What are that likely factors that affect the GE LM 70 30 Genius Bus LAN to drop off?

We have add of device & lost of device in the PLC fault table.
What also causes high bus faults?

 

> What are that likely factors that affect the GE LM 70 30 Genius Bus LAN to drop off?

1. Wrong Cable

2. Crossed Wires

3. Bad Connections (splices)

4. Termination

 

Thanks for the reply Brian