Detecting ...

[Guest Mike_H]

Hi. Is there a method or data area in a PLC that indicates the number of modules directly connected |-|-| <<. This may not be possible. I would like to externaly detect the units / type / contacts for each module. Thanks -- Michael

[Jay Anthony 118]

Low byte of Word AR 22 holds the number of input modules mounted to the CPU in 2 digit BCD. High byte of Word AR 22 holds the number of output modules mounted to the CPU in 2 digit BCD. The CQM1 does not haver an I/O table and the bus is not wide enough to interrogate each module for it's voltage and type. Guess what! If it had been C200H or higher, an MB command could have read the I/O table.

[Guest Mike_H]

Thanks Jay. IIRC. operations or programming manual mention something about 'used to store system bits'. I suspect the modules are defined in ' system bits'. I will likely be working with other models.. so I will get back to you on the MB comand. -- Michael