Part 2

400 Plug-In Assembly ConfigurationFigure 90. Option 050 - Digital Inputllnterrupt AssemblyInterrupt ModeWith interrupt mode, only the first eight channels (0-7) can be used. Refer to Figure91 which shows sample input connections to trace the sequence of operation forinterrupt mode. For the inputs shown, assume that we want to interrupt the controllerwhen the switch in channel 0 closes, but not interrupt when a switch closesin any other channel.In the circuit of Figure 91, a switch closure causes a high-to-low transition (can beconfigured for low-to-high) which causes the channel bit in the input byte to be settrue ("1 "1. In Figure 91, transitions have occurred on channels 0 and 7, so bits 0and 7 in the input byte are set to 1.Since interrupt is desired only for channel 0, we've set the assembly mask (not thesame as the SRQ or interrupt mask in the 3497A) with a DE slot#,O command. Sincethe mask bit 0 and the input byte bit 0 are both true, channel 0 of the interrupt byteis set. Note that even though bit 7 of the input byte is set by the transition of channel7 input, bit 7 of the interrupt byte is NOT set, since the mask bit 7 is not set.Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com