sharing information about cj1m

[ahuat 0]

Dear All, I want to share my experience with CJ1M CPU11 i connect CPU into 5 CJ1W ID211 and 5 CJ1W OC211, configuration is Power Supply, CPU, 5 Input unit, 5 output unit. It runs correctly until one day i was called because of the malfunction in PLC. I found the malfunction are only in the OC211 module, sometimes the relay didn't work although the small leds are on. After i spend few hours check the system, finally i found the cabinet backplane for the CPU, was not really flat anymore, because it's an old backplane, maybe too thin, and after few years the machine running, the backplane was not flat enough that it could make DIN rail for the CJ also slighty bended, and i assume the voltage bus between PA205 and the output module was cut because of that. The remedy was i add another backplane ( 2mm thickness ) as a support for the PLC unit only. hope can help. regards ahuat