Kinetix 6000 -E38 Intermittent SERCOS Ring Drops

Good Evening ,

We have a bank of Kinetix 6000 servo drives and we get intermittent E38 Faults ( Ring Fault ) . We have a number of Fiber jumpers on these drives returning to a Serco's Interface in a ControlLogix rack. I have not seen a lot on this issue. Have many of you seen this issue ? Does these fibers break down in time ? I can't imagine they would .

Thanks so much in advance ,

In the Indramat (BRC) world, each station has a parameter that describes "how far it is to the next station", so that it can set the outgoing gain on the SERCOS II fiber optic signal.
I don't know if Rockwell has such a parameter, but that would be a good place to start looking.