Kinetis Can frame retransmission

bataliero · ‎09-25-2012

Hi , I am trying to use FlexCan on K60 with PLL 96MHz ( cristal 8MHz). When I set up bitrate from Processor Expert to 20kbps and standard parameters (Propagation segment:0, seg1 : 7, seg 2: 3, RSJ: 1, One Sample) everything is ok. After changing value of bit rate to 250kbps or 500kbps Can frame is retransmitted 3 and 5 times ( I dont change anything in code just parameters in Processor Expert ) to external device .

Petr_H · ‎10-09-2012

Hello,

There might be a problem with CAN settings - please see check properties Segment, segment1,2. These settings are sensitive especially for high CAN bitrates. These settings should be set according to capacitance of the CAN bus. The repeated transmissions may occur because MK60 doesn't get acknowledge from the counterpart device, so the FlexCAN repeats sending frame while invoking the OnError event. Please try to enable OnError event and put there an error handling code. You can use there the GetError() method that returns a type of the error (e.g. ACK error).

best regards

Petr Hradsky

Processor Expert Support Team

View solution in original post

Petr_H · ‎10-09-2012

Hello,

There might be a problem with CAN settings - please see check properties Segment, segment1,2. These settings are sensitive especially for high CAN bitrates. These settings should be set according to capacitance of the CAN bus. The repeated transmissions may occur because MK60 doesn't get acknowledge from the counterpart device, so the FlexCAN repeats sending frame while invoking the OnError event. Please try to enable OnError event and put there an error handling code. You can use there the GetError() method that returns a type of the error (e.g. ACK error).

best regards

Petr Hradsky

Processor Expert Support Team