I was looking for some other things on here regarding a how to question, and ran into all these push button being stuck on PLC. I under stand why it is happening and how it can be left in the on state if disconnected from SCADA with bad luck. So now, I am a little paranoid.
So lets say that the HMI on button does stay stuck like the image above, when the connection comes back from SCADA will it zero out the HMI on button ? If not, ever time they hit the start button it will restart.
the 2nd line has another example of moving some number into another register, I have put a one shot In case it also gets stuck, same question applies to this one.
From reading all the posts, it seems to me to make an array of HMI_PB’s maybe of 100. they will all be momentary PB’s coming from SCADA, if any one is left on maybe for 5 secs, I can clear them on the PLC using CLR function.
Note: not saying ignition has a issue, I would still apply this to all software SCADA’s