I am using s7-300 314C-2DP and it has connected 3 drives via profibus. Plc is in normal state but lenze drives EVS9321-EP, EVS9323-EP showing some error. Same fault on all of them. What would be the possible cause of this. Try to restart the system but no luck. Video link here. [snip]

Hello,

very sry, really I'm curious here that PLC is in good state, no errors indications. What about diagnostic buffer on PLC? You can't connect to any drive and see inside diag buffer also?

Hello,

I recommend in this strange situation check PB DP cable if it goes really to S7-300 CPU. In case yes then are 2 possibilities:

1. there is nothing defined inside CPU about this PB network, no error in CPU definitely but no cfg on Slaves, errors are presented.

2. PB network with Drives is ok but PN network what I see there also is faulty. Then I recommend what I did already, connect to Lenze and check internal things.

Look to documentation about Lenze Drives about their LED status indications as is clear from your video, this can be also interesting and can maybe help you to solve your problem.