Part 2

Example 3497A Configurations 561EXAMPLE 2SINGLE-ENDED MEASUREMENTSDESCRIPTPOAs factory configured, the 3497A is set to measure input voltages using 3-wire(guarded) measurement techniques. If your application doesn't require the accuracyof 3-wire measurements and if the LOW sides of all your voltage sources can betied together, you can use 20 channnel relay multiplexer assemblies (Option 010)in the 5 slots of a 3497A to measure the inputs of up to 277 single-ended voltageinputs.One way to do this is to use channels BO, 61 and B2 on a relay multiplexer in slot4 to form a second level of multiplexing and then use the AC chan#,chan# commandto simultaneously close a channel in slot 0, 1, 2 or 3 and the BO, B1 or 82channel in slot 4 to measure the voltage from a specified input.PROCEDUREFigures 183 and 184 show the setup for single-ended measurements used in thisexample. Figure 183 shows the setup for an assembly in slot 0 and Figure 184shows the configuration for an assembly in slot 4. Configurations for assemblies inslots 1 through 3 are identical to that in slot 0.As shown in Figure 183, voltages V1 through V60 are input to relays A0 throughB9. The HIGH outputs of each relay are connected to relay BO of the assembly inslot 4 (channel 90), the LOW outputs to relay B1 (channel 91) and the GUARD out-puts to relay B2 (channel 92). Similarly, V61 - V90 are input to slot 1, V91 - V120are input to slot 2, etc.As shown in Figure 184, for the assembly in slot 4 ONLY, channels BO, B1 and B2(channels 90, 91 and 92) are reserved for secondary multiplexing, so only 37voltages can be input to the slot 4 card. Total channel capacity is thus 60 x 4 =240 + 37 = 277 single-ended inputs.To measure a voltage, use the AC chan#,chan# command to simultaneously closethe relay connected to the desired input AND relay BO, 61 or B2 of the assemblyin slot 4. For example, in Figure 183, V1, V2 and V3 are connected to relay A0(channel 0). Thus, to measure V1, use AC0,90 to simultaneously close relay A0 inslot 0 and relay BO in slot 4. To measure V2, use AC0,91 and to measure V3, useAC0,92.Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com