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Questions
No master CAN fault message
We have a system with MC43FS > MD5-10 > MC43FS layout. The MD5 display is central between the MC43's using the CAN in/out pins for connections. CAN terminations (software enabled) on both MC43 master and diagnostic busses (each MC43 module is end of line).
We had a fault where there was no comms on the master bus using APP IN/OUT between any of the 3 modules, just indicated red in IQAN design and state 'timeout' on the app in's. No error flash on the MC43 LED and no error message shown on the MD5.
We found that the master bus wired in the MD5 was the wrong way around (CAN high /CAN low incorrect), but it did not show this as an error, no logs suggested what the problem would be. I'm sure normally if this happens we get a bus error/ CAN fault shown on the screen, pointing us to where the problem may be, but this doesn't seem to have happened in our case. Could be helpful for future fault finding if it was available or showed a message?
IQAN Design 7.05.27.10982
Customer support service by UserEcho
Is this with Diagnostics bus and Master bus wired separately?
We have had the same issue when one of.the pins of the masterbus wasn't property seated in our multi master system.
It can be tricky to troubleshoot this issue as you don't get any error messages, all moduls will report status OK and all indicators on the display will usually work normally (as those signals goes through the diagnosis bus)
So there is no immediate indication that something is wrong with the system, just those particular functions sending data through the faculty part of the master bus will stop responding.
Apparently there is no heartbeat signal on the masterbus, so one would have to monitor the status of a channel going through the masterbus and throw a condition error message if that channel status is "timeout", to get an error message on the display.
It would be rather useful if the system, in the future, could have some sort of heartbeat signal for the masterbus by default, for troubleshooting purposes.
Yes agreed, additional diagnostics to point towards the issue would be helpful in this scenario. Glad I'm not the only one that's experienced this issue!
Yes separate master and diagnostic busses: