. Lead Resistance:

(4-wire ohms)

Input Protection:

DC Current

Shunt Resistor:

Input Protection:

Selectable 4-wire or 2-wire ohms.

Current source referenced to LO input.

10% of range per lead for 100

Ω

, 1 k

Ω ranges. 1 k Ω per lead on all other ranges.

1000 V on all ranges

0.1

Ω for 1A, 3A. 5 Ω for 10 mA, 100 mA

Externally accessible 3A, 250 V fuse

Internal 7A, 250 V fuse

Continuity / Diode Test

Response Time:

Continuity Threshold:

300 samples/sec with audible tone

Adjustable from 1

Ω

to 1000

Ω

DC:DC Ratio

Measurement Method:

Input HI-LO

Reference HI-Input LO

Input to Reference

Integration Time

100 PLC / 1.67s (2s)

10 PLC / 167 ms (200 ms)

1 PLC / 16.7 ms (20 ms)

0.2 PLC / 3 ms (3 ms)

0.02 PLC / 400

µ s (400

µ s)

Input HI-LO / Reference HI-LO

100 mV to 1000 V ranges

100 mV to 10 V ranges (autoranged)

Reference LO to Input LO voltage < 2 V

Reference HI to Input LO voltage < 12V

Measurement Noise Rejection

60 Hz ( 50 Hz )

[ 5 ]

DC CMRR 140 dB

Normal Mode Rejection

60 dB

0 dB

0 dB

[ 7 ]

60 dB

[ 7 ]

60 dB

[ 7 ]

[ 6 ]

[12] Accuracy specifications are for the voltage measured at the input terminals only. 1 mA test current is typical. Variation in the current source will create some variation in the voltage drop across a diode junction.

Operating Characteristics

[ 8 ]

Function

DCV, DCI, and

Resistance

Digits

6

6

5

5

4

1

1

1

⁄

⁄

2

2

1

⁄

2

⁄

2

1

⁄

2

Readings/s

0.6 (0.5)

6 (5)

60 (50)

300

1000

Additional

Noise Error

0% of range

0% of range

0.001% of range

0.001% of range

[10]

0.01% of range [10]

System Speeds

[ 9 ]

Function Change

Range Change

Autorange Time

ASCII readings to RS-232

ASCII readings to GPIB

Max. Internal Trigger Rate

Max. External Trigger Rate to Memory

Max. External Trigger Rate to GPIB

26/sec

50/sec

<30 ms

55/sec

1000/sec

1000/sec

1000/sec

900/sec

Autozero OFF Operation

Following instrument warm-up at calibration temperature

±

1°C and <10 minutes, add 0.0002% range additional error + 5 µ V.

Settling Considerations

Reading settling times are affected by source impedance, cable dielectric characteristics, and input signal changes.

Measurement Considerations

Agilent recommends the use of PTFE

â

or other high-impedance, low-dielectric absorption wire insulation for these measurements.

[ 1 ]

[ 2 ]

Specifications are for 1-hour warm-up at 6

Relative to calibration standards.

1

⁄

2 digits.

[ 3 ]

20% overrange on all ranges, except 1000 Vdc, 3 A range.

[ 4 ]

Specifications are for 4-wire ohms function, or 2-wire

ohms using Math Null. Without Math Null, add 0.2 Ω

additional error in 2-wire ohms function.

[ 5 ]

For 1 k

Ω

unbalance in LO lead.

[ 6 ]

For power-line frequency

±

0.1%.

[ 7 ]

For power-line frequency ± 1%, subtract 20 dB.

For ± 3%, subtract 30 dB.

[ 8 ]

Readings speeds for 60 Hz and ( 50 Hz ) operation,

Autozero Off.

[ 9 ]

Speeds are for 4

1

⁄

2

digits, Delay 0, Autozero OFF,

and Display OFF. Includes measurement and data

transfer over GPIB.

[ 10 ]

Add 20

µ

V for dc volts, 4

µ

A for dc current, or

20 m

Ω

for resistance.

[ 11 ]

For these ranges, inputs beyond

±

17V are

clamped through 100 k Ω (typical).

217

8

Chapter 8 Specifications

AC Characteristics

AC Characteristics

Accuracy Specifications

± ( % of reading + % of range ) [ 1 ]

Function

True RMS

AC Voltage

[ 4 ]

Range

[ 3 ]

100.0000 mV

1.000000 V

to

750.000 V

Frequency

3 Hz

–

5 Hz

5 Hz

–

10 Hz

10 Hz

–

20 kHz

20 kHz

–

50 kHz

50 kHz

–

100 kHz

100 kHz

–

300 kHz

[6]

3 Hz

–

5 Hz

5 Hz

–

10 Hz

10 Hz

–

20 kHz

20 kHz

–

50 kHz

50 kHz

–

100 kHz

[5]

100 kHz

–

300 kHz

[6]

3 Hz

–

5 Hz

5 Hz

–

10 Hz

10 Hz

–

5 kHz

24 Hour

[ 2 ]

23°C

±

1°C

90 Day

23°C

±

5°C

1.00 + 0.03

0.35 + 0.03

0.04 + 0.03

0.10 + 0.05

0.55 + 0.08

4.00 + 0.50

1.00 + 0.02

0.35 + 0.02

0.04 + 0.02

0.10 + 0.04

0.55 + 0.08

4.00 + 0.50

1.00 + 0.04

0.30 + 0.04

0.10 + 0.04

1.00 + 0.04

0.35 + 0.04

0.05 + 0.04

0.11 + 0.05

0.60 + 0.08

4.00 + 0.50

1.00 + 0.03

0.35 + 0.03

0.05 + 0.03

0.11 + 0.05

0.60 + 0.08

4.00 + 0.50

1.00 + 0.04

0.30 + 0.04

0.10 + 0.04

1 Year

23°C

±

5°C

1.00 + 0.04

0.35 + 0.04

0.06 + 0.04

0.12 + 0.05

0.60 + 0.08

4.00 + 0.50

1.00 + 0.03

0.35 + 0.03

0.06 + 0.03

0.12 + 0.05

0.60 + 0.08

4.00 + 0.50

1.00 + 0.04

0.30 + 0.04

0.10 + 0.04

True RMS

AC Current

[ 4 ]

1.000000 A

3.00000 A 3 Hz

–

5 Hz

5 Hz

–

10 Hz

10 Hz

–

5 kHz

1.10 + 0.06

0.35 + 0.06

0.15 + 0.06

1.10 + 0.06

0.35 + 0.06

0.15 + 0.06

1.10 + 0.06

0.35 + 0.06

0.15 + 0.06

0.100 + 0.006

0.035 + 0.006

0.015 + 0.006

Additional Crest Factor Errors ( non-sinewave )

[ 7 ]

Additional Low Frequency Errors ( % of reading )

Frequency

10 Hz

–

20 Hz

20 Hz

–

40 Hz

40 Hz

–

100 Hz

100 Hz

–

200 Hz

200 Hz

–

1 kHz

> 1 kHz

AC Filter

Slow Medium Fast

0 0.74

––

0 0.22

––

0 0.06 0.73

0 0.01 0.22

0 0 0.18

0 0 0

Crest Factor

1

–

2

2

–

3

3

–

4

4

–

5

Error ( % of reading )

0.05%

0.15%

0.30%

0.40%

Sinewave Transfer Accuracy ( typical )

Frequency

10 Hz

–

50 kHz

50 kHz

–

300 kHz

Error ( % of range )

0.002%

0.005%

Conditions:

Sinewave input.

Within 10 minutes and

±

0.5°C.

Within

±

10% of initial voltage and

±

1% of initial frequency.

Following a 2-hour warm-up.

Fixed range between 10% and 100% of full scale ( and <120 V ).

Using 6

1 ⁄

2

digit resolution.

Measurements are made using accepted metrology practices.

Temperature

Coefficient/°C

0°C – 18°C

28°C – 55°C

0.100 + 0.004

0.035 + 0.004

0.005 + 0.004

0.011 + 0.005

0.060 + 0.008

0.20 + 0.02

0.100 + 0.003

0.035 + 0.003

0.005 + 0.003

0.011 + 0.005

0.060 + 0.008

0.20 + 0.02

0.100 + 0.006

0.035 + 0.006

0.015 + 0.006

218

Chapter 8 Specifications

AC Characteristics

Measuring Characteristics

Measurement Noise Rejection

[ 8 ]

AC CMRR 70 dB

True RMS AC Voltage

Measurement Method:

Crest Factor:

AC Filter Bandwidth:

Slow

Medium

Fast

Input Impedance:

Input Protection:

True RMS AC Current

Measurement Method:

AC-coupled True RMS

–

measures the ac component of input with up to 400 Vdc of bias on any range.

Maximum 5:1 at full scale

3 Hz

1 M

Ω

–

20 Hz

±

300 kHz

–

200 Hz

300 kHz

–

300 kHz

2%, in parallel with 100 pF

750 V rms all ranges

Shunt Resistor:

Burden Voltage:

Input Protection:

Direct coupled to the fuse and shunt.

AC-coupled True RMS measurement

(measures the ac component only).

0.1

Ω

for 1 A and 3 A ranges

1 A range: < 1 V rms

3 A range: < 2 V rms

Externally accessible 3A, 250 V fuse

Internal 7A, 250 V fuse

Settling Considerations

Applying >300 V rms (or >1 A rms) will cause self-heating in signal-conditioning components. These errors are included in the instrument specifications. Internal temperature changes due to self-heating may cause additional error on lower ac voltage ranges. The additional error will be less than 0.02% of reading and will generally dissipate within a few minutes.

Operating Characteristics

[ 9 ]

Function

ACV, ACI

Digits

6

6

6

6

6

1

⁄

2

1

1

1

⁄

⁄

2

2

⁄

2

1

⁄

2

Reading/s

7 sec/reading

1

1.6

[ 10 ]

10

50

[ 11 ]

System Speeds

[ 11 ]

,

[ 12 ]

Function or Range Change

Autorange Time

ASCII readings to RS-232

ASCII readings to GPIB

Max. Internal Trigger Rate

Max. External Trigger Rate to Memory

Max. External Trigger Rate to GPIB/RS-232

AC Filter

Slow

Medium

Fast

Fast

Fast

5/sec

<0.8 sec

50/sec

50/sec

50/sec

50/sec

50/sec

[ 1 ]

Specifications are for 1-hour warm-up at 6

Slow ac filter, sinewave input.

1

⁄

2

digits,

[ 2 ]

[ 3 ]

Relative to calibration standards.

20% overrange on all ranges, except 750 Vac, 3 A range.

[ 4 ]

Specifications are for sinewave input >5% of range.

For inputs from 1% to 5% of range and <50 kHz,

add 0.1% of range additional error. For 50 kHz to 100 kHz,

add 0.13% of range.

[ 5 ]

[ 6 ]

[ 7 ]

750 Vac range limited to 100 kHz or 8x10

7

Volt-Hz.

Typically 30% of reading error at 1 MHz.

For frequencies below 100 Hz, slow AC filter specified

for sinewave input only.

[ 8 ]

[ 9

For 1 k

Ω

unbalance in LO lead.

] Maximum reading rates for 0.01% of ac step

additional error. Additional settling delay required

when input dc level varies.

[ 10 ]

For External Trigger or remote operation using default

settling delay ( Delay Auto ).

[ 11 ]

Maximum useful limit with default settling delays defeated.

[ 12 ]

Speeds are for 4

Fast AC filter.

1

⁄

2

digits, Delay 0, Display OFF, and

219

8

Chapter 8 Specifications

Frequency and Period Characteristics

Frequency and Period Characteristics

Accuracy Specifications

Function Range

[ 3 ]

Frequency

24 Hour

23°C

±

Frequency,

Period

[ 4 ]

100 mV

to

750 V

3 Hz

–

5 Hz

5 Hz

–

10 Hz

10 Hz

–

40 Hz

40 Hz

–

300 kHz

Additional Low-Frequency Errors ( % of reading )

[ 4 ]

0.10

0.05

0.03

0.006

Frequency

3 Hz

5 Hz

–

–

10 Hz

40 Hz

5 Hz

10 Hz

–

–

100 Hz

100 Hz

–

300 Hz

300 Hz

–

1 kHz

> 1 kHz

40 Hz

Resolution

6

1

⁄

2

5

1

⁄

2

4

1

⁄

2

0 0.12 0.12

0 0.17 0.17

0 0.2 0.2

0 0.06 0.21

0 0.03 0.21

0 0.01 0.07

0 0 0.02

Transfer Accuracy ( typical )

0.0005% of reading

[ 2 ]

1°C

90 Day

23°C

±

5°C

0.10

0.05

0.03

0.01

1 Year

23°C

0.10

0.05

0.03

0.01

±

5°C

Temperature

Coefficient/°C

0°C – 18°C

28°C – 55°C

0.005

0.005

0.001

0.001

Conditions:

Within 10 minutes and

±

0.5°C.

Within

±

10% of initial value.

Following a 2-hour warm-up.

For inputs > 1 kHz and > 100 mV.

Using 6

1 ⁄

2

digit slow resolution ( 1 second gate time ).

Measurements are made using accepted metrology practices.

220

Chapter 8 Specifications

Frequency and Period Characteristics

Measuring Characteristics

Frequency and Period

Measurement Method:

Voltage Ranges:

Gate Time:

Reciprocal-counting technique.

AC-coupled input using the ac voltage measurement function.

100 mV rms full scale to 750 V rms.

Auto or manual ranging.

10 ms, 100 ms, or 1 sec

Settling Considerations

Errors will occur when attempting to measure the frequency or period of an input following a dc offset voltage change. The input blocking RC time constant must be allowed to fully settle ( up to

1 sec ) before the most accurate measurements are possible.

Measurement Considerations

All frequency counters are susceptible to error when measuring low-voltage, low-frequency signals. Shielding inputs from external noise pickup is critical for minimizing measurement errors.

Operating Characteristics

[ 5 ]

Function

Frequency,

Period

Digits

6 1

⁄

2

5

4

1 ⁄

2

1 ⁄

2

System Speeds

[ 5 ]

Configuration Rates

Autorange Time

ASCII readings to RS-232

ASCII readings to GPIB

Max. Internal Trigger Rate

Max. External Trigger Rate to Memory

Max. External Trigger Rate to GPIB/RS-232

Reading/s

1

9.8

80

14/sec

<0.6 sec

55/sec

80/sec

80/sec

80/sec

80/sec

[ 1 ]

Specifications are for 1-hour warm-up at 6

1

⁄

2

digits.

[ 2 ]

[ 3 ]

Relative to calibration standards.

20% overrange on all ranges, except 750 Vac range.

[ 4 ]

Input > 100 mV.

For 10 mV to 100 mV inputs, multiply % of reading

error x10.

[ 5 ]

Speeds are for 4

1

⁄

2

digits, Delay 0, Display OFF,

and Fast AC filter.

221

8

Chapter 8 Specifications

General Information

General Information

General Specifications

Power Supply:

Power Line Frequency:

Power Consumption:

Operating Environment:

Storage Environment:

Rack Dimensions (HxWxD):

Weight:

Safety:

EMC:

Vibration and Shock:

Warranty:

100 V / 120 V / 220 V / 240 V ± 10%.

45 Hz to 66 Hz and 360 Hz to 440 Hz.

Automatically sensed at power-on.

25 VA peak ( 10 W average )

Full accuracy for 0

°

C to 55

°

C

Full accuracy to 80% R.H. at 40°C

-40°C to 70°C

88.5 mm x 212.6 mm x 348.3 mm

3.6 kg (8 lbs)

See Delcaration of Conformity

See Declaration of Conformity

MIL-T-28800E Type III, Class 5

(data on file)

1 year standard

Accessories Included

Test Lead Kit with probes, alligator, and grabber attachments.

User’s Guide, Service Guide, test report, and power cord.

Triggering and Memory

Reading HOLD Sensitivity:

Samples per Trigger:

Trigger Delay:

External Trigger Delay:

External Trigger Jitter:

Memory:

0.01%, 0.1%, 1%, or 10% of reading

1 to 50,000

0 to 3600 sec ( 10

µ s step size )

< 1 ms

< 500 µ s

512 readings

Math Functions

Null, Min/Max/Average, dB, dBm, Limit Test (with TTL output).

dBm reference resistances: 50, 75, 93, 110, 124, 125, 135, 150,

250, 300, 500,

600

, 800, 900, 1000, 1200, or 8000 ohms.

Standard Programming Languages

SCPI (

Standard Commands for Programmable Instruments

)

Agilent 3478A Language Emulation

Fluke 8840A, Fluke 8842A Language Emulation

Remote Interface

GPIB (IEEE-488.1, IEEE-488.2) and RS-232C

This ISM device complies with Canadian ICES-001.

Cet appareil ISM est conforme à la norme NMB-001 du Canada.

N10149

222

Chapter 8 Specifications

Product Dimensions

Product Dimensions

103.8 mm

261.1 mm

379.4 mm

212. 6 mm

88. 5 mm

348. 3 mm

TOP

All dimensions are shown in millimeters.

223

8

Chapter 8 Specifications

To Calculate Total Measurement Error

To Calculate Total Measurement Error

Each specification includes correction factors which account for errors present due to operational limitations of the multimeter. This section explains these errors and shows how to apply them to your measurements.

Refer to “Interpreting Multimeter Specifications,” starting on page 226, to get a better understanding of the terminology used and to help you interpret the multimeter’s specifications.

The multimeter’s accuracy specifications are expressed in the form:

( % of reading + % of range ). In addition to the reading error and range error, you may need to add additional errors for certain operating conditions. Check the list below to make sure you include all measurement errors for a given function. Also, make sure you apply the conditions as described in the footnotes on the specification pages.

•

•

•

If you are operating the multimeter outside the 23°C ± 5°C temperature range specified, apply an additional temperature

coefficient error.

For dc voltage, dc current, and resistance measurements, you may need to apply an additional reading speed error or autozero OFF error.

For ac voltage and ac current measurements, you may need to apply an additional low frequency error or crest factor error.

Understanding the “ % of reading ” Error

The reading error compensates for inaccuracies that result from the function and range you select, as well as the input signal level. The reading error varies according to the input level on the selected range. This error is expressed in percent of reading. The following table shows the reading error applied to the multimeter’s 24-hour dc voltage specification.

Range

10 Vdc

10 Vdc

10 Vdc

Input Level

10 Vdc

1 Vdc

0.1 Vdc

Reading Error

(% of reading)

0.0015

0.0015

0.0015

Reading

Error Voltage

≤

150

µ

V

≤ 15 µ V

≤ 1.5 µ V

224

Chapter 8 Specifications

To Calculate Total Measurement Error

Understanding the “ % of range ” Error

The range error compensates for inaccuracies that result from the function and range you select.

The range error contributes a constant error, expressed as a percent of range, independent of the input signal level. The following table shows the range error applied to the multimeter’s 24-hour dc voltage specification.

Range

10 Vdc

10 Vdc

10 Vdc

Input Level

10 Vdc

1 Vdc

0.1 Vdc

Range Error

(% of range)

0.0004

0.0004

0.0004

Range

Error Voltage

≤

40

µ

V

≤

40

µ

V

≤ 40 µ V

Total Measurement Error

To compute the total measurement error, add the reading error and range error. You can then convert the total measurement error to a “percent of input” error or a “ppm (part-permillion) of input” error as shown below.

% of input error =

Total Measurement Error

Input Signal Level

× 100

ppm of input error =

Total Measurement Error

Input Signal Level

× 1,000,000

Error Example

Assume that a 5 Vdc signal is input to the multimeter on the 10 Vdc range.

Compute the total measurement error using the 90-day accuracy specifications:

±

(0.0020% of reading + 0.0005% of range).

Reading Error

Range Error

Total Error

= 0.0020%

×

5 Vdc

= 0.0005%

×

10 Vdc

= 100

µ

V + 50

µ

V

= 100

µ

V

= 50

µ

V

=

±

150

µ

V

=

±

0.0030% of 5 Vdc

=

±

30 ppm of 5 Vdc

225

8

Chapter 8 Specifications

Interpreting Multimeter Specifications

Interpreting Multimeter Specifications

This section is provided to give you a better understanding of the terminology used and will help you interpret the multimeter’s specifications.

Number of Digits and Overrange

The “number of digits” specification is the most fundamental, and sometimes, the most confusing characteristic of a multimeter.

The number of digits is equal to the maximum number of “9’s” the multimeter can measure or display. This indicates the number of full

digits. Most multimeters have the ability to overrange and add a partial or “ 1 ⁄

2

” digit.

For example, the Agilent 34401A can measure 9.99999 Vdc on the 10 V range. This represents six full digits of resolution. The multimeter can also overrange on the 10 V range and measure up to a maximum of

12.00000 Vdc. This corresponds to a 6 1 ⁄

2

-digit measurement with 20% overrange capability.

Sensitivity

Sensitivity is the minimum level that the multimeter can detect for a given measurement. Sensitivity defines the ability of the multimeter to respond to small changes in the input level. For example, suppose you are monitoring a 1 mVdc signal and you want to adjust the level to within

±

1

µ

V. To be able to respond to an adjustment this small, this measurement would require a multimeter with a sensitivity of at least 1

µ

V.

You could use a 6 1 ⁄

2

-digit multimeter if it has a 1 Vdc or smaller range.

You could also use a 4 1 ⁄

2

-digit multimeter with a 10 mVdc range.

For ac voltage and ac current measurements, note that the smallest value that can be measured is different from the sensitivity. For the

Agilent 34401A, these functions are specified to measure down to 1% of the selected range. For example, the multimeter can measure down to

1 mV on the 100 mV range.

226

Chapter 8 Specifications

Interpreting Multimeter Specifications

Resolution

Resolution is the numeric ratio of the maximum displayed value divided by the minimum displayed value on a selected range. Resolution is often expressed in percent, parts-per-million (ppm), counts, or bits.

For example, a 6

1 ⁄

2

-digit multimeter with 20% overrange capability can display a measurement with up to 1,200,000 counts of resolution.

This corresponds to about 0.0001% (1 ppm) of full scale, or 21 bits including the sign bit. All four specifications are equivalent.

Accuracy

Accuracy is a measure of the “exactness” to which the multimeter’s measurement uncertainty can be determined relative to the calibration reference used. Absolute accuracy includes the multimeter’s relative accuracy specification plus the known error of the calibration reference relative to national standards (such as the U.S. National Institute of

Standards and Technology). To be meaningful, the accuracy specifications must be accompanied with the conditions under which they are valid.

These conditions should include temperature, humidity, and time.

There is no standard convention among multimeter manufacturers for the confidence limits at which specifications are set. The table below shows the probability of non-conformance for each specification with the given assumptions.

Specification

Criteria

Mean ± 2 sigma

Mean ± 3 sigma

Mean

±

4 sigma

Probability

of Failure

4.5%

0.3%

0.006%

Variations in performance from reading to reading, and instrument to instrument, decrease for increasing number of sigma for a given specification. This means that you can achieve greater actual measurement precision for a specific accuracy specification number.

The Agilent 34401A is designed and tested to meet performance better than mean

±

4 sigma of the published accuracy specifications.

227

8

Chapter 8 Specifications

Interpreting Multimeter Specifications

Transfer Accuracy

Transfer accuracy refers to the error introduced by the multimeter due to noise and short-term drift. This error becomes apparent when comparing two nearly-equal signals for the purpose of “transferring” the known accuracy of one device to the other.

24-Hour Accuracy

The 24-hour accuracy specification indicates the multimeter’s relative accuracy over its full measurement range for short time intervals and within a stable environment. Short-term accuracy is usually specified for a 24-hour period and for a

±

1°C temperature range.

90-Day and 1-Year Accuracy

These long-term accuracy specifications are valid for a 23°C ± 5°C temperature range. These specifications include the initial calibration errors plus the multimeter’s long-term drift errors.

Temperature Coefficients

Accuracy is usually specified for a 23°C

±

5°C temperature range.

This is a common temperature range for many operating environments.

You must add additional temperature coefficient errors to the accuracy specification if you are operating the multimeter outside a 23°C

±

5°C temperature range (the specification is per °C).

228

Chapter 8 Specifications

Configuring for Highest Accuracy Measurements

Configuring for Highest Accuracy Measurements

The measurement configurations shown below assume that the multimeter is in its power-on or reset state. It is also assumed that manual ranging is enabled to ensure proper full scale range selection.

DC Voltage, DC Current, and Resistance Measurements

:

•

•

•

•

Set the resolution to 6 digits (you can use the 6 digits slow mode for further noise reduction).

Set the input resistance to greater than 10 G

Ω

(for the 100 mV, 1 V, and 10 V ranges) for the best dc voltage accuracy.

Use 4-wire ohms for the best resistance accuracy.

Use Math Null to null the test lead resistance for 2-wire ohms, and to remove interconnection offset for dc voltage measurements.

AC Voltage and AC Current Measurements

:

•

•

Set the resolution to 6 digits.

Select the slow ac filter (3 Hz to 300 kHz).

Frequency and Period Measurements

:

•

Set the resolution to 6 digits.

229

8

230

Index

If you have questions relating to the operation of the multimeter, call 1-800-452-4844 in the United States, or contact your nearest

Agilent Sales Office.

“

1 ⁄

2

” digit, 21, 54

2-wire ohms

See two-wire ohms

34398A Cable Kit, 149

34399A Adapter Kit, 149

3478A compatibility, 166

34812A BenchLink Software, 1

4-wire ohms

See four-wire ohms

“9.90000000E+37”, 61, 131

A

a/d convertor, 55, 57 abort measurement, 76 ac bandwidth detector, 51, 214 ac current connections, 18 math functions allowed, 63, 124 ranges, 18 signal filter, 51, 214 ac settling times, 51 ac signal filter, 51, 214 ac voltage connections, 17 loading errors, 209 math functions allowed, 63, 124 ranges, 17 signal filter, 51, 214 accessories included, 13, 222 accuracy, highest, 229 adapters (RS-232), 149 address, GPIB, 91, 161 addressed commands (IEEE-488), 169

Agilent Express, 6 alternate language compatibility

Agilent 3478A, 166

Fluke 8840A/8842A, 167 annunciators, 4 aperture time, 58 automatic trigger delays, 81 autoranging front-panel key, 20 threshold values, 20, 61 auto trigger, 42, 73 autozero definition, 59, 213 vs. integration time, 59 vs. resolution, 59 average (min-max) measurements beeper control, 88 description, 39, 64 front-panel, 39 functions allowed, 63, 124

B

bandwidth detector, 51, 214 bandwidth error, 208 baud rate, 93, 148, 151, 163 beeper continuity threshold, 19 diode threshold, 19 enable/disable, 88

BenchLink software (34812A), 1

BNC connectors

Ext Trig, 5, 83

VM Comp, 5, 83 boolean parameters, 159 bumpers, removing, 23 burden voltage, 205, 212 bus triggering, 75, 127

C

cables (RS-232), 150

CALCulate:FUNCtion

, 63, 124

CALCulate:STATe

, 63, 124

CALibration:COUNt?

, 98, 146

CALibration:SECure

, 97, 146

CALibration:STRing

, 99, 147 calibration changing security code, 98 commands, 146 count, 98 errors, 180 message, 99 secure procedure, 97 security code, factory setting, 95 unsecure procedure, 96 carrying handle adjusting, 16 removing, 23 chassis ground, 5

CLEAR

, 76 comma separator, 37, 89 command compliance (SCPI), 168 summary, 105-111 syntax conventions, 50, 105, 155 common commands, 169 common mode rejection (CMR), 201 complete self-test, 13, 86

CONFigure

, 113, 119 preset state, 110

Conformity, Declaration, 237 connections

2-wire ohms, 17

4-wire ohms, 17 ac current, 18 ac volts, 17 continuity, 19 dc current, 18 dc volts, 17 dcv:dcv ratio, 44 diode, 19 frequency, 18 period, 18 connectors

Ext Trig, 5, 83

GPIB interface, 5

RS-232 interface, 5

VM Comp, 5, 83 continuity connections, 19 current source, 19 math functions allowed, 63, 124 threshold resistance, 52 crest factor error, 207, 224 current ac current connections, 18 math functions allowed, 63, 124 ranges, 18 signal filter, 51, 214 dc current connections, 18 math functions allowed, 63, 124 measurement errors, 205 ranges, 18 current input fuses, replacing, 100 current source continuity, 19 diode, 19

231

Index

D

DATA:FEED

, 65, 126, 130

DATA:FEED?

, 65, 126, 130

DATA:POINts?

, 84, 133 data logging to printer, 91, 160 data types (SCPI), 158 data formats, output, 159 dB measurements description, 40, 67 front-panel, 40 functions allowed, 63, 124 relative value, 40, 67 dBm measurements description, 41, 68 front-panel, 41 functions allowed, 63, 124 resistance values, 41, 68 dc current connections, 18 math functions allowed, 63, 124 measurement errors, 205 ranges, 18 dc input resistance, 53 dc voltage connections, 17 input resistance, 53 loading errors, 199 math functions allowed, 63, 124 ranges, 17 dcv:dcv ratio measurements connections, 44 front panel, 44 math functions allowed, 63, 124 selecting, 45

Declaration of Conformity, 237 delay settling, 204 trigger, 79

DETector:BANDwidth

, 51, 123 detector bandwidth, 51, 214 device clear, 152, 157, 160 dielectric absorption, 204 digits, number of, 54, 226 dimensions, product, 223 discrete parameters, 158 diode beeper control, 88 beeper threshold, 19 connections, 19 current source, 19 math functions allowed, 63, 124 display annunciators, 4 comma separator, 37, 89 enable/disable, 87 formats, 22 message, 87

DISPlay:TEXT

, 87, 132

DISPlay:TEXT:CLEar

, 87, 132

DTR/DSR handshake, 151

E

enable register clearing, 136, 141, 143 definition, 134 error messages calibration errors, 180 error queue, 85, 172 error string length, 85, 172 execution errors, 173 self-test errors, 179 errors bandwidth, 208 burden voltage, 212 common mode, 212 crest factor, 207, 224 leakage current, 199 service request generation, 69, 137 temperature coefficient, 224 test lead resistance, 204 thermal EMF, 198

EOI (end-or-identify), 157 even parity, 93 event register clearing, 141, 143 definition, 134 examples

CONFigure

, 116 front-panel menu, 31-36

MEASure?

, 115

Ext Trig terminal, 5, 83 external trigger, 42, 74, 83

F

fast ac filter, 51, 214

FETCh?

, 115, 132 filler panel kit, 24 filter, ac signal, 51, 214 firmware revision query, 89 fixed range, 61 fixed input resistance, 53 flange kit, 24 flowchart (triggering), 72

Fluke 8840A/8842A compatibility, 167 format, output data, 159 four-wire ohms connections, 17 math functions allowed, 63, 124 ranges, 17

FREQuency:APERture

, 58, 122 frequency aperture time, 58 connections, 18 math functions allowed, 63, 124 measurement band, 18 front panel annunciators, 4 beeper, 88 comma separator, 37, 89 display formats, 22 enable/disable, 87 menu examples, 31-36 messages displayed, 30 overview, 3 quick reference, 27-28 tree diagram, 29 messages, front-panel, 87 front-panel keys menu, 29 range, 20 resolution, 21 trigger, 42

Front/Rear switch, 2, 58 fuses current input, 5, 100 power-line, 14, 100 fuse-holder assembly, 5, 15

232

Index

G

gate time, 58

GPIB (IEEE-488) address displayed at power-on, 13 factory setting, 91 setting the, 91, 161

TALK ONLY mode, 91, 160 compliance information, 168 connector location, 5 selecting interface, 92, 162 ground, chassis, 5 ground loop noise, 202

Group Execute Trigger (GET), 75

H

“half” digit, 21, 54 hardware lines (IEEE-488), 169 handle adjusting, 16 removing, 23 hardware, rack mounting, 24 hardware handshake (RS-232), 151

HP-IB (See GPIB)

I

identification string, 89 idle trigger state, 76, 129

*IDN?

, 89

IEEE-488 (GPIB) address displayed at power-on, 13 factory setting, 91 setting the, 91, 161

TALK ONLY mode, 91, 160 compliance information, 168 connector location, 5 selecting interface, 92, 162 induced voltages, 201

INITiate

, 115, 130 input bias current, 199

INPut:IMPedance:AUTO

, 53, 123 input message terminators, 157 input resistance, dc volts, 53 input signal range frequency, 18 period, 18 input terminals

Front/Rear switch, 2, 58 query setting, 58 input message terminators, 157 integration time definition, 57 vs. autozero, 59, 60 vs. resolution, 54, 57, 59 interface (remote)

GPIB connector, 5

GPIB selection, 92, 162 language restrictions, 92, 94

RS-232 connector, 5, 150

RS-232 selection, 92, 162 internal reading memory functions allowed, 46, 84 number of readings stored, 84 retrieving readings, 46 storing readings, 46 internal triggering, 75

L

L1, L2, L3, 94, 166 language command summary, 105-111 compatibility, 166 compliance (SCPI), 168 restrictions, 92, 94 selecting, 94, 162 lead resistance, 38, 65, 204 leakage current errors, 199 limit test beeper control, 88 description, 69 functions allowed, 63, 124

RS-232 pass/fail outputs, 70 service request, 69, 142 line frequency noise, 57 line voltage factory setting, 14 selector module, 15 setting the, 15 loading errors ac volts, 209 dc volts, 53, 199 lock-link kit, 24

M

magnetic loops, 201 maintenance, 100 manual range, 20, 61 math operations description, 63, 124 functions allowed, 63, 124

MEASure?

, 113, 117 preset state, 112 measurement band frequency, 18 period, 18 measurement errors, 224 measurement function math combinations allowed, 63, 124 measurement range autoranging, 20, 61 front-panel keys, 20 overload, 61, 142 selecting, 20 measurement ranges

2-wire ohms, 17

4-wire ohms, 17 ac current, 18 ac volts, 17 dc current, 18 dc volts, 17 dcv:dcv ratio, 44 frequency, 18 period, 18 measurement resolution front-panel keys, 21

“half” digit, 21, 54 setting, 21 power line cycles, 54 vs. autozero, 59 vs. integration time, 54 measurement terminals

Front/Rear switch, 2, 58 query setting, 58 measurement tutorial, 197 medium ac filter, 51, 214 memory, internal functions allowed, 46, 84 number of readings stored, 84 retrieving readings, 46 storing readings, 46

233

Index

menu examples, 31-36 overview, 3 messages displayed, 30 quick reference, 27-28 tree diagram, 29 messages displayed front-panel, 87 menu, 30 message terminators, 157 min-max measurements beeper control, 88 description, 39, 63 front-panel, 39 functions allowed, 63, 124

N

noise ground loop, 202 magnetic loops, 201 power-line voltage, 200 noise pickup, 53, 199 noise rejection, 21, 57, 200 no parity, 93 normal mode rejection (NMR), 57, 200

NPLC, 54, 57, 200 null measurements description, 38, 65 front panel, 38 functions allowed, 63, 124

Null Register, 38, 66 null test lead resistance, 38, 65, 204 number of digits, 54, 226 number of readings, 77 numeric parameters, 158

O

odd parity, 93 offset (null) measurements description, 38, 65 front panel, 38 functions allowed, 63, 124

Null Register, 38, 66 null test lead resistance, 38, 65, 204 offset voltages, 59, 196 ohms

2-wire connections, 17 math functions allowed, 63, 124 ranges, 17

4-wire connections, 17 math functions allowed, 63, 124 ranges, 17

*OPC,

137 operator maintenance, 100 output data format, 159 output buffer, 139 overload, 61, 142

“OVLD”, 61, 142

P

parameter types, 158 parity, 93, 164 parts-per-million, 227 pass/fail limit test beeper control, 88 description, 69 functions allowed, 63, 124

RS-232 pass/fail outputs, 70 service request, 69, 142

PERiod:APERture

, 58, 122 period aperture time, 58 connections, 18 math functions allowed, 63, 124 measurement band, 18 power cord, 15 power dissipation effects, 204 power line cycles, 54, 57, 200 power-line frequency power-on sensing, 200 power-line fuse factory configuration, 14 installation, 15 power-line noise, rejecting, 200 power-line voltage factory setting, 14 selector module, 15 setting the, 15 power-on self-test, 13 sequence, 13 state, 101 product dimensions, 223 product specifications, 215 programming language command summary, 105-111 compatibility, 166 compliance (SCPI), 168 restrictions, 92, 94 selecting, 94, 165 pushbuttons (front panel), 2

Q

questionable data register bit definitions, 142 clearing, 143

R

rack mounting bumpers, removing, 23 carrying handle, removing, 23 filler panel kit, 24 flange kit, 24 lock-link kit, 24 sliding-shelf kit, 24 ranges

2-wire ohms, 17

4-wire ohms, 17 ac current, 18 ac volts, 17 dc current, 18 dc volts, 17 dcv:dcv ratio, 44 frequency, 18 period, 18

234

Index

ranging autoranging, 20, 61 front-panel keys, 20 overload, 61, 142 selecting, 20 ratio (dcv:dcv) measurements connections, 44 front panel, 44 math functions allowed, 63, 124 selecting, 45

READ?

, 114, 130 reading hold beeper control, 88 description, 43, 82 front-panel, 43 sensitivity band, 43, 82 reading memory functions allowed, 46, 84 number of readings stored, 84 retrieving readings, 46 storing readings, 46 readings, number of, 77 rear panel input terminals, 5 pictorial overview, 5 rear terminals query setting, 58, 123 selecting, 58 reciprocal counting technique, 213 register diagram (status), 135 regulatory requirements, 237 relative value (dB), 40, 67 relative measurements description, 38, 65 front panel, 38 functions allowed, 63, 124

Null Register, 38, 66 null test lead resistance, 38, 65, 204 remote interface

GPIB connector, 5

GPIB selection, 92, 162 language restrictions, 92, 94

RS-232 connector, 5, 150

RS-232 selection, 92, 162 replacing fuses, 100 reset state, 101 resistance

2-wire connections, 17 math functions allowed, 63, 124 ranges, 17

4-wire connections, 17 math functions allowed, 63, 124 ranges, 17 resistance, input, 53 resolution front-panel keys, 21

“half” digit, 21, 54 power line cycles, 54 setting, 21 vs. autozero, 59 vs. integration time, 54 retrieving stored readings, 46 revision query (firmware), 89

ROUTe:TERMinals?

, 58, 123

RS-232 interface baud rate selection, 93, 148, 163 cables recommended, 150 commands, 153 connector location, 5, 150 connector pinout, 150 data format, 159 handshake protocol (DTR/DSR), 151 parity selection, 93, 164 pass/fail outputs, 70, 150 pin definitions, 150 selecting interface, 92, 162

TALK ONLY mode, 91, 160 rubber bumpers, removing, 23

S

SAMPle:COUNt

, 77, 131 samples, number of, 77

SCPI command summary, 105-111 compliance information, 168 data types, 158 language introduction, 154 status model, 134 syntax conventions, 50, 105, 155 version query, 90, 133 security code (calibration) changing, 98 factory setting, 95 rules, 95 string length, 95 self-heating errors, 210 self-test complete test, 13, 86 errors, 179 reading memory, 84, 86 power-on test, 13, 86 sensitivity, 226 sensitivity band (reading hold), 43, 82 serial interface (RS-232) baud rate selection, 93, 148, 163 cables recommended, 95, 150 commands, 153 connector location, 5, 150 connector pinout, 150 data format, 159 handshake protocol (DTR/DSR), 151 parity selection, 93, 164 pass/fail outputs, 70, 150 pin definitions, 150 selecting interface, 92, 162

TALK ONLY mode, 91, 160 serial poll, 137 service request (SRQ), 69, 137 settling delays, 204 trigger, 79 signal filter, 51, 214 single trigger, 42, 73 sliding-shelf kit, 24 slow ac filter, 51, 214 software (bus) triggering, 75, 127 specifications, 215 standard event register bit definitions, 140 clearing, 141 status byte bit definitions, 136 clearing, 136 summary register, 136

235

Index

status register commands, 144 description, 134 diagram, 135 enable register, 134 event register, 134

*STB?

, 138, 145 stop bits, 148 storing readings functions allowed, 46, 84 number of readings stored, 84 retrieving readings, 46 storing readings, 46 string length calibration message, 99 displayed message, 87 error queue, 85 identification string, 89 string parameters, 159 summary register clearing, 136 definition, 136 support-shelf kit, 24 syntax conventions, 50, 105, 155

SYSTem:BEEPer

, 88, 133

SYSTem:ERRor?

, 85, 133

T

TALK ONLY mode, 91, 92, 160 temperature coefficient, 210, 224, 228 terminals

Ext Trig, 5, 83

Front/Rear switch, 2, 58

GPIB interface, 5 query setting, 58

RS-232 interface, 5

VM Comp, 5, 83 terminators, input message, 157 test complete self-test, 13, 86 power-on self-test, 13, 86 reading memory, 84, 86 self-test errors, 179 test lead resistance, 38, 64, 198 thermal EMF errors, 198 threshold resistance, continuity, 52 transfer accuracy, 228

*TRG

, 75

TRIGGER

, 75

TRIGger:COUNt

, 78, 131

TRIGger:DELay

, 80, 131

TRIGger:DELay:AUTO

, 80, 131

TRIGger:SOURce

, 73, 130 triggering abort measurements, 76 auto trigger, 42, 73 commands, 130 delay, 79 external trigger, 42, 74, 83 flowchart, 72 front-panel, 42 idle trigger state, 76, 129 internal, 75 multiple readings (samples), 77 multiple triggers, 78 single trigger, 42, 73 software (bus) trigger, 75, 127 sources, 73

“wait-for-trigger” state, 76, 129

*TST?

, 86 tutorial front-panel menu, 29 measurement, 197 twisted-pair connections, 201 two-wire ohms connections, 17 math functions allowed, 63, 124 ranges, 17

V

vacuum-fluorescent display, 1 version firmware, 89

SCPI, 90

VM Comp terminal, 5, 83 voltage ac voltage connections, 17 loading errors, 209 math functions allowed, 63, 124 ranges, 17 signal filter, 51, 214 dc voltage connections, 17 input resistance, 53 loading errors, 199 math functions allowed, 63, 124 ranges, 17 voltage selector module, 15

Voltmeter Complete terminal, 5, 83

W

“wait-for-trigger” state, 76, 129 warranty information, inside front cover weight, product, 222 wiring adapter (RS-232), 149 wiring connections

2-wire ohms, 17

4-wire ohms, 17 ac current, 18 ac volts, 17 continuity, 19 dc current, 18 dc volts, 17 dcv:dcv ratio, 44 diode, 19 frequency, 18 period, 18

Z

zero measurements, 59, 213

236