Part 2

376 Plug-in Assembly ConfigurationRelay Card ConfigurationBy using jumpers JMPl through JMP6 you can configure the assembly for fourmodes of operation. In addition, by removing resistors R27, 28, 29 and/or R30, 31,32 you can make accurate two-wire ohms measurements. The following chart showsthe function of these components and Figure 75 shows their locations. REF refersto the numbers in Figure 75.RELAY CARD - FUNCTIONSREFTITLE I FUNCTION12345TIC COMP JUMPERTREE SWITCH JUMPERS(JMP1,2,3)DECADE A TO DECADE BJUMPERS(JMP4,5,6)A DECADE SERIESRESISTORS(R27,28,29)B DECADE SERIESRESISTORS(R30,31,32)1 Leave set to NO TIC COMP position.Enables signals from the A decade and Bdecade relays to be passed to the treeswitch relay. Remove these jumpers whenyou don't want signals input to the 3497Amainframe.These jumpers connect decade A relaysoutput to decade B relay outputs. Removethese jumpers for four-wire ohmsmeasurements. With jumpers removed, Adecade output ONLY is available to theDVM (when tree switch is closed).Provide current limiting protection for Adecade. Short the resistors (by solderingacross the shorting pins) when making twowireohms measurements on the A decade.Provide current limiting protection for Bdecade. Short the resistors (by solderingacross the shorting pins) when making twowireohms measurements on the B decade.Shorting the Series ResistorsAs factory configured, there are three 100 ohm resistors in series with the A decadecommon output (R27, R28 and R29) and three 100 ohm resistors in series with theB decade common output (R30, R31 and R32). For more accurate two-wireresistance measurements, these resistors can be shorted out.-- --#Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com