07/28/2026
If youโve ever chased a rung that should energize but doesnโt, this will look familiar.
๐ง OTU (Unlatch) โ hidden unlatches in other routines overriding what you see
๐ง JSR (Jump to Subroutine) โ logic not executing because the routine isnโt being scanned
๐ง MCR (Master Control Reset) โ rungs evaluating false inside a control zone even when inputs appear true
If your team works with RSLogix or Studio 5000, this is a quick visual refresher worth sharing.
Hereโs the video:
Having trouble with illogical PLC rungs in RSLogix? This video w...