I have a controllogix PLC utilising devicenet I/O, and am having problems that I believe are due to the prescan.
Certain logic utilises examine offs of inputs to execute logic (turn off latches). I would normally utilise an examine on in series (eg. circuit breaker contact), but was unable to do this.
No problem thought I, I'll jump the logic upon power up until the I/O is up and running (takes about 40 seconds for the devicenet to burst into life!).
The problem is, some latches still turn themselves off after stopping/starting the PLC(grrrrrr). I assume this is the annoying prescan that is scanning my logic and turning the latches off (because the I/O is all off) even though I am trying to Jump over it. Any ideas as to what I can do to prevent this prescan turning off the latches?
TIA
Certain logic utilises examine offs of inputs to execute logic (turn off latches). I would normally utilise an examine on in series (eg. circuit breaker contact), but was unable to do this.
No problem thought I, I'll jump the logic upon power up until the I/O is up and running (takes about 40 seconds for the devicenet to burst into life!).
The problem is, some latches still turn themselves off after stopping/starting the PLC(grrrrrr). I assume this is the annoying prescan that is scanning my logic and turning the latches off (because the I/O is all off) even though I am trying to Jump over it. Any ideas as to what I can do to prevent this prescan turning off the latches?
TIA