PLC not responding

Hi, I just wanna know why is it that when I down loaded my program in a Mitsubishi PLC and monitor it, the PLC does'nt seem to read my program. Though the coil at the ladder is already turned on, the PLC output corresponding to it does not turn on. When I tried a shorter program just to test that particular output terminal, it responds well. Hope you can answer why and how to prevent it.Thanks a lot.

The output is probably being overwritten later in the scan. Around here, we commonly call that "Double Coil Syndrome". Have a look at THIS thread.

beerchug

-Eric