Posted 21 Apr 2016 (edited) Hello system is Q06UDEH GX developer 8116W Large system 2 PLcs with 60K lines of code between them, SFC ladder, Issue, all conditions HIGH, coil not ON or visa versa (not all condition ON but coil high) also happen with data comparisons, moves etc. what i have looked at so far, -batch monitor confirms HIGH/LOW states - programs all scanned (all 35 of them) -no MC control ( some CJ and for NEXT seems unrelated) -force history is clear - not willing to rest CPU as this is a large press and it is running -widespread condition throughout the code - only monitor one window at a time Q - is there some monitor setting that I haven't found? over lapping registers Have gone online with original backup just to make sure something didn't happen with the read. No way i'm doing an edit when I cant tell whats going on with this. thanks! Edited 21 Apr 2016 by Maintenance guy wrong information on hardware Share this post Link to post Share on other sites
Posted 22 Apr 2016 It sounds like coils are being used more than once in a scan. Look for instructions with k4Mxxxx in them (writing bits in blocks of nibbles) or FROM instructions batch writing to bits. They often cause trouble. Or maybe a HMI or other device is manipulating them in some way and it hasn't been documented properly in the code. Share this post Link to post Share on other sites
Posted 22 Apr 2016 Thanks Luke i'll try and figure out HMIs and other PLC, unfortunately no mapping between hardware supplied, might be difficult to get a starting point I did just find some M0Z0 instructions thinking this may be a little above my pay grade..... Share this post Link to post Share on other sites