Just wondering if anyone does tests on their serial communications lines to determine the ‘health’ of their serial comms?
At our workplace here we have several patient call systems (not Opto22) that use RS485 communications to gather information from remote I/O. We used to have a lot of trouble with some of the I/O boards failing with errors on the main system until we were asked to check the communications line to determine its health. It would involve unplugging the master controller from the 485 line and measuring a dc voltage between each tx/rx line to dc ground. Around 2.5Vdc was considered healthy but under 2Vdc was considered problematic. The solution is easy, just replace the line driver chips.
We are currently experiencing some funny serial communications issues between an S1, some B3000 serial and G4 mistic brains, and was wondering if there was a similar technique that can be used on Opto22 hardware to determine if the serial line has an issue? i know i cannot replace the serial chips as per above, but it could give a good indication of which serial line to follow (if your controller is in the middle)
I have measured a couple of 485 lines with the controller unplugged and they measure around .2Vdc WRT gnd.