Communication failures typically fall in to 2 categories:
1. bad interconnecting wiring
2. board faults
If you’re not using Belden 8162 or 8163, you run the risk of causing a communications problem that gets worse with time.
The LON originates on the Stack LON board AND the IG-1 serial gateway. If either board is faulted, unpowered, corrupted, blown power supply, or whatever then you’ll get COMM FAULTS.
Call for more details.