Chapter 8 Tutorial

Low-Level Signal Multiplexing and SwitchingLow-Level Signal Multiplexing and Switching

Low-level multiplexers are available in the following types: one-wire,

2-wire, and 4-wire. The following sections in this chapter describe each type of multiplexer. The following low-level multiplexer modules are available with the HP 34970A.

∙HP 34901A 20-Channel Armature Multiplexer

∙HP 34902A 16-Channel Reed Multiplexer

∙HP 34908A 40-Channel Single-Ended Multiplexer

An important feature of a multiplexer used as a DMM input channel is that only one channel is connected at a time. For example, using a multiplexer module and the internal DMM, you could configure a voltage measurement on channel 1 and a temperature measurement on channel 2. The instrument first closes the channel 1 relay, makes the voltage measurement, and then opens the relay before moving on to channel 2 (called break-before-makeswitching).

Other low-level switching modules available with the HP 34970A include the following:

∙HP 34903A 20-Channel Actuator

∙HP 34904A 4x8 Two-Wire Matrix

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