Thanks for the input everyone.
Flex727.
The coil in question is the last coil in the second picture "N2 Purge Ready." Essentially, is it possible the Positive Transition Coil for the HMI input to get stuck in the off setting since the button becomes invisible and thus is never checked again for the return to off state (HMI button is always true since it never "resets")
Would a Positive Transition Contact resolve the issue discussed here? Seems like it would if the question above is false.
Ausman.
Yes, this is something I definitely try to be aware of when writing these because it's happened in previous code (probably to everyone). I would love to be able to simulate and test-play, which is why it would be absolutely fantastic if Unitronics ever develops a simulation program because the amount of IO and wiring that needs to be installed/bypassed to test even these smaller aspects (invisibility and state transitions, as this programs required X,Y,Z to happen before states can move forward) can be significant time sinks.
It's also a little disappointing that Unitronics doesn't have a "momentary push button" option which is what the set/reset logic is supposed to emulate, and is virtually standard throughout all programming libraries except Unitronics. But, it looks like they sort of get around this with the Positive Transition Contact, however, it's far less than ideal.
I chose Unitronics on this project because of its smaller scope and features that come built-into the HMI, and would definitely use it again. But, ff I were doing something mission critical or needed to do significant prior testing I would probably use a software that had simulation tools so I can test out various aspects of the buttons, etc.
Thanks for the input everyone.