Instek Instek GOM-805 Manual

D.C. Milli-Ohm Meter

GOM-804 & GOM-805

USER MANUAL

GW INSTEK PART NO. 82OM-80500E01

ISO-9001 CERTIFIED MANUFACTURER

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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 the 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 right to change specifications, equipment, and maintenance
procedures at any time without notice.

Table of Contents

Table of Contents

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

Safety Symbols .................................................... 5

Safety Guidelines ................................................ 6

GETTING STARTED ............................................................ 9

GOM-804/805 Characteristics........................... 10

Key Features ...................................................... 13

Model Lineup .................................................... 14

Front Panel Overview ........................................ 15

TFT-LCD Overview ............................................ 19

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

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

MEASUREMENT ............................................................... 27

Resistance Measurement .................................. 29

Compare Function ............................................. 41

Binning Function ............................................... 46

Temperature Measurement ............................... 50

Temperature Compensation .............................. 52

Temperature Conversion ...................................

Measurement Settings ...................................... 60

System Settings ................................................ 69

56

HANDLER/SCAN INTERFACE .......................................... 77

Handler Overview ............................................. 78

Pin Definitions for the Handler Interface .......... 80

Scan Overview ................................................... 82

Configure Interface ........................................... 90

SAVE/RECALL ................................................................... 99

COMMAND OVERVIEW ................................................. 102

Command Syntax ............................................ 102

Command List ................................................. 105

3

GOM-804 & GOM-805 User Manual

BINNing Commands ....................................... 108

Calculate Commands ...................................... 113

Memory Commands ........................................ 120

Sense Commands ............................................ 122

Source Commands .......................................... 126

Status Commands ........................................... 127

System Commands.......................................... 128

Temperature Commands ................................. 133

Trigger Commands .......................................... 138

Userdefine Commands .................................... 141

IEEE 488.2 Common Commands ..................... 143

Status system .................................................. 146

FAQ ................................................................................ 147

APPENDIX ...................................................................... 148

Temperature Measurement ............................. 149

Specifications .................................................. 152

Dimensions ..................................................... 155

Declaration of Conformity ............................... 156

INDEX ............................................................................ 157

4

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 instrument 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
when operating the GOM-804/805 or when keeping it in storage. Read the
following before any operation to insure your safety and to keep the
GOM-804/805 in the best possible condition.

Safety Symbols

These safety symbols may appear in this manual or on the GOM-804/805.

5

Safety Guidelines

General Guideline

CAUTION

 Do not place any heavy objects on the instrument.
 Avoid severe impact or rough handling that leads to

damaging the instrument.

 Do not discharge static electricity to the instrument.
 Use only mating connectors, not bare wires, for the

terminals.

 Do not disassemble the instrument unless you are

qualified as service personnel.

(Note) EN 61010-1:2010 specifies the measurement categories and
their requirements as follows. The GOM-804/805 doesn’t fall
under category II, III or IV.

 Measurement category IV is for measurements performed at the

source of low-voltage installation.

 Measurement category III is for measurements performed in the

building installation.

 Measurement category II is for measurements performed on the

circuits directly connected to the low voltage installation.

Power Supply

WARNING

 AC Input voltage: 100 - 240 V AC, 50 - 60Hz, 25VA
 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.

Cleaning the
GOM-804/805

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

detergent and water. Do not spray any liquid into the
instrument.

 Do not use chemicals or cleaners 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)

 Relative Humidity: < 80%
 Altitude: < 2000m
 Temperature: 0°C to 40°C (operation)

GOM-804 & GOM-805 User Manual

6

SAFETY INSTRUCTIONS

(Note) EN 61010-1:2010 specifies the pollution degrees and their
requirements as follows. The GOM-804/805 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: −10°C to 70°C

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.

7

GOM-804 & GOM-805 User Manual

Green/ Yellow:

Earth

Blue:

Neutral

Brown:

Live (Phase)

Power cord for the United Kingdom

When using the instrument 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.

8

GETTING STARTED

Characteristics

GOM-804/805 Characteristics ................................ 10

Key Features ........................................................... 13

Model Lineup ......................................................... 14

Panel Overview

Front Panel Overview ............................................. 15

TFT-LCD Overview ................................................. 19

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

Setup

Tilt Stand ................................................................ 23

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

4 Wire Kelvin Connection ....................................... 25

Zeroing (Relative Function) .................................... 26

GETTING STARTED

This chapter describes the GOM-804/805 in a nutshell, including its main
features as well as its front and rear panels. After going through the panel
overview, follow the Power-up sequence before attempting to use the
instrument.

Please note the information in this manual was correct at the time of printing.
However as GW Instek continues to improve its products, changes can occur
at any time without notice. Please see the GW Instek website for the latest
information and content.

9

GOM-804 & GOM-805 User Manual

Easy to Use
Features

Each test function on the GOM-804/805 can be easily
activated by pressing a single front panel key. All the
settings and measurement results are displayed and set on
the TFT-LCD panel at the same time making each
function naturally intuitive to use.

Each primary and secondary measurement result is
displayed prominently on the display along with any
corresponding settings. For sequential measurement
results, such as those from the scan or binning function,
are tabulated in an intuitive and easy-to-read format.

In addition, the meters can recall previously used settings
upon startup, allowing the meter to be ready the next
time it used in a matter of moments. The meters can also
save or recall up to 20 sets of function settings.

Performance

The GOM-804/805 has nine selectable measurement
ranges from 50mΩ to 5MΩ, a constant current source of
1uA to 1A, an accuracy of up to 0.05%, a 1uΩ resolution
and performs measurements using four wire Kelvin
connections for accurate, consistent measurements.

The ability to choose between high accuracy
measurements at 10 samples/sec (full scale at 50000
counts) or high speed measurements at 60 samples/sec
(full scale at 50000 counts), allows the GOM-804/805 the
flexibility to fulfill a number of different measurement
roles.

GOM-804/805 Characteristics

GOM-804 and GOM-805 are modern high precision programmable DC
Milli-ohm meters suitable for low resistance measurements of switches, relays,
connectors, PCB tracks and a variety of other devices. The meters feature a
color TFT-LCD screen with easy-to-read measurement results. With the
easy-to-use features, superior performance and automatic test interfaces, these
meters are dependable instruments for resistance measurements.

10

GETTING STARTED

Advanced
Temperature
Measurements

The GOM-804/805 has a number of advanced
temperature functions that can be used with the optional
temperature probe, PT-100.

The temperature compensation function can extrapolate
what the resistance of a DUT will be at a desired
temperature, if the temperature coefficient of the DUT
and the resistance of the DUT at ambient temperature
are known.

The temperature conversion function can be used to
extrapolate what the temperature rise of a DUT will be at
specified resistance if the initial resistance, initial
temperature and the constant for the DUT are known.

Drive Signals

The GOM-805 can select a number of different drive
signals to suit a number of different measurement
scenarios, for example the Pulse setting can be used to
cancel the effects of thermoelectric EMF on the
measurement results.

Dry Circuit
Testing

Dry circuit testing allows the GOM-805 to measure the
contact resistance of switches and connectors according
to the DIN IEC 512 and ASTM B539 standards. The
open circuit voltage will not exceed 20mV in this mode
to prevent the oxidization layer on metal switches and
connector points from breakdown. GOM-805 only.

Automatic
Testing

For automatic testing The GOM-804/805 has a handler
interface designed for automatic testing. The handler
interface outputs the status of PASS, FAIL, HI, LO,
READY and EOT signals and inputs a trigger control
signal. Automatic testing is used with the binning,
compare and scan functions.

For computer control applications, RS-232 and USB are
standard remote interfaces, with GPIB as standard only
for the GOM-805 and GOM-804G.

11

GOM-804 & GOM-805 User Manual

Applications

 Production testing for contact resistance of switches,

relays, connectors, cables and printed circuit boards
and other low resistance devices.

 Component testing of resistors, motors, fuses and

heating elements.

 Incoming inspection and quality assurance testing.

 Conductivity evaluation for product design.

12

Key Features

 50,000 counts

 Measurement Range: 50mΩ~5MΩ

 Accuracy of up to 0.05%

 Compare function

 Binning function

 Manual or Auto-ranging

 Continuous or Triggered measurement modes

 Temperature measurement, temperature

compensation and temperature conversion

 Four-wire Kelvin measurement method

 Selectable power-on settings

 Diode test

 Alarm settings for function-specific PASS/FAIL test

results

 Sampling rate: 10 or 60 sampling/sec

 Standard interfaces:

USB/RS232/Scan/Handler/GPIB(GOM-805,
GOM-804G)

 Save/Recall settings: 20 memory sets

 External I/O logic function

GETTING STARTED

13

Model Lineup

Feature / Model

GOM-804

GOM-804G*

GOM-805

Ohm Measurement

✔

✔

✔

Compare Function

✔

✔

✔

Diode Measurement

✔

✔

✔

Temp. Compensation

✔

✔

✔

Temp. Conversion

✔

✔

✔

Temp Measurement

✔

✔

✔

Dry Circuit

✘ ✘ ✔

Drive Selection

✘ ✘ ✔

Binning Function

✘ ✘ ✔

GPIB Interface

✘

✔

✔

* The GOM-804G is simply the GOM-804 with the factory-installed
GPIB option. Please note that the GPIB option cannot be
user-installed on the GOM-804. The option must be ordered prior to
purchase.

GOM-804 & GOM-805 User Manual

14

Front Panel Overview

SOURCE SENSE

POWER

SENSE SOURCE

Rx

DC Milliohm Meter

GOM-805

Ohm Compare Binning

TEMP

TCONVTC

Speed

REL RT

Trigger

DryScan

Display

Diode

Drive

ESC

GND

GUARD

Enter

Local

Range

ESC key

GND
terminal

Function keyLCD display

Power key

Arrow keys,
Enter keys

GUARD
terminal

Sense+, Source+Sense-, Source-

Power Switch

POWER

GND

GUARD

Range

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

Measurement Terminals

Source, Sense
Terminals

Rx

SOURCE

SENSE SENSE

SOURCE

Sense + and Sense - terminals.

Current source terminals: Source + and
Source -.

CAUTION

When measuring components
with polarity, connect Source+
to the positive potential and
connect Source- to the negative
potential of the component.

WARNING

Discharge any DUT before
measurement to avoid
damaging the GOM-804/805.

GETTING STARTED

15

GOM-804 & GOM-805 User Manual

GND Terminal

GND

Connect the GND (ground) terminal to
the earth ground.

GUARD Terminal

GUARD

The GUARD terminal has the same
potential as earth, but cannot be
substituted for it. Connect the GUARD
terminal to the cable shield layer of the
test leads to help reduce noise.

Function Keys

Ohm

The Ohm key activates the resistance
measurement function.

Compare

The Compare key activates the
comparator function.

Binning

The Binning key activates the binning
function to grade the DUTs into eight
bins according to the tolerance settings.
GOM-805 only.

TC

The TC key activates the TC
(temperature compensation) function
which calculates the resistance of a
DUT at a specified temperature given
the resistance of the DUT at the
ambient temperature and the
temperature coefficient of the DUT is
known.

TCONV

The TCONV (Temperature
Conversion) function calculates the
temperature of a DUT given an initial
temperature, initial resistance, measured
resistance and a constant (inferred zero
resistance temperature) for the DUT.

TEMP

The TEMP key activates the
temperature measurement function.

16

GETTING STARTED

Speed

The Speed key toggles between 10
samples per second and 60 samples per
second (Slow rate and Fast rate).

REL

The REL key is used to perform a zero
adjustment to the test leads or a DUT.

RT

The RT key is used to display the
real-time (not averaged) measured
resistance value.

Scan

The Scan key is used to turn on the
Scan function.

Dry

The Dry key is used to turn on the dry
circuit measurement mode which allows
the GOM-805 to measure the contact
resistance of switches and connectors
according to DIN IEC 512 and ASTM
B539 standards. GOM-805 only.

Trigger

When in the internal trigger mode,
pressing the Trigger key will turn on the
external trigger mode. When in the
external trigger mode, pressing the
Trigger key will perform a manual
trigger.

A long press of the Trigger key when in
external trigger mode will reset the
trigger mode back to the internal trigger
mode.

Display

The Display key toggles between the
standard display mode and the
simplified display mode (sans menus
and display icons).

Local

The LOCAL key will switch the
milliohm meter between local and
remote mode.

Diode

The Diode key is used to turn on the
Diode measurement function.

17

GOM-804 & GOM-805 User Manual

Drive

+

Enter

The Drive key in conjunction with the
up/down arrow keys is used to select
the measuring signal: DC+, DC-, Pulse,
PWM, Zero. In particular, the Zero
setting can be used as a +/-10mV DC
voltmeter to measure the EMF of
passive components. See page 33 for
details. GOM-805 only. The drive signal
is fixed to DC+ on the GOM-804.

Range

Long pressing the Range key will
activate the auto ranging mode.

Range

+

Enter

The Range key in conjunction with the
up/down arrow keys is used to select
the resistance measurement range.

When in auto ranging mode, pressing
the Range key will activate the manual
ranging mode.

ESC

The ESC key cancels the current setting
and returns the cursor to its default
location or returns to the previous
menu, depending on the circumstances.

Arrow Keys,
Enter Key

Enter

The arrow keys and Enter key are
used to edit parameters, to navigate
the menu system and to select
parameter ranges.

18

TFT-LCD Overview

Drive signal

RangeFunction mode

Function
mode
settings

Trigger mode

Main
measurement
display

Secondary menus

REL value

Memory
number

Function control
indicators

Average value Dry circuit

Rate

Remote mode

Remote error

Function Control
Indicators

The function control indicators show all the currently
active settings for the selected function mode:

Func

Currently selected function mode

Range

The measurement range. Auto
indicates that auto ranging is
active

Trigger mode

Int/Ext

Rate

Slow/Fast

Drive:

DC+, DC-, Pulse, PWM, Zero

Rel

Shows the relative (nominal)
reference value

Avg

Number of samples used for the
Average function.

Dry

Indicates that the dry circuit
function is active

Err

Indicates a remote command
error

GETTING STARTED

19

GOM-804 & GOM-805 User Manual

RMT

Indicates that the unit is in
remote control mode

Mem No.

Indicates which memory setting
has been recalled

Main
Measurement
Display

Shows all measurement results for the selected function
mode.

Function Mode
Settings

Shows any function mode-specific settings.

Secondary
Menus

The secondary menus show global menus (Meas. Setup),
System, Memory) as well as function-specific secondary
menus.

Meas. Setup

Goes to the global Measurement Setup
menu.

System

Goes to the global System menu

Memory

Allows you to save, recall and clear
memory settings.

View

Shows the all results for all the channels
when a scan has finished.

Clear

Clears the measurement results in the
Binning function when the display
mode is set to Count.

20

Rear Panel Overview

REMOVE INPUTS BEFORE OPENING.

TO AVOID SHOCK,

WARNING

RS232

SER.NO. LABEL

100 240V , 50 60Hz

25VA MAX

AC

HANDLER / SCAN / EXT I/O

TC SENSOR

GPIB

RS232 portGPIB port Handler/Scan/Ext I/O

USB B
port

Temperature sensor portAC power input

AC Input

100 240V , 50 60Hz

25VA MAX

AC

Accepts the power cord. AC 100 ­240Vac; 50 - 60Hz.

For the power up sequence, see page

24.

RS-232 Port

RS232

Accepts an RS-232C cable for remote
control; DB-9 male connector.

For remote control details, see page 92.

GPIB Port

GPIB

Accepts a GPIB cable for remote
control. See page 93 for details.

USB Device Port

USB device port for remote control.
See page 90 for details.

Handler / Scan /

EXT I/O Port

HANDLER / SCAN / EXT I/O

The Handler / Scan / EXT I/O
port is used to output
pass/fail/high/low comparison
results. This port is also used for
the user-programmable EXT I/O
pins.

GETTING STARTED

21

GOM-804 & GOM-805 User Manual

Temperature
Sensor Port

TC SENSOR

The temperature sensor input is for the
optional PT-100 temperature probe.

22

Set Up

Tilt

To tilt, pull the legs forward, as shown below.

Stand Upright

To stand the unit upright, push the legs back under the
casing as shown below.

Tilt Stand

GETTING STARTED

23

Power Up

1. Connection

Ensure that the input AC power voltage is within the
range of 100~240 V.

Connect the power cord to the AC Voltage input.

CAUTION

Ensure the ground connector of the power cord is
connected to a safety ground. This will affect the
measurement accuracy.

1. Power up

Press the main power switch on the front panel.

The display will light up and show the last setting used
before the last shut down.

Example:
Resistance
measurement
mode

GOM-804 & GOM-805 User Manual

24

4 Wire Kelvin Connection

Background

The GOM-804/805 uses 4 wire Kelvin connections for
accurate measurements.

Connection
Diagram

GUARD

SOURCE SENSE SENSE

SOURCE

shielding

+

-

Description

Source +

The Source + terminal carries the
measuring current source. It is
connected to the + side of the DUT.

Source -

The Source - terminal accepts the signal
return current and connects to the –
side of the DUT.

Sense +

Monitors the positive (+) potential.

Sense -

Monitors the negative (-) potential.

Guard

Grounds the shielding layer of the test
lead cables to reduce noise.

GND

Provides a reference ground for the
GOM-804/805.

GETTING STARTED

25

Zeroing (Relative Function)

Background

The Relative function is used to perform a zero
adjustment on the test leads.

After the Relative value is pre-set, each measurement that
is displayed is equal to the actual value minus the relative
preset value.

1. Short the
cables

Short the test cables together as shown in the diagram
below:

SOURCE SENSE SENSE

SOURCE

Source+
/Sense+

Source-

/Sense-

2. Set the
Reference value

Press the

REL

key.

3. Relative mode
display appears

Before REL

After REL

Rel:

Indicates the Relative function is active

GOM-804 & GOM-805 User Manual

26

MEASUREMENT

Ohm

TC

Speed

Compare Binning

TCONV TEMP

REL RT

Scan Dry

Display Local Diode Range

ESC

Enter

Trigger

Drive

Resistance

Resistance Measurement ....................................... 29

Select the Resistance Range ................................... 30

Drive Signal

Measuring Signal (Drive) Overview ........................ 31

Select Measuring Signal (Drive) ............................. 33

Rate

Select Measurement Rate ....................................... 34

Display Mode

Display Mode ......................................................... 35

Real-Time

View Real-Time Measurement ................................ 36

Dry-Circuit

Dry-Circuit Measurement ....................................... 37

Trigger

Using the Trigger Function ..................................... 38

Diode

Diode Function ....................................................... 40

Compare
Function

Compare Function .................................................. 41

Binning
Function

Binning Function .................................................... 46

MEASUREMENT

27

GOM-804 & GOM-805 User Manual

Temperature
Measurement

Temperature Measurement .................................... 50

Temperature
Compensation

Temperature Compensation ................................... 52

Temperature
Conversion

Temperature Conversion ........................................ 56

Measurement
Settings

Average Function ................................................... 60

Measure Delay ....................................................... 61

Trigger Delay .......................................................... 63

Trigger Edge ........................................................... 64

Temperature Unit ................................................... 65

Ambient Temperature ............................................ 66

Line Frequency ....................................................... 67

PWM Setting .......................................................... 68

System Settings

System Information ............................................... 69

Power On Status Setup .......................................... 70

Interface................................................................. 71

Brightness .............................................................. 72

User Define Pins .................................................... 73

Handler Mode ........................................................ 74

Beep ....................................................................... 76

28

Resistance Measurement

1. Select the
Resistance
function.

Press

Ohm

to access the Resistance measurement

mode.

2. Resistance
mode display
appears.

Ohm measurement

function indicator

Ohm measurement

Resistance range

and mode

3. Connect the
test lead and
measure

4-wire resistance:

Use the SOURCE + and the SOURCE - terminal for
measurement, and the SENSE +, and SENSE - terminal
for sensing.

GUARD

SOURCE SENSE SENSE

SOURCE

shielding

Note

When switching between measurement ranges, please
allow a moment for the circuits to settle before
measuring.

MEASUREMENT

29

Select the Resistance Range

Background

The resistance range can be used with normal resistance
measurement as well as the temperature compensation
function.

Manual

Press the

Range

key and use the up and down arrow

keys to manually select the resistance range.

Ohm range

Ohm measurement

Range select

indicator

Set range

Auto Range

Long press the

Range

key to turn on automatic

ranging.

Range, Auto range

Selection List

Range

Resolution

50mΩ

1uΩ

500mΩ

10uΩ

5Ω

100uΩ

50Ω

1mΩ

500Ω

10mΩ

5kΩ

100mΩ

50kΩ

1Ω

500kΩ

10Ω

5MΩ

100Ω

Note

For detailed specifications, please see the specifications
on page 152.

GOM-804 & GOM-805 User Manual

30

Measuring Signal (Drive) Overview

Background

Resistance measurement has 5 different measuring signals
that can be applied to obtain a resistance measurement:
DC+, DC-, Pulse, PWM, Zero.
These 5 signals are described in below.

Note

The drive function is only applicable to the GOM-805.
The drive signal for the GOM-804 is fixed to DC+.

DC+

~ +6.5V

Open circuit

voltage

0V

V

t

Default drive
signal.

DC-

~ -6.5V

Open circuit

voltage

0V

V

t

Negative drive
signal.

Pulse

~-6.5V

0V

V

t

~+6.5V

50ms

50ms

This mode can be used to
eliminate the thermoelectric
EMF formed on the contact
between a test lead and a
DUT.

PWM

0V

V

t

~+6.5V

ON duty

This mode can be used to
avoid heating up the DUT
and thus avoid having the
measurement accuracy
compromised on
temperature-sensitive DUTs.

Zero

0V

V

t

In this mode, GOM-805
outputs no measuring signal
on the Source loop; therefore,
the Sense loop can be used as
a voltage meter which can
measure up to +/-10mV for
thermoelectric EMF
measurement. This function
is useful for measuring the
Vemf of thermocouple wires.

MEASUREMENT

31

GOM-804 & GOM-805 User Manual

A note about Thermoelectric EMF

When making low resistance measurements, thermoelectric electromotive
force (Vemf) can affect measurement accuracy. Vemf is created at the junction
of two dissimilar metals, such as the contact point of a test lead and the pin
of a DUT. Vemf adds a small but measurable voltage to the measurement.

There are primarily two different methods to compensate for Vemf in low
resistance measurements: Offset Compensation and Vemf Cancelling. The
GOM-805 uses Vemf Cancelling with the pulse drive signal setting (see page

33).

The Pulse drive mode supplies a positive and a negative measurement current
source.

V

I

R

Vemf

This produces a positive and negative measurement voltage across the DUT,
which also includes the Vemf (V1+Vemf & V2+Vemf).

0V

t

Vemf

V1

V2

To cancel the Vemf, V2 is deducted from V1 and divided by 2 to get the
average measurement, as shown in the formula below:

2

)2()1( VemfVVemfV

Vx





Where Vx = measured voltage sans Vemf.

32

Select Measuring Signal (Drive)

Background

Resistance measurement has 5 different measuring signals
that can be applied to obtain a resistance measurement:
DC+, DC-, Pulse, PWM, Zero.

Note

The drive function is only applicable to the GOM-805.
The drive signal for the GOM-804 is fixed to DC+.

1. Select Drive

Press the

Drive

key and use the up and down arrow

keys to select a drive signal.

Drive mode

Drive selection

indicator

Set drive signal

Drive Range

DC+, DC-, Pulse, PWM, Zero

MEASUREMENT

33

Select Measurement Rate

Background

The resistance measurement speed has 2 ranges: slow and
fast. Slow speed is the most accurate with 10
measurements/second. Fast speed has 60
measurements/second. Both have the same measurement
resolution.

The rate selection function is not applicable in Diode
measurement mode. When the PWM drive signal is used
or when the Scan function is activated, the only available
rate setting is fast.

1. Select Rate

Press the

Speed

key to toggle between the Slow and Fast

rates.

Measurement rate

GOM-804 & GOM-805 User Manual

34

Display Mode

Background

The Display key can be used to toggle between the
normal and the simplified display mode. The simplified
display mode clears all text, menus and function
indicators from the screen except for the measurement
and measurement mode indicators.

1. Toggle Display
mode

Press the

Display

key to toggle the display between
normal and simplified. The display will change
accordingly.

Simplified
Display Mode
Example

Measurement

Measurement mode

MEASUREMENT

35

View Real-Time Measurement

Background

When measurements are smoothed using the averaging
function, the RT key can be used to view the real-time
results in addition to the averaged results.

See page 60 for Average configuration.

1. Toggle
Real-Time
display

Press the

RT

key to toggle the real-time display on

or off.

The real-time measurement will appear in the bottom
left-hand corner.

Real-time

measurement

GOM-804 & GOM-805 User Manual

36

Dry-Circuit Measurement

Background

The Dry Circuit measurement function is used where the
maximum open-circuit voltage must be kept to a
minimum for applications such as measuring the contact
resistance of switches, relays and connectors. The
GOM-805 provides a maximum of up to 20mV in this
mode.

Note

Dry circuit testing is for switch and connector contact
resistance. Switch and connector contact resistance
measurement is in accordance with DIN IEC 512 and
ASTM B539 which requires that the open circuit voltage
of the measuring device should not exceed 20mV DC.
Voltage at such low levels avoids the breakdown of any
oxides that may be present on the contacts. In this mode
the open circuit measuring voltage is limited <20mV,
while modes like DC+ or pulse mode can have an open
circuit measuring voltage as high as 6.5V.

Dry Limitations

When the Dry Circuit measurement function is turned
on, the measurement range is reduced. See the
specifications for more details.

Range

Dry Mode

Rate

50mΩ

✘

500mΩ

✔

Slow/Fast

5Ω

✔

Slow/Fast

50Ω

✔

Slow/Fast

500Ω

✘

5kΩ

✘

50kΩ

✘

500kΩ

✘

5MΩ

✘

MEASUREMENT

37

GOM-804 & GOM-805 User Manual

1. Toggle Dry
mode on or off

Press the

Dry

key to toggle the dry circuit

measurement mode on or off.

The DRY function indicator will appear in the middle of
the display when active.

Dry Circuit measurement

mode indicator

Background

The GOM-804/805 can use internal or manual triggering
for the Resistance, Temperature, Temperature
Compensation, Temperature Conversion, Binning,
Handler and Scan modes.
By default the GOM-804/805 is set to internal triggering
mode.

1. Select Manual
Trigger

Short press

Trigger

to switch to manual triggering mode.

The Ext indicator will be shown on the display
when the manual trigger is active.

Trigger source

2. Manually
Triggering
Measurements

Short press the

Trigger

key each time you want to start a

single measurement (when in the manual mode).

Using the Trigger Function

38

MEASUREMENT

3. Internal
Triggering

Long press

Trigger

to return the triggering mode back to

internal mode.

The Int indicator will be shown on the display.

Internal trigger source

39

Diode Function

Background

The Diode function can be used to measure the forward
bias voltage of a diode under test.

1. Select the
Diode function.

Press

Diode

to access the Diode measurement mode.

2. Diode mode
appears.

Diode function

indicator

Forward bias voltage

3. Connect the
test lead and
measure

Connect the Sense+, Source+ to the anode.

Connect the Sense-, Source- to the cathode.

SOURCE SENSE SENSE

SOURCE

GOM-804 & GOM-805 User Manual

40

Compare Function

Background

The compare function compares a measured value to a
“Reference” value that has an upper (HI) and lower (LO)
limit. If the measured value is within the upper and lower
limit, then the measured value is judged as IN.

There are three compare modes that can be used to make
a judgment: ABS, △% and % modes.

The ABS mode displays the absolute difference between
the measured and the reference value (shown as △) and
compares the measured value to the upper (HI) and

lower (LO) limit. The upper and lower limits are set as
absolute resistance values.

Compare function

indicator

Absolute
difference of
measured value
from Reference
value

Measured value

Reference, limits, compare

mode and beep mode

Pass/Fail
judgment

A measured value that falls within the upper and lower
limits is considered IN (pass), a value that falls below the
lower limits is considered LO, and a value that falls over
the upper limit is a HI.

Reference

value

Upper

limit

Lower

limit

IN HILO

[Note that the reference value in the ABS mode is only
for reference purposes and is not used to make a
judgment.]

MEASUREMENT

41

GOM-804 & GOM-805 User Manual

The △% compare function displays the deviation of the
measured value from the reference value as a percentage.

{ [(Measured Value-Reference)/Reference]%}.

Compare function

indicator

Deviation of the

measured value from

the reference value as

a percentage

Measured value

Reference, limits, compare

mode and beep mode

Pass/Fail judgment

The upper (HI) and low (LO) limits are set as a
percentage from the reference value. (Identical to the %
compare mode)

A measured value that falls within the upper and lower
limits is considered IN (pass), a value that falls below the
lower limits is considered LO, and a value that falls over
the upper limit is a HI.

Reference

value

Upper

limit

Lower

limit

IN HILO

%

%

The % compare mode displays the measured value as a
percentage of the reference value [(Measured
Value/Reference Value)%].

The upper (HI) and low (LO) limits are set as a
percentage from the reference value. (Identical to the △
% compare mode)

42

MEASUREMENT

Compare function

indicator

Measured value as a

percentage of the

reference value

Measured value

Reference, limits, compare

mode and beep mode

Pass/Fail judgment

A measured value that falls within the upper and lower
limits is considered IN (pass), a value that falls below the
lower limits is considered LO, and a value that falls over
the upper limit is a HI.

Reference

value

Upper

limit

Lower

limit

IN HILO

%

%

For all the compare modes, IN, HI or LO will be shown
on the display for each judgment.

1. Select the
compare function

Press

Compare

to access the compare mode, as shown

above.

2. Select the
compare mode

Use the arrow keys to navigate to the Mode setting. Press
the Enter key to toggle the compare mode.

Mode

Move

Toggle

Enter

Range

Abs,△ %, %

43

GOM-804 & GOM-805 User Manual

3. Reference
value setting

Use the arrow keys to navigate to the Reference setting
and press Enter.

Use the left and right arrow keys to select a digit. Use the
up and down arrow keys to edit the value of the selected
digit and the unit. Press Enter to confirm the setting.

Reference

Move

and edit

Select and

confirm

Enter

Range:

000.0001~ 999.9999
(mΩ/Ω/kΩ/MΩ)

Note

After setting the Reference value, the displayed △, % or

△% values will be changed to reflect the new Reference

value setting.

4. Upper & lower
limit setting

Use the arrow keys to navigate to the Upper or Lower
limit setting and press Enter.

Use the left and right arrow keys to select a digit. Use the
up and down arrow keys to edit the value of the selected
digit. Press Enter to confirm the setting.

Repeat for the other limit (Upper or Lower).

Upper, Lower reference

Move

and edit

Select and

confirm

Enter

Setting Range:

ABS mode: 000.0000~999.9999
(mΩ/Ω/kΩ/MΩ)

△% and % mode:

-999.99 ~ +999.99

Note

The upper limit must be higher than the lower limit. Not
setting the upper limit higher than the lower limit is not
allowed. Likewise the lower limit cannot be set higher
than the upper limit.

44

MEASUREMENT

5. Beep setting

Use the arrow keys to navigate to the Beep setting.

Press Enter to toggle the beep setting.

Beep setting

Move

Toggle

Enter

Beep Setting:

Off, Pass, Fail

Note

The Beep setting can also be set from the
System>Utility>Beep>Compare menu.

45

Binning Function

Background

The Binning function is used to grade DUTs into eight
different bins according to 8 sets of upper and lower
limits. Two compare modes can be used in this function,

ABS and △% modes.

Binning function

indicator

Upper and lower

limits for the 8

bins

Grading results

Reference, compare mode, beep

mode and display mode

1. Select the
Binning function

Press the

Binning

key to access this function.

2. Select the
compare mode

Use the arrow keys to go to the Mode setting.

Press Enter to toggle between ABS or △% compare
modes.

Mode setting

Move

Toggle

Enter

ABS Mode

The ABS mode allows you to set
the upper and lower limits of each
bin as absolute resistance values.

△ %

The Delta % mode allows you to
set the upper and lower limits of
each bin as percentage valu e from
the reference value.

GOM-804 & GOM-805 User Manual

46

MEASUREMENT

Note

For further details on the ABS or △% compare modes,
see the description in the Compare section, page 41.

3. Reference
value setting

Although the 8 bins have their own upper and lower
limits, they still share a common reference value.

Use the arrow keys to go to the Reference setting and
press Enter.

Use the left and right arrow keys to select a digit. Use the
up and down arrow keys to edit the value of the selected
digit and the unit. Press Enter to confirm the setting.

Reference

Move

and edit

Select and

confirm

Enter

Range

000.0001~

999.9999(mΩ/Ω/kΩ/MΩ)

4. Upper & lower
limit settings

Use the arrow keys to go to the upper limit of the first
bin and press Enter.

Use the Left and Right arrow keys to select a digit. Use
the Up and Down arrow keys to edit the value of the
selected digit and unit. Press the Enter key to confirm the
setting.

Repeat for the lower setting.

Repeat for the remaining bins.

Upper, lower

reference

Move

and edit

Select and

confirm

Enter

Setting range

ABS mode: 000.0000~999.9999
(mΩ/Ω/kΩ/MΩ)

△% mode: -999.99 ~ +999.99

47

GOM-804 & GOM-805 User Manual

Note

The upper limit must be higher than the lower limit. Not
setting the upper limit higher than the lower limit is not
allowed. Likewise the lower limit cannot be set higher
than the upper limit.

5. Beep setting

Use the arrow keys to navigate to the Beep setting.

Press Enter to toggle the beep setting.

Beep setting

Move

Toggle

Enter

Beep Setting:

Off, Pass, Fail

Note

The Beep setting can also be set from the
System>Utility>Beep>Binning menu.

6. To start
binning

The binning function starts automatically if you are in
internal trigger mode.

If you are using the manual triggering mode, press the

Trigger

button or apply a pulse on the trigger pin of the

Handler interface to start binning.

See page 38 to set the triggering modes.

7. Display the
binning results

There are two different display modes to view results.

The Comp (Compare) display mode is the default display
mode. This mode will display the currently measured
value and displays which of the bins (if any) the
measured value is graded as.

Measurement

Grading results:

Green = IN
Red = OUT

48

MEASUREMENT

The Count display mode tabulates the results on the
right-hand side of the display and shows the bin settings
on the left.

Overall

results

Tabulated result

of each bin

Upper and lower limits of Bin 1~8

Clear

results

To toggle the display mode, go to the Disp setting and
press Enter.

Disp setting

Move

Toggle

Enter

8. How to clear
the result count

When in the Count display mode, press the

ESC

key.
Go to the Clear setting and press Enter. The accumulated
results will be cleared from the display.

Clear setting

Move

Clear results

Enter

49

GOM-804 & GOM-805 User Manual

Background

The temperature measurement function uses the optional
PT-100 temperature probe. The measured temperature is
displayed on the display. For more information on the
optional PT-100 sensor, see the appendix on page 149.

There is only one range for the temperature function.
However the resistance measurement range can still be
changed when in the temperature function.

Note:

The temperature measurement function is used in
conjunction with the Ohm measurement function. The
two measurements share the same display, so the Ohm
readings stay on the display even after the temperature
measurement function is activated. Thus when the
Temperature function is selected, “Ohm+T” is shown as
the selected function.

1. Select the
Temperature
function

Press

TEMP

to enter the temperature measurement

function.

Temperature + Ohm

function indicator

(Ambient)
temperature
source

Resistance measurement

Ambient
temperature

The temperature is displayed on the Ohm display.

2. Select the
temperature
units

From the bottom menu, go to Meas. Setup>Temperature
Unit and select ºC or ºF.

See page 65 for setting details.

Temperature Measurement

50

MEASUREMENT

3. Ambient
Temperature

The Ambient temperature setting should be turned off
when using the temperature function.

From the bottom menu go to Meas. Setup > Ambient
Temperature and turn the Ambient Temperature setting
off.

See page 66 for setting details.

4. Temperature
mode
connection

The temperature sensor uses the rear panel TC Sensor
port for input.

REMOVE INPUTS BEFORE OPENING.

TO AVOID SHOCK,

WARNING

RS232

SER.NO. LABEL

100 240V , 50 60Hz

25VA MAX

AC

HANDLER / SCAN / EXT I/O

TC SENSOR

GPIB

PT-100 temperature

sensor

51

GOM-804 & GOM-805 User Manual

Background

If the resistance of a DUT at a particular temperature is
needed, the compensation function can be used. This
function can simulate the resistance of a DUT at a
desired temperature. If the ambient temperature and the
temperature coefficient of the DUT are known, it is
possible to determine the resistance of a DUT at any
temperature.

The Temperature Compensation works on the following
formula:

)(1 000t-tα

R

R

t

t

t





Where:

Rt = Measured resistance value (Ω)
Rt0 = Corrected resistance value (Ω)

T0 = Inferred absolute temperature

t0 = Corrected temperature (ºC)
t = Current ambient temperature (ºC)

αto = Temperature coefficient of resistance at the correct

temperature.

00 |

1

tT|

ato





.

Temperature Compensation

52

MEASUREMENT

1. Select the
Temperature
Compensation
mode

Press

TC

to access the Temperature Compensation

function.

The temperature-compensated resistance measurement
will appear on the display.

Temperature

compensation

function indicator

Ambient
temperature
source

Extrapolated resistance

measurement at the desired

(“correct”) temperature

Correct Temperature,

Temperature Coefficient settings

Ambient
temperature

2. Ambient
Temperature

The ambient temperature can be either measured with
the PT-100 sensor or be set manually.

If using the PT-100 sensor the Ambient temperature
setting should be turned off. If the PT-100 probe is not
used, then the ambient temperature needs to be manually
set.

From the bottom menu, go to Meas. Setup > Ambient
Temperature and set the ambient temperature.

See page 66 for setting details.

Range

Off, -50.0 ºC ~ 399.9ºC

53

GOM-804 & GOM-805 User Manual

3. Temperature
compensation

Use arrow keys to go to Correct Temperature or to
Temperature Coefficient and press Enter to select the
setting.

To edit the setting values use the left and right arrow keys
to select a digit and use the up and down arrow keys to
edit the digit. Press Enter to confirm the setting.

Correct temperature, temperature

coefficient settings

Move

and edit

Select and

confirm

Enter

Desired Temperature range

-50.0 ~ +399.9 ˚C

Temperature Coefficient range

-9999 ~ +9999 ppm

Below are the inferred zero resistance temperatures of
some common conductors:

Material

Inferred Absolute Temperatures

Silver

-243

Copper

-234.5

Gold

-274

Aluminium

-236

Tungsten

-204

Nickel

-147

Iron

-162

54

MEASUREMENT

3. Temperature
compensation
connection

Sensor Connection:

REMOVE INPUTS BEFORE OPENING.

TO AVOID SHOCK,

WARNING

RS232

SER.NO. LABEL

100 240V , 50 60Hz

25VA MAX

AC

HANDLER / SCAN / EXT I/O

TC SENSOR

GPIB

PT-100 temperature

sensor

Note: If the sensor is not connected, then the Ambient
temperature needs to be manually set.

DUT connection:

4 wire Kelvin:

GUARD

SOURCE SENSE SENSE

SOURCE

shielding

55

Background

The Temperature Conversion function allows you to
determine the temperature change of a DUT at any given
resistance, if the initial temperature, the inferred zero
resistance temperature for the DUT and the initial
resistance of the DUT are known. The displayed result
can also be the extrapolated to calculate the final
temperature (T) or the extrapolated temperature

difference (△T)*.

Temperature Conversion function works on the following
formula:

10

20

1

2

tt

tt

R

R







Where:
R2 = resistance @ temperature t2
R1 = resistance @ temperature t1

t0 = inferred zero resistance temperature in ºC**
t1 = temperature at R

1

t2 =temperature at R2

The temperature conversion function is can be used to
determine the temperature of transformer windings,
electric motors, or other materials where it may not be
practical to embed a temperature sensor.

*(T) Final temperature = t2 = △T +T

A

(TA) Ambient temperature = Ambient temperature when
R2 is measured. TA can either by manually measured with
the PT-100 sensor or it can be manually set.

(△T) Extrapolated temperature difference = T - T

A

**“Constant” setting on the panel display is equivalent to
the absolute value of the inferred zero resistance
temperature.

GOM-804 & GOM-805 User Manual

Temperature Conversion

56

MEASUREMENT

Common inferred
zero resistance
temperatures

Metallic conductors show increased resistivity when
temperature is increased, and likewise show reduced
resistivity when temperature is reduced. Inferred zero
resistance temperature is simply the inferred temperature
at which the material will have no resistance. This value is
derived from the temperature coefficient of the material.
Note: the inferred zero resistance temperature is an ideal
value, and not a real-world value.

Material

Inferred zero resistance temp. in ºC

Silver

-243

Copper

-234.5

Gold

-274

Aluminium

-236

Tungsten

-204

Nickel

-147

Iron

-162

1. Select the
Temperature
compensation
mode.

Press TCONV to access the temperature compensation
function.

The temperature-converted measurement will appear on
the display.

Temperature

conversion function

indicator

(Ambient)
temperature
source

Resistance measurement

Extrapolated
temperature
difference or final
temperature

57

GOM-804 & GOM-805 User Manual

2. Initial
Resistance,
Initial
Temperature and
Constant settings

Use the arrows keys to go to Initial Resistance, Initial
Temperature or Constant (inferred initial resistance
temperature) and press Enter.

Use the left and right arrow keys to select a digit and use
the up and down arrow keys to edit the digit. Press Enter
to confirm the edit.

Initial Resistance, Initial Temperature

and Constant settings

Move

and edit

Select and

confirm

Enter

Initial Resistance

000.0001~999.9999 mΩ, Ω, kΩ,
MΩ

Initial Temperature

-50.0 ~ +399.9 ℃

Constant

000.0~999.9

3. Display mode

Use the arrow keys to go to Disp. Press Enter to toggle
between the T and △T modes.

Disp setting

Move

Toggle

Enter

T displays the extrapolated temperature at the measured
resistance of the DUT.

△T displays the difference from the extrapolated
temperature at the measured resistance of the DUT and

the ambient temperature. Please refer to page 56 for
further details.

3. Temperature
compensation
connection.

Sensor Connection:

REMOVE INPUTS BEFORE OPENING.

TO AVOID SHOCK,

WARNING

RS232

SER.NO. LABEL

100 240V , 50 60Hz

25VA MAX

AC

HANDLER / SCAN / EXT I/O

TC SENSOR

GPIB

PT-100 temperature

sensor

58

MEASUREMENT

DUT connection

4 wire Kelvin:

GUARD

SOURCE SENSE SENSE

SOURCE

shielding

59

GOM-804 & GOM-805 User Manual

Background

The following measurement settings are used to
configure the various measurement modes.

Background

The average function smoothes measurements using a
moving average. The average function sets the number of
samples used for the moving average; a higher number
results in smoother measurement results. The average
function is turned off by default.

1. Select Average
setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to Meas. Setup and press Enter.

Go to Average and press Enter.

Meas. Setup

menu icon

Move

Select menu

or setting

Enter

2. Average
setting appears

Use the arrow keys to turn Average on and set the
average number. Press Enter to confirm the setting.

Average settings

Average

OFF, ON: 2~10

Note

Pressing ESC before pressing ENTER will exit the Average
function settings.

Measurement Settings

Average Function

60

Measure Delay

Background

The Measure Delay setting inserts a delay time between
each measurement. Measure delay is turned off by
default.

Test signal

Default Measurement

start time

Measurement start with

Measure delay time

Measure delay time

The measure delay setting is useful for measuring
components that need some time to charge if the default
measurement start time is not adequate. An adequate
delay time allows the meter to avoid the effects of
transient disturbances that are usually seen when

measuring reactive DUTs with a current source.

1. Select
Measure Delay
setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to Meas. Setup and press Enter.

Go to Measure Delay and press
Enter.

Meas. Setup

menu icon

Move

Select menu

or setting

Enter

2. Measure Delay
setting appears

Use the arrow keys to turn Measure Delay on and set the
delay time. Press Enter to confirm the setting.

Measure delay

setting

Measure Delay*

OFF, ON: 000.000 ~ 100.000s

* When the set value is > 0.1s, the resolution is 0.1s.
When the set value is < 0.1S, the resolution is 1mS.

MEASUREMENT

61

GOM-804 & GOM-805 User Manual

Note

Pressing ESC before pressing ENTER will exit the Measure
Delay settings.

62

Trigger Delay

Background

The Trigger Delay setting adds a delay to when an
external trigger signal is recognized. Normally the
external trigger is recognized when there is no contact
bounce in the signal for a fixed length of time, this time
is known as the bounce monitoring window. This ensures
that the external trigger signal is stable before it is
recognized. The Trigger Delay time starts right after the
bounce monitoring window ends.

Start measurement

period

External

Trigger signal

Bounce monitoring

window

Trigger

delay time

Measurement

period

Measurement

process

Contact

bounce

Measurement

delay time

Measurement

time

The Trigger Delay setting is turned off by default.

Note

Pin 2 of the Handler/Scan/Ext I/O interface is used for
external triggering, See page 77 for pinout details.

1. Select Trigger
Delay setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to Meas. Setup and press Enter.

Go to Trigger Delay and press
Enter.

Meas. Setup

menu icon

Move

Select menu

or setting

Enter

MEASUREMENT

63

2. Trigger Delay
setting appears

Use the arrow keys to turn Trigger Delay on and set the
delay time. Press Enter to confirm the settings.

Trigger Delay

setting

Trigger Delay

OFF, ON: 0 ~ 1000ms

Note

Pressing ESC before pressing ENTER will exit the Trigger
Delay settings.

Trigger Edge

Background

The Trigger Edge setting sets the external trigger edge as
rising or falling. By default the trigger edge is set to rising.

1. Select Trigger
Edge setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to Meas. Setup and press Enter.

Go to Trigger Edge and press Enter.

Meas. Setup

menu icon

Move

Select menu

or setting

Enter

2. Trigger Edge
setting appears

Use the arrow keys to set the Trigger Edge. Press Enter
to confirm the setting.

Trigger Edge

setting

Trigger Edge

Rising, Falling

Note

Pressing ESC before pressing ENTER will exit the Trigger
Edge settings.

GOM-804 & GOM-805 User Manual

64

Temperature Unit

Background

Temperature units can be set to Fahrenheit or Celsius for
all temperature measurements.

1. Select
Temperature Unit
setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to Meas. Setup and press Enter.

Go to Temperature Unit and press
Enter.

Meas. Setup

menu icon

Move

Select menu

or setting

Enter

2.Temperature
Unit setting
appears

Use the arrow keys to set the Temperature Unit. Press
Enter to confirm the setting.

Temperature

Unit

Temperature Unit

Fahrenheit, Celsius

Note

Pressing ESC before pressing ENTER will exit the
Temperature Unit setting.

MEASUREMENT

65

Ambient Temperature

Background

The Ambient Temperature setting is used to set the
ambient (room temperature) for the Temperature
Compensation or Temperature Conversion function in
the absence of the PT-100 temperature sensor. See page
52 and 56 respectively for details.

1. Select Ambient
Temperature
setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to Meas. Setup and press Enter.

Go to Ambient Temperature and
press Enter.

Meas. Setup

menu icon

Move

Select menu

or setting

Enter

2.Ambient
Temperature
setting appears

Use the arrow keys to set the Ambient Temperature.
Press Enter to confirm the setting.

Ambient

Temperature

Ambient Temperature

Off, On: -50ºC ~ 399.9ºC

Note

Pressing ESC before pressing ENTER will exit the Ambient
Temperature setting.

GOM-804 & GOM-805 User Manual

66

Line Frequency

Background

The Line Frequency setting selects the appropriate line
filter to reduce the influence of the AC line frequency on
the milliohm measurements. This setting is set to AUTO
by default.

1. Select Line
Frequency
setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to Meas. Setup and press Enter.

Go to Line Frequency and press
Enter.

Meas. Setup

menu icon

Move

Select menu

or setting

Enter

2.Line Frequency
setting appears

Use the arrow keys to set the Line Frequency. Press Enter
to confirm the setting.

Line Frequency

Line Frequency

Auto, 50Hz, 60Hz

Note

Pressing ESC before pressing ENTER will exit the Line
Frequency setting.

MEASUREMENT

67

PWM Setting

Background

The PWM setting will set the duty of the PWM Drive
setting. The duty is set with ON and OFF times for the
waveform.

OFF time

ON

time

See page 31 for Drive setting details.

1. Select PWM
setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to Meas. Setup and press Enter.

Go to PWM and press Enter.

Meas. Setup

menu icon

Move

Select menu

or setting

Enter

2.PWM setting
appears

Use the arrow keys to set the ON and OFF time for the
duty. Press Enter to confirm the setting.

PWM

ON
OFF

03 ~ 99 time units*
0100 ~ 9999 ms

*The ON time setting is set in “time units”, not
milliseconds. The amount of time in a time unit depends
on the line frequency settings (see page 67).

Line frequency

1 Time Unit

60Hz

16.6mS

50Hz

20mS

Note

Pressing ESC before pressing ENTER will exit the PWM
setting.

GOM-804 & GOM-805 User Manual

68

System Settings

Background

The System settings are used to view the system
information, set the power on state, the remote interface,
screen brightness, external interface and beep settings as
well as access the calibration menu.

Background

The System Information will show the manufacturer,
model, software version and serial number of the unit.
The system information is the equivalent of the return
string from the *idn? query (page 144).

1. View System
Information

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to System and press Enter.

System information will be displayed
at the top of the System menu.

System

menu icon

Move

Select menu

or setting

Enter

System Information

Note

Pressing ESC will exit from the System menu.

System Information

MEASUREMENT

69

Power On Status Setup

Background

The Power On Status Setup allows you to either load the
previous settings or the default settings on startup.

1. Select Power
On Status
setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to System and press Enter.

Go to Power On Status Setup and
press Enter.

System

menu icon

Move

Select menu

or setting

Enter

2. Power On
Status Setup
appears

Use the arrow keys to set Power ON Status Setup. Press
Enter to confirm the setting.

Power On

Status Setup

Power On Status

Recall Previous Settings,
Load Default

Note

Pressing ESC before pressing ENTER will exit the Power
On Status Setup.

GOM-804 & GOM-805 User Manual

70

Interface

Background

The remote interface can be set to RS232, GPIB or USB.

Note

The GPIB interface is only available on the GOM-804G
and the GOM-805.

1. Select
Interface setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to System and press Enter.

Go to Utility and press Enter.

Go to Interface and press Enter.

System

menu icon

Move

Select menu

or setting

Enter

2. Interface
setting appears

Use the arrow keys to choose an interface and to set the
baud rate (RS232) or primary address (GPIB). Press
Enter to confirm the setting.

Interface

GPIB, Primary Address (1 ~ 30)

RS232, Baud Rate (1200, 2400, 4800,
9600, 19200, 38400, 57600, 115200)

USB

Note

Pressing ESC before pressing ENTER will exit from the
Interface settings.

MEASUREMENT

71

Brightness

Background

The Brightness setting sets the backlight brightness of
the TFT-LCD panel.

1. Select
Brightness
setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to System and press Enter.

Go to Utility and press Enter.

Go to Brightness and press Enter.

System

menu icon

Move

Select menu

or setting

Enter

2. Brightness
setting appears

Use the arrow keys to set the brightness level. Press
Enter to confirm the setting.

Brightness

Brightness

01 (dim) ~ 05 (bright)

Note

Pressing ESC before pressing ENTER will exit from the
Brightness settings.

GOM-804 & GOM-805 User Manual

72

User Define Pins

Background

The External I/O User Define Pin settings set the logic
and the active level for the Define 1 and Define 2 pins on
the Handler/Scan/EXT I/O port on the rear panel. The
External I/O pins are used with the compare or bin
functions. The logic settings can be based on the pass,
fail, high, low or bin grade results of the selected
function.

1. Select External
I/O Setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to System and press Enter.

Go to Utility and press Enter.

Go to External I/O and press
Enter.

System

menu icon

Move

Select menu

or setting

Enter

2. External I/O
Menu Appears

Use the arrow keys to choose either User Define 1 or
User Define 2 and press Enter.

Use the arrow keys to set the active level of the pin when
the logic conditions are true and to set the logic settings.
Press Enter to confirm the settings.

User Define 1

User Define 2

User Define 1/2:

Pin Active:

High, Low

Logic:

Operand1

Operator

Operand2

Fail

Logical OR,

Logical

AND,
OFF*

Fail

Pass

Pass

Low

Low

High

High

Bin O**

Bin O**

Bin 1 ~ 8

Bin 1 ~ 8

MEASUREMENT

73

*The OFF operator sets the Logic as
true when Operand1 is true.

** Bin O is defined as outside bin 1~ 8.

Note

The Bin logic settings are not available for the GOM-804.

Pressing ESC before pressing ENTER will exit from the
selected External I/O setting.

Handler Mode

Background

The Handler Mode setting determines the behavior of
the result signals from the handler interface. There are
two settings, Clear and Hold. The Clear setting will clear
the results of the previous test before starting the
succeeding one and the Hold setting will keep the test
result of the previous test until the succeeding test has
completed.

The timing diagrams below are used as examples. All the
result signals in the examples are active high.

Clear example

Clear: All result signals (PASS, Fail, High and Low) are
cleared at the falling edge of EOT and the results from
the current test are output at the rising edge of the EOT
signal.

Previous

results

cleared

New

results

Trigger

Ready

EOT
Pass

Fail

High

Low

EOT falling

edge

EOT rising

edge

Previous

results

GOM-804 & GOM-805 User Manual

74

MEASUREMENT

Hold example

Hold: The results of the previous tests are held until the
current test has completed.

Previous results

held

New results

Trigger

Ready

EOT
Pass

Fail

High

Low

EOT falling

edge

EOT rising

edge

Previous

results

1. Select External
I/O setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to System and press Enter.

Go to Utility and press Enter.

Go to External I/O and press
Enter.

System

menu icon

Move

Select menu

or setting

Enter

2. External I/O
menu appears

Use the arrow keys to choose Handler Mode and press
Enter.

Use the arrow keys to set the handler mode. Press Enter
to confirm the setting.

Handler Mode

Handler Mode

HOLD, CLEAR

Note

Pressing ESC before pressing ENTER will exit from the
Handler Mode setting.

75

Beep

Background

The Beep setting will configure the beeper sound for the
key presses, the Compare function and the Binning
function.

For the Compare and Binning function the beep can be
configured to beep on a pass or fail judgment.

1. Select Beep
setting

From one of the main screens, press
the

ESC

key so that the menu
system at the bottom of the display
has focus.

Go to System and press Enter.

Go to Utility and press Enter.

Go to Beep and press Enter.

System

menu icon

Move

Select menu

or setting

Enter

2. Beep menu
appears

Use the arrow keys to choose a beep setting and press
Enter.

Use the arrow keys to set the selected setting and press
Enter to confirm.

Key Click Setting

Compare Setting

Binning Setting

Beep Settings:

Key Click

On, Off

Compare

Off. Pass, Fail

Binning

Off. Pass, Fail

Note

Pressing ESC before pressing ENTER will exit from the
selected Beep setting.

GOM-804 & GOM-805 User Manual

76

HANDLER/SCAN INTERFACE

Handler

Handler Overview ................................................... 78

Pin Definitions for the Handler Interface ............... 80

Handler Interface for Binning and Compare

Functions ............................................................... 80

Scan

Scan Overview ........................................................ 82

Pin Definitions for the SCAN Interface ................... 83

Scan Interface ........................................................ 83

Scan Setup ............................................................. 84

Scan Output ........................................................... 88

GOM-802
Compatibility

GOM-802 Compatibility for Scan and Handler

Interfaces ............................................................... 89

GOM-805 to GOM-802 Handler/Scan Interface ..... 89

Remote Interface

Configure USB Interface ......................................... 90

Install USB Driver .................................................. 91

Configure RS-232 Interface ..................................... 92

Configure GPIB Interface ....................................... 93

RS232/USB Function Check ................................... 93

Using Realterm to Establish a Remote Connection

............................................................................... 94

GPIB Function ........................................................ 96

HANDLER/SCAN

INTERFACE

77

Handler Overview

Background

The Handler interface is used to help grade components
based on the Compare or Binning function test results.
The appropriate pins on the handler interface are active
when the Compare or Binning function is used.

There are 17 TTL outputs and 1 TTL inputs. The
Handler interface is only applicable with the Binning
function or Compare measurement modes.

Note

Please see following pages for related functions and
settings:
Compare function: 41
Binning function: 46
Ext I/O settings: 73
Handler mode settings 74

Interface and pin
assignment

25-Pin D-SUB
(Female)

HANDLER / SCAN / EXT I/O

Pin assignment

TRIGGER

Starts the trigger for a single
measurement.

READY

High when the measurement has
finished. The instrument is ready for
the next trigger.

EOT

High when the AD conversion has
completed. The DUT is ready to be
changed.

BIN 1~8

High when the sorting result is in one
of the eight bin grades. Bin1~8 (pass).

BIN OUT

High when the sorting result is out of
all the eight bin grades (Bin1~8). The
status of this pin reflects either a HI or
LO result (fail).

LOW

High when the compare result is
deemed LO.

HIGH

High when the compare result is
deemed HI.

GOM-804 & GOM-805 User Manual

78

HANDLER/SCAN INTERFACE

FAIL

High when the compare result is either
HI or LO (fail).

PASS

High when the compare result is IN
(pass).

For the full pin definition, please refer to the table listed below.

Note

The output current from all the pins and the VINT(+5V)
pin cannot exceed 60mA.

79

GOM-804 & GOM-805 User Manual

HANDLER / SCAN / EXT I/O

1

14

13

25

Pin

Name

Description

Active
modes

In/
Out

1, 17

Reserved

2

Trigger

Trigger for a single measurement.

All

In

3, 14,
18

GND

Ground.

4

Fail

High when the compare result is
either HI or LO (fail).

Compare

Out

5

High

High when the compare result is
deemed HI.

Compare

Out

6

Pass

High when the compare result is IN
(pass).

Compare

Out

7

EOT

High when the AD conversion has
completed. The DUT is ready to be
changed.

Ext
trigger
mode

Out

8

VINT

Internal DC Voltage +5V.

Out

9

Bin1

High when the binning sorting result
is within the bin1 setting range.

Binning

Out

10

Bin2

High when the binning sorting result
is within the bin2 setting range.

Binning

Out

11

Bin3

High when the binning sorting result
is within the bin3 setting range.

Binning

Out

12

Bin4

High when the binning sorting result
is within the bin4 setting range.

Binning

Out

Pin Definitions for the Handler

Interface

As this interface is used for the handler and scan functions, the interface
pinout depends on the function mode. The following pinout is only applicable
when using the Binning or Compare function.

Handler Interface for Binning and Compare Functions

80

HANDLER/SCAN INTERFACE

13

Bin5

High when the binning sorting result
is within the bin5 setting range.

Binning

Out

15

Userdefine2

High or low when the user define2
logic conditions are met.

Compare,
Binning

Out

16

Userdefine1

High or low when the user define1
logic conditions are met.

Compare,
Binning

Out

19

VEXT

External DC Voltage, acceptable
range is +5V.

In

20

Ready

High when the measurement has
finished. The instrument is ready for
the next trigger.

Ext
trigger
mode

Out

21

Bin6

High when the binning sorting result
is within the bin6 setting range.

Binning

Out

22

Low

High when the compare result is
deemed LO.

Compare

Out

23

Bin7

High when the binning sorting result
is within the bin7 setting range.

Binning

Out

24

Bin8

High when the binning sorting result
is within the bin8 setting range.

Binning

Out

25

Bin Out

High when the binning sorting result
is out of all the bin setting ranges.

Binning

Out

For backwards compatibility with the GOM-802 handler interface, please see
page 89.

81

Scan Overview

Background

The Scan function is used to automatically bin groups of
up to 100 components. The associated pins in the handler
interface are active when the Scan function is activated.

There are a total of 6 outputs, 3 inputs as well as a GND
and power (+5V) pin.

Interface and pin
assignment

25Pin D-SHELL
(Female)

HANDLER / SCAN / EXT I/O

Pin Assignment

Relay

Controls the relay output.

Pass

Pass signal. Indicates the compare result
is IN(pass).

Low

Low signal. Indicates a LO compare
result.

High

High signal. Indicates a HI compare
result.

Clock

The clock signal will pulse high when
each group of output signals (Relay,
Pass, Low, High) are ready. There are up
to 100 groups of output signals

STRB

After all (100) output groups are ready,
the STRB signal will pulse high.

GOM-804 & GOM-805 User Manual

82

HANDLER/SCAN INTERFACE

HANDLER / SCAN / EXT I/O

1

14

13

25

Pin

Name

Description

In/Out

1,9-13,15-17,21,23

-25

Reserved
2

Trigger

Start for Scan measurement.

In

3,14,18

GND

Ground.

4

High

High signal. Indicates a HI compare
result.

Out

5

Clock

The clock signal will pulse high when
each group of output signals (Relay,
Pass, Low, High) are ready. There are
up to 100 groups of output signals.

Out

6

Low

Low signal. Indicates a LO compare
result.

Out

7

Pass

Pass signal. Indicates an IN compare
result (pass).

Out
8

VINT

Internal DC Voltage +5V.

Out

19

VEXT

External DC Voltage, acceptable
range is +5V.

In
20

Relay

Controls the relay output.

Out

22

STRB

After all (up to 100) output groups
are ready, the STRB signal will pulse
high.

Out

Pin Definitions for the SCAN Interface

As this interface is used for the handler and scan functions, the interface
pinout depends on the function mode. The following pinout is only applicable
when using the Scan function.

Scan Interface

For backwards compatibility with the GOM-802 scanner interface, please see
page 89.

83

GOM-804 & GOM-805 User Manual

Background

The Scan function sequentially scans up to 100 channels
and grades the resistance of the DUT on each channel to
a reference value. An automated handler or test fixture is
required to interface the DUTs to the measurement
terminals and the scan interface that controls the timing
of each scan.

GOM-805

Scan I/O

Measurement terminals

Automated Handler/Test Fixture

1 2 3 4 5 6 NChannel

DUT 1~N

S+ Source+Source- S-

·····

Note: The automated handler/test fixture is
user-supplied. Please see your distributor for support and
technical details.

Grading of each DUT is essentially the same as the
compare function (page 41), the difference being the
Scan function will compare up to 100 DUTs sequentially,
whereas the Compare function will compare only one
DUT at a time.

The scan function compares a measured value to a
“Reference” value that has an upper (HI) and lower (LO)
limit. If the measured value is within the upper and lower
limit, then the measured value is judged as IN.

There are two modes that can be used to make a
judgment: ABS and △% modes.

The ABS mode compares the measured value to the
upper (HI) and lower (LO) limits. The upper and lower
limits are set as absolute resistance values.

The △% compare function compares the deviation of

Scan Setup

84

HANDLER/SCAN INTERFACE

the measured value from the reference value as a
percentage.
{ [(Measured Value-Reference)/Reference]%}.

A measured value that falls within the upper and lower
limits is considered IN (pass), a value that falls below the
lower limits is considered LO, and a value that falls over
the upper limit is a HI.

Reference

value

Upper

limit

Lower

limit

IN HILO

For both scan modes, the IN, HI or LO will be shown on
the display for each judgment (if the time between each
judgment is not too fast).

Display Overview

Scan function

indicator

Ready to start scan message

Reference, limits, scan mode, current

channel, measurement delay

Change

display view

1. Select the
Scan function

Press

Scan

Scan to access the scan mode, as shown

above.

2. Select the
compare mode

Use the arrow keys to navigate to the Mode setting. Press
the Enter key to toggle the compare mode.

Mode

Move

Toggle

Enter

Range

Abs, △ %

85

GOM-804 & GOM-805 User Manual

3. Channel
setting

The Channel setting sets the number of DUT channels
that are used.

Use the arrow keys to navigate to the Channel setting and
press Enter.

Use the left and right arrow keys to select a digit. Use the
up and down arrow keys to edit the value of the selected
digit. Press Enter to confirm the setting.

Channel setting

Move

and edit

Select and

confirm

Enter

Channel Range:

01 ~100

4. Delay setting

The Delay setting adds a pause between each channel
measurement.

The Use the arrow keys to navigate to the Delay setting
and press Enter.

Use the left and right arrow keys to select a digit. Use the
up and down arrow keys to edit the value of the selected
digit. Press Enter to confirm the setting.

Delay setting

Move

and edit

Select and

confirm

Enter

Delay Range:

400ms ~ 30000ms

5. Start the scan.

Press the

Trigger

key or input a pulse signal on the
Trigger pin of the SCAN interface port to start a scan
test.

Note

See page 64 to set the external trigger edge as a rising or
falling leading edge.

The results will be displayed on the screen as each test is
performed. The results will also be output through the
scan port until the scan has finished.

86

HANDLER/SCAN INTERFACE

Scan function

indicator

Pass/Fail

judgment

Measured value

Reference, limits, scan mode, current

channel, measurement delay

Change

display view

6. View Results

After the last SCAN test has
finished, press the

ESC

key
so that the menu system at the
bottom of the display has focus.

Go to View and press Enter to
view the results of each channel.

View display

results

Move

Select

Enter

Use the Previous and Next soft-keys to view each page.

Use the Back soft-key to return to the previous window.

Channel number

Pass/High/Low

(P/H/L)

judgment results

Previous

results page

Return to

the

previous

window

Measurement

results

Next results

page

87

Scan Output

Background

The timing diagrams for the scan output under different
conditions are shown below.

Ready message displayed…

After the manual trigger key is
pressed….

Relay

Pass

Low

High

Clock

STRB

100 99 98 97 2 1

Relay

Pass

Low

High

Clock

STRB

100 99 2 1

Scan channel 1. Delay time has
elapsed.

Scan channel n. Delay time has
elapsed.

Relay

Pass

Low

High

Clock

STRB

100 99 2 1

Relay

Pass

Low

High

Clock

STRB

100 99 n+1 198

n

Scan Channel 100. Delay time has
elapsed.

Scan output signal timing.

Relay

Pass

Low

High

Clock

STRB

100 99 2 198 97

Data
Pass

STRB

20us

168us

38us

20us

GOM-804 & GOM-805 User Manual

88

HANDLER/SCAN INTERFACE

GOM-805 Handler Interface

GOM-802 Handler Interface

Pin

Handler

Scan

Pin

Handler

Scan

1, 17

Reserved

Reserved

2

Trigger

Trigger

→

3

Start

NC

3, 14,
18

GND

GND

→

2

GND

GND

4

Fail

High

→

7

Fail

High

5

High

Clock

→

8

High

Clock

6

Pass

Low

→

6

Pass

Low

7

EOT

Pass

→

5

EOT

Pass

8

VINT

+5V

→

1

+5V

+5V

9

Bin1

10

Bin2

11

Bin3

12

Bin4

13

Bin5

15

Userdefine2

16

Userdefine1

19

VEXT

VEXT

20

Ready

Relay

→

4

Ready

Relay

21

Bin6

22

Low

STRB

→

9

Low

STRB

23

Bin7

24

Bin8

25

Bin Out

GOM-802 Compatibility for Scan and Handler Interfaces

As the handler interface on GOM-802 is a 9-pin D-sub and the GOM-805 is a
25-pin D-sub, the GOM-805 handler interface cannot be used with existing
GOM-802 ATE equipment or environments without modification.

For backwards compatibility with the GOM-802 handler interface, please refer
to the chart below:

GOM-805 to GOM-802 Handler/Scan Interface

89

Configure Interface

Overview

The RS-232 and USB interfaces are standard for all
models, however the GPIB interface is only applicable
for the GOM-804G and GOM-805. The remote control
interfaces allow the GOM-804/805 to be programmed
for automatic testing.

For more information on remote control programming,
please see the Command Overview chapter on page 102.

Interface

USB

USB HOST

RS-232

DB-9 male port

GPIB

24 pin female GPIB port (GOM-804G,
GOM-805 only)

Background

The Type B USB port on the rear panel is used for
remote control. This interface creates a virtual COM port
when connected to a PC.

Note

The USB interface requires the USB driver to be
installed. See page 91 to install the USB driver.

1. Connect and
configure to
USB.

Configure the interface to USB in
System>Utility>Interface menu.

Page 71

Connect the Type A-B USB cable to the
rear panel USB B port on the
GOM-804/805.

Connect the other end to the Type A port
on the PC.

GOM-804 & GOM-805 User Manual

Configure USB Interface

90

Install USB Driver

Background

The USB driver needs to be installed when using the USB
port for remote control. The USB interface creates a
virtual COM port when connected to a PC.

1. Select the USB
driver.

Configure the interface to USB in
System>Utility>Interface menu.

Page 71

Connect the Type A-B USB cable to the
rear panel USB B port on the
GOM-804/805. Connect the other end to
the Type A port on the PC.

Go to the Windows Device Manager.
For Windows 7 go to:
Start Menu > Control Panel > Hardware and Sound >
Device Manager

The GOM-804/805 will appear as an unknown Virtual
Com Port under “Other Devices”.

Right-click Other Devices and select “Update Driver

Software”.

Select “Browse my computer for driver software” and

select the driver on the User Manual CD.

The GOM-805 and the COM port that it is assigned to
will now appear in under the Ports (COM & LPT) node.

HANDLER/SCAN INTERFACE

91

Configure RS-232 Interface

Background

The GOM-804/805 can also use an RS-232C connection
for remote control. When connecting to a PC ensure the
correct baud rate, parity, data bits, stop bit and data
control settings are used.

Settings

Baud rate

1200, 2400, 4800, 9600, 19200, 38400,
57600, 115200

Parity

None

Data bits

8

Stop bit

1

Data flow
control

None

1. Select the
RS-232 baud rate

Configure the interface to RS232 and
set the baud rate in
System>Utility>Interface menu.

Page 71
Connect the RS-232C cable to the rear

panel RS232 port.

RS232

RS-232 pin
assignment

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

195

6

PC – GOM
RS-232C
connection

The RS232C connection uses a Null-modem connection,
in which transmit (TxD) and receive (RxD) lines are
cross-linked.

GOM PC

TxD

RxD

GND

Pin2
Pin3

Pin5

TxD

RxD

GND

Pin2
Pin3

Pin5

GOM-804 & GOM-805 User Manual

92

Configure GPIB Interface

Background

The GPIB interface is SCPI-1994, IEEE488.1 and
IEEE488.2 compliant.

Note

The GPIB interface is only available on the GOM-804G
and GOM-805.

1. Select the
GPIB address

Configure the interface to GPIB and set
the GPIB address in
System>Utility>Interface menu.

Page 71

Connect one end of the
GPIB cable to the computer
and the other end to the
GPIB port on the
GOM-805.

GPIB

Operation

Invoke a terminal application such as Realterm.

For RS-232, set the COM port, baud rate, stop bit, data
bit and parity accordingly.

To check the COM settings in Windows, see the Device
Manager. For example, in WinXP go to the Control panel

→ System → Hardware tab.

Run this query from the terminal.

*idn?

This should return the Manufacturer, Model number, and
Firmware version.

GWINSTEK,GOM805,GXXXXXXXX,V1.00

Note

If you are not familiar with using a terminal application
to send/receive remote commands from the serial port or
via a USB connection, please page 94 (Using Realterm to
Establish a Remote Connection) for more information.

HANDLER/SCAN INTERFACE

RS232/USB Function Check

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GOM-804 & GOM-805 User Manual

Background

Realterm is a terminal program that can be used to
communicate with a device attached to the serial port of
a PC or via an emulated serial port via USB.

The following instructions apply to version 2.0.0.70.
Even though Realterm is used as an example to establish
a remote connection, any terminal program can be used
that has similar functionality.

Note

Realterm can be downloaded on Sourceforge.net free of
charge.

For more information please see
http://realterm.sourceforge.net/

1. Install
Realterm

Download Realterm and install according to the
instructions on the Realterm website.

2. Configure
connection

Connect the GOM-804/805 via USB (page 90) or via
RS232 (page 92).

If using RS232, make note of the configured baud rate.

Go to the Windows device manager and find the COM
port number for the connection.
For example in Windows 7, go to the Start menu >
Control Panel > Hardware and Sound > Device Manager

Double click the Ports icon to reveal the connected serial
port devices and the COM port for each connected
device.

If using USB, the baud rate, stop bit and parity settings
can be viewed by right-clicking connected device and
selecting the Properties option.

Using Realterm to Establish a Remote Connection

94

HANDLER/SCAN INTERFACE

2. Run Realterm

Start Realterm on the PC as an administrator.
Click:
Start menu>All Programs>RealTerm>realterm

Tip: to run as an administrator, you can right click the
Realterm icon in the Windows Start menu and select the
Run as Administrator option.

After Realterm has started, click on the Port tab.

Enter the Baud, Parity, Data bits, Stop bits and Port
number configuration for the connection.

The Hardware Flow Control and Software Flow Control
options can be left at the default settings.

Press Open to connect to the GOM-804/805.

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GOM-804 & GOM-805 User Manual

3. Test remote
command

Click on the Send tab.

In the EOL configuration, check on the +CR and +LF
check boxes.

Enter the query:
*idn?

Click on Send ASCII.

The terminal display will return the following:

GWINSTEK,GOM805,GXXXXXXXX,V1.00

(manufacturer, model, serial number, version)

4. Errors or
Problems

If Realterm fails to connect to the GOM-804/805, please
check all the cables and settings and try again.

Background

Please use the National Instruments Measurement &
Automation Controller software to confirm GPIB/LAN
functionality.

See the National Instrument website, http://www.ni.com
for details.

1. Operation

Start the NI Measurement and
Automation Explorer (MAX) program.
Using Windows, press:

GPIB Function

96

HANDLER/SCAN INTERFACE

Start>All Programs>National
Instruments>Measurement & Automation

Step a.

From the Configuration panel access;

My System>Devices and Interfaces>GPIB0

Step b.

Press the Scan for Instruments button.

Step c.

In the Connected Instruments panel the GOM-804/805
should be detected as Instrument 0 with the address the
same as that configured on the unit.

Step d.

Double click the Instrument 0 icon.

a

b

c

d

Step e.

Click on the Attributes tab at the bottom.

Step f.

Click on Communicate with Instrument.

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GOM-804 & GOM-805 User Manual

Step g.

In the NI-488.2 Communicator window, ensure *IND? is
written in the Send String: text box.

Click on the Query button to send the *IDN? query to
the instrument.

Step h.

The String Received text box will display the query
return:

GWINSTEK,GOM805,GXXXXXXXX,V1.00

(manufacturer, model, serial number, version)

f

g
h

e

The function check is complete.

98

SAVE/RECALL

Background

The save function saves the current function as well the
settings related to that function.

There are 20 memory slots that can be used to save and
recall settings on the GOM-804/805.

1. Enter the
Memory menu

When you are in the desired function mode, press the

ESC

key (if necessary) to so that the menu system at

the bottom of the display has focus.

Use the arrow keys to navigate to the Memory setting
and press Enter.

Move

Select menu

or setting

Enter

Memory setting

Function mode

SAVE/RECALL

The settings for all the major functions can be saved and recalled from 20
memory slots.

Settings can saved/recalled for the following functions:
Ohm, Compare, Binning, TC, TCONV, TEMP, Scan, Diode.

Save/Recall Settings

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GOM-804 & GOM-805 User Manual

The Recall/Save Setup menu will appear.

2. Save/
Recall/Clear
Memory

The No. setting should be already highlighted when
entering the Recall/Save Setup menu. If not, use the
Left/Right arrow keys to highlight the No. setting.

No. setting

Recall, Save, Clear settings

Move

and edit

Select and

confirm

Enter

Use the up and down arrow keys to select a memory
space.

Range

01~20

*If a memory space has been used before , the
settings for that memory slot will also be shown
on the display.

To Save:
Use the arrow keys to go to Save
and press Enter.

To Recall:
Use the arrow keys to go to Recall
and press Enter.

To Clear:
Use the arrow keys to go to Clear
and press Enter.

100