Challenge
A RS485 network can often lead to mysterious problems, which can be hard to troubleshoot and explain.
The customers network installations would often vary in length and number of devices. Combined with end-user installation often using poor cable quality and questionable topology layout it provides the protentional major error source.
The customer would like to have this issue addressed and needed a solution that could monitor this and provide the answer itself.
The goal was to create an ‘active termination’ that could help to detect faulty networks and possible adjust this – live.
Solution
All electrics measurement of signal edge quality and capacitive bus load etc. was performed on a separate board which handled the adjustment termination and biasing directly in hardware.
The micro controller would receive actual values on A/D channels and incorporate this into the overall network status.
Furthermore, the customers protocol was implemented in order to perform live message statistics including error counters for checksum, framing and size. Bus throughput and bus utilization was also a part of the statistics which all could be requested over the same network.