Error Frames
Error frames can be received or discarded by configuring the parameter AllowErrorFrames on the connected PCAN Channel. This is carried out using the SetValue(PcanChannel, PcanParameter, UInt32) method.
The error frame data will be placed into a PcanMessage object. The field MsgType of these objects will have the flag Error set.
The following list shows the elements of an error frame:
Field | Information from... | Contents |
|---|---|---|
ID | ECC register SJA1000 (Error Code Capture), bits 6 and 7 (ERRC0, ERRC1) | 0: The message only transports updated error counter values 1: Bit error 2: Form error 4: Stuff error 8: Other type of error |
DATA[0] | ECC register, bit 5 (DIR) | 0: Error has occurred during transmission 1: Error has occurred during reception |
DATA[1] | ECC register, bits 0 to 4 (SEG0 to SEG4) | Current position of the bit stream processor: 2: ID.28 to ID.21 3: Start of frame 4: Bit SRTR 5: Bit IDE 6: ID.20 to ID.18 7: ID.17 to ID.13 8: CRC Sequence 9: Reserved Bit 0 10: Data Field 11: Data Length Code 12: Bit RTR 13: Reserved Bit 1 14: ID.4 to ID.0 15: ID.12 to ID.5 17: Active Error Flag 18: Intermission 19: Tolerate Dominant Bits 23: Error Delimiter 24: CRC Delimiter 25: Acknowledge Slot 26: End of Frame 27: Acknowledge Limiter 28: Overload Flag |
DATA[2] | RX Error Counter Register (RXERR) | Current value of the receive error counter |
DATA[3] | TX Error Counter Register (TXERR) | Current value of the transmit error counter |
Remarks
For further information about this, see Philips Data Sheet SJA1000 Stand-alone CAN controller.