HP 34401A User Manual

User’s Guide

Part Number 34401-90004 February 1996

For Safety information, Warranties, and Regulatory information, see the pages behind the Index.

HP 34401A Multimeter

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

The HP 34401A is a 6

⁄

-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

• HP-IB (IEEE-488) interface and RS-232 interface

• Standard programming languages: SCPI, HP 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 HP 34812A BenchLink/Meter Software

for Microsoft

Windows

HP 34401A Multimeter

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

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: HP-IB 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.

Display Annunciators

Adrs Rmt Man Trig Hold Mem Ratio Math ERROR Rear Shift

Turns on during a measurement. Multimeter is addressed to listen or talk over the HP-IB 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.

Multimeter is in 4-wire ohms function. Multimeter is in continuity test function. Multimeter is in diode test function.

Press “Shift” again to turn off.

To review the display annunciators, hold down the Shift key as you turn on the multimeter.

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 HP-IB (IEEE-488) Interface connector 8 RS-232 interface connector

Use the front-panel Input / Output Menu to:

• Select the HP-IB or RS-232 interface (see chapter 4).

• Set the HP-IB bus address (see chapter 4).

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

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 HP 34401A, call 1-800-452-4844 in the United States, or contact your nearest Hewlett-Packard Sales Office.

If your HP 34401A fails within three years of purchase, HP will repair or replace it free of charge. Call 1-800-258-5165 (“Express Exchange”)

in the United States, or contact your nearest Hewlett-Packard Sales Office.

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

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

HP-IB 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

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 HP-IB 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

Contents

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

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

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

Shift DC V .

press

Shift (the Shift

If you accidentally press

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.

Shift , just press it again to turn off the

Chapter 1 Quick Start

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 Hewlett-Packard 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 multimeter powers up in the dc voltage function with autoranging enabled.

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

3Perform a complete self-test.

The complete self-test performs a more extensive series of tests than those performed at power-on. Hold down 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, “ not successful, “ on. See the Service Guide for instructions on returning the multimeter to Hewlett-Packard for service.

Shift as you turn on the multimeter.

FAIL” is displayed and the ERROR annunciator turns

HP-IB bus address is displayed. Notice that the

Shift as you press the

PASS” is displayed. If the self-test is

Chapter 1 Quick Start

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 Hewlett-Packard 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 power-line fuse installed. If you determine that the fuse is faulty, replace it with one that has the same rating as indicated on the multimeter’s rear panel.

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

To replace the 250 mAT fuse, order HP part number 2110-0817. To replace the 125 mAT fuse, order HP part number 2110-0894.

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.

3 Rotate the line-voltage selector until the

correct voltage appears in the window.

2 Remove the line-voltage selector from

the assembly.

See rear panel for proper fuse rating

HP Part Number: 2110-0817 (250 mAT) 2110-0894 (125 mAT)

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.

Chapter 1 Quick Start

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

Chapter 1 Quick Start

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

To Measure Resistance

Ranges: 100 Ω, 1 kΩ, 10 kΩ, 100 kΩ, 1 MΩ, 10 MΩ, 100 MΩ Maximum resolution: 100 µΩ (on 100 ohm range)

Chapter 1 Quick Start

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 µsec)

Input signal range: 100 mVac to 750 Vac Technique: reciprocal counting

Chapter 1 Quick Start

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)

To Check Diodes

Test current source: 1 mA

Maximum resolution: 100 µV (range is fixed at 1 Vdc) Beeper threshold: 0.3 volts ≤ V

measured

≤ 0.8 volts (not adjustable)

Chapter 1 Quick Start

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.

Toggles between autoranging and manual ranging.

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

• Autorange thresholds:

Man annunciator is on when manual range is enabled.

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 (“

• For frequency and period measurements from the front panel,

OVLD”).

ranging applies to the signal’s input voltage, not its frequency.

• The range is fixed for continuity (1 kΩ 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.

Chapter 1 Quick Start

To Set the Resolution

You can set the display resolution to 4

⁄

, 5

⁄

, or 6

⁄

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 “

” digit,

since it can only be a “0” or “1.”

Press the Shift key.

Selects 4

⁄2 digits.

Selects 51⁄2 digits.

Selects 61⁄2 digits (

most noise rejection

• The resolution is set to 5

⁄

digits at power-on and after a remote

interface reset.

• The resolution is fixed at 5

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

⁄

digits for continuity and diode tests.

(however, the integration time is not changed).

Fewer More Digits D igits

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.

5 digits

Chapter 1 Quick Start

Front-Panel Display Formats

– Negative sign or blank (positive)

H “

⁄2 ” digit (0 or 1)

-H.DDD,DDD EFFF

Front-panel display format.

10.216,5 VDC

D Numeric digits E Exponent ( m, k, M ) F Measurement units ( VDC, OHM, HZ, dB )

“1⁄2” digit

⁄

This is the 10 Vdc range, 5

digits are displayed.

-045.23 mVDC

⁄

This is the 100 mVdc range, 4

digits are displayed.

113.325,6 OHM

⁄

This is the 100 ohm range, 6

digits are displayed.

OVL.D mVDC

This is an overload indication on the 100 mVdc range.

Chapter 1 Quick Start

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

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

HP System II instrument

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

Front

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

Rear (bottom view)

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 149 4-0015 ( for a sing le instr ument , also orde r filler panel 50 02-3999 ).

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.

Chapter 2 Front-Panel Menu Operation

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.

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.

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: HP-IB ADDR  2: INTERFACE  3: BAUD RATE  4: PARITY  5: LANGUAGE

1: HP-IB ADDR 2: INTERFACE 3: BAUD RATE 4: PARITY 5: LANGUAGE

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

Sets the HP-IB bus address (0 to 31). Selects the HP-IB 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, HP 3478, or Fluke 8840/42.

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.

Chapter 2 Front-Panel Menu Operation

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 > .

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,

Shift Recall .

press

+ 206 hidden pages