Lee Wood
Member
Hope can get some help. Today we had a senior, very AB PLC competent engineer in our plant to look at a PLC 5 problem. The program can be uploaded, downloaded and modified online as you would expect but the PLC is not responding with acknowledgement of inputs or outputs changing state. THe software seems to be running but we can find no reason for the fact that the inputs/outputs are not changing in line with software that is running. Bet you have all heard this before "never seen this in 20 years of programming". We can't think what we are missing?