Keithley 4712-1,1 Datasheet

T

ECHNICAL DATA

MODEL 2750

MULTIMETER/SWITCH SYSTEM

M

ODEL 2750 M ULTIMETER

/SWITCH S YSTEM

2

Introduction

The Model 2750 6½-digit Multimeter/Switch system blends Keithley’s high performance DMM
technology, our switching expertise, and our data acquisition knowledge into a compact, affordable,
easy-to-use package. This technical data booklet provides a comprehensive overview of the system
and includes complete detailed specifications.

The Model 2750 Multimeter/Switch System consists of the 2750 mainframe and a choice of nine
switch/control modules. The five-slot mainframe allows five different types of multiplexer, matrix,
or control modules to operate simultaneously. Input modules can be mixed or matched to provide
a broad range of measurement, acquisition, and control capabilities.

The Model 2750 provides up to 200 channels of multiplexed measurement and control or 240 chan­nels of matrix crosspoints in a 19˝ rack mount or a benchtop enclosure. Each channel can be
configured independently. Settings can be configured via the computer controller (over GPIB or
RS-232) or the front panel of the Model 2750 mainframe.

If you have any questions after reviewing this information, please contact your local Keithley repre­sentative or call one of our Applications Engineers at 1-800-552-1115 (U.S. only). Check Keithley’s
website (www.keithley.com) for the names and numbers of representatives around the world.

Figure 1. Model 2750 System Diagram

Model 2750

Switch/Control

Modules

MEASURE

DCV
Ohms
Temperature
ACV
Frequency
DC & AC Current
Totalizer

CONTROL

Analog Output
Digital I/O
Multiplex Switching
Independent Switching
Matrix Switching

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Table of Contents

Overview · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·4

Front and Rear Panel Views · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·4

Measurement Ranges · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·5

Switch/Control Module Capabilities · · · · · · · · · · · · · · · · · · · · · · · · · · · ·5

Module Capabilities Overview · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·5

Module Selector Guide · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·6

Connector Guide for Keithley 2750 Modules · · · · · · · · · · · · · · · · · · · · · ·6

Channel Configuration Capabilities · · · · · · · · · · · · · · · · · · · · · · · · · · · ·7

Scanning Capabilities · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·7

Triggering and I/O Capabilities · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·8

Alarm Limits/Digital Outputs · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·9

Electrical Capabilities · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·9

On-board Data Storage · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·9

Saving/Recalling a Setup · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·10

Power Failure Recovery · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·10

Channel Monitor · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·10

Measurement Performance · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·10

Filtering · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·11

NPLC · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·11

Line Cycle Synchronization · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·11

Autozero · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·11

Low Ohms Measurement · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·11

Offset Compensation · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·12

Voltage Limit/Dry Circuit Ohms (DRYCKT) · · · · · · · · · · · · · · · · · · · · ·12

Temperature Measurements · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·12

Calibration · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·13

Model 2750 Specifications · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·15

Switch/Control Module Specifications

7700 20-Channel Differential Multiplexer w/Automatic CJC · · · · · · ·19

7701 32-Channel Differential Multiplexer · · · · · · · · · · · · · · · · · · · · · · · ·20

7702 40-Channel Differential Multiplexer · · · · · · · · · · · · · · · · · · · · · · · ·21

7703 32-Channel High Speed Differential Multiplexer · · · · · · · · · · · ·22

7705 40-Channel Control Module · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·23

7706 All-in-One I/O Module · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·24

7707 Multiplexer-Digital I/O Module · · · · · · · · · · · · · · · · · · · · · · · · · · · ·25

7708 40-Channel Differential Multiplexer Module · · · · · · · · · · · · · · · ·26

7709 6×8 Matrix Module · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·27

Module Configuration Examples · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·29

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Overview

Built-in

independently

programmable

alarm limits
per channel.

View slot capacity

and channel

closure status

from front panel.

Front panel input

jacks simplify
manual probing,
troubleshooting,

and calibration.

Open lead detection

protects against

false readings

due to lead

disconnections.

Familiar DMM-like front

panel scheme makes it

easier to use on bench or

rack. Select or change

functions with the push

of a button.

1Ω range with

1µΩ resolution

Voltage clamp

ohms (dry circuit)

clamps voltage to

20mV.

Non-volatile memory allows

time-stamped storage of

110K readings. Has built-in

real-time clock.

Open or close single or

multiple channels from

the front panel.

Manually step through

channels or scan

automatically. Each

channel independently

configurable.

Initialize the system

with one of three

fully programmable

set-up conditions.

Use mX+b or 1/x %

scaling to convert

sensor/transducer

outputs directly into

engineering units.

Built-in digital I/O lines

provide for control,external

triggering, and HI/LO

alarm/limit outputs.

Trigger Link enables tightly

synchronized triggering

with other instruments in

large ATE systems.

GPIB and RS-232

interfaces are

standard.

Build-in noise

rejection circuitry

ensures stable,

predictable

measurements.

IDC connectors on

selected modules are

compatible with standard

ribbon cable.

Rugged D-sub

bulkhead connectors on

selected modules.

Built-in relay cycle

counters on each module

for ease of maintenance.

A variety of measurement and control

modules make it simple to mix, match, and

change input signals or control lines whenever

needed. Install up to five modules at once to

create a system of up to 200 channels.

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ECHNICAL DATA

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Measurement Ranges for the Model 2750

Switch/Control Module Capabilities

The flexibility to mix and match switch/control modules in a single mainframe simplifies configur­ing Model 2750-based systems for a wide range of applications. Each module offers a different
combination of capabilities, such as number of channels, speed, etc. Before selecting a module, it
is critical to analyze the needs of the application carefully and consider future requirements for
expansion.

Module Capabilities Overview

7700 7701 7702 7703 7705 7706 7707 7708 7709

DC Volts ✓✓✓✓ ✓✓✓✓

DC Current ✓✓

Temperature

T/C w/Automatic CJC ✓✓✓

T/C w/External CJC ✓✓✓✓ ✓✓✓✓

RTD ✓✓✓✓ ✓✓✓✓

Thermistor ✓✓✓✓ ✓✓✓✓

Resistance (2- or 4-wire) ✓✓✓✓ ✓✓✓✓

Continuity ✓✓✓✓ ✓✓✓✓

AC Volts ✓✓✓✓ ✓✓✓✓

AC Current ✓✓

Frequency ✓✓✓✓ ✓✓✓✓

Event Counter/Totalizer ✓

Signal Routing/Control ✓✓✓✓✓✓✓✓✓

Digital Input ✓

Digital Output ✓✓

Analog Output ✓

Figure 2. Measurement Ranges

1n 1µ 1m 1 1k 1M 1G

DC Voltage

AC Voltage

DC Current

AC Current

Frequency

Period

Resistance (2-Wire)

Resistance (4-Wire)

Logarithmic scale

Temperature–RTD

Temperature–TC

Temperature–Thermistor

Linear scale

100nV 1000V

100nV 750V

10nA 3A

1µA 3A

3Hz 500kHz

2µs 333ms

10µΩ 120MΩ

1µΩ 120MΩ

–500 0 500 1000 1500 2000

–200°C 630°C

–200°C 1820°C

–80°C 150°C

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Module Selector Guide

This selector guide may prove helpful in identifying the best module for a specific application. Install
up to five modules at a time in the 2750 mainframe.

Max. Current

# Analog Type of Max. Switched Measurement Digital Switch

Module Inputs Configuration Differential* 4-pole Connector Voltage Current Channels I/O Speed Other

7700 20 Multiplexer 1 × 20 or 1 × 10 Screw 300V 1A 2 channels N/A 3 ms Maximum power = 125VA.

w/CJC two 1 × 10 terminals @ 3A

7701 32 Multiplexer 1 × 32 or 1 × 16 D-sub 150V 1A N/A N/A 3 ms Maximum power = 125VA.

two 1 × 16

7702 40 Multiplexer 1 × 40 or 1 × 20 Screw 300V 1A 2 channels N/A 3 ms Maximum power = 125VA.

two 1 × 20 terminals @ 3A

7703 32 Multiplexer 1 × 32 or 1 × 16 D-sub 300V 500mA N/A N/A 1 ms Reed relays.

two 1 × 16

7705 40 Independent N/A N/A D-sub 300V 2A N/A N/A 3 ms Maximum power = 125VA.

SPST

7706 20 Multiplexer 1 × 20 or 1 × 10 Screw 300V 1A N/A 16 Digital 3 ms (2) ±12V analog output

w/CJC two 1 × 10 terminals Out Only channels & 100kHz event

counter/totalizer.
Maximum power = 125VA.

7707 10 Multiplexer/ 1 × 10 or 1 × 5 D-sub 300V 1A N/A 32 Digital 3 ms Maximum power = 125VA.

Digital I/O two 1 × 5 I/O (4) eight-bit word I/O.

7708 40 Multiplexer 1 × 40 or 1 × 20 Screw 300V 1A N/A N/A 3 ms Maximum power = 125VA.

w/CJC two 1 × 20 terminals

7709 48 6 × 8 Matrix Yes Yes D-sub 300V 1A N/A N/A 3 ms Connects to internal DMM.

Daisy chain multiple cards
for up to a 6 × 40 matrix.
Maximum power = 125VA.

* Can be disconnected from internal DMM for routing external signals

Connector Guide for Keithley 2750 Modules

Module Type of Connector Included Accessories Optional Accessories

7700 Oversize screw terminals Strain relief N/A

7701 50 pin female D-sub & (1) 50 pin male IDC ribbon cable connector w/strain relief & Keithley part number 7789 includes

25 pin female D-sub (1) 25 pin male IDC ribbon cable connector w/strain relief (1) 50 pin & (1) 25 pin male D-sub

connectors with solder cup. Keithley part
number 7790 includes IDC ribbon cable
connector kit (ribbon cable not included).

7702 Oversize screw terminals Strain relief N/A

7703 Two 50 pin female D-sub (2) 50 pin male D-sub connectors with solder cups. Cabling not Keithley part number 7788 includes 50 pin

included. Not compatible with IDC ribbon cable connectors. male connectors with solder cups.

7705 Two 50 pin female D-sub (2) 50 pin male D-sub connectors with solder cups. Cabling not Keithley part number 7788 includes 50 pin

included. Not compatible with IDC ribbon cable connectors. male connectors with solder cups.

7706 Screw terminals Strain relief N/A

7707 50 pin male D-sub & (1) 50 pin female IDC ribbon cable connector w/strain relief & Keithley part number 7790 includes IDC

25 pin female D-sub (1) 25 pin male IDC ribbon cable connector w/strain relief Ribbon Cable Connector kit (ribbon cable

not included).

7708 Oversize screw terminals Strain relief N/A

7709 50 pin female D-sub & (1) 50 pin male IDC ribbon cable connector w/strain relief & Keithley part number 7789 includes

25 pin female D-sub (1) 25 pin male IDC ribbon cable connector w/strain relief (1) 50 pin & (1) 25 pin male D-sub

connectors with solder cup. Keithley part
number 7790 includes IDC ribbon cable
connector kit (ribbon cable not included).

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Channel Configuration Capabilities

• Measurement functions: The 2750 can measure many different parameters: DC voltage, DC
current, AC voltage, AC current, 2-wire Ω, 4-wire Ω, voltage clamped Ω, temperature (using
thermocouples, RTDs, and thermistors), frequency, period, and continuity.

• Math functions:A variety of math functions are available at the push of a button, including
channel average and ratio, mX+b scaling, min, max, average and standard deviation. All are
available on a per-channel basis.

• Measurement setup: Each channel can be configured independently for making
measurements. Selectable channel parameters include:

• Speed

• Range

• Resolution

• Number of power line
cycles (NPLC)

• Math functions

• Ratio calculation

• Individual “m” and “b”
values in mX+b format

• Channel averaging

• Hi-Low limits

• Resistance measurement
method (2- or 4-wire)

• Offset compensation

• CJC type

• Thermistor type

• Thermocouple type

• RTD type

• Voltage clamp ohms
(dry circuit)

• DUT- to-modules connections: The 2750 makes it easy to connect the device under test to the
switch/control modules. The 7703 and 7705 modules use dual 50-pin “D-sub” input connectors
for secure, quick connections. These connectors are especially convenient for rapid system
set-up. The 7701, 7707, and 7709 modules use “D-sub” connectors that are compatible with
off-the-shelf standard ribbon cable. When greater connection flexibility is required, the 7700,
7702, and 7708 modules provide oversize screw-terminal connectors that simplify setup by
eliminating the need to handle small connectors. The standard wires used are 20AWG.

• Mainframe-to-modules connection: Secure screws connect the modules to the mainframe. At
power-up, the mainframe detects any attached modules automatically, which minimizes set-up
time. All signals are routed internally from module to mainframe.

• Front/rear switch:The Model 2750’s front inputs are used for manual probing, troubleshooting,
and calibration. A switch on the front panel makes it easy to shift between the front and rear
inputs. This eases setting up the equipment and speeds verifying proper setup and connections
prior to automating the measurement.

Scanning Capabilities

• Relay Closure Counts: Relay closure counts are logged in the 2750 every time a channel is
closed. These counts are permanently written to the EEPROM on the module at a user-settable
time interval (factory default of 10 minutes) or whenever the counts are queried. Valid intervals
(set in integer number of minutes) are between 1 and 1440 minutes (24 hours). Relay closures
are counted when a relay cycles from open to closed state.

Note: Any modules previously used in a 2700 and plugged into a 2750 will record relay closures
only while in the 2750. No relay closures from the 2700 will be retrievable.

• Open Sense Lead Indication.The Model 2750 can alert the user if there is a sense lead
disconnection on any channel. In this case, the front panel display will show “OVERFLOW.”
Therefore, the Model 2750 does not need other equipment or calibration to inspect the broken
connection or failed relay on the scanner card. In addition, the Model 2750 will protect against
erroneously passed conditions.

• Scan count: The Model 2750 can be programmed to run a given number of scans up to 110,000
automatically and to record readings into the internal memory buffer. The instrument also
allows programming the trigger source used to initiate each scan. (Refer to page 8 for more
information on triggering.)

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8

• Scan interval: The user can set the interval after which each succeeding scan will begin. Scan
intervals can be set anywhere from 0 to 99 hours in increments of 1ms.

• Scan sequence/omitting channels: In addition to scanning in numerical sequence, the Model
2750 can be programmed to skip any channels that are not required for a particular test. This
avoids recording irrelevant data and speeds the data acquisition process. This makes scanning
both faster and more flexible.

• Ratio (DCV only): The instrument can calculate and display the ratio of measurements of
paired channels. Ratios can only be determined for specific channel pairs, depending upon the
input module used. For example, channel pairs on the Model 7702 include Channels 1 and 21,
Channels 2 and 22, etc. Hi/Lo limits are fully supported.

• Channel average (DCV and thermocouple only):The instrument can calculate and display the
average of two channel measurements. As with ratio calculations, only paired channels can be
averaged. Hi/Lo limits are fully supported.

Triggering & I/O Capabilities

Trigger sources

Any of the following sources can be used for triggering a reading or scan sequence:

A. Immediate: The 2750 self-triggers automatically. This default method is the simplest way to

take a measurement on a single channel.

B. An external trigger is received via the Trigger Link connector. Triggering through Trigger Link

is very precise (0.5ms trigger latency) and provides tight timing control for synchronization
in larger systems. Therefore, measurements can be taken at a precise time with very little
uncertainty. This capability can be valuable when optimizing coordination with other system
instruments, such as the Model 2400 SourceMeter

®

instrument in larger rack & stack applica-

tions.

C. A bus trigger is received (GET or *TRG) on GPIB or *TRG on RS-232.

D. Manual: Use of front panel TRIG key.

E. Analog trigger: A display reading on a particular channel can be programmed as an analog

trigger. A scan sequence is started whenever such a reading is reached [programmed for either
a greater than (>) or less than (<) condition as a trigger]. In other words, this feature can be
used to initiate a scan sequence based on some external factor, such as a temperature, rising
above a pre-set limit. After scanning all the configured channels on the instrument, the instru­ment then returns to the channel that acted as the analog trigger, and checks for the reading to
be in conditional limits. Depending on the limits and current reading, the instrument decides
whether to start the next scan. Only the data of interest are acquired, eliminating the need to
spend hours searching through reams of normal readings to find anomalous data.

F. Digital trigger: Two digital inputs (TTL-level) are standard on the 2750 mainframe—one

to serve as a trigger input and one to serve as a hardware interlock. The digital trigger is logical
“and”-ed with the interlock. The interlock is default true. Therefore, the digital trigger input
would be recognized for triggering only when the digital trigger and the interlock are both true.
Thus, the interlock provides the user with a controlling mechanism for recognizing the digital
trigger if necessary (see Figure 3).

B

C

D

E

F

Figure 3

Scan

Value

Time

Hardware
Interlock

Trigger
Event

To 2750
Microprocessor

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ECHNICAL DATA

9

Alarm Limits/Digital Outputs

The Model 2750’s digital output lines can trigger external alarms without the need for a PC connec­tion. The instrument can be programmed to provide alarms when any pre-set limits are breached.
Limits can be applied to all measurement functions except continuity, which has its own alarm
beeper. The limit test is performed after “mX + b” and math operations.

Limit types: Each channel has four independently programmable limits, each of which can be
assigned a value. These are:

1. Limit1 High (for example, 1% higher than the expected reading)

2. Limit1 Low (for example, 1% less than the expected reading)

3. Limit2 High (for example, 5% higher than the expected reading)

4. Limit2 Low (for example, 5% less than the expected reading)

The outputs can be positive or negative true, pulse, or fixed level. Pulse widths are programmable.

Master Limit: In addition to these limit alarms, a master limit is provided. It is
logically “or”-ed with the four limits and is active every time any of the other
limits are breached.

Each of the alarm limits and the master alarm is mapped to a specific output
pin on the 9-pin male connector that handles the output of that alarm limit.

Electrical Capabilities

• 250mA sink (output).

• TTL level outputs (no external supply is needed).

• Open collector output up to 33V with external supply.

• Ability to trigger or start a scan by connecting to one of the digital input lines.

On-board Data Storage

Buffer size and type: The 2750 has a 110,000-point non-volatile “read and transmit” memory (in

other words, the buffer can be emptied while it is being filled.) The buffer can be configured in “wrap
around” mode for recording readings continuously for long periods. There is no need to stop taking
data, reset the instrument, or change memory cards. The wrap around memory can be configured
to issue a Service Request (SRQ) at predetermined points in the scan. An SRQ can be issued when
the buffer is one-quarter full, one-half full, three-quarters full, or completely full. The instrument
can be commanded to download the readings without interfering with the current acquisition;
therefore, data acquisition and retrieval can occur simultaneously. When the buffer is full, the instru­ment returns to the beginning of the buffer and starts writing in the locations emptied by the
previous download.

Timestamp: The readings in the memory can be timestamped to trace the progress of a test. The
time can be configured as either:

• Real time: The actual calendar day and time.

• Relative Time: Time is relative to the first reading stored in the buffer.

Figure 4. Structure of the 9-Pin Male Digital I/O Connector

Master Limit Alarm

Limit 2 Low Alarm

Limit 2 High Alarm

Limit 1 Low Alarm

Limit 1 High Alarm

5

4

3

2

1

Ground

9

Interlock (input pin)

8

Flyback Protection Diode

7

External Trigger (input pin)

6

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Saving/Recalling a Setup

All current set-up information for individual channels and the mainframe is battery backed and the
measurement data is stored in the non-volatile memory. Therefore, while the instrument is switched
off, the configuration for each channel is saved in the memory, then automatically recalled when
the product is switched on again. Up to three different sets of setups can be recorded for each chan­nel, so it’s unnecessary to set up each channel before a different test.

Power Failure Recovery

All set-up information is battery backed and data is stored in non-volatile RAM, so the Model 2750
is immune to power failures and can resume scanning where it stopped once power is restored.
There is no need to restart interrupted tests from the beginning. The scan resumption feature is
user-selectable.

Channel Monitor

The channel monitor feature allows monitoring any specific input channel on the front panel
display at any time during a scan. The Model 2750 can scan across channels very rapidly, so the
channel monitor offers a convenient way to view only the channel of interest without interrupting
a scan.

Keithley’s patented
measurement
engine provides
true 6

1

⁄

2

-digit (22­bit) performance
under similar
conditions.

Typical 61⁄2-digit
meters actually
deliver 5

1

⁄

2

-digit
(≤18-bit)
performance at
faster reading
rates.

Figure 5. When the measurements matter,Keithley provides up to 10× better

performance at equivalent reading rates or up to 10× faster speeds at
equivalent measurement performance. Our patented A/D converter and high
performance signal conditioning circuitry make this possible.

Specification Conversion Factors

Percent PPM Digits Bits dB Portion of 10V

10% 100000 1 3.3 –20 1 V

1% 10000 2 6.6 –40 100 mV

0.1% 1000 3 10 –60 10 mV

0.01% 100 4 13.3 –80 1 mV

0.001% 10 5 16.6 –100 100 µV

0.0001% 1 6 19.9 –120 10 µV

0.00001% 0.1 7 23.3 –140 1 µV

0.000001% 0.01 8 26.6 –160 100 nV

0.0000001% 0.001 9 29.9 –180 10 nV

Model 2750 Performance

(6

1

⁄2-digit, 22-bit)

Figure 6.

Measurement Performance

The Model 2750 is a true 6½-digit (22-bit) instrument
designed for high measurement precision. Its high preci­sion enhances measurement repeatability and stability.

Measurement performance is a key advantage of all of
Keithley’s products. The Model 2750 is based on a number
of advanced technologies that improve its overall perfor­mance dramatically, including:

• Patented A/D converter IC circuitry design to increase
the resolution, precision, and speed of measurement.

• Advanced signal conditioning hardware to filter out
unwanted noise and provide necessary isolation.

• A unique “servo” front end design (Figure 6). While
conventional DMMs typically measure and correct for
the zero drift of front-end circuitry, the Model 2750’s
servo front end eliminates zero drift, which also
eliminates the wasted measurement time usually
required to check zero, further increasing
measurement speed.

Gain

×1
×10
×100

To A/D

Input

Servo
Correction
Amplifier

–

+

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ECHNICAL DATA

11

Filtering

For each major measurement function, users can employ either averaging or advanced digital fil­tering to reduce noise and increase the effective resolution.

Averaging Filter

The averaging filter operates over a range of from 2 to 100 readings. All readings included in the filter
range are weighted equally. A step input of any size will ramp up linearly to the final value after
obtaining the number of readings specified by the user. The averaging filter may be configured as
either a moving averaging or as a repeat filter. Operation over the GPIB bus is often done in “repeat”
mode to ensure that all readings are fully filtered. Also, taking filtered measurements in repeat mode
requires only one trigger, simplifying programming. Only the repeat filter can be used while
scanning.

Advanced Filter

When a DMM is used in bench mode, it’s often desirable for it to respond immediately upon con­nection to a test point, without the slow response associated with an averaging filter. The Model
2750’s advanced filter addresses this need by providing a filter reset level. If the measured value devi­ates significantly from previous values, the filter is reset to the new value, and filtering is restarted.
In this way, the user can set the filter reset level just above the maximum noise level anticipated and
the multimeter will respond to new values immediately.

NPLC

Selectable power line cycle integration allows the user to specify the number of power line cycles
(NPLC) over which to integrate (1, 5, 10, etc.). Use of line cycle integration provides rejection of noise
from line cycle interference, the most common source of noisy readings. In general, the longer the
integration time chosen, the greater the noise rejection will be. The 2750 can also be set to less than
1 NPLC integration time, as fast as 0.01NPLC (≈167µs) for faster data measurement (but without
power line noise rejection).

Line Cycle Synchronization

To attain the highest possible line cycle noise rejection, it is important
to trigger the reading at the beginning of a power line cycle. The Model
2750 can be set to start a measurement precisely when the power line
signal crosses zero (see Figure 7). This function increases the normal
mode noise rejection 30dB, providing an additional ×30 reduction in
noise due to line cycle interference.

Autozero

Internal autozeroing is used to maintain the best measurement performance. The Model 2750’s
advanced firmware design does the required calculation automatically in the background. This
enables the 2750 to provide faster reading rates (competitive products spend half their measure­ment time validating their own zero). Autozero can be disabled to increase measurement speed, but
this may result in greater measurement uncertainty.

Low Ohms Measurement

The Model 2750 can measure low ohms on all of its switch/control modules that have multiplexers
or matrix configurations. The 4-wire ohms measurement supports low ohms measurements down
to the 1Ω range, with micro-ohm resolution. Measurements can be accommodated through ribbon
cable or discrete wiring. On 4-wire ohms measurements, up to five additional ohms of cable/switch
card resistance can be tolerated per cable lead. This allows the use of ribbon cable without over­loading the range.

Figure 7

1 PLC

Trigger

# 1

Conversion

A/D

Reading

Done

Trigger

# 2

A/D

Conversion

Reading

Done

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ODEL 2750 M ULTIMETER

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12

Offset Compensation

For more accurate low resistance measurements, the Model 2750 provides the offset compensation
mode to eliminate errors from the thermoelectric EMF effects (V

EMF

). During the measurement
cycle, the built-in ohms current source is turned off, then turned on again, and the resulting EMF
error is automatically subtracted. This technique is typically used when measuring values less than
100Ω using the 4-wire ohms method.

Voltage Limit/Dry Circuit Ohms (DRYCKT)

The use of dry circuit mode on the 2750, when selected, limits the open-circuit voltage to 20mV. This
allows resistance measurements to be made with low power. When measuring contact and
connector resistances, it is important not to puncture oxides and films that may have formed.
Standard resistance measurements have open-circuit voltage levels from 5.4V to 12.8V, depending
on the selected range.

Dry circuit ohms can be used on the 1Ω, 10Ω, 100Ω, and 1kΩ ranges for the four-wire ohms (Ω4)
function. Also, offset compensated ohms (OCOMP) can be used with dry circuit ohms to cancel the
effect of thermoelectric EMFs.

Dry circuit ohms should be used for any device that could be damaged by high open-circuit voltage.
If not sure, and the slightly degraded accuracy is not a consideration, it is good practice to use dry
circuit ohms to measure low resistance.

The accuracy specifications for all dry circuit ohms ranges are with offset compensated ohms and
line synchronization enabled.

Temperature Measurements

The Model 2750 supports three major types of temperature sensors with built-in signal condition­ing and linearization: thermocouples, RTDs, and thermistors.

Thermocouples RTDs Thermistors

Temperature Range –200 ~ 1820°C –200 ~ 630°C –80 ~ 150°C

Advantage • Self-powered • High stability • Interchangeability

• Wide temperature • High accuracy • No CJC required
range • No CJC required • High accuracy over

limited temperature
range

Cost Low High Medium

The 2750 has built-in algorithms for a variety of thermocouples, RTDs, and thermistors. To begin
using a sensor, simply hook it up and the 2750 does the rest.

• Thermocouples: Type J, K, N, T, E, R, S, B

• RTDs: D100, F100, PT100, PT385, PT3916, or user type

• Thermistors: 2250Ω, 5K, and 10K

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ECHNICAL DATA

13

Cold Junction Compensation Methods

Thermocouple measurements always require that the temperature be known at the point where the
thermocouple is connected to the instrument. This connection point is known as the “cold­junction.” The Model 2750 supports three different methods for including this “cold-junction”
temperature in the temperature measurements.

Automatic CJC

The CJC sensors are mounted on the multiplexer module’s PC board (7700, 7706, and 7708). They
sense the actual temperature across the module’s connector, then compensate all temperature
measurements accordingly. The CJC scaling is done automatically (in the background, like an
autozero) so the user does not have to acquire it separately.

External CJC

A thermistor or RTD is attached to Channel 1 by the end user. This thermistor or RTD is then
used to measure the temperature of the point(s) where the thermocouples are connected to the
instrument or to copper wires leading to the instrument. The precision of the actual temperature
measurement depends on the accuracy of the cold junction reading and how close the sensor is
to the actual temperature of the connection.

Simulated CJC

When the “change” in temperature is of interest rather than the absolute temperature value, the
user can enter a parameter as a cold junction reference point (for example, 23°C for room tem­perature). This parameter will be used to adjust the actual temperature measurement for each
channel. This simulated temperature must be updated manually if ambient conditions change.
This is also the method used when an actual ice bath is used to establish a cold junction of 0°C.
The simulated parameter is then set to 0°C or 32°F.

Open Thermocouple Detect

The Model 2750 can alert the user if any thermocouple becomes broken or otherwise disconnected
from the input terminal blocks. When the Open T/C Detect feature is enabled, the Model 2750 will
perform (in the background) a 2-wire resistance measurement across each thermocouple input
channel. If an open connection is detected, the front panel display will show “OVERFLOW” for that
channel.

Calibration

The design of the Model 2750 and its calibration procedure were developed to address a variety of
critical calibration issues. For example, the 2750 has front panel input jacks, so there’s no need to
disassemble the system for periodic recalibrations. There’s also no need to buy, stock, and track
spare “cal only” modules. The 2750 is connected to the calibrator through the front panel input
jacks. The Model 2750’s calibration procedure covers both verification and adjustment and can be
performed through either the front panel or GPIB. The calibration interval is user-selectable.

M

ODEL 2750 M ULTIMETER

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14

T

ECHNICAL DATA

15

Specifications are subject to change without notice.

Download the latest specs from www.keithley.com.

M

ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

16

M ODEL 2750 S PECIFICATIONS

DC CHARACTERISTICS

1

CONDITIONS: MED (1 PLC)2or 10 PLC or MED (1 PLC) with Digital Filter of 10

TEST INPUT

ACCURACY: ±(ppm of reading + ppm of range)

CURRENT ±5% RESISTANCE

(ppm = parts per million) (e.g., 10ppm = 0.001%)

TEMPERATURE

OR BURDEN OR OPEN CKT. 24 Hour

4

90 Day 1 Year COEFFICIENT

FUNCTION RANGE RESOLUTION VOLTAGE VOLTAGE

3

23°C±1° 23°C±5° 23°C±5° 0°–18°C & 28°–50°C

Voltage

11

100.0000 mV 0.1 µV >10 GΩ 15 + 30 25 + 35 30 + 35 (1 + 5)/°C

1.000000 V 1.0 µV >10 GΩ 15 + 6 25 + 7 30 + 7 (1 + 1)/°C

10.00000 V 10 µV >10 GΩ 10 + 4 20 + 5 30 + 5 (1 + 1)/°C

100.0000 V 100 µV 10 MΩ ± 1% 15 + 6 35 + 9 45 + 9 (5 + 1)/°C

1000.000 V

5

1mV 10MΩ ± 1% 20 + 6 35 + 9 50 + 9 (5 + 1)/°C

Resistance

6,8

1.000000 Ω 1µΩ 10 mA 5.9 V 25 + 80 80 + 80 100 + 80 (8 + 1)/°C

10.00000 Ω 10 µΩ 10 mA 5.9 V 20 + 20 80 + 20 100 + 20 (8 + 1)/°C

100.0000 Ω 100 µΩ 1 mA 12.2 V 20 + 20 80 + 20 100 + 20 (8 + 1)/°C

1.000000 kΩ 1mΩ 1 mA 12.2 V 20 + 6 80 + 6 100 + 6 (8 + 1)/°C

10.00000 kΩ 10 mΩ 100 µA 6.8 V 20 + 6 80 + 6 100 + 6 (8 + 1)/°C

100.0000 kΩ 100 mΩ 10 µA 12.8 V 20 + 6 80 + 10 100 + 10 (8 + 1)/°C

1.000000 MΩ

23

1.0 Ω 10 µA 12.8 V 20 + 6 80 + 10 100 + 10 (8 + 1)/°C

10.00000 MΩ

7, 23

10 Ω 0.7 µA // 10M Ω 7.0 V 150 + 6 200 + 10 400 + 10 (35 + 1)/°C

100.0000 MΩ

7, 23

100 Ω 0.7 µA // 10M Ω 7.0 V 800 + 30 2000 + 30 2000 + 30 (200 + 1)/°C

Dry Circuit 1.000000 Ω 1µΩ 10 mA 20mV 80 + 40 80 + 40 100 + 40 (8 + 1)/°C
Resistance

21

10.00000 Ω 10 µΩ 1 mA 20mV 25 + 40 80 + 40 100 + 40 (8 + 1)/°C

100.0000 Ω 100 µΩ 100 µA 20mV 25 + 40 90 + 40 140 + 40 (8 + 1)/°C

1.000000 kΩ 1mΩ 10 µA 20mV 25 + 90 180 + 90 400 + 90 (8 + 1)/°C

Continuity (2W) 1.000 kΩ 100 mΩ 1 mA 12.2 V 40 + 100 100 + 100 100 + 100 (8 + 1)/°C

Current 20.00000 mA 10 nA < 0.2 V 60 + 15 300 + 40 500 + 40 (50 +5)/°C

100.0000 mA 100 nA < 0.1 V 100 + 150 300 + 400 500 + 400 (50 +50)/°C

1.000000 A 1.0 µA < 0.3 V

9

200 + 15 500 + 40 800 + 40 (50 +5)/°C

3.000000 A 10 µA < 1.0 V

9

1000 + 15 1200 + 40 1200 + 40 (50 +5)/°C

Channel (Ratio)

10

Ratio Accuracy = Accuracy of selected Channel Range + Accuracy of Paired Channel Range

Channel (Average)

10

Average Accuracy = Accuracy of selected Channel Range + Accuracy of Paired Channel Range

TEMPERATURE

19

(Displayed in °C, °F, or K. Exclusive of probe errors.)

Thermocouples (Accuracy based on ITS-90.)

90 Day/1 Year (23°C ± 5°C)
Relative to Using CJC Temperature
Simulated from Plug-In Coefficient

Type Range Resolution Reference Junction Module 0°–18°C & 28°–50°C

J –200 to +760 °C 0.001°C 0.2°C 1.0°C 0.03°C/°C

K –200 to +1372°C 0.001°C 0.2°C 1.0°C 0.03°C/°C

N –200 to +1300°C 0.001°C 0.2°C 1.0°C 0.03°C/°C

T –200 to +400°C 0.001°C 0.2°C 1.0°C 0.03°C/°C
E –200 to +1000°C 0.001°C 0.2°C 1.0°C 0.03°C/°C
R 0 to +1768°C 0.1 °C 0.6°C 1.8°C 0.03°C/°C
S 0 to +1768°C 0.1 °C 0.6°C 1.8°C 0.03°C/°C
B +350 to +1820°C 0.1 °C 0.6°C 1.8°C 0.03°C/°C

4-Wire RTD:
(100Ω platinum [PT100], D100, F100,PT385, PT3916, or user type. Offset compensation On)

–200° to 630°C 0.01 °C 0.06°C 0.003°C/°C

Thermistor: (2.2kΩ,5kΩ,and 10kΩ)

20

–80° to 150°C 0.01 °C 0.08°C 0.002°C/°C

DC SYSTEM SPEEDS

15,18

RANGE CHANGES16: 50/s (42/s).

FUNCTION CHANGES

16

: 50/s (42/s).

AUTORANGE TIME

16

: <30ms.
ASCII READINGS TO RS-232 (19.2k BAUD): 55/s.
MAX. INTERNAL TRIGGER RATE: 2000/s.
MAX. EXTERNAL TRIGGER RATE: 375/s.

DC MEASUREMENT SPEEDS

15

Single Channel, 60Hz (50Hz) Operation

FUNCTION DIGITS READINGS/s PLCs
DCV, DCI, Ω (<10M), 6.5

12,16

5 (4) 10

Thermocouple, 6.5

16

35 (28) 1

Thermistor 6.5

12,16

45 (36) 1

5.5

12,16

150 (120) 0.1

5.5

16, 17

300 (240) 0.1

5.5

17

500 (400) 0.1

4.5

17

2500 (2000) 0.01

4WΩ (<10M) 6.5

16

1.4 (1.1) 10

6.5

16

15 (12) 1

5.5

17

33 (25) 0.1

4WΩ OComp, RTD

22

6.5

16

0.9 (0.7) 10

6.5

16

8 (6.4) 1

5.5

16, 17

18 (14.4) 0.1

Channel (Ratio), 6.5

16

2.5 (2) 10

Channel (AVG) 6.5

16

15 (12) 1

5.5

17

25 (20) 0.1

Multiple Channels, Into and Out of Memory to GPIB

15, 18

Channels/s

7703 Scanning DCV 200/s
7703 Scanning DCV with Limits or Time Stamp On 180/s
7703 Scanning DCV alternating 2W 70/s
7702 Scanning DCV 65/s
7700, 7706, and 7708 Scanning Temperature (T/C) 50/s

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ECHNICAL DATA

17

M ODEL 2750 S PECIFICATIONS

DC Notes

1. 20% overrange except on 1000V and 3A.

2. Add the following to “ppm of range” uncertainty; 100mV 15ppm; 1V and 100V 2ppm; Dry Circuit Ω
40ppm; <1MΩ 2ppm, 20mA and 1A 10ppm, 100mA 40ppm.

3. ±2% (measured with 10MΩ input resistance DMM, >10GΩ DMM on 10MΩ and 100MΩ ranges).

4. Relative to calibration accuracy.

5. For signal levels >500V, add 0.02ppm/V uncertainty for portion exceeding 500V.

6. Specifications are for 4-wire Ω, 1Ω, 10Ω, and 100Ω with offset compensation on. With offset compen­sation on, OPEN CKT. VOLTAGE is 12.8V. For 2-wire Ω add 1Ω additional uncertainty. 1Ω range is 4-wire
only.

7. Must have 10% matching of lead resistance in Input HI and LO.

8. Add the following to “ppm of reading” uncertainty when using plug in modules:

10 kΩ 100 kΩ 1 MΩ 10 MΩ 100 MΩ

All Modules: 220 ppm 2200 ppm
7701, 7703, 7707,7709 Modules: 10 ppm 100 ppm 1000 ppm 1% 10%
7706, 7708 Modules: 5 ppm 50 ppm 500 ppm 5000 ppm 5%

9. Add 1.5V when used with plug in modules.

10. For RATIO, DCV only. For AVERAGE, DCV and Thermocouples only. Available with plug in modules only.

11. Add 6µV to “of range” uncertainty when using Models 7701, 7703, and 7707, and 3µV for Models 7706 and

7709.

12. Auto zero off.

13. For LSYNC On, line frequency ±0.1 %. For LSYNC Off, use 60dB for ≥ 1PLC.

14. For 1kΩ unbalance in LO lead. AC CMRR is 70dB.

15. Speeds are for 60Hz (50Hz) operation using factory defaults operating conditions (*RST). Autorange off,
Display off, Limits off, Trigger delay = 0.

16. Speeds include measurements and binary data transfer out the GPIB (reading element only).

17. Sample count = 1024, auto zero off.

18. Auto zero off, NPLC = 0.01.

19.

Additional Uncertainty Plug-In Modules

7709 7701, 7703, 7707 7700, 7708 7706

Simulated Simulated Using Using

Type Range Ref. Junction Ref. Junction CJC CJC

J –200 to 0°C 0.1 0.3 0.8 1.6
K –200 to 0°C 0.2 0.4 0.8 1.6
N –200 to 0°C 0.3 0.6 0.8 1.6
T –200 to 0°C 0.1 0.3 0.8 1.6
E –200 to 0°C 0.1 0.2 0.8 1.6
R 0 to +400°C 0.6 1.1 0.5 1.0
S 0 to +400°C 0.6 1.2 0.5 1.0
B +350 to +1100°C 0.3 0.5 0.5 1.0

20. For lead resistance >0Ω, add the following uncertainty/Ω for measurement temperatures of:

70°–100°C 100°–150°C

2.2 kΩ (44004) 0.22°C 1.11°C

5.0 kΩ (44007) 0.10°C 0.46°C
10 kΩ (44006) 0.04°C 0.19°C

21. For 4-wire Ω only, offset compensation on, LSYNC on.

22. For Dry Circuit 1kΩ range, 2 readings/s max.

23. For Front Inputs, operating environment specified for 0°C to 50°C and 50% RH at 35°C.

AC SPECIFICATIONS

1

Accuracy: ±(% of reading + % of range), 23°C ± 5°C

Calibration 3 Hz– 10 Hz– 20 kHz– 50 kHz– 100 kHz–

Function Range Resolution Cycle 10 Hz 20 kHz 50 kHz 100 kHz 300 kHz
Voltage

2

100.0000 mV 0.1 µV 90 Days 0.35 + 0.03 0.05 + 0.03 0.11 + 0.05 0.6 + 0.08 4.0 + 0.5

1.000000 V 1.0 µV

10.00000 V 10 µV 1 Year 0.35 + 0.03 0.06 + 0.03 0.12 + 0.05 0.6 + 0.08 4.0 + 0.5

100.0000 V 100 µV

750.000 V 1.0 µV
(Temp.Coeff.)/°C30.035 + .003 0.005 + .003 0.006 + .005 0.01 + .006 0.03 + .01

3 Hz–10 Hz 10 Hz–5 kHz

Current

2

1.000000 A 1.0 µA 90 Day/1 Yr. 0.30 + 0.04 0.10 + 0.04

3.00000 A

14

10 µA 0.35 + 0.06 0.15 + 0.06

(Temp.Coeff.)/°C30.035 + 0.006 0.015 + 0.006

(3 Hz–500 kHz) (333 ms–2 µs)

Frequency

4

100 mV 0.333 ppm 90 Day/ 1 Yr. 100 ppm + 0.333 ppm (SLOW, 1s gate)

and Period to 3.33 ppm 100 ppm + 3.33 ppm (MED, 100ms gate)

750 V 33.3 ppm 100 ppm + 33.3 ppm (FAST, 10ms gate)

DC SPEED vs. NOISE REJECTION

RMS Noise

Rate Filter Readings/s12Digits 10V Range NMRR CMRR

14

10 50 0.1 (0.08) 6.5 < 1.2 µV 110 dB13140 dB
1 Off 15 (12) 6.5 < 4 µV 90 dB

13

140 dB

0.1 Off 500 (400) 5.5 < 22 µV — 80 dB

0.01 Off 2500 (2000) 4.5 < 150 µV — 80 dB

DC MEASUREMENT CHARACTERISTICS

DC Volts

A-D LINEARITY: 2.0 ppm of reading + 1.0 ppm of range.

INPUT IMPEDANCE:

100mV–10V Ranges: Selectable >10GΩ // with <400pF or 10MΩ ±1%.
100V, 1000V Ranges: 10MΩ ±1%.

Dry Circuit: 100kΩ ± 1% // <1µF.
INPUT BIAS CURRENT: <75pA at 23°C.
COMMON MODE CURRENT: <500nApp at 50Hz or 60Hz.
AUTOZERO ERROR: Add ±(2ppm of range error + 5µV ) for < 10 minutes

and ±1°C.

INPUT PROTECTION: 1000V, all ranges. 300V with plug in modules.

Resistance

MAX 4WΩ LEAD RESISTANCE: 80% of range per lead (Dry Ckt mode). 5Ω

per lead for 1Ω range; 10% of range per lead for 10Ω, 100Ω, and 1kΩ

ranges; 1kΩ per lead for all other ranges.
OFFSET COMPENSATION: Selectable on 4WΩ, 1Ω, 10Ω, 100Ω, 1kΩ, and

10kΩ ranges.

CONTINUITY THRESHOLD: Adjustable 1 to 1000 Ω
INPUT PROTECTION: 1000V, all Source Inputs, 350V Sense Inputs. 300V

with plug-in modules.

DC Current

SHUNT RESISTORS: 100mA–3A, 0.1Ω. 20mA, 5Ω.
INPUT PROTECTION: 3A, 250V fuse.

Thermocouples

CONVERSION: ITS-90.
REFERENCE JUNCTION: Internal, External, or Simulated (Fixed).
OPEN CIRCUIT CHECK: Selectable per channel. Open >12kΩ.
EARTH ISOLATION: 500V peak, >10GΩ and <300pF any terminal to

chassis.

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ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

18

M ODEL 2750 S PECIFICATIONS

Additional Uncertainty ±(% of reading)

Low Frequency Uncertainty MED FAST

20 Hz - 30 Hz 0.3 —
30 Hz - 50 Hz 0 —

50 Hz - 100 Hz 0 1.0
100 Hz - 200 Hz 0 0.18
200 Hz - 300 Hz 0 0.10

>300 Hz 0 0

CREST FACTOR:

5

1 -2 2 - 3 3 - 4 4 - 5

Additional Uncertainty: 0.05 0.15 0.30 0.40
Max. Fundamental Freq.: 50kHz 50kHz 3kHz 1kHz

AC MEASUREMENT CHARACTERISTICS

AC Volts

MEASUREMENT METHOD: AC-coupled, True RMS.
INPUT IMPEDANCE: 1MΩ ±2% // by <100pF.
INPUT PROTECTION: 1000Vp or 400VDC. 300Vrms with plug in mod-

ules.

AC Current

MEASUREMENT METHOD: AC-coupled, True RMS.
SHUNT RESISTANCE: 0.1Ω.
BURDEN VOLTAGE: 1A <0.3Vrms, 3A <1.5Vrms. Add 1Vrms when used

with plug in modules.

INPUT PROTECTION: 3A, 250V fuse.

Frequency and Period

MEASUREMENT METHOD: Reciprocal Counting technique.
GATE TIME: SLOW 1s, MED 100ms, and FAST 10ms.

AC General

AC CMRR6: 70dB.
MAXIMUM CREST FACTOR: 5 at full-scale.
VOLT HERTZ PRODUCT: <= 8 × 10

7

.

AC MEASUREMENT SPEEDS

7

Single Channel, 60Hz (50Hz) Operation

Function Digits Readings/s Rate Bandwidth
ACV, ACI 6.5

8

2s/Reading SLOW 3 Hz–300 kHz

6.5

8

1.4 (1.1) MED 30 Hz–300 kHz

6.5

9

4.8 (4) MED 30 Hz–300 kHz

6.5

9

35 (28) FAST 300 Hz–300 kHz

Frequency, 6.5 1 (1) SLOW 3 Hz–300 kHz
Period 5.5 9 (9) MED 30 Hz–300 kHz

4.5 35 (35) FAST 300 Hz–300 kHz

4.5

10

65 (65) FAST 300 Hz–300 kHz

Multiple Channel

7703 SCANNING ACV

10,13

: 180/s.

AC SYSTEM SPEEDS

7, 11

RANGE CHANGES12: 4/s (3/s).

FUNCTION CHANGES

12

: 4/s (3/s).
AUTORANGE TIME: < 3s.
ASCII READINGS TO RS-232 (19.2k baud): 50/s.
MAX. INTERNAL TRIGGER RATE: 300/s.
MAX. EXTERNAL TRIGGER RATE: 250/s.

AC Notes

1.20 % overrange except on 750V and 3A.

2. Specification are for SLOW mode and sine wave inputs >5% of range. SLOW
and MED are multi-sample A/D conversions. FAST is DETector:BANDwidth
300 with nPLC = 1.0.

3.Applies to 0°–18°C and 28°–50°C.

4.For square wave inputs >10% of ACV range, except 100mV range. 100mV
range frequency must be >10Hz if input is <20mV.

5.Applies to non-sine waves >5Hz.

6.For 1kΩ unbalance in LO lead.

7.Speeds are for 60Hz (50Hz) operation using factory defaults operating con­ditions (*RST). Autorange off, Display off, Limits off, Trigger delay=0.
Includes measurement and binary data transfer out GPIB (Reading Element
only).

8.0.01% of step settling error. Trigger delay = 400ms.

9.Trigger delay = 0.

10. Sample count = 1024.

11. DETector:BANDwidth 300 with nPLC = 0.01.

12. Maximum useful limit with trigger delay = 175ms.

13. For Auto Delay On = 1.8/s.

14. For signal levels >2.2A, add additional 0.4% to “of reading” uncertainty.

GENERAL SPECIFICATIONS:

EXPANSION SLOTS: 5.
POWER SUPPLY: 100V / 120V / 220V / 240V ±10%.
LINE FREQUENCY:45Hz to 66Hz and 360Hz to 440Hz, automatically

sensed at power-up.

POWER CONSUMPTION: 35VA.
OPERATING ENVIRONMENT: Specified for 0°C to 50°C. Specified to

80% RH at 35°C.

STORAGE ENVIRONMENT: –40°C to 70°C.
BATTERY: Lithium battery-backed memory, 3 years @ 23°C.
WARRANTY: 3 years.
EMC: Conforms to European Union Directive 89/336/EEC EN61326-1.
SAFETY: Conforms to European Union Directive 73/23/EEC EN61010-1,

CAT I.

VIBRATION: MIL-PRF-28800F Class 3, Random.
WARM-UP: 2 hours to rated accuracy.

DIMENSIONS:

Rack Mounting: 89mm high × 485mm wide × 370mm deep (3.5 in × 19

in × 14.563 in).

Bench Configuration (with handle and feet): 104mm high × 485mm

wide × 370mm deep (4.125 in × 19 in × 14.563 in).

SHIPPING WEIGHT: 13kg (28 lbs.).
DIGITAL I/O: 2 inputs, 1 for triggering and 1 for hardware interlock.

5 outputs, 4 for Reading Limits and 1 for Master Limit. Outputs are
TTL compatible or can sink 250mA, diode clamped to 40V.

TRIGGERING AND MEMORY:

Window Filter Sensitivity: 0.01%, 0.1 %, 1%, 10%, or Full-scale of

range (none).

Reading Hold Sensitivity: 0.01%, 0.1 %, 1%, or 10% of reading.
Trigger Delay: 0 to 99 hrs (1ms step size).
External Trigger Delay: <1ms.
External Trigger Jitter: <500µs.
Memory Size: 110,000 readings.

MATH FUNCTIONS: Rel, Min/Max/Average/Std Dev/Peak-to-Peak (of

stored reading), Limit Test, %, 1/x, and mX + b with user defined
units displayed.

REMOTE INTERFACE:

GPIB (IEEE-488.2) and RS-232C.
SCPI (Standard Commands for Programmable Instruments)
LabVIEW Drivers

ACCESSORIES SUPPLIED: Model 1751 Safety Test Leads, User Manual,

Service Manual.

Specifications are subject to change without notice.

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ECHNICAL DATA

19

7700 20-Channel Differential Multiplexer
w/Automatic CJC

Features

• 20 channels for general-purpose measurements, plus two channels to
measure current.

• 2- or 4-wire measurement.

• Oversize screw terminal connection blocks are standard for easier con­nections.

• Automatic CJC sensors on the scanner card mean there are no other
accessories are required to make thermocouple temperature measure­ments.

• Configurable as two independent banks of multiplexers.

• 300V, 1A capacity for voltage channels; 60W, 125VA.

• 3A capacity for current channels.

• Relay closures stored in on-board memory.

GENERAL

20 CHANNELS: 20 channels of 2-pole relay input. All channels configur-

able to 4-pole.

2 CHANNELS: 2 channels of current only input.
RELAY TYPE: Latching electromechanical.
ACTUATION TIME: <3ms.

CAPABILITIES

CHANNELS 1-20: Multiplex one of 20 2-pole or one of 10 4-pole signals

into DMM.

CHANNELS 21-22: Multiplex one of 2 2-pole current signals into DMM.

INPUTS

MAXIMUM SIGNAL LEVEL:

Channels (1-20): 300V DC or rms, 1A switched, 60W, 125VA maximum.
Channels (21-22): 60V DC or 30V rms, 3A switched, 60W, 125VA maxi-

mum.

CONTACT LIFE (typ): >10

5

operations at max signal level.

>108operations cold switching.

CONTACT RESISTANCE: <1Ω at end of contact life.
CONTACT POTENTIAL: <±500nV typical per contact, 1µV max.

<±500nV typical per contact pair, 1µV max.

OFFSET CURRENT: <100pA.
CONNECTOR TYPE: Screw terminal, #20 AWG wire size.
ISOLATION BETWEEN ANY TWO TERMINALS: >10

10

Ω, <100pF.

ISOLATION BETWEEN ANY TERMINAL AND EARTH: >10

9

Ω, <200pF.

CROSS TALK (10MHz, 50Ω Load): <–40dB.
INSERTION LOSS (50Ω Source, 50Ω Load): <0.1dB below 1MHz.

<3dB below 2MHz.

COMMON MODE VOLTAGE: 300V between any terminal and chassis.
T/C COLD JUNCTION: 1.0°C (18°–28°C Mainframe Temp)

1.5°C (0°–18°C & 28°–50°C Mainframe Temp).

ENVIRONMENTAL:

OPERATING ENVIRONMENT: Specified for 0°C to 50°C.

Specified to 80% R.H. at 35°C.

STORAGE ENVIRONMENT: –25°C to 65°C.
WEIGHT: 0.45kg (1 lb).

S WITCH/CONTROL M ODULE S PECIFICATIONS

7700

Card Input

Card Sense

Cold junction
Ref x3

Channel 1

(Channels 2–9)

Channel 10

Cold junction
Ref x3

Channel 11

(Channels 12–19)

Channel 20

Channel 21

Channel 22

Card

LO

LO

LO

LO

LO

LO

LO

AMPS

LO

HI

HI

LO

HI

HI

HI

HI

HI

HI

Channel 23

2-Pole (Open)

4-Pole (Closed)

(see Note)

3A

3A

Channel 25

(see Note)
Backplane

isolation

Channel 24

(see Note)

Backplane

isolation

NOTE Channels 23–25 in this schematic

refer to the designations used for
control and not actual available channels.

For more information, refer to the
ROUTe:MULTiple command section
in the Model 2700 or 2750 User’s Manual.

Channels 24 and 25 can be individually
controlled using ROUTe:MULTiple if the
module is not to be connected to the
internal DMM.

AMPS

HI

Input

LO

HI

Sense

LO

To Model 2700
or 2750
Backplane

M

ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

20

7701 Low-Voltage 32-Channel
Differential Multiplexer

Features

• Configurable for 32 channels of differential measurements, with up to
16 channels of 4-pole measurements.

• Configurable for 32 channels of common-side 4-wire ohms.

• Configurable as two independent banks of multiplexers.

• Two female D-shell connectors are standard for secure hook-up and
quick teardown.

• 150V, 1A capacity for voltage channels; 60W, 125VA.

• Two mating IDC connectors for ribbon cable (Model 7790) are supplied.

• Relay closures stored in on-board memory.

• Screw terminal jumpers allow user-configurable DMM connections.

GENERAL

32 CHANNELS: 32 channels of 2-pole relay input. All channels configur-

able to 4-pole.

RELAY TYPE: Latching electromechanical.
ACTUATION TIME: <3ms.
FIRMWARE: Specified for Model 2700 rev. B03 and Model 2750 rev. A01.
DMM CONNECTIONS: Screw terminals provide internal DMM connec-

tions to channels 34 and 35 and connections to external wiring access.

CAPABILITIES

CHANNELS 1–32: Multiplex one of 32 2-pole or one of 16 4-pole signals

into DMM. Configuration supports dual 1×16 independent multi­plexers.

INPUTS

MAXIMUM SIGNAL LEVEL: Any channel to Any Channel (1–32): 150V

DC or 150Vrms (212V peak) for AC waveforms, 1A switched, 60W, 125VA
maximum.

SAFETY: Conforms to European Union Directive 73/23/EEC EN61010-1,

CAT I.

CONTACT LIFE (typ): >10

5

operations at max signal level.

>108operations cold switching.

CONTACT RESISTANCE: <1Ω any path and additional 1Ω at end of con-

tact life.

CONTACT POTENTIAL: <6µV per contact pair.
OFFSET CURRENT: <100pA.
CONNECTOR TYPE: 50-pin female D-shell, Channels 1–24.

25-pin female D-shell, Channels 25–32.

Supplied with male IDC ribbon cable connectors.

ISOLATION BETWEEN ANY TWO TERMINALS: >10

9

Ω, <200pF.

ISOLATION BETWEEN ANY TERMINAL AND EARTH: >10

9

Ω, <400pF.

CROSS TALK (1MHz, 50Ω Load): <–35dB.
INSERTION LOSS (50Ω Source, 50Ω Load): <0.35dB below 1MHz.

<3dB below 2MHz.

COMMON MODE VOLTAGE: 300VDC or 300Vrms (425V peak) for AC

waveforms between any terminal and chassis.

ENVIRONMENTAL:

OPERATING ENVIRONMENT: Specified for 0°C to 50°C.

Specified to 50% R.H. at 35°C.

STORAGE ENVIRONMENT: –25°C to 65°C.
WEIGHT: <0.52kg (1.16 lb).

ACCESSORIES AVAILABLE:

Model 7789 50/25 Pin Male D-Shell Solder Cup Connectors
Model 7790 50/50/25 Pin Female/Male D-Shell IDC Connectors

S WITCH/CONTROL M ODULE S PECIFICATIONS

7701

See page 36 for common-side 4-wire ohms configuration example.

External
Wiring Access

Multiplexer 1

Channel 1

(Channels 2–15)

Channel 16

Channel 17

(Channels 18–31)

Channel 32

Multiplexer 2

HI

LO

HI

LO

HI

LO

Channel 33
2-Pole (Open)
4-Pole (Closed)

(see Note)

HI

LO

HI

LO

HI

LO

Channel 35

Channel 34

NOTE Channels 33–35 in this schematic refer to the designations

User
Configurable
Screw
Terminals

(see Note)

Backplane
Isolation

(see Note)

Backplane
Isolation

The Model 7701 is rated for low-voltage applications.
When connecting the 7701 to the internal DMM via
the screw terminals, all other modules in the
mainframe must be derated to 150VDC or 150Vrms
(212V peak) for AC waveforms.

used for control and not actual available channels.

For more information, refer to the ROUTE:MULT command
section in the Model 2700 or 2750 User’s Manual.

HI

LO

HI

LO

Screw

Terminals

Screw

Terminals

HI
DMM Input
LO

HI
DMM Sense
LO

To
Internal
DMM

T

ECHNICAL DATA

21

7702 40-Channel Differential Multiplexer

Features

• There are 40 channels for general-purpose measurement, plus 2 chan­nels to measure current.

• 2- or 4-wire measurement.

• Oversize screw terminal connection blocks are standard for easier con­nection.

• Configurable as two independent banks of multiplexers.

• 300V, 1A capacity for voltage channels; 60W, 125VA.

• 3A capacity for current channels.

• Relay closures stored in on-board memory.

GENERAL

40 CHANNELS: 40 channels of 2-pole relay input.

All channels configurable to 4-pole.

2 CHANNELS: 2 channels of current only input.
RELAY TYPE: Latching electromechanical.
ACTUATION TIME: <3ms.

CAPABILITIES

CHANNELS 1-40: Multiplex one of 40 2-pole or one of 20 4-pole signals

into DMM.

CHANNELS 41-42: Multiplex one of 2 2-pole current signals into DMM.

INPUTS

MAXIMUM SIGNAL LEVEL:

Channels (1-40): 300V DC or rms, 1A switched, 60W, 125VA maximum.
Channels (41-42): 60V DC or 30V rms, 3A switched, 60W, 125VA maxi-

mum.

CONTACT LIFE (typ): >10

5

operations at max signal level.

>108operations cold switching.

CONTACT RESISTANCE: <1Ω at end of contact life.
CONTACT POTENTIAL: <±500nV typical per contact, 1µV max.

<±500nV typical per contact pair, 1µV max.

OFFSET CURRENT: <100pA.
CONNECTOR TYPE: Screw terminal, #20 AWG wire size.
ISOLATION BETWEEN ANY TWO TERMINALS: >10

10

Ω, <100pF.

ISOLATION BETWEEN ANY TERMINAL AND EARTH: >10

9

Ω, <200pF.

CROSS TALK (10MHz, 50Ω Load): <–40dB.
INSERTION LOSS (50Ω Source, 50Ω Load):<0.1dB below 1MHz.

<3dB below 2MHz.

COMMON MODE VOLTAGE: 300V between any terminal and chassis.

ENVIRONMENTAL

OPERATING ENVIRONMENT: Specified for 0°C to 50°C.

Specified to 80% R.H. at 35°C.

STORAGE ENVIRONMENT: –25°C to 65°C.
WEIGHT: 0.5kg (1.1 lb).

S WITCH/CONTROL M ODULE S PECIFICATIONS

7702

Card Input

Card Sense

Channel 1

(Channels 2–19)

Channel 20

Channel 21

(Channels 22–39)

Channel 40

Channel 41

Channel 42

HI

LO

HI

LO

HI

LO

HI

LO

HI

LO

HI

LO

HI

LO

HI

LO

Channel 43

2-Pole (Open)

4-Pole (Closed)

(see Note)

3A

3A

Channel 45

(see Note)
Backplane

isolation

Channel 44

(see Note)

Backplane

isolation

NOTE Channels 43–45 in this schematic

refer to the designations used for
control and not actual available channels.

For more information, refer to the
ROUTe:MULTiple command section
in the Model 2700 or 2750 User’s Manual.

Channels 44 and 45 can be individually
controlled using ROUTe:MULTiple if the
module is not to be connected to the
internal DMM.

AMPS

HI

Input

LO

HI

Sense

LO

To Model 2700
or 2750
Backplane

M

ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

22

7703 32-Channel High Speed Differential
Multiplexer

Features

• There are 32 channels for general purpose measurement.

• Relay actuation time of less than 1ms for high-speed scanning.

• 2 or 4 wire measurement.

• Two 50-pin female “D-sub” connectors are standard for secure hook-up
and quick teardown.

• Configurable as two independent banks of multiplexers.

• Reed relay based design with 300 volt, 500mA; 10VA.

• Two mating connector with solder cup (Model 7788) are supplied.

• Relay closures stored in on-board memory.

GENERAL

32 CHANNELS: 32 channels of 2-pole relay input.

All channels configurable to 4-pole.

RELAY TYPE: Reed.
ACTUATION TIME: <1ms.

CAPABILITIES

CHANNELS 1-32: Multiplex one of 32 2-pole or one of 16 4-pole signals

into DMM.

INPUTS

MAXIMUM SIGNAL LEVEL:

Channels (1-32): 300V DC or rms, 0.5A switched, 10W maximum.
Contact Life (typ): >5×10

4

operations at max signal level.

>108operations cold switching.

CONTACT RESISTANCE: <1Ω at end of contact life.
CONTACT POTENTIAL: <±3µV typical per contact, 6µV max.

<±3µV typical per contact pair, 6µV max.

OFFSET CURRENT: <100pA.
CONNECTOR TYPE: 50 pin D-sub × 2.
RELAY DRIVE CURRENT: 20mA per channel.
ISOLATION BETWEEN ANY TWO TERMINALS: >10

9

Ω, <200pF.

ISOLATION BETWEEN ANY TERMINAL AND EARTH: >10

9

Ω, <400pF.

CROSS TALK (1 MHz, 50Ω Load): <–40dB.
INSERTION LOSS (50Ω Source, 50Ω Load): <0.35dB below 1MHz.

<3dB below 2MHz.

COMMON MODE VOLTAGE: 300V between any terminal and chassis.

ENVIRONMENTAL

OPERATING ENVIRONMENT: Specified for 0°C to 50°C.

Specified to 80% R.H. at 35°C.

STORAGE ENVIRONMENT: –25°C to 65°C.
WEIGHT: 0.8kg (1.75 lbs).

S WITCH/CONTROL M ODULE S PECIFICATIONS

7703

HI

Card Input

LO

HI

Card Sense

LO

HI

Channel 1

LO

(Channels 2–15)

HI

Channel 16

LO

HI

Channel 17

LO

(Channels 18–31)

HI

Channel 32

LO

Channel 35
2-Pole (Closed)
4-Pole (Open)

(see Note)

NOTE Channels 33–35 in this schematic

refer to the designations used for
control and not actual available channels.

For more information, refer to the
ROUTE:MULT command section
in the Model 2700 or 2750 User’s Manual.

Channel 33

(see Note)

Backplane
isolation

Channel 34

(see Note)

Backplane
isolation

HI

Input

LO

HI

Sense

LO

To Model 2700
or 2750
Backplane

T

ECHNICAL DATA

23

7705 40-Channel Control Module

Features

• 40 channels designed for controlling power to the DUT, switching
loads, controlling light indicators and relays, etc.

• Two 50-pin female “D-sub” connectors are standard for secure hook-up
and quick teardown.

• 300V, 2A capacity.

• Two mating connectors with solder cup pins (Model 7788) are supplied.

• Relay closures stored in on-board memory.

GENERAL

RELAY SWITCH CONFIGURATION: 40 independent channels of 1-pole

switching. Isolated from internal DMM.

CONTACT CONFIGURATION: 1 pole Form A.
RELAY TYPE: Latching electromechanical.
CONNECTOR TYPE: Two 50-pin female D-sub connectors.

INPUTS

MAXIMUM SIGNAL LEVEL: 300VDC or rms, 2A switched, 60W (DC, resis-

tive), 125VA (AC, resistive).

CONTACT LIFE: Cold Switching: 108closures.

At Maximum Signal Levels: 105closures.
CHANNEL RESISTANCE (per conductor): <1Ω.
CONTACT POTENTIAL: ≤4µV per contact.
OFFSET CURRENT: <100pA.
ACTUATION TIME: 3ms.
ISOLATION: Channel to Channel: >10

9

Ω, <50pF.

Common Mode: >109Ω, <100pF.
CROSSTALK (1MHz,50Ω load): <–35dB.
INSERTION LOSS (50Ω source, 50Ω load): <0.3dB below 1MHz, <3dB

below 10MHz.

COMMON MODE VOLTAGE: 300V between any terminal and chassis.

ENVIRONMENTAL

OPERATING ENVIRONMENT: Specified for 0°C to 50°C.

Specified to 80% R.H. at 35°C.

STORAGE ENVIRONMENT: –25°C to 65°C.
WEIGHT: 0.45kg (1 lb).

S WITCH/CONTROL M ODULE S PECIFICATIONS

7705

Channel 1

(Channels 2–39)

Channel 40

IN

OUT

IN

OUT

M

ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

24

7706 All-in-One I/O Module

Features

• 20 channels of analog input (w/automatic CJC) for general-purpose
measurement.

• 16 channels of digital output.

• Event counter/totalizer can monitor and control system components,
such as fixturing, limit switches, pass/fail indicators, external voltage
sources, loads, door closures, revolutions, etc., while performing mixed
signal measurement.

• 300V, 1A capacity; 60W, 125VA maximum.

• Configurable as two independent banks of multiplexers.

• Two analog outputs (±12V, 5mA).

• Relay closures stored in on-board memory.

GENERAL

20 CHANNELS: 20 channels of 2-pole relay input.

All channels configurable to 4-pole.

RELAY TYPE: Latching electromechanical.
ACTUATION TIME: <3ms.

CAPABILITIES

CHANNELS 1–20: Multiplex one of 20 2-pole or one of 10 4-pole signals

into DMM.

Channels 21–25 are referenced to chassis ground.

CHANNELS 21–22: 16 Digital Outputs.
CHANNELS 23–24: Analog Voltage Output (2).
CHANNELS 25: Totalize Input.

INPUTS

MAXIMUM SIGNAL LEVEL (Channels 1–20): 300V DC or rms, 1A

switched, 60W, 125VA maximum.

CONTACT LIFE (typ.): >105operations at max. signal level: >108opera-

tions cold switching.

CONTACT RESISTANCE: <1Ω at end of contact life.
CONTACT POTENTIAL: <±2µV typical per contact, 3µV max.
OFFSET CURRENT: <100pA.
CONNECTOR TYPE: Screw terminal, #20 AWG wire size.
ISOLATION BETWEEN ANY TWO TERMINALS: >10

9

Ω, <100pF.

ISOLATION BETWEEN ANY TERMINAL AND EARTH: > 10

9

Ω, <200pF.

CROSS TALK (10MHz, 50Ω Load): <–35dB.
INSERTION LOSS (50Ω Source, 50Ω Load): <0.1dB below 1MHz.

<3dB below 2Mhz.

COMMON MODE VOLTAGE: 300V between any terminal and chassis.
T/C COLD JUNCTION: 1.0°C (18°C to 28°C mainframe temp.).

1.5°C (0°–18°C & 28°–50°C mainframe temp.).

TOTALIZE INPUT

MAXIMUM COUNT: 232–1.
TOTALIZE INPUT: 100kHz (max), rising or falling edge, programmable.
SIGNAL LEVEL: 1Vp-p (min), 42Vpk (max).
THRESHOLD: 0V or TTL, jumper selectable.
DATE INPUT: TTL-Hi, TTL-Lo, or none.
COUNT RESET: manual or Read+Reset.
READ SPEED: 50/s.

ANALOG VOLTAGE OUTPUT

DAC 1, 2: ±12V in 1mV increments, non-isolated.
RESOLUTION: 1mV.

I

OUT

: 5mA max.

SETTLING TIME: 1ms to 0.01% of output.

ACCURACY ±(% of output + mV):

1 year ±5°C: 0.15% + 19mV;
90 day ±5°C: 0.1% + 19mV;
24 hour ±1°C: 0.04% + 19mV.

TEMPERATURE COEFFICIENT:

±(0.015% + 1mV)/°C.

DIGITAL OUTPUT

V

OUT

(L): <0.8V @ Iout = 400mA.

V

OUT

(H): >2.4V @ Iout = 1mA.

V

OUT

(H)MAX.: <42V with external open drain pull-up.

WRITE SPEED: 50/s.

ENVIRONMENTAL

Specified for Model 2750 firmware revision AO2 or later.
OPERATING ENVIRONMENT: Specified for 0°C to 50°C.

Specified to 80% R.H. at 35°C.

STORAGE ENVIRONMENT: –25°C to 65°C.
WEIGHT: 0.5kg (1.1 lbs).

S WITCH/CONTROL M ODULE S PECIFICATIONS

7706

HI

Input

LO

HI

Sense

Cold junction
Ref x2

Cold junction
Ref x2

Channel 11

(Channels 12–19)

LO

Channel 1

LO

(Channels 2–9)

Channel 10

LO

LO

Channel 20

LO

16

Digital
Output

HI

HI

HI

HI

Channel 26

2-Pole (Open)

4-Pole (Closed)

(see Note)

Bit

0
1
2
3

Channel 21

4
5
6
7

0
1
2
3

Channel 22

4
5
6
7

NOTE Non-isolated

grounds ( )
are referenced to
chassis ground.

NOTES Channels 26–28 in this schematic

refer to the designations used for
control and not actual available channels.

Channels 26, 27, and 28 can be individually
controlled using ROUTe:MULTiple if the
module is not to be connected to the
internal DMM.

For more information, refer to the
ROUTe:MULTiple command section
in the Model 2700 or 2750 User’s Manual.

Channel 28

(see Note)

Backplane

isolation

HI

Input

LO

HI

Sense

LO

Channel 23

Channel 24

+IN

–IN

+GATE
–GATE

To Model 2700
or 2750
Backplane

Channel 25

Channel 27

(see Note)

Backplane

isolation

16

16

32

Channel 23

DAC

Channel 24

DAC

Totalizer

T

ECHNICAL DATA

25

7707 Multiplexer-Digital I/O Module

GENERAL

10 CHANNELS: 10 channels of 2-pole relay input.

All channels configurable to 4-pole.

RELAY TYPE: Latching electromechanical.
ACTUATION TIME: <3ms.
FIRMWARE: Specified for Model 2700 rev. B03 and Model 2750 rev. A01.
CAPACITY: Model 2700: (1) 7707 and (1) 770X, except 7706.

Model 2750: (3) 7707 and (2) 770X, except 7706. A 7706

module may be substituted for a 7707 module.

CAPABILITIES

CHANNELS 1–10: Multiplex one of 10 2-pole or one of 5 4-pole signals

into DMM.

CHANNELS 11–14: 32 Digital Inputs/Outputs referenced to chassis

ground.

THERMAL PROTECTION: Channels 11–14 are thermally protected to 1A.

INPUTS (Channels 1–10)

MAXIMUM SIGNAL LEVEL: Any Channel to Any Channel (1–10):

300VDC or 300Vrms (425V peak) for AC waveforms, 1A switched, 60W,
125VA maximum.

SAFETY CATEGORY: Conforms to European Union Directive 73/23/EEC

EN 61010-1, CAT I.

CONTACT LIFE (typ.): >10

5

operations at max. signal level: >108opera-

tions cold switching.

CONTACT RESISTANCE: <1Ω any path and additional 1Ω at end of con-

tact life.

CONTACT POTENTIAL: <6µV typical per contact pair and additional

5µV with Channels 11–14 at rate V

OUT

(L).

OFFSET CURRENT: <100pA.
CONNECTOR TYPE: 50-pin male D-shell, Channels 11–14.

25-pin female D-shell, Channels 1–10.

Supplied with female and male IDC ribbon cable connectors.

ISOLATION BETWEEN ANY TWO TERMINALS: >10

9

Ω, <100pF with iso-

lation channels 16 and 17 open.

ISOLATION BETWEEN ANY TERMINAL AND EARTH: > 10

9

Ω, <200pF.

CROSS TALK (10MHz, 50Ω Load): <–35dB.
INSERTION LOSS (50Ω Source, 50Ω Load): <0.1dB below 1MHz.

<3dB below 2MHz.

COMMON MODE VOLTAGE: 300VDC or 300Vrms (425V peak) for AC

waveforms between any terminal and chassis.

DIGITAL INPUT/OUTPUT (Channels 11–14)

VIN(L): <0.8V (TTL).

V

IN

(H): >2V (TTL).

V

OUT

(L): <1.0V @ I

OUT

= 100mA.

V

OUT

(H): >2.4V @ I

OUT

= 1mA.

V

OUT

(H)MAX.: <40V with external open drain pull-up.

READ/WRITE SPEED: 50/s.

ENVIRONMENTAL

OPERATING ENVIRONMENT: Specified for 0°C to 50°C.

Specified to 50% R.H. at 35°C.

STORAGE ENVIRONMENT: –25°C to 65°C.
WEIGHT: <0.5kg (1.1 lbs).

ACCESSORY AVAILABLE:

Model 7790 50/50/25 Pin Female/Male D-Shell IDC Connectors

S WITCH/CONTROL M ODULE S PECIFICATIONS

7707

Features

• 10 channels of analog input for general-purpose measurement.

• 32 channels of digital input and output (four 8-bit ports) for I/O control.

• 300V, 1A capacity; 60W, 125VA maximum (analog).

• Configurable as two independent banks of multiplexers.

• 33V, 100mA capacity (digital).

• Two mating IDC connectors supplied (Model 7790).

• Digital outputs are short circuit protected.

• Relay closures stored in on-board memory.

1–16

HI

LO

HI

LO

HI

LO

HI

LO

HI

LO

HI

LO

Digital I/O

DIO

Channel 15

2-Pole (Open)

4-Pole (Closed)

(see Note)

Bit

0
1
2
3

Channel 11

4
5
6
7

0
1
2
3

Channel 12 Channel 14

4
5
6
7

Card Input

Card Sense

Channel 1

(Channels 2–4)

Channel 5

Channel 6

(Channels 7–9)

Channel 10

Channel 17

(see Note)
Backplane

isolation

Channel 16

(see Note)
Backplane

isolation

NOTES Channels 15–17 in this schematic

refer to the designations used for
control and not actual available channels.

For more information, refer to the
ROUTe:MULT command section
in the Model 2700 or 2750 User’s Manual.

Digital I/O

17–32

DIO

Bit

0
1
2
3
4
5
6
7

0
1
2
3
4
5
6
7

HI

Input

LO

HI

Sense

LO

Channel 13

To
Internal
DMM

M

ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

26

7708 40-Channel Differential Multiplexer
Module

Features

• 40 differential channels for general-purpose measurements.

• 2- or 4-wire measurements.

• Oversize screw terminal connection blocks are standard for easier con­nection.

• 300V, 1A capacity for voltage channels; 60W, 125VA.

• Configurable as two independent banks of multiplexers.

• Built-in CJC sensors automatically linearize thermocouples.

• Relay closures stored in on-board memory.

GENERAL

40 CHANNELS: 40 channels of 2-pole relay input. All channels config-

urable to 4-pole.

RELAY TYPE: Latching electromechanical.
ACTUATION TIME: <3ms.

CAPABILITIES

CHANNELS 1–40: Multiplex one of 40 2-pole or one of 20 4-pole signals

into DMM.

INPUTS

MAXIMUM SIGNAL LEVEL:

Channels (1–40): 300V DC or rms, 1A switched, 60W, 125VA maximum.

CONTACT LIFE (typ): >10

5

operations at max. signal level.

>108operations cold switching.

CONTACT RESISTANCE: <1Ω at end of contact life.
CONTACT POTENTIAL: <±500nV typical per contact, 1µV max.

<±500nV typical per contact pair, 1µV max.

OFFSET CURRENT: <100pA.
CONNECTOR TYPE: Screw terminal, #20 AWG wire size.
ISOLATION BETWEEN ANY TWO TERMINALS: >10

10

Ω, <100pF.

ISOLATION BETWEEN ANY TERMINAL AND EARTH: >10

9

Ω, <200pF.

CROSS TALK (10MHz, 50Ω Load): <–40dB.
INSERTION LOSS (50Ω Source, 50Ω Load): <0.1dB below 1MHz.

<3dB below 2MHz.

COMMON MODE VOLTAGE: 300V between any terminal and chassis.

ENVIRONMENTAL:

T/C COLD JUNCTION: 1.0°C (18°–28°C).

1.5°C (0°–18°C and 28°–50°C).

OPERATING ENVIRONMENT: Specified for 0°C to 50°C.

Specified to 80% R.H. at 35°C.

STORAGE ENVIRONMENT: –25°C to 65°C.
WEIGHT: 0.52kg (1.16 lb).

S WITCH/CONTROL M ODULE S PECIFICATIONS

7708

HI

Card Input

Card Sense

Cold Junction
Ref XY

Channel 1

(Channels 2–19)

Channel 20

Cold Junction
Ref XY

Channel 21

(Channels 22–39)

Channel 40

LO

LO

LO

LO

LO

LO

HI

HI

HI

HI

HI

Channel 43

2-Pole / 4-Pole

(see Note)

Channel 45

(see Note)
Backplane

isolation

Channel 44

(see Note)
Backplane

isolation

NOTE Channels 43–45 in this schematic

refer to the designations used for
control and not actual available channels.

For more information, refer to the
ROUTe:MULTiple command section
in the Model 2700 or 2750 User’s Manual.

HI

Input

LO

HI

Sense

LO

To Model 2700
or 2750
Backplane

T

ECHNICAL DATA

27

7709 6×8 Matrix Module

Features

• Automatic 2- or 4-wire connection to DMM

•6 row × 8 column matrix

• Two female “D-sub” connectors are standard for secure hook-up and
quick teardown.

• 300V, 1A capacity.

• Two mating IDC connectors for ribbon cable (Model 7790) are supplied.

• Relay closures stored in on-board memory.

GENERAL

MATRIX CONFIGURATION: 6 rows × 8 columns.
CONTACT CONFIGURATION: 2 pole Form A.
FIRMWARE: Specified for Model 2700 rev. B03 and Model 2750 rev. A01.
RELAY TYPE: Latching electromechanical.
ACTUATION TIME: <3ms.

CAPABILITIES

DMM CONNECTION:

2-Wire Functions

Row 1, channels 1–8, through channel 50.

4-Wire Functions

Row 1, channels 1–4 (Source) through channel 50 and Row 2, chan-

nels 13–16 (Sense), through channel 49.

CLOSE CHANNEL: CLOSE command connects channels 1–8 to DMM.

For 4-wire, channels 1–4 are automatically paired with channels 13–16.
ROUTe:MULTiple allows any combination of rows and columns to be
connected at the same time.

INPUTS

MAXIMUM SIGNAL LEVEL: Any Channel to Any Channel (1–48):

300VDC or 300Vrms (425V peak) for AC waveforms, 1A switched, 60W,
125VA maximum.

SAFETY: Conforms to European Union Directive 73/23/EEC EN61010-1,

CAT I.

CONTACT LIFE (typ): >10

5

operations at max signal level.

>108operations cold switching.

CONTACT RESISTANCE: <1Ω any path and additional 1Ω at end of con-

tact life.

CONTACT POTENTIAL: <3µV per contact pair.
OFFSET CURRENT: <100pA.
CONNECTOR TYPE: 50-pin female D-shell for rows and columns.

25-pin female D-shell for “daisy-chain” rows.

Supplied with male IDC ribbon cable connectors.

ISOLATION BETWEEN ANY TWO TERMINALS: >10

9

Ω, <200pF.

ISOLATION BETWEEN ANY TERMINAL AND EARTH: >109Ω, <400pF.
CROSS TALK (1MHz, 50Ω Load): <–35dB.
INSERTION LOSS (50Ω Source, 50Ω Load): <0.35dB below 1MHz.

<3dB below 2MHz.

COMMON MODE VOLTAGE: 300VDC or 300Vrms (425V peak) for AC

waveforms between any terminal and chassis.

ENVIRONMENTAL:

OPERATING ENVIRONMENT: Specified for 0°C to 50°C.

Specified to 50% R.H. at 35°C.

STORAGE ENVIRONMENT: –25°C to 65°C.
WEIGHT: <0.52kg (1.16 lb).

ACCESSORIES AVAILABLE:

Model 7789 50/25 Pin Male D-Shell Solder Cup Connectors
Model 7790 50/50/25 Pin Female/Male D-Shell IDC Connectors

S WITCH/CONTROL M ODULE S PECIFICATIONS

7709

Rows

1 2 3 4 5

12345 678

1

9 10111213 141516

2

17 18 19 20 21 22 23 24

3

25 26 27 28 29 30 31 32

4

33 34 35 36 37 38 39 40

5

41 42 43 44 45 46 47 48

6

Columns

678

HI

Matrix Crosspoint

LO

50

HI

Input

LO

49

HI
LO

Sense

To DMM
Backplane

M

ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

28

T

ECHNICAL DATA

29

M

ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

30

Thermocouple connections

NOTE: The red lead is the LO signal on all thermocouples.

7708 Configuration Examples

Thermocouple Configuration Example
Using Internal CJC

Thermocouple connections

Dual multiplexer mode example #1

NOTE: The red lead is the LO signal on all thermocouples.
This applies to U.S. standards.

Thermocouple Configuration Example Using
External CJC

HI

Channel 1

LO

(Channels 2–19)

HI

Channel 20

LO

Thermocouple

HI

Channel 1

LO

HI

Channel 2

LO

(Channels 3–39)

HI

Channel 40

LO

NOTE: If an RTD is connected as the cold junction reference,

Channel 21 will be used for the sense leads of the RTD and
is not available for connection of a thermocouple.

Externally
supplied
cold
junction
reference*

Thermocouple

*Connect Thermistor
or RTD (see Note)

Internal

DMM

Ch. 44

See Model 7708 specifications.

Channel 43 .....Closed

Channel 44 .....Open

Channel 45 .....Closed for DMM

External

DC Power

Supply

measure

HI

Card Sense

LO

Ch. 21

.
.
.

Ch. 40

NOTE: This configuration example can be duplicated with

DUT

the 7700, 7701, 7702, 7703, 7706, 7707, and 7708
modules. See module specifications for their
channel configurations.

Ch. 1

.
.
.

Ch. 20

Ch. 45

HI

Internal

DMM

LO

HI

External

Scope

LO

T

ECHNICAL DATA

31

Using internal DMM and external instruments

Typical connections—indicator lamps,alarm, and relay

7705 Configuration Examples

7708 Configuration Examples (continued)

HI

Ch. 45

LO

HI

Ch. 1

Ch. 20

.
.
.

Card Input

LO

Internal

DMM

Scope

See Model 7708 specifications.

Channel 43 .....Open

Channel 44 .....Open

Channel 45 .....Closed

Ch. 21

Ch. 40

Ch. 43

.
.
.

Card Sense

DUT

Model 7705

IN 1

Ch. 1

5V

IN 2

Ch. 2

IN 3

Ch. 3

12V

IN 4

Ch. 4

HI

LO

Counter

NOTE: This configuration example

can be duplicated with the
7700, 7701, 7702, 7703,
7706, 7707, and 7708
modules. See module
specifications for their
channel configurations.

OUT 1

Indicator

OUT 2

OUT 3

OUT 4

Lamp

Alarm

30V

IN 5

IN 6

Ch. 5

Ch. 6

Equivalent Circuit

OUT 5

OUT 6

Relay

M

ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

32

Variable AC line/load test connections

7705 Configuration Examples (continued)

Single Pole (Single Point Ground) Switching Example

Using the 7705 for independent switching and the 7701 to bring measurement of DUT to internal DMM of 2750

Model 7705

AC

Source

HI

IN 1

IN 2

AC

Source

LO

Source is impedance limited from mains (Safety Category I signals).

OUT 1

OUT 2

CAUTION: Maximum switch current is 2A.

DUT

Model 7705

10%
Load
Resistor

IN 3

OUT 3

IN 4

OUT 4

90%
Load
Resistor

+5V

7705

7701

Screw

Terminals

DUT 1

.
.
.

Ch. 1

.
.
.

HI

LO

Ch. 1

Ch. 35

Internal

DMM

DUT 40

Ch. 40

See Model 7701 specifications.

Channel 33 .....Closed

Channel 34 .....Closed

Channel 35 .....Closed

T

ECHNICAL DATA

33

7705 independent switch and 7701 multiplexer example

7705 Configuration Examples (continued)

7705

+

–

Input

Power

+

–

48VDC

48VDC

DUT 1

DC to DC

Converter

.
.
.

DUT 16

DC to DC

Converter

Output

Output

7701

HI

LO

HI

LO

HI

LO

HI

LO

Ch. 1 Ch. 2

Ch. 31 Ch. 32

Ch. 1

Ch. 2

.
.
.

Ch. 16

Ch. 33

.

Ch. 17

.
.

Ch. 31

Ch. 32

Screw

Terminals

HI

Ch. 35

LO

See Model 7701 specifications.

Channel 33 .....Closed

Channel 34 .....Open

Channel 35 .....Closed

Screw

Terminals

HI

Ch. 34

LO

Chs. 1–32

To Internal

DMM

M

ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

34

Analog Output and Digital I/O Examples

Typical digital output w/external power supply

Typical digital output (no external power supply)

Digital Output

The 7706 module has two non-isolated 8-bit
output ports that can be used for outputting
digital patterns. The two ports can be com­bined to output a single 16-bit word or a dual
8-bit byte. A simplified diagram of a single
output bit is shown here.

The 7707 module has four non-isolated 8-bit
input/output ports that can be used for out­putting digital patterns. The two ports can be
combined to output a 16-bit word, or dual or
quad 8-bit bytes.

The 7707 can also be configured (in blocks of

8) as digital inputs.

7706 analog output

NOTE: The 7706 module
has two ±12V analog
output channels.

7706/7707

Output

+5V

Digital ground
(non-isolated,
referenced to
chassis)

Digital

I/O

Terminal

Sink

400mA

(7706)

100mA

(7707)

User supplied circuitry

+

–

42V (7706)
40V (7707)

7706

Output

+5V

Digital ground
(non-isolated,
referenced to
chassis)

Digital
Output

Terminal

(1 of 8)

±12V

V

OUT

5mA max.

(16-bit resolution)

V

O

Output Common
(non-isolated,
instrument to chassis)

User supplied circuitry

Logic Circuit

Logic Ground

T

ECHNICAL DATA

35

The 7709 Matrix Module can connect any combination of six differential channels of instrumentation to any combina­tion of eight differential DUT channels. The instrumentation can be the 2750’s internal DMM or external equipment (AC
and DC sources, internal or external meters, oscilloscopes, etc.) This matrix configuration allows wide flexibility for com­plex test systems.

Matrix Configuration Example

7709 6×8 Matrix configuration example

Connecting the Model 7707 Digital I/O module to industry standard solid-state relays (SSRs) to switch high VA (up to 980VA).

Analog Output and Digital I/O Examples (continued)

7707 Digital I/O

1

.

Dig. I/O Ch. 11

Dig. I/O Ch. 12

Dig. I/O Ch. 13

Dig. I/O Ch. 14

CAUTION: Adequate insulation barriers must be used on PB-24SM and cable for systems with >42V.

.
.

8

1

.
.
.

8

1

.
.
.

4
5

.
.
.

8

1

.
.
.

4
5

.
.
.

8

Available

Available

8

8

4

4

DB-50

50-Pin

Card Edge

Cable

Industry Standard PB-24SM
24 SSR Baseboard

SSR1

SSR2

SSR3

.

Optically

.

isolated

.

SSR24

Output Relays: SM-ODC5, SM-ODC5A,

Input Relays: SM-IDC5, SM-IAC5,

SM-OAC5, SM-OAC5A,
SM-OAC5R

SM-IAC5A

.
.
.

User

Supplied

Switch or

Sense

.
.
.

DUT

Input

12V DC Source

Scope

Counter

Signal Generator

5V DC Source

To 2750

DMM

M

ODEL 2750 M ULTIMETER

/SWITCH SYSTEM

7701 Configuration Example

Specifications are subject to change without notice.
All Keithley trademarks and trade names are the property of Keithley Instruments, Inc.

All other trademarks and trade names are the property of their respective companies.

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1-888-KEITHLEY (534-8453) www.keithley.com

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CHINA: Keithley Instruments China Yuan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-6202-2886 • Fax: [phone]
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GREAT BRITAIN: Keithley Instruments Ltd. Unit 2 Commerce Park, Brunel Road • Theale, Berkshire RG7 4AB • Phone: [phone] • Fax: [phone]
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© Copyright 2001 Keithley Instruments, Inc. No. 2294
Printed in the U.S.A. 20128KOP

7701 32-Channel common-side
4-wire Ohms configuration example

D-Sub

DMM Sense HI

DMM Input HI

DUT1

*Common Side Bus

DUT2

Connectors

Installed

Jumpers

Ch. 35

User
Configurable
Screw
Terminals

User

Sense HI

Input HIInput HI

DUT3

DUT4

*NOTE: Common side connections must be made carefully to eliminate all lead

resistance from the 4-wire ohms measurement. The common side bus
should be a single wire or bus bar that connects the HI side of all the
DUTs. DMM Input HI should be connected to one end of the common
side bus and DMM Sense HI should be connected to the other end.

**Ch. 33

(Open)

Ch. 34

2750
DMM

Sense LO

Input LO

7701

**NOTE: Refer to ROUTE:MULT

section of the 2700 or 2750
manual for more information.