S7 vat table

we are having ghost stops on our machine which could be caused by several faults. the faults reset themselves during the scan, so eyeballing the input isn't possible, especially with several remote modules aboard. is there anyway to set the bits up in the vat table and have the vat table let me know which one made the transition? thanks.

No, I'm afraid not. The best you can do is to code some "traps" in the places where the faults might occur (by the way, these "ghost" faults look like sloppy programming to me, and that should be looked at when you have time). All you need to do is find some free bits (preferably Mx.x so you don't worry about which DB is open), and plug them in as necessary.

If you don't have the source code or the blocks are protected, then your options are more limited. If it is a real world input that is flickering, then you could hook it to a second controller and monitor it I suppose. Or, you could connect the inputs one by one to an oscope and look for abnormalies.

thanks S7GUY

that's what i was afraid of, thanks for your reply. i have been latching them in using free bits, narrowing the problem down, maybe 8 bits at a time. i can get it pinpointed after bout 5 faults. just time consuming, was hoping the vat table could do the work for me. and i do agree with you, it is sloppy programming, i plan to put permanent latches in there seeing how that is my only alternative. thanks again.