Instek GDM-8351 User's Manual

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Page 1

Dual Measurement Multimeter

GDM-8351

USER MANUAL

GW INSTEK PART NO. 82DM-83510E01

ISO-9001 CERTIFIED MANUFACTURER

Page 2

This manual contains proprietary information, which is protected by copyright. All rights are reserved. No part of this manual may be photocopied, reproduced or translated to another language without prior written consent of Good Will company.

The information in this manual was correct at the time of printing. However, Good Will continues to improve products and reserves the rights to change specification, equipment, and maintenance procedures at any time without notice.

Good Will Instrument Co., Ltd. No. 7-1, Jhongsing Rd., Tucheng Dist., New Taipei City 236, Taiwan.

Page 3

Table of Contents

SAFETY INSTRUCTIONS ................................................... 5

GETTING STARTED ......................................................... 10

Characteristics .......................................... 11

Appearance ............................................... 13

Set Up ....................................................... 23

OPERATION .................................................................... 28

Basic Measurement Overview ................... 30

AC/DC Voltage Measurement .................... 32

AC/DC Current Measurement ................... 37

Resistance Measurement .......................... 42

Diode Test ................................................ 45

Capacitance Measurement ........................ 46

Continuity Test .......................................... 48

Frequency/Period Measurement ............... 51

Temperature Measurement ....................... 53

Dual Measurement Overview .................... 57

Advanced Measurement Overview ............ 62

dBm/dB/W Measurement ......................... 63

Max/Min Measurement ............................. 66

Relative Measurement .............................. 67

Hold Measurement ................................... 69

Compare Measurement ............................. 70

Math Measurement ................................... 72

SYSTEM/DISPLAY CONFIGURATION .............................. 76

View Serial Number .................................. 77

View Version Number ............................... 77

Brightness Settings ................................... 78

Input Resistance Settings ......................... 79

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GDM-8351 User Manual

Frequency/Period Input Jack Settings ........ 80

Digital Filter .............................................. 81

Restore Factory Default Settings ............... 85

Trigger ...................................................... 86

DIGITAL I/O .................................................................... 88

Digital I/O Overview ................................. 89

REMOTE CONTROL ........................................................ 93

Configure Remote Control Interface .......... 94

Return to Local Control ............................. 98

COMMAND OVERVIEW .................................................. 99

Command Syntax ...................................... 99

Command List ......................................... 103

FAQ ............................................................................... 138

APPENDIX ..................................................................... 139

System Menu Tree ................................... 139

Factory Default Settings .......................... 140

Replacing the AC Source Fuse ................. 141

Replacing the Input Fuse......................... 142

Status system ......................................... 144

Specifications ......................................... 145

Additional Specifications ........................ 150

Dimensions ............................................ 156

Declaration of Conformity ....................... 157

INDEX ............................................................................ 158

Page 5

SAFETY INSTRUCTIONS

WARNING

Warning: Identifies conditions or practices that could result in injury or loss of life.

CAUTION

Caution: Identifies conditions or practices that could result in damage to the DMM or to other properties.

DANGER High Voltage

Attention Refer to the Manual

Protective Conductor Terminal

Earth (ground) Terminal

Do not dispose electronic equipment as unsorted municipal waste. Please use a separate collection facility or contact the supplier from which this instrument was purchased.

SAFETY INSTRUCTIONS

This chapter contains important safety instructions that you must follow during operation and storage. Read the following before any operation to ensure your safety and to keep the instrument in the best possible condition.

Safety Symbols

These safety symbols may appear in this manual or on the instrument.

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GDM-8351 User Manual

General Guideline

CAUTION

 Make sure that the voltage input level does not

exceed DC1000V/AC750V.

 Make sure the current input level does not

exceed 12A.

 Do not place any heavy object on the

instrument.

 Avoid severe impact or rough handling that can

lead to damaging the instrument.

 Do not discharge static electricity to the

instrument.

 Use only mating connectors, not bare wires, for

the terminals.

 Do not block or obstruct the cooling fan vent

opening.

 Do not perform measurement at the source of a

low-voltage installation or at building installations (Note below).

 Do not disassemble the instrument unless you

are qualified as service personnel.

 Make sure that the COM terminal to earth is

limited to 500Vpk.

 Remove all test leads before disconnecting the

mains power cord from the socket.

(Note) EN 61010-1:2010 specifies the measurement categories and their requirements as follows. The GDM-8351 falls under category II 600V.

 Measurement category IV is for measurement performed at the

source of low-voltage installation.

 Measurement category III is for measurement performed in the

building installation.

 Measurement category II is for measurement performed on the

circuits directly connected to the low voltage installation.

Safety Guidelines

Page 7

SAFETY INSTRUCTIONS

Power Supply

WARNING

 AC Input voltage: 100/120/220/240 V AC  50/60Hz  The power supply voltage should not fluctuate

more than 10%.

 Connect the protective grounding conductor of

the AC power cord to an earth ground, to avoid electrical shock.

Fuse

WARNING

 Fuse type: 0.125AT 100/120VAC

0.063AT 220/240 VAC

 Make sure the correct type of fuse is installed

before power up.

 To avoid risk of fire, replace the fuse only with

the specified type and rating.

 Disconnect the power cord before fuse

replacement.

 Make sure the cause of a fuse blowout is fixed

before fuse replacement.

Cleaning the Instrument

 Disconnect the power cord before cleaning.  Use a soft cloth dampened in a solution of mild

detergent and water. Do not spray any liquid.

 Do not use chemicals containing harsh material

such as benzene, toluene, xylene, and acetone.

Operation Environment

 Location: Indoor, no direct sunlight, dust free,

almost non-conductive pollution (Note below)

 Temperature: 0°C to 50°C  Humidity: 0~35°C : < 90%RH

>35°C: <80%RH

 Altitude: <2000m

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GDM-8351 User Manual

(Note) EN 61010-1:2010 specifies the pollution degrees and their requirements as follows. The GDM-8351 falls under degree 2.

 Pollution refers to “addition of foreign matter, solid, liquid, or

gaseous (ionized gases), that may produce a reduction of dielectric strength or surface resistivity”.

 Pollution degree 1: No pollution or only dry, non-conductive

pollution occurs. The pollution has no influence.

 Pollution degree 2: Normally only non-conductive pollution

occurs. Occasionally, however, a temporary conductivity caused by condensation must be expected.

 Pollution degree 3: Conductive pollution occurs, or dry, non-

conductive pollution occurs which becomes conductive due to condensation which is expected. In such conditions, equipment is normally protected against exposure to direct sunlight, precipitation, and full wind pressure, but neither temperature nor humidity is controlled.

Storage environment

 Location: Indoor  Temperature: -40°C to 70°C  Humidity: 0~35°C: <90%RH

>35°C: <80%RH

Disposal

Do not dispose this instrument as unsorted municipal waste. Please use a separate collection facility or contact the supplier from which this instrument was purchased. Please make sure discarded electrical waste is properly recycled to reduce environmental impact.

Page 9

SAFETY INSTRUCTIONS

Green/ Yellow:

Earth

Blue:

Neutral

Brown:

Live (Phase)

Power cord for the United Kingdom

When using the unit in the United Kingdom, make sure the power cord meets the following safety instructions.

NOTE: This lead/appliance must only be wired by competent persons

WARNING: THIS APPLIANCE MUST BE EARTHED IMPORTANT: The wires in this lead are coloured in accordance with the following code:

As the colours of the wires in main leads may not correspond with the coloured marking identified in your plug/appliance, proceed as follows:

The wire which is coloured Green & Yellow must be connected to the Earth terminal marked with either the letter E, the earth symbol

or coloured Green/Green & Yellow.

The wire which is coloured Blue must be connected to the terminal which is marked with the letter N or coloured Blue or Black.

The wire which is coloured Brown must be connected to the terminal marked with the letter L or P or coloured Brown or Red.

If in doubt, consult the instructions provided with the equipment or contact the supplier.

This cable/appliance should be protected by a suitably rated and approved HBC mains fuse: refer to the rating information on the equipment and/or user instructions for details. As a guide, a cable of 0.75mm2 should be protected by a 3A or 5A fuse. Larger conductors would normally require 13A types, depending on the connection method used.

Any exposed wiring from a cable, plug or connection that is engaged in a live socket is extremely hazardous. If a cable or plug is deemed hazardous, turn off the mains power and remove the cable, any fuses and fuse assemblies. All hazardous wiring must be immediately destroyed and replaced in accordance to the above standard.

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GDM-8351 User Manual

Characteristics ................................................................ 11

Accessories ................................................................. 12

Appearance ..................................................................... 13

GDM-8351 Front Panel .............................................. 13

Display Overview ....................................................... 19

Rear Panel .................................................................. 21

Set Up ............................................................................. 23

Tilting the Stand ......................................................... 23

Power Up .................................................................... 24

How to Use the Instrument ....................................... 25

GETTING STARTED

This chapter describes the GDM-8351 multimeter in a nutshell, including accessories, package contents, its main features and front / rear panel introduction.

Page 11

GETTING STARTED

Performance

 DCV accuracy: 0.012%  High current range: 10A  High Voltage range: 1000V  High ACV frequency response: 100kHz

Features

 The fastest sampling rate is (320 Readings / sec)

for ADC and PC transmission.

 The diode test open-circuit voltage is ≑

6V/1mA.

 120000 count display  Multiple functions: ACV, DCV, ACI, DCI, 2WR,

4WR, Cap, Freq, Period ,Temp, Continuity, Diode test, MAX/MIN, Avg, REL, dB, dBm, Hold, MX+B, 1/X, REF, %, Compare.

 Manual or Auto ranging  AC true RMS  Data logging to PC using an Excel Add-In.

Interface

 USB device port supports USBCDC and

USBTMC.

 RS232  Digital I/O port can used in either pass/fail

testing (Compare function) or have the output state remotely controlled. Only one function at a time can be used.

Software

 Excel Addins  LABVIEW driver

Characteristics

The GDM-8351 is a portable, dual-display digital multimeter suitable for a wide range of applications, such as production testing, research, and field verification.

Page 12

Accessories

Standard Accessories

Part number

Description

82DM-83510E x1

CD-ROM (User Manual, Software, Driver)

82DM-83511M x1

Safety Instruction Sheet

GTL-207

Test leads

Optional Accessories

Part number

Description

GTL-246

USB Cable, USB 2.0, A-B type, 1200mm

GTL-205

Temperature Probe Adapter with Thermal Coupling (K-type)

GDM-8351 User Manual

Page 13

GETTING STARTED

DCV ACV

/2W/4W

Hz/P 2ND

REL MX/MN HOLD FILTER MENU

EXIT

SHIFT

RANGE

Enter

POWER

GDM-8351

120000 Counts Dual Measurement Multimeter

DCI ACI dB

LOCAL

REL# MATH COMP TYPE

1000V

750V

500Vpk

INPUT

FUSE

1.25A/1000V

Auto

DC + AC

TEMP

SENSE

COM

200Vpk

H I

10A 1A

CAT II 600V

dBm

Function keys

Sense LO TerminalPower Switch

Main Display

DC/AC 1A Terminal,

1.25A/1000V Fuse Holder

COM Terminal

Arrow keys

DC/AC 10A Terminal

Sense HI Terminal

V Terminal

Power Switch

POWER

Turns On or Off the main power. For the power up sequence, see page 24.

Main Display

Shows measurement results and parameters. For display configuration details, see page 78 (brightness setting).

For an overview of the main display, see page 19.

Input

Terminal

1000V

750V

INPUT

This terminal is used for all measurements except for DC/AC current measurements.

Appearance

GDM-8351 Front Panel

Page 14

GDM-8351 User Manual

COM Terminal

1000V

750V

500Vpk

INPUT

V W

COM

Accepts ground (COM) line in all measurements.

The maximum withstand voltage between this terminal and earth is 500Vpk.

DC/AC 1A Terminal

AMPS Fuse Holder

1000V

750V

500Vpk

INPUT

FUSE

1.25A/1000V

V W

COM

Low current measurement terminal. Accepts DC/AC Current input. For details see page 37.

DC: 10mA~1A AC: 10mA~1A

As a fuse, protects the instrument from over-current. Rating: F1.25A, 1000V.(This terminal accepts DC/AC current input)

For the fuse replacement procedure, see page 142.

DC/AC 10A Terminal

1000V

750V

500Vpk

INPUT

FUSE

1.25A/1000V

V W

SENSE

W 4W

COM

200Vpk

H I

10A 1A

CAT II 600V

High range current measurement terminal. Accepts DC/AC Current input. For DCI or ACI details, see page 37.

Page 15

GETTING STARTED

Sense HI Terminal

1000V

750V

500Vpk

INPUT

SENSE

COM

200Vpk

H I

Accepts HI sense line in 4W resistance measurement.

Sense LO Terminal

Accepts LO sense line in 4W resistance measurement.

Measurement Keys

The top row of measurement keys are used for basic DMM measurements such as voltage, current, resistance, capacitance and frequency. The bottom row of measurement functions are used for more advanced functions.

Each key has a primary and secondary function. The secondary function is accessed in conjunction with the SHIFT key.

Upper Measurement keys

DCV

DCI

Measures DC Voltage (page 32).

DCI (SHIFT→DCV)

SHIFT

EXIT

→

DCV

DCI

Measures DC Current (page

37).

ACV

ACI

Measures AC Voltage (page 32).

ACI (SHIFT→ACV)

SHIFT

EXIT

→

ACV

ACI

Measures AC Current (page

37).

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GDM-8351 User Manual

DCV + ACV

DCV

DCI

ACV

ACI

Measures DC + AC voltage (page 32).

DCI+ACI

SHIFT

EXIT

→

DCV

DCI

ACV

ACI

Measures DC + AC current (page 37).

2W/4W

TEMP

Measures resistance (2W or 4W) See page 42.

TEMP (SHIFT → 2W/4W)

SHIFT

EXIT

→

2W/4W

TEMP

Measures temperature. See page 53.

Measures diodes or continuity, depending on the selected mode. See page 45 and 48, respectively.

(SHIFT→

)

SHIFT

EXIT

→

Measures capacitance. See page 46.

Hz/P

Measures the frequency or period of a signal, depending on the selected mode. See page 51.

dB (SHIFT →

Hz/P

)

SHIFT

EXIT

→

Hz/P

Measures dB. See page 65.

Page 17

GETTING STARTED

2ND

LOCAL

As the 2ND key, selects the measurement item on the 2nd display (page 57). Pressing and holding for more than 1 second turns off the 2nd display.

As the Local key, releases the unit from remote control and returns the instrument to local panel operation (page 97).

Lower Measurement keys

REL

REL#

Measures the Relative value (page

67).

REL# (SHIFT→REL)

SHIFT

EXIT

→

REL

REL#

Manually sets the reference value for the Relative value measurement.

MX/MN

MATH

Measures the Maximum or the Minimum value (page 66).

MATH (SHIFT→ MX/MN)

SHIFT

EXIT

→

MX/MN

MATH

Enters the Math measurement mode. The supported math functions include MX+B, REF% and 1/X. See page 72 for details.

HOLD

COMP

Activates the Hold function (page

69).

Page 18

GDM-8351 User Manual

COMP (SHIFT→HOLD)

SHIFT

EXIT

→

HOLD

COMP

Activates the compare measurement function. See page 70.

FILTER

TYPE

Turns the digital filter on or off. See page 81.

TYPE (SHIFT→FILTER)

SHIFT

EXIT

→

FILTER

TYPE

Sets the type of filter and the size of the rolling window. See page 82.

dBm

Enters the configuration menu for System Settings, Measurement Settings, Temperature measurement settings, I/O settings, Terminal character settings and Firmware installation. See page 76 for the system menu.

dBm (SHIFT→MENU)

SHIFT

EXIT

→

dBm

Measures dBm/W, see page 63.

SHIFT/EXIT

SHIFT

EXIT

When used as a SHIFT key, it is used to access the secondary functions associated with the measurement keys.

When used as an EXIT key, it will exit out of menu systems.

Page 19

GETTING STARTED

AUTO/ENTER

Auto

Enter

When used as an AUTO key, it will set the range of the selected function to autorange.

When used as an ENTER key, it will confirm the entered value or menu item.

Arrow Keys

RANGE

The arrow keys are used to navigate the menu system and edit values.

The Up and Down arrow keys will also manually set the range for the voltage and current measurements.

The Left and Right arrow keys will also toggle the refresh rate between the fast, medium and slow (F, M, S) rates.

Primary Display

Secondary Display

Function status icons

Secondary

measurement units

Primary measurement units

Primary measurement

function icons

Secondary measurement function icons

REARGPIBUSBLANRS232FILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

USBSTOnμFMEMRATIO UNCAL

n μ F

120000 Counts Dual Measurement Multimeter

GDM-8351

Primary Measurement Function Icons

Displays the primary measurement function.

Display Overview

Page 20

GDM-8351 User Manual

Primary Measurement Units

Displays the units for the primary measurement function.

Secondary Display

Displays the results of the secondary measurement.

Secondary Measurement Units

Displays the units for the secondary measurement function.

Secondary Measurement function icons

Displays the secondary measurement function.

Function Status Icons

Display status icons for operations/functions that are not linked to the primary or secondary functions.

Primary Display

Displays the results of the primary measurement.

Page 21

Rear Panel

USB Device Port

Power Cord Socket

RS232 Port

Digital I/O port

100

220

120

240

SER.NO. LABEL

50 / 60 Hz

15VA MAX.

LINE RATING

FUSE LINE

100VAC 120VAC

220VAC 240VAC

0.125AT

0.063AT

TEST LEADS BEFORE REPLACING FUSE

DISCONNECT POWER CORD AND

REMOVE INPUTS BEFORE OPENING.

TO AVOID SHOCK,

WARNING

DIGITAL I / O

RS232

H.F L.F PASS EOM

SET3SET2SET1 SET4

TRIG

GND

Fuse 0.125AT/

0.063AT

Digital I/O Port

DIGITAL I / O

H.F L.F PASS EOM

SET3SET2SET1 SET4

TRIG

GND

The Digital I/O port is used for outputting the comparison test results, external triggering and as a user-defined output port. See page 89.

Power Cord Socket

100

220

120

240

Accepts the power cord. AC 100/120/220/240V ±10%, 50/60Hz

For power on sequence, see page 24.

Fuse Socket

100

220

120

240

Holds the main fuse:

100/120 VAC: 0.125AT 220/240 VAC: 0.063AT

For fuse replacement details, see page 141.

GETTING STARTED

Page 22

GDM-8351 User Manual

RS232

RS232 port. This port is used for remote control. See page 94.

USB Device Port

Type B USB port. This port is used for remote control. See page 94.

Page 23

GETTING STARTED

From the base of the handle, gently pull the handle out sideways and then rotate it to one of the following positions.

Horizontal position

Tilt stand position

Carry position

Set Up

Tilting the Stand

Page 24

Power Up

Steps

1. Ensure the correct line

voltage is lined up with the arrow on the fuse holder. If not, see page 141 to set the line voltage and fuse.

2. Connect the power

cord to the AC voltage input.

Note

Make sure the ground connector on the power cord is connected to a safety ground. This will influence the measurement accuracy.

3. Push to turn on the main

power switch on the front panel.

4. The display turns on and shows the last

function that was used before the power was reset.

GDM-8351 User Manual

Page 25

GETTING STARTED

Background

The following section will introduce to you how to access the basic functions on the DMM as well as how to navigate the menu system and edit the parameter values.

Using the Function keys

Any of the primary functions can be used by simply pressing the desired function key.

For example: To activate the DCV function, press the DCV key.

DCV

DCI

To activate a secondary function, first press the SHIFT key followed by the function key for the secondary function.

For example: To activate DCI measurement, first press the SHIFT key. SHIFT will be highlighted on the display. Next, press the DCV function key. This will activate the DCI mode.

SHIFT

EXIT

→

DCV

DCI

How to Use the Instrument

Page 26

GDM-8351 User Manual

Navigating the Menu System

The menu system is navigated with the Up, Down, Left and Right arrow keys, the Auto/Enter key and the SHIFT/EXIT key.

SHIFT

EXIT

Auto

Enter

RANGE

To enter the menu system, press the MENU key. See page 139 for the System Menu tree.

dBm

 Pressing the Left and Right arrow keys will

navigate to each of the menu items on the current menu level.

 Pressing the Down key will go down to the

next level of the menu tree.

 Conversely pressing the Up key will allow

you to go back to the previous menu level.

 Pressing Down or Enter on the last item in

a menu tree will allow you to edit the settings or parameters for that particular item or setting.

 Pressing the Exit key will allow you to exit

from the current settings and return to the previous menu tree level.

Page 27

GETTING STARTED

Editing a Setting or Parameter

When you access a menu or parameter setting, the Up, Down, Left and Right keys can be used again to edit the parameter as well.

Auto

Enter

RANGE

 If a setting or parameter is flashing, it

indicates that that particular parameter can be edited.

 Pressing the Left or Right arrow key will

allow you to select a digit or character to edit.

 Pressing the Up or Down keys will allow

you to edit the selected character.

Page 28

GDM-8351 User Manual

Basic Measurement Overview .......................................... 30

Refresh Rate ............................................................... 30

Reading Indicator ....................................................... 31

Automatic/Manual Triggering ................................... 31

AC/DC Voltage Measurement .......................................... 32

Select the Voltage Range ........................................... 33

Voltage Conversion Table .......................................... 35

Crest Factor Table ...................................................... 36

AC/DC Current Measurement .......................................... 37

Select the Current Range ........................................... 39

Resistance Measurement ................................................. 42

Select the Resistance Range ...................................... 44

Diode Test ....................................................................... 45

Capacitance Measurement ............................................... 46

Select the Capacitance Range .................................... 47

Continuity Test ................................................................ 48

Set Continuity Threshold ........................................... 49

Continuity Beeper Settings ........................................ 50

Frequency/Period Measurement ...................................... 51

Frequency/Period Settings ........................................ 52

Temperature Measurement .............................................. 53

Set the Temperature Units ........................................ 54

Select Thermocouple Type ........................................ 55

OPERATION

Page 29

OPERATION

Set the Reference Junction Temperature ................... 56

Dual Measurement Overview ........................................... 57

Supported dual measurement modes ....................... 57

Using Dual Measurement Mode ............................... 58

Advanced Measurement Overview ................................... 62

Supported Advanced Measurement Functions ........ 62

dBm/dB/W Measurement ................................................ 63

dBm/dB Calculation ................................................... 63

Measuring dBm/W .................................................... 63

Measure dB ................................................................ 65

Max/Min Measurement ................................................... 66

Relative Measurement ..................................................... 67

Hold Measurement ......................................................... 69

Compare Measurement ................................................... 70

Math Measurement ......................................................... 72

Math Measurement Overview ................................... 72

Measure MX+B .......................................................... 72

Measure 1/X ............................................................... 73

Measure Percentage................................................... 74

Page 30

GDM-8351 User Manual

Background

The refresh rate defines how frequently the DMM captures and updates measurement data. A faster refresh rate yields a lower accuracy. A slower refresh rate yields a higher accuracy. Consider these tradeoffs when selecting the refresh rate.

For further details, please see the specifications.

Refresh rate (Reading/S)

Function

S M F

Continuity/Diode

320

DCV/DCI

320

ACV/ACI

320

Frequency/Period

9.8

Temperature

320

Resistance

320

Capacitance

2 2 2

Steps

1. Press the left or right arrow keys to change the

refresh rate.

2. The refresh rate will be

shown at the top of the display.

F ↔ M ↔ S

Note

The refresh rate cannot be set for capacitance measurement.

Basic Measurement Overview

Refresh Rate

Page 31

OPERATION

Overview

1. The reading indicator next to the 1st display

flashes according to the refresh rate setting.

Overview

By default, the GDM-8351 automatically triggers according to the refresh rate. See the previous page for refresh rate setting details.

The TRIG IN pin of the digital I/O port or the *TRG remote command can be used to manually trigger acquisition when the trigger mode is set to EXT. See page 86 for trigger setting details.

Note

Manual triggering is not supported for capacitance measurements.

Reading Indicator

Automatic/Manual Triggering

Page 32

GDM-8351 User Manual

Set to ACV/DCV Measurement

1. Press the DCV or ACV key to measure DC or

AC voltage. For AC + DC voltage, press the ACV and DCV keys at the same time.

2. The mode will switch to AC, DC or AC+DC

mode immediately, as shown below.

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

AC & DC

indicator

Voltage

units

Measurement

range

Connection

Connect the test lead between the VΩ and the COM terminal. The display updates the reading.

1000V

750V

500Vpk

INPUT

FUSE

1.25A/1000V

SENSE

COM

200Vpk

H I

10A 1A

CAT II 600V

AC/DC Voltage Measurement

The GDM-8351 can measure up to 750VAC or 1000VDC, however the CATII measurement is only rated up to 600V.

Page 33

OPERATION

Auto Range

To turn the automatic range selection On/Off, press the AUTO key.

Manual Range

Press the Up or the Down key to select the range. The AUTO indicator turns Off automatically. If the appropriate range is unknown, select the highest range.

Selectable Voltage Ranges

Range

Resolution

Full scale

100mV

1μV

120mV

10μV

1.2V

10V

0.1mV

12V

100V

1mV

120V

750V (AC)

10mV

765V

1000V (DC)

10mV

1020V

Note

For further details, please see the specifications on page 145.

Note

DC voltages with AC components cannot be accurately measured if the DC+AC component exceeds the dynamic range for the selected DC range. Any voltage exceeding the dynamic range will be clipped at the upper/lower range limit. Under these conditions the range that is chosen with the Auto range function may be too small.

Select the Voltage Range

The voltage range can be set automatically or manually.

Page 34

GDM-8351 User Manual

For example:

Dynamic Range

C D

A,B: Input exceeds the dynamic range.

C,D: The DCV offset causes the input to exceed the upper dynamic range.

E: The DCV offset causes the input to exceed the lower dynamic range.

The DC voltage range should be manually selected when all of the following conditions are true:

 When DCV measurement is used.  When the signals being measured contain both

DC and AC components.

 When the amplitude of the AC component in

the measured signal is higher or lower than the dynamic range of the range being currently selected by the auto-range function.

Maximum DCV Dynamic Range

Selected DCV Range

Dynamic Range

DC 100mV

±180mVmax

DC 1V

±1.8Vmax

DC 10V

±18Vmax

DC 100V

±180Vmax

DC 1000V

±1000Vmax

Page 35

OPERATION

Waveform

Peak to Peak

AC (True RMS)

Sine

2.828

1.000

0.000

Rectified Sine (full wave)

1.414

0.435

0.900

Rectified Sine (half wave)

2.000

0.771

0.636

Square

2.000

1.000

0.000

Rectified Square

1.414

0.707

Rectangular Pulse

2.000

( DD 

D=X/Y

Triangle Sawtooth

3.464

1.000

0.000

PK-PK

Voltage Conversion Table

This table shows the relationship between an AC and DC reading for various waveforms.

Page 36

GDM-8351 User Manual

Background

Crest factor is the ratio of the peak signal amplitude to the RMS value of the signal. It determines the accuracy of AC measurement.

If the crest factor is less than 3.0, voltage measurement will not result in error due to dynamic range limitations at full scale.

If the crest factor is more than 3.0, it usually indicates an abnormal waveform as seen from the below table.

Crest Factor Table

Waveform

Shape

Crest factor

Square wave

1.0

Sine wave

1.414

Triangle sawtooth

1.732

Mixed frequencies

1.414 ~ 2.0

SCR output 100% ~ 10%

1.414 ~ 3.0

White noise

3.0 ~ 4.0

AC Coupled pulse train

>3.0

Spike

>9.0

Crest Factor Table

Page 37

OPERATION

Set to ACI/DCI Measurement

1. Press SHIFT → DCV or SHIFT → ACV to

measure DC or AC current, respectively.

For AC+DC current, press SHIFT followed by both the DCV and ACV key at the same time.

2. The mode will switch to AC, DC or AC+DC

mode immediately, as shown below.

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

AC & DC

indicator

Current

units

Measurement

range

Connection

Connect the test lead between the 10A terminal and the COM terminal or DC/AC 1A terminal and the COM terminal, depending on the input current.

For current ≤ 1A use the 1A terminal; For current up to 10A use the 10A terminal. The display updates the reading.

AC/DC Current Measurement

The GDM-8351 series DMMs have two input terminals for current measurement. A 1A terminal for current less than 1A and a 10A terminal for measurements up to 10A.

The units can measure 0 ~ 10A for both AC and DC current.

Page 38

GDM-8351 User Manual

1000V

750V

500Vpk

INPUT

FUSE

1.25A/1000V

SENSE

COM

200Vpk

H I

10A 1A

CAT II 600V

Max 1A

Max 10A

Page 39

OPERATION

Auto Range

To turn the automatic range selection On/Off, press the AUTO key. The most appropriate range for the currently used input jack will be automatically selected. The DMM is able to do this by remembering the last manually selected range and using that information to determine the smallest current range that the auto-range function will switch to.

When the current input is switched to another terminal, the range must be manually set.

Manual Range

Press the Up or the Down key to select the range. The AUTO indicator turns Off automatically. If the appropriate range is unknown, select the highest range.

Selectable Current Ranges

Range

Resolution

Full scale

INJACK

10mA

100nA

12mA

100mA

1μA

120mA

100μA

1.2A

10A

1mA

12A

10A

Note

For further details, please see the specifications on page 145.

Select the Current Range

The current range can be set automatically or manually.

Page 40

GDM-8351 User Manual

Note

DC currents with AC components cannot be accurately measured if the DC+AC component exceed the dynamic range for the selected DC range. Any current exceeding the dynamic range will be clipped at the upper/lower range limit. Under these conditions the range that is chosen with the Auto range function may be too small.

For example:

Dynamic Range

C D

A,B: Input exceeds the dynamic range.

C,D: The DCI offset causes the input to exceed the upper dynamic range.

E: The DCI offset causes the input to exceed the lower dynamic range.

The DC current range should be manually selected when all of the following conditions are true:

 When DCI measurement is used.  When the signals being measured contain both

DC and AC components.

 When the amplitude of the AC component in

the measured signal is higher or lower than the dynamic range of the range being currently selected by the auto-range function.

Page 41

OPERATION

Maximum DCI Dynamic Range

Selected DCI Range

Dynamic Range

DC 10mA

± 30mA max

DC 100mA

± 300mA max

DC 1A

± 1.25A max

DC10A

± 12A max

Page 42

GDM-8351 User Manual

Measurement Type

2-wire

Uses the standard V-COM ports. Recommended for measuring resistances larger than 1kΩ.

4-wire

Compensates the test lead effect using the 4W compensation ports(HI/LO sense ports), in addition to the standard V-COM ports. Recommended for measuring sensitive resistances smaller than 1kΩ.

Set to 2W or 4W Measurement

1. Press the 2W/4W key once to activate 2W

resistance measurement.

Press the 2W/4W key twice to activate 4W resistance measurement.

2. The mode will switch to the selected resistance

mode immediately, as shown below.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

2W/4W

indicator

Resistance

units

Measurement

range

Connection

For 2W measurement, connect the test leads between the VΩ terminal and the COM terminal.

For 4W measurement, connect the test leads between the VΩ terminal and the COM terminal, as you would for 2W measurement. Connect the sense leads between the LO and HI sense terminals.

Resistance Measurement

Page 43

OPERATION

1000V

750V

500Vpk

INPUT

FUSE

SENSE

COM

200Vpk

H I

10A 1A

CAT II 600V

4W only

4W & 2W

Page 44

GDM-8351 User Manual

Auto Range

To turn the automatic range selection On/Off, press the AUTO key.

Manual Range

Press the Up or the Down key to select the range. The AUTO indicator turns Off automatically. If the appropriate range is unknown, select the highest range.

Selectable Resistance Ranges

Range

Resolution

Full scale

100Ω

1mΩ

120Ω

1kΩ

10mΩ

1.2kΩ

10kΩ

100mΩ

12kΩ

100kΩ

1Ω

120kΩ

1MΩ

10Ω

1.2MΩ

10MΩ

100Ω

12MΩ

100MΩ

1kΩ

120MΩ

Note

For further details, please see the specifications on page 147.

Select the Resistance Range

The resistance range can be set automatically or manually.

Page 45

OPERATION

Set to Diode Measurement

1. Press the

key once to activate diode measurement. Note: pressing the

key twice will activate

the continuity measurement instead.

2. The mode will switch to Diode mode

immediately, as shown below.

Display

Diode

state

Diode function

indicator

CVCCSWEEPFILTRCLSTOCOMP2ND

SHIFTERRLIMITAUTOMATH4W2WDCAC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDC

Connection

Connect the test lead between the VΩ terminal and COM terminal; Anode-V, Cathode-COM. The display updates the reading.

1000V

750V

500Vpk

INPUT

FUSE

SENSE

COM

200Vpk

H I

10A 1A

CAT II 600V

Diode Test

The diode test checks the forward bias characteristics of a diode by running a constant forward bias current of approximately 1mA through the DUT.

Page 46

GDM-8351 User Manual

Set to Capacitance Measurement

1. Press the SHIFT →

( ) keys to activate

capacitance measurement.

2. The mode will switch to capacitance mode

immediately, as shown below.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

μF

Capacitance

indicator

Capacitance

units

Measurement

range

Connection

Connect the test lead between the VΩ

terminal and COM terminal; Positive-V, Negative-COM. The display updates the reading.

1000V

750V

500Vpk

INPUT

FUSE

SENSE

COM

200Vpk

H I

10A 1A

CAT II 600V

Capacitance Measurement

The capacitance measurement function checks the capacitance of a component.

Page 47

OPERATION

Auto Range

To turn the automatic range selection On/Off, press the AUTO key.

Manual Range

Press the Up or the Down key to select the range. The AUTO indicator turns Off automatically. If the appropriate range is unknown, select the highest range.

Selectable Capacitance Ranges

Range

Resolution

Full scale

10nF

10pF

12nF

100nF

100pF

120nF

1μF

1nF

1.2μF

10μF

10nF

12μF

100μF

100nF

120μF

Note

For further details, please see the specifications on page 149.

Note

The refresh rate settings and the EXT trigger cannot be used in the capacitance mode.

Select the Capacitance Range

The capacitance range can be set automatically or manually.

Page 48

GDM-8351 User Manual

Procedure

1. Press the

key twice to activate continuity testing. Note: pressing the

key once will activate

diode testing.

2. The mode will switch to continuity testing

immediately, as shown below.

Display

Continuity

state

Continuity function

indicator

Connection

Connect the test lead between the VΩ terminal and COM terminal. The display updates the reading.

1000V

750V

500Vpk

INPUT

FUSE

1.25A/1000V

SENSE

COM

200Vpk

H I

10A 1A

CAT II 600V

Continuity Test

The continuity test checks that the resistance in the DUT is low enough to be considered continuous (of a conductive nature).

Page 49

OPERATION

Range

Threshold

0 to 1000Ω (Default Threshold:10Ω)

Resolution

1Ω

Procedure

1. Press MENU.

2. Go to the MEAS menu on level 1

3. Go to the CONT menu on level 2

4. Set the continuity threshold level in ohms.

5. Press the Enter key to confirm the continuity

settings.

6. Press EXIT to exit the CONT setting menu.

Display

Continuity

setting

Continuity function

indicator

Set Continuity Threshold

The continuity threshold defines the maximum resistance allowed in the DUT when testing the continuity.

Page 50

GDM-8351 User Manual

Range

PASS

Beeps when the continuity passes.

FAIL

Beeps when the continuity fails.

OFF

Beeper is turned off.

Procedure

1. Press MENU.

2. Go to the SYSTEM menu on level 1

3. Go to the BEEP menu on level 2

4. Set the BEEP setting to PASS, FAIL or OFF.

5. Press the Enter key to confirm the beeper

settings.

6. Press EXIT to exit the BEEP setting menu.

Display

Beep

setting

Beep menu

indicator

Continuity Beeper Settings

The beeper setting defines how the GDM-8351 notifies the continuity test result to the user.

Note: When the Beeper setting is off it will also turn off the keypad tones as well as any error or warning tones.

Page 51

OPERATION

Range

Frequency

10Hz~1MHz

Period

1.0μs ~100ms

Procedure

To measure frequency, press the Hz/P key once. The frequency will be displayed on the primary screen and the range will be displayed on the secondary display.

To measure the period, press the Hz/P key twice. The period will be displayed on the primary screen and the range will be displayed on the secondary display.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Measurement

Frequency or

period units

Voltage/Current

range setting

Connection

Connect the test lead between the VΩ terminal and the COM terminal. The display updates the reading.

1000V

750V

500Vpk

INPUT

SENSE

COM

200Vpk

H I

Frequency/Period Measurement

The GDM-8351 can be used to measure the frequency or period of a signal. This function can measure either the voltage frequency/period or current frequency/period, depending on which jack the input signal is input from.

Page 52

GDM-8351 User Manual

Range

Voltage

100mV, 1V, 10V, 100V, 750V

Current

10mA, 100mA, 1A, 10A

Note

The input jack setting determines whether the voltage frequency/period or current frequency/period is being measured. See page 80 for details.

Manual Range

Set the range with the Up and Down keys. The AUTO indicator will turn off when a new range is selected.

Autorange

1. Press the Auto/Enter key.

2. AUTO will be displayed on the screen again.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

Vmm

HzWkM

SFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Autorange

indicator

Voltage/Current

range setting

Note

Pressing the 2nd key twice will toggle the view of the second display between the voltage/current range and the menu function (FREQ or PERIOD).

Note that the voltage/current range can actually still be set even when the secondary display has been toggled to show the menu function.

Frequency/Period Settings

The input voltage/current range for frequency/period measurements can be set to Auto range or to Manual. By default, the voltage/current range is set to Auto for both the period and frequency.

Page 53

OPERATION

Temperature Range & Type

Thermocouple:

-200°C ~ +300°C

Type:

J, K, T

Procedure

To make temperature measurements, press SHIFT → 2W/4W (TEMP).

The temperature mode appears showing the temperature on the primary display and the type of sensor on the secondary display.

Display

GPIBCVCCSWEEPFILTRCLSTOCOMP2ND

EXTSHIFTERRLIMITAUTOMATH4W2WDCAC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Measurement

Temp.

units

Sensor type

Connection

Connect the sensor lead between the VΩ terminal and the COM terminal. The display updates the reading.

1000V

750V

500Vpk

INPUT

FUSE

1.25A/1000V

SENSE

COM

200Vpk

H I

10A 1A

CAT II 600V

Temperature Measurement

The GDM-8351 can measure temperature using a thermocouple. To measure temperature, the DMM accepts a thermocouple input and calculates the temperature from the voltage fluctuation. The thermocouple type and reference junction temperature are also considered.

Page 54

GDM-8351 User Manual

Range

Units

˚C, ˚F

Procedure

1. Press the MENU key.

2. Go to TEMP on level 1.

3. Go to UNIT on level 2.

4. Select either C (Celsius) or F (Farenheit).

5. Press the Enter key to confirm.

6. Press the EXIT key to exit from the temperature

menu.

Display

Temperature

unit setting

Unit menu

indicator

Set the Temperature Units

Page 55

OPERATION

Thermocouple type and range

Type

Measurement Range

Resolution

J -200 to +300˚C

0.01 °C

K -200 to +300˚C

0.01 °C

T -200 to +300˚C

0.01 °C

Procedure

1. Press the MENU key.

2. Go to TEMP on level 1.

3. Go to SENSOR on level 2.

4. Select the thermocouple type (J, K, T).

5. Press the Enter key to confirm.

6. Press the EXIT key to exit from the temperature

menu.

Display

Thermocouple

type setting

Sensor menu

indicator

Select Thermocouple Type

The GDM-8351 accepts thermocouple inputs and calculates the temperature from the voltage difference of two dissimilar metals. Thermocouple type and reference junction temperature are also considered.

Page 56

GDM-8351 User Manual

Range

SIM

0 ~ 50˚C (default: 23.00˚C)

Resolution

0.01˚C

Procedure

1. Press the MENU key.

2. Go to TEMP on level 1.

3. Go to SIM on level 2.

4. Set the SIM (simulated) reference junction

temperature.

5. Press the Enter key to confirm.

6. Press the EXIT key to exit from the temperature

menu.

Display

Reference junction

temperature setting

SIM menu

indicator

Set the Reference Junction Temperature

When a thermocouple is connected to the DMM, the temperature difference between the thermocouple lead and the DMM input terminal should be taken into account and be cancelled out; otherwise an erroneous temperature might be added. The value of the reference junction temperature should be determined by the user.

Page 57

OPERATION

Supported Dual Measurement modes

Primary

Display

Secondary Display

ACV

DCV

ACI

DCI

Hz/P

Ω

ACV

● ● ● ● ●

DCV

● ● ●

●

X X ACI

● ● ● ● ●

DCI

● ● ●

●

Hz/P ● X ● X ● X Ω X X X X X

●

Dual Measurement Overview

The dual measurement mode allows you to use the 2nd display to show another item, thus allowing you to view two different measurement results on the screen.

When the multimeter is used in dual measurement mode, both displays are updated from either a single measurement or from two separate measurements. If the primary and secondary measurement modes have the same range, rate and rely on the same fundamental measurement, then a single measurement is taken for both displays; such as ACV and frequency/period measurements. If the primary and secondary displays use different measurement functions, ranges or rates, then separate measurements will be taken for each display. For example, ACV and DCV measurements.

Most of the basic measurement functions, except for resistance/continuity can be used in the dual measurement mode.

Supported Dual Measurement Modes

The following table lists all the measurement functions that are supported with the dual measurement function.

Page 58

GDM-8351 User Manual

Procedure

1. Choose one of the basic measurement functions

from the table above to set the measurement mode for the primary display.

For example, press DCV to set the first display to DCV measurement.

2. To set a measurement mode for the second

display, press the 2ND key and then select the second measurement mode.

For example, press 2ND, SHIFT, ACV(ACI) to select ACI measurement for the second display.

Display

Indicators for 1st

measurement

2nd measurement

and unit

Indicators for 2nd

measurement

1st measurement

and unit

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Using Dual Measurement Mode

Page 59

OPERATION

Editing the Measurement Parameters

After the secondary measurement function has been activated, the rate, range and measurement item can be edited for either the primary or secondary display. Note however, it is more practical to configure the first or second measurement items before activating dual measurement mode.

To edit measurement parameters in dual measurement mode, you must first set which display is the active display. The 2ND icon under the secondary display determines which display is the active display.

Procedure

1. Toggle whether the primary or secondary

display is the active display by pressing the 2ND key:

Primary display is the active display: 2ND is not visible on the display.

Secondary display is the active display: 2ND is visible on the display.

Note

Do not hold the 2ND key. This will turn the dual measurement mode off.

2. Edit the range, rate or measurement item for

the active display in the same way as for single measurement operation. See the Basic Measurement chapter for details (page 30).

Turn Off 2nd Measurement

To turn Off the second measurement, press and hold the 2ND key for more than 1 second.

Page 60

GDM-8351 User Manual

Connection

The diagrams below describe how to connect the DMM to measure a number of common dual measurement items.

Voltage and Frequency/Period measurement

1000V

750V

500Vpk

INPUT

FUSE

1.25A/1000V

SENSE

COM

200Vpk

H I

10A 1A

CAT II 600V

Page 61

Voltage/Frequency/Period and Current Measurement

1000V

750V

500Vpk

INPUT

FUSE

1.25A/1000V

SENSE

COM

200Vpk

CAT II 600V

Load

0~1A

0~10A

Note: DC Current measurements will be displayed as a negative value as the polarity of the current leads has been reversed.

Please take into account the resistance of the test leads and internal resistance of the current connection as it is in series with the test circuit.

The above measuring configuration is used to measure the voltage present on the resistance under test and the current through the resistance under test when using the DCI/DCV or ACI/ACV dual measurement function.

OPERATION

Page 62

GDM-8351 User Manual

Advanced

Meas.

Basic Measurement

ACV/

DCV

ACI/

DCI

Ω

Hz/P

TEMP

DIODE

CAP

dB ● X X X X X

dBm ● X X X X X

Max/Min

● ● ● ● ●

●

Relative

● ● ● ● ●

●

Hold

● ● ● ● ●

Compare

● ● ● ● ●

●

Math

● ● ● ● ●

Advanced Measurement Overview

Advanced measurement mainly refers to the type of measurement which uses the result obtained by one of the basic measurements: ACV, DCV, ACI, DCI, Resistance, Diode/Continuity, Frequency/Period, and Temperature.

Supported Advanced Measurement Functions

The following table lists all the advanced measurement functions and which of the basic measurement functions that they support.

Page 63

OPERATION

Overview

Using the ACV or DCV measurement results, the DMM calculates the dB or dBm value based on a reference resistance value in the following way:

dBm= 10 x log10 (1000 x Vreading2 / Rref)

dB= dBm – dBmref

W= Vreading2/Rref

Where: Vreading= Input Voltage, ACV or DCV;

Rref= Reference resistance simulating an output load;

dBmref= Reference dBm value

Procedure

1. Select ACV or DCV measurement. See page 32.

2. To measure dBm, press SHIFT →

MENU(dBm)

The primary display will show the dBm measurement while the secondary display shows the reference resistance.

dBm/dB/W Measurement

dBm/dB Calculation

Measuring dBm/W

Page 64

GDM-8351 User Manual

Display

dBm

measurement

Reference

resistance

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

Vmm

HzWkM

SFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Setting the Reference Resistance

To set the reference resistance, use the Up and Down arrow keys.

The selectable reference resistances are shown below.

Selectable reference resistances

2 4 8 16

110

124

125

135

150

250

300

500

600

800

900

1000

1200

8000

View the result in Watts

When the reference resistance is less than 50Ω, it is possible to calculate the power (in watts). If the reference resistance is equal to or greater than 50Ω, then this step can be ignored.

Press SHIFT →

MENU(dBm)

again to view the

result in watts.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Power measurement

and unit

Reference

resistance

Exit dBm Measurement

Press SHIFT →

MENU(dBm)

again to exit the

dBm measurement, or simply activate another measurement function.

Page 65

OPERATION

Procedure

1. Select ACV or DCV measurement. See page 32.

2. Press the SHIFT → Hz/P(dB) keys to activate

the dB measurement mode.

The 1st display shows the dB reading, the second display shows the voltage reading.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

measurement

Voltage

reading

View the dBm Reference Value

To view the dBm reference value, press the 2ND key.

The Up and Down arrow keys can also be used to change the voltage range or the reading.

Exit dB Measurement

Press the SHIFT → Hz/P(dB) keys again to exit the dB measurement, or simply activate another measurement function.

Measure dB

dB is defined as [dBm−dBmref]. When the dB measurement is

activated, the DMM calculates the dBm using the reading at the first moment and stores it as dBmref.

Page 66

GDM-8351 User Manual

Applicable measurements

The Max/Min function can be used with the following basic measurement functions:

ACV, DCV, ACI, DCI, Ω, Hz/P, TEMP,

Procedure

For Max measurement, press the MX/MN key once.

For Min measurement, press the MX/MN key twice.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Basic meas.

function

Max/Min indicator

Measurement

range

View Max/Min Value

Press the 2ND key to view the Max or Min value.

Display

CVCCSWEEPFILTRCLSTOCOMP2ND

SHIFTERRLIMITAUTOMATH4W2WDCAC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Max/Min

reading

Max/Min

mode

Deactivate Max/Min Measurement

Hold the MX/MN key for two seconds to deactivate, or simply activate another measurement function.

Max/Min Measurement

Maximum and Minimum measurement function stores the highest (maximum) or lowest (minimum) reading and shows it on the first display when the 2ND key is pressed.

Page 67

OPERATION

Applicable measurements

The relative function can be used with the following basic measurement functions: ACV, DCV, ACI, DCI, Ω, Hz/P, TEMP,

Procedure

Press the REL key. The measurement reading at that instant becomes the reference value.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Relative

value

Range

View Relative Reference Value

Press the 2ND key to view the relative reference value at full scale.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Relative

reference value

Relative Measurement

Relative measurement stores a value, typically the data at that instant, as the reference. The measurement following the reference is displayed as the delta between the reference. The reference value will be cleared upon exiting.

Page 68

GDM-8351 User Manual

Manually Set the Relative Reference Value

1. To manually set the relative reference value,

press SHIFT → REL(REL#).

The REL value is displayed on the screen at full scale.

2. Use the Left and Right arrow keys to navigate

to the digit to be edited or to select the decimal point.

Use the Up and Down arrow keys to edit the selected digit or to place the position of the decimal point.

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

3. Press the Enter key to confirm, alternatively

press Exit to cancel setting the relative reference value.

Display

Relative

value setting

REL setting

mode

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Deactivate Relative Measurement

Press the REL key again to deactivate the Relative measurement mode, or simply activate another measurement function.

Page 69

OPERATION

Applicable measurements

The hold function can be used with the following basic measurement functions:

ACV, DCV, ACI, DCI, Ω, Hz/P, TEMP

Procedure

1. Press the HOLD key.

2. The measurement reading appears on the

primary display and the hold threshold on the secondary display.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

Vmm

WkM

SFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Measurement

reading

Hold

threshold

Set the Hold Threshold

Use the Up and Down arrow keys to select a hold threshold level, as a percentage.

Range

0.01%, 0.1%, 1%, 10%

Deactivate Hold Measurement

Press the HOLD key for 2 seconds to deactivate the hold measurement, or simply activate another measurement function.

Hold Measurement

The Hold Measurement function retains the current measurement data and updates it only when it exceeds the set threshold (as a percentage of the retained value).

Page 70

GDM-8351 User Manual

Applicable measurements

The compare function can be used with the following basic measurement functions:

ACV, DCV, ACI, DCI, Ω, Hz/P, TEMP,

Procedure

1. Press SHIFT → HOLD(COMP).

2. The high limit setting appears.

Use the Left and Right arrow keys to navigate to the digit to be edited, or to select the decimal point.

Use the Up and Down arrow keys to edit the selected digit, or to place the position of the decimal point.

3. Press the Enter key to save the high limit setting

and automatically go on to the low limit setting.

4. Enter the low limit setting in the same fashion

as the high setting.

5. Press the Enter key to confirm the low limit

settings.

6. The compare measurement results will appear

immediately:

If the current measurement reading is between

Compare Measurement

Compare measurement checks to see if the measurement data stays between a specified upper (high) and lower (low) limit.

Page 71

OPERATION

the high and low limits, PASS will be displayed on the secondary display, If the reading is below the low limit, LOW will be displayed. If the reading is above the high limit, HIGH will be displayed.

Display

GPIBCVCCSWEEPFILTRCLSTOCOMP2ND

EXTSHIFTERRLIMITAUTOMATH4W2WDCAC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Measurement

reading

Compare

result

Deactivate Compare Measurement

Press SHIFT → HOLD(COMP) to deactivate compare measurements, or simply activate another measurement function.

Page 72

GDM-8351 User Manual

Applicable Measurements

The math function can be used with the following basic measurement functions: ACV, DCV, ACI, DCI, Ω, Hz/P, TEMP

Overview of Math Functions

MX+B

Multiplies the reading (X) by the factor (M) and adds/subtracts offset (B).

1/X

Inverse. Divides 1 by the reading (X).

Percentage

Runs the following equation:

100%

Reference

Reference)-(ReadingX

Procedure

1. Press SHIFT → MX/MN(MATH) to enter the

MATH menu.

The MX+B setting appears. The M factor will be flashing, indicating that the M factor is to be set.

2. Use the Left and Right arrow keys to navigate

to the digit to be edited or to select the decimal point.

Use the Up and Down arrow keys to edit the selected digit or to place the position of the

Math Measurement

Math Measurement Overview

Math measurement runs three types of mathematical operations, MX+B, 1/X and Percentage based on the other measurement results.

Measure MX+B

Page 73

OPERATION

decimal point.

3. Press Enter to confirm the M factor settings and

to automatically move onto the B offset setting.

4. Edit the B offset in the same fashion as the M

factor was edited.

5. Press Enter to confirm the B offset setting and

to begin the MX+B measurement.

Display

GPIBCVCCSWEEPFILTRCLSTOCOMP2ND

EXTSHIFTERRLIMITAUTOMATH4W2WDCAC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

MX+B meausurement

reading

MX+B math

indicator

Deactivate Math Measurement

Press SHIFT → MX/MN(MATH) to deactivate the MATH function, or simply activate another measurement function.

Procedure

1. Press SHIFT → MX/MN(MATH) to enter the

MATH menu.

The MX+B setting appears.

2. Press the Down key twice to skip past MX+B

settings and go to the 1/X settings.

1/X will be flashing in the secondary display.

Measure 1/X

Page 74

GDM-8351 User Manual

3. Press Enter to activate the 1/X math function.

The results begin immediately.

Display

GPIBCVCCSWEEPFILTRCLSTOCOMP2ND

SHIFTERRLIMITAUTOMATH4W2WDCAC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

1/X

measurement

1/X math

indicator

Deactivate Math Measurement

Press the SHIFT → MX/MN(MATH) to deactivate the MATH function, or simply activate another measurement function.

Procedure

1. Press SHIFT → MX/MN to enter the MATH

menu.

2. The MX+B setting appears. Press the Up key to

skip past MX+B settings and go to the REF% settings.

REF% will be flashing in the secondary display.

3. Use the Left and Right arrow keys to navigate

to the digit to be edited or to select the decimal point.

Use the Up and Down arrow keys to edit the selected digit or to place the position of the decimal point.

Measure Percentage

Page 75

OPERATION

4. Press Enter to confirm the REF% setting and to

begin the Percentage measurement.

Display

SDCVAUTO

MATH

Calculated percentage

meausurement

% function

indicator

Deactivate Math Measurement

Press SHIFT → MX/MN to deactivate the MATH function, or simply activate another measurement function.

Page 76

GDM-8351 User Manual

View Serial Number ......................................................... 77

View Version Number ...................................................... 77

Brightness Settings ......................................................... 78

Input Resistance Settings ................................................ 79

Frequency/Period Input Jack Settings .............................. 80

Digital Filter .................................................................... 81

Digital Filter Overview ............................................... 81

Digital Filter Type Settings......................................... 83

Restore Factory Default Settings ...................................... 85

Trigger ............................................................................ 86

Trigger Settings .......................................................... 86

External Trigger .......................................................... 87

SYSTEM/DISPLAY

CONFIGURATION

Page 77

SYSTEM/DISPLAY CONFIGURATION

Procedure

1. Press the MENU key.

2. Go to SYSTEM on level 1.

3. Go to S/N on level 2.

4. The serial number will be displayed across both

the primary and secondary display.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Exit

Press the EXIT key twice to go back to the measurement screen.

Procedure

1. Press the MENU key.

2. Go to FW on level 1.

3. Go to VER on level 2.

4. The firmware version number will be displayed

in the secondary display.

5. Press Exit to exit from the version menu.

Display

Note

For details about firmware updates, please contact the GW Instek Service Center or visit the GW Instek website at www.gwinstek.com.

View Serial Number

View Version Number

Page 78

GDM-8351 User Manual

Range

Brightness

1 (dim) ~ 5 (bright)

Procedure

1. Press the MENU key.

2. Go to SYSTEM on level 1.

3. Go to LIGHT on level 2.

4. Set the light setting between 1 (dim) and 5

(bright).

5. Press the Enter key to confirm.

6. Press the EXIT key to exit from the brightness

settings.

Display

Brightness setting

Brightness Settings

The display has 5 settable brightness levels.

Page 79

SYSTEM/DISPLAY CONFIGURATION

Range

Input resistance

10MΩ, 10GΩ

Default

10MΩ

Procedure

1. Press the MENU key.

2. Go to MEAS on level 1.

3. Go to INPUT R on level 2.

4. Set the input resistance to 10MΩ or 10GΩ

5. Press the Enter key to confirm.

6. Press the EXIT key to exit from the input

resistance menu.

Display

Input resistance

setting

Input Resistance Settings

The 100mV and 1V DC voltage ranges can be set to an input

resistance of 10MΩ or 10GΩ. This setting is only applicable for DC

voltage.

Page 80

GDM-8351 User Manual

Range

Injack

VOLT, 1A, 10A

Default

VOLT

Procedure

1. Press the MENU key.

2. Go to MEAS on level 1.

3. Go to INJACK on level 2.

4. Set the INJACK setting to either VOLT, 1A or

10A.

5. Press the Enter key to confirm.

6. Press the EXIT key to exit from the INJACK

menu.

Display

INJACK setting

Frequency/Period Input Jack Settings

The INJACK settings set which input terminal is used for frequency or period measurements.

Page 81

SYSTEM/DISPLAY CONFIGURATION

Filter Basics

The digital filter converts the analog input signal into digital format before passing it to the internal circuits for processing. The filter affects the amount of noise included in the measurement result.

Filter Type

The digital filter averages a specific number of input signal samples to generate one reading. The filter type defines the averaging method. The following diagrams show the differences between each filter type, using 4 samples per reading as an example.

Moving Filter

The moving filter takes in one new sample and discards the oldest sample per reading. This is the default behavior when the digital filter is not specified, and is recommended for most applications.

Repeating Filter

The repeating filter renews all the samples per reading.

1Sample #

1st reading Sample 1 - 4

2nd reading Sample 2 - 5

32 4 5 6 7 8 9 10 11 12

3rd reading Sample 3 - 6

1Sample #

1st reading

Sample 1 - 4

2nd reading

Sample 5 - 8

32 4 5 6 7 8 9 10 11 12

3rd reading

Sample 9 - 12

Digital Filter

Digital Filter Overview

Page 82

GDM-8351 User Manual

Filter Count

Filter count defines the number of samples to be averaged per reading. More samples offer low noise but a longer delay between measurements. Less samples offer high noise but a shorter delay between measurements.

Range:

2 ~ 320

Filter Window

The filter window defines the threshold for when the digital filter data is updated again. When the AD data falls in the range between TH and TL, the filter keeps processing. When the AD data falls out of the range between TH and TL, the filter will restart. When measuring unstable signals, appropriately setting the filter window can improve the measurement speed.

Time

AD data

TH TL

Filter

Restart

TH: Threshold High, TL: Threshold Low

Filter Window Formula

Previous data*(1-window)< threshold< previous data*(1+window).

Range:

10%, 1%, 0.1%, 0.01% and none

Page 83

SYSTEM/DISPLAY CONFIGURATION

Procedure

1. Press SHIFT → FILTER(TYPE) to enter the

(Digital Filter) Type settings menu.

2. Use the Left and Right arrow keys to navigate

to the filter type setting or to select the digit to be edited.

Use the Up and Down arrow keys to edit the selected digit or to toggle the filter type (REP<>MOV).

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

3. Press Enter to confirm the filter type and the

CNT setting. The DMM will now automatically go to the WINDOW setting.

4. Use the Up and Down arrow keys to set the

window threshold settings.

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

5. Press Enter to confirm the settings.

6. Press EXIT to cancel.

Digital Filter Type Settings

Page 84

GDM-8351 User Manual

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

Filter indicator

Deactivate Digital Filter

Press FILTER to deactivate the FILTER function.

Page 85

SYSTEM/DISPLAY CONFIGURATION

Range

Factory DEF

YES, NO

Procedure

1. Press the MENU key.

2. Go to SYSTEM on level 1.

3. Go to FACTORY on level 2.

4. Set the (FACTORY) DEF setting to YES or NO.

Choosing YES will restore the factory default settings.

5. Press the Enter key to confirm and to restore

the factory default settings immediately.

“OK DEF” will be displayed when the default settings are restored.

Display

Factory default setting

Restore Factory Default Settings

The factory default settings can be restored at anytime from the System menu. Please see the Appendix on page 140 for a list of the factory default settings.

Page 86

GDM-8351 User Manual

Range

Trigger

INT, EXT

Procedure

1. Press the MENU key.

2. Go to MEAS on level 1.

3. Go to TRIG on level 2.

4. Set the TRIG setting to either INT or EXT.

5. Press the Enter key to confirm.

6. Press the EXIT key to exit from the TRIG menu.

Display

GPIBCVCCSWEEPFILTRCLSTOCOMP2ND

SHIFTERRLIMITAUTOMATH4W2WDCAC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

INJACK setting

Trigger

The measurements can be triggered internally or externally. When set to internal, the DMM will be triggered automatically according the refresh rate. When set to external, the DMM will wait for an external trigger signal from the Digital I/O port or from the *TRG command. See page 88 & 137 for more details.

Trigger Settings

Page 87

SYSTEM/DISPLAY CONFIGURATION

Digital I/O

Pin 5

Pin 6

Digital I/O Terminal

Trigger input

≥10μs

External Trigger

The external trigger uses the digital I/O pin for manual triggering of the DMM. Pin 5 of the digital I/O port is normally high. To trigger the DMM a low pulse of ≥10μs is needed.

The *TRG command can also be used to externally trigger the DMM when the DMM is in the external trigger mode. See page 137 for details.

Page 88

GDM-8351 User Manual

Digital I/O Overview ....................................................... 89

Normal Mode ............................................................. 90

User Mode .................................................................. 91

DIGITAL I/O

Page 89

DIGITAL I/O

Pinout

DIGITAL I / O

H.F L.F PASS EOM

SET3SET2SET1 SET4

TRIG

GND

Pin No.

Normal Mode

User Mode

1 High Fail

Set 1

2 Low Fail

Set 2

3 Pass

Set 3

4 EOM

Set 4

5 TRIG IN

TRIG IN

6 Ground

Ground

Digital I/O Overview

The Digital I/O port is a dual function port. By default (Normal Mode) the port is used with the compare function to output Hi Fail, Lo Fail, Pass, and EOM (end of measurement) signals. In addition there is also a TRIG IN input pin.

As a secondary function (User Mode), the Digital I/O port can have the output state of pins 1 ~4 controlled via remote control.

Page 90

Wiring Diagram Pins 1 ~ 4

Pins 1 ~ 4 are open-collector outputs, with a max input of 30mA. All outputs are active low.

Pin 1-4

Imax = 30mA

Digital I/O

Terminal

Ext Vcc

Wiring Diagram Trig In (Pin 5)

Pin 5

Pin 6

Trigger input

Digital I/O

Terminal

Normal Mode

Overview

The Normal Mode outputs the pass/fail results of the Compare function. Each signal is an active low signal. In addition an active low pulse of approximately 5µs is output to indicate the end of compare measurement (EOM).

When the input signal exceeds the high threshold or the low threshold, the High Fail or Low Fail pin is pulled low. When the signal stays within the threshold levels, the Pass pin is pulled low.

GDM-8351 User Manual

Page 91

DIGITAL I/O

Timing Diagram

Low limit

High limit

P P P

EOM

Pin 3 PASS

Pin 4 EOM

Pin 1 HIGH FAIL

Pin 2 LOW FAIL

Pin 1-4

Output

Compare On

Compare Off

Related Commands

DIGitalio:MODE {USER|NORM|?} DIGitalio{X}:SETup {ON|OFF}

Procedure

1. Connect to the GDM-8351 remotely, see page 93

for remote control options.

2. Enable the user mode using the

DIGitalio:MODE command. See page 133.

3. Set the state of pins 1 ~ 4 using the

DIGitalio{X}:SETup command. See page 133.

User Mode

User mode can only used when using a remote control interface. Likewise this mode can only be enabled or disabled via remote control. Please see the digital I/O commands on page 133 for full usage details.

Page 92

GDM-8351 User Manual

Example

DIG:MODE? >NORM DIG:MODE USER DIG1:SETup ON DIG2:SETup ON DIG3:SETup ON DIG4:SETup ON DIG4:SETup? >1 DIG:MODE NORM

Queries the mode. Returns Norm mode. Sets to USER mode. Turns pin1 output on. Turns pin2 output on. Turns pin3 output on. Turns pin4 output on. Queries pin4 output state. Returns pin4 output state. Sets back to NORM mode.

Page 93

REMOTE CONTROL

Configure Remote Control Interface ................................. 94

USB Interface ............................................................. 94

Configure USB Interface ............................................ 94

Configure RS232 Interface ......................................... 95

Configure EOL Character ........................................... 97

Return to Local Control ................................................... 98

REMOTE CONTROL

This chapter describes basic configuration of IEEE488.2 based remote control. For a command list, refer to the Command Overview chapter on page 99.

Page 94

GDM-8351 User Manual

Note

*To use the TMC interface National Instruments Measurement and Automation Explorer can be used. This program is available on the NI website, www.ni.com., via a search for the VISA Run-time Engine page, or

“downloads” at the following URL,

http://www.ni.com/visa/

USB Configuration

PC connector

Type A, host

DMM connector

Rear panel Type B, slave

Speed

1.1/2.0 (full speed/high speed)

USB Class

TMC (USB T&M class), CDC (Communications device class)

Hardware flow control

Off

Data Bits

Stop bit

Configure Remote Control Interface

USB Interface

The USB device port on the rear panel is used for remote control. The USB port can be configured as either a TMC or CDC interface.

When configured as a TMC interface, the DMM can be controlled using National Instruments NI-Visa software*. NI-Visa version 3.0 and above supports USB TMC.

When configured to CDC, the USB port on the DMM will appear as a virtual COM port to a connected PC. Any terminal program that can communicate via a serial port can be used for remote control. Before the DMM can be used for remote control using the CDC or TMC USB class, install the appropriate CDC or TMC USB driver included on the User Manual CD.

Configure USB Interface

Page 95

REMOTE CONTROL

Steps

1. Connect the USB cable to the rear panel type B

USB port.

2. Press MENU.

3. Go to I/O on level 1.

4. Go to USB on level 2.

5. Select USB-CDC or USB-TMC.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

USB class

setting

USB menu

indicator

RS232 Configuration

Selectable Baud rate

9600, 19200, 38400, 57600, 115200

Parity

None

Hardware flow control

Off Data Bits

Stop bit

Steps

1. Connect the RS232 cable to the rear panel RS232

port.

Configure RS232 Interface

Page 96

GDM-8351 User Manual

2. Press MENU.

3. Go to I/O on level 1.

4. Go to RS232 on level 2 and press Enter.

5. The baud rate settings appear. Set the baud

rate.

6. Press Enter to confirm the RS232 settings.

7. Press EXIT to exit from the System menu.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2W

nμF

Baud rate

setting

BAUD menu

indicator

RS232 Pin Assignments

Pin 2: RxD Pin 3: TxD Pin 5: GND Pin 1, 4, 6 ~ 9: No Connection

2345

6789

PC Connection

Use a Null Modem connection as shown in the diagram below.

DMM PC

RxDPin2 RxD Pin2

GNDPin5 GND Pin5

TxD Pin3

TxDPin3

Page 97

REMOTE CONTROL

Overview

The TX EOL settings set the EOL (end of line) character for return messages. The EOL characters that can be received from a PC include CR, LF, CR+LF or LF+CR, with CR+LF being the most common.

EOL Characters

CR+LF, LF+CR, CR, LF

Steps

1. Press MENU.

2. Go to TX TERM on level 1.

3. Go to TX EOL on level 2.

4. Set the EOL character.

5. Press Enter to confirm the EOL settings.

6. Press EXIT to exit from the System menu.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

TX EOL

setting

TX EOL menu

indicator

Configure EOL Character

Page 98

GDM-8351 User Manual

Background

When the unit is in remote control mode, the RMT icon above the main display can be seen. When this icon is not displayed, it indicates that the unit is in local control mode.

Procedure

1. Press the LOCAL/2ND key when in remote

mode.

2. The unit will go back into local mode and the

RMT icon will turn off.

Display

REARGPIBCVCCSWEEPFILTRCLSTOCOMP2ND

dBmEXTSHIFTERRLIMITAUTOMATH4W2WDCAC

AVmm

HzWkM

WSFC

mdB

AVmm

HzWkM

WSFC

RMTMAXMINRELHOLDSMFAUTO4W2WDCAC

nμF

Remote control

indicator

Return to Local Control

Page 99

COMMAND OVERVIEW

Compatible Standard

IEEE488.2

Partial compatibility

SCPI, 1994

Partial compatibility

Command Structure

SCPI (Standard Commands for Programmable Instruments) commands follow a tree-like structure, organized into nodes. Each level of the command tree is a node. Each keyword in a SCPI command represents each node in the command tree. Each keyword (node) of a SCPI command is separated by a colon (:).

For example, the diagram below shows an SCPI sub-structure and a command example.

:DCAC:DC :AC

CONFigure:VOLTage:DC

:VOLTage

CONFigure

COMMAND OVERVIEW

The Command overview chapter lists all programming commands in functional order as well as alphabetical order. The command syntax section shows you the basic syntax rules you have to apply when using commands.

Command Syntax

Page 100

GDM-8351 User Manual

Command Types

There are a number of different instrument commands and queries. A command sends instructions or data to the unit and a query receives data or status information from the unit.

Command types

Simple

A single command with/without a parameter

Example

CONFigure:VOLTage:DC

Query

A query is a simple or compound command followed by a question mark (?). A parameter (data) is returned.

Example

CONFigure:RANGe?

Command Forms

Commands and queries have two different forms, long and short. The command syntax is written with the short form of the command in capitals and the remainder (long form) in lower case.

The commands can be written either in capitals or lower-case, just so long as the short or long forms are complete. An incomplete command will not be recognized.

Below are examples of correctly written commands.

Long form

CONFigure:DIODe

CONFIGURE:DIODE

Configure:diode

100