smdhannan

I have a problem about omron plc. the cpu is cj1m cpu12 and counter module is ct021. when i programmed the cpu by memory stick, the machine is run ok but after 1or 2 day the couter module get ERC led error, no run led shown in counter module. but cpu is still run mode.

again i upload prog memory to cpu then machine run ok. but same problem come again.

ok. but why this cause.