roghenr Posted December 10, 2021 Report Share Posted December 10, 2021 I have an input that triggers on a positive transition, but when I power up the v130 goes to the main screen backup.mextra.vlp Quote Link to comment Share on other sites More sharing options...
MVP 2021 Flex727 Posted December 10, 2021 MVP 2021 Report Share Posted December 10, 2021 You need to understand how Positive Transitions work. The only way for the PLC to know that the bit changed state is to have saved the state of the bit on the previous scan and do the comparison. On the very first scan of the PLC that is not possible since it has nothing previous to compare it to. You will need to rework your logic to account for that. You could do something like this: Also, while I'm at it, you need to understand what Ladder Logic is all about. The program is divided up into ladder rungs purposefully to separate logic threads. Do not place multiple logic threads in a single ladder rung. It works most of the time, but can cause problems unexpectedly and is VERY poor programming practice. Quote Link to comment Share on other sites More sharing options...
roghenr Posted December 11, 2021 Author Report Share Posted December 11, 2021 it's the first time I've worked with unitronics and I'm having a hard time understanding even subroutines I could give you an example of what you commented on doing separate in rows of stairs. Thank you very much for your help and sorry for the words as I'm from Brazil and I'm translating. Quote Link to comment Share on other sites More sharing options...
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