I'm a new user of Ladder Logic and M91 PLC's. I'm trying to debug a program I have uploaded off of an old PLC.
I understand that in U90 there is no way to force input/output states. Considering this how can you check that your logic is correct?
E.g. how can I check that a certain combination of inputs will cause a change of state or particular output?
[i don't consider a red flow of logic sufficient, especially as I can only see it for the power on state.]
Thanks