CI801 I/O modules Failure led
The CI801 is communicating with no issues. But the I/O modules(DI810,DO810) cannot be reached and the Failure led stays active. I' am using a TU810V1 as a termination unit. I hope someone can help. Thank you.
try to disconnect all terminal units and check pins in their side connectors. It happens rarely that some pins bend while connecting terminal units each other. That causes random communication error between CI and IO cards.
Or try to hot unplug and plug again profibus master CI854 if it is possible.
Sorry for stupid question. Did you lock S800 IO cards by plastic lock of terminal unit? It is located at right front side of the terminal unit. If plastic lock is in vertical postion IO card is enabled, otherwise IO card does not communicate with CI801.
Don't forget to adjust Power supervision option in settings of DI & DO cards.