Control Cabinet with 1 ProSoft MVI69-PDPMV1 Master and two Siemens 6ES7972-0AA02-0XA0 repeaters feeding 54 Powerflex 40 VFDs. Over the last couple week's we've been having random motor faults across all sections of the network. Running ProfiTrace isolated a single run that appeared to be the source of the issue. After faulting (F071 - Communications loss), restarting would bring up the network again.
Yesterday a failure led to a 4 hour downtime where the network did not recover, and a single VFD was found to have a broken pin to the ribbon cable connecting the 22-comm-p card (2nd up from the bottom).
A couple questions. Has anyone seen a failure on on side of a repeater that would cause VFDs on the other side to fault. Does anyone have a pinout of the connector for the ribbon cable. Does anyone have similar experiences with similar or even different root causes. The big question though, was the broken pin actually the fault, or did we do something to the network (moving cable, reseating connector, etc) that could have returned it to service, and it might be a matter of time before it bites us in the *** again.