AnsweredAssumed Answered

Incomplete frame trigger the error active event?

Question asked by Chen Zhuoru on Nov 2, 2015
Latest reply on Nov 5, 2015 by Martin Kovar

We found a problem that when we initialize SBC to change the transceiver mode to active mode, CAN bus is disturbed and error frame on bus may occurs.

 

First our MCU initialize our CAN controller inside MPC5604, then we initialize CAN transceiver in SBC(UJA1164) to let the transceiver mode change from Offline mode to Actice mode.

One of the difference between Offline mode and Active mode is CAN Line in the transceiver is floating or real connecting to CAN bus.

So, when we change the transceiver mode to Active mode, CAN Line of transceiver connect to the CAN bus and the transceiver is able to receive signal on bus and convert the signal
as CAN_Rx(TTL) to MCU. At this time, MCU may receive an incomplete frame when bus load is high. So this situation trigger Error Active
event in MCU, which let MCU send a stuffing
error frame purposely to inform other nodes on bus that there is some mistake on bus.

 

So, am I right if MCU receive an incomplete frame will trigger the error active event?

 

Waiting for your reply, thanks so much!

Outcomes