CAN transceiver reset

Olivier Cote 2 years ago in IQANdesign updated by Gustav Widén (System support) 2 years ago 5

CAN bus latched failure status doesn't allow normal working before eather a software reflashing or a power reset. It's just unacceptable that the device crash and there is no way to reset it softwarely or even have this feature build-in in the low level firmware layers. Every other components can achive that "return to normal state" when the fault disappears. 

We tested it today by shorting can bus conductors together. We where expecting that disabling and re-enabling components would get them "back to life" for the Parker IQAN system. Finally not, the bus error stays (bus-off), other components of the system (Motors, battery and controllers) get back to normal state and keep "talking" despite IQAN MC43-FS device is still flagging "Timout" on their Can messages and "No Contact" on Can its message outputs.

It's major ! With actual safety related involvment ! 

By chance, that time it happened on a charging infrastructure so while the vehicle where immobilized, but what could we do if an error occures while the vehicle is circulating on the highway ?! It's just not acceptable to permanently lose power (by controlling a drivetrain) while the error / fault is gone. It must have a way to reset the bus !

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Thanks for following-up !


I agree.  Parker needs to implement a solution to this issue quickly...is been ongoing for a long time now.

This is indeed a nuisance since at least 10 years. There is no way to reset a CANbus. In automotive applications the different ECUs reset the fault counter and retry once in a while after a bus failure. It would also be pretty useful to have access to the fault counter of the bus.

It sounds like the function you need is bus off recovery? Bus-off recovery function? / Software / IQAN

This was added for the MC4x/MC4xFS some time ago, see release notes version 6.03


Thanks @Gustav ! I just upgrated my version. I was "stuck" in 2019 with the 6.02 version.

We did the CAN bus short test with the 6.08 version, Parker is getting back to life after these CAN bus wires get un-shorted  ♥♥♥