Tektronix 7702 User manual

Keithley Instruments

28775 Aurora Road
Cleveland, Ohio 44139
1-800-935-5595

tek.com/keithley

Model 7702 Multiplexer Module

Instructions for use with DAQ6510

077144400 / April 2018 *P077144400* 1

Introduction

The 7702 40-Channel Differential Multiplexer Module offers 40 channels of 2-pole or 20 channels of 4-pole
multiplexer switching that can be configured as two independent banks of multiplexers. The 7702 provides two
additional protected channels for current measurements. It is ideal for RTD, thermistor, and thermocouple
temperature applications.

Figure 1: Model 7702 40-Channel Differential Multiplexer Module

Item shipped may vary from model pictured here.

Model 7702 Multiplexer Module Instructions for use with DAQ6510

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The 7702 includes the following features:

▪ Two-wire or four-wire resistance measurements (automatically pairs switches for four-wire

measurements — n + 20)

▪ Two protected channels for current measurements (external shunts not required)
▪ Temperature applications (RTD, thermistor, thermocouple)
▪ Latching type relays (relays hold their position after power is removed)
▪ Screw terminal connections

The 7702 can be used with the DAQ6510 Data Acquisition and Multimeter System.

If you are using this switching module with the 2700, 2701, or 2750, please see Model 7700, 7702,
and 7703 Multiplexer Modules User's Guide, Keithley document number PA-695.

Connections

Connection and wiring procedures in this document are intended for use by qualified
personnel only. Do not perform these procedures unless qualified to do so. Failure to
recognize and observe normal safety precautions could result in personal injury or death.

Do not exceed the maximum specifications for the 7702. Refer to the specifications provided
in the data sheet. Failure to recognize and observe normal safety precautions could result in
personal injury or death.

The following information describes how to make connections to the switching module and define the channel
designations. A connection log is provided that you can use to record your connections.

The connections include:

▪ Connections to measurement functions (provided automatically through the backplane connector when the

switching module is installed in the instrument)

▪ Current provided through two protected channels (channels 41 and 42)
▪ INPUT connections
▪ SENSE (4-wire resistance) connections
▪ AMP and LO common connections to the DMM

Model 7702 Multiplexer Module Instructions for use with DAQ6510

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Wiring procedure

Use the following procedure to make connections to the 7702 switching module. Make all connections using the
correct wire size (up to 20 AWG).

All wiring must be rated for the maximum voltage in the system. For example, if 1000 V is
applied to the front terminals of the instrument, the switching module wiring must be rated
for 1000 V. Failure to recognize and observe normal safety precautions could result in
personal injury or death.

Equipment needed:

▪ Flat-blade screwdriver
▪ Cable ties

To make connections to the 7702 switching module:

1. Make sure all power is discharged from the 7702 switching module.

2. Use a screwdriver to turn the access screw to unlock and open the cover.

Figure 2: Screw terminal access

Model 7702 Multiplexer Module Instructions for use with DAQ6510

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3. Using a small flat-blade screwdriver, loosen the terminal screws and install wires as needed. The following
figure shows the connections, including the connections to Input and Sense.

Figure 3: Screw terminal channel designations