CANOpen TPDO5 cob-id

  • chab

    chab - 2011-11-30

    I use the CAN_Local_Device (CANOpen slave).
    PDO1 to 4 use the "pre-defined connection set".
    When adding the 5th PDO, I noticed that the cob-id equals 0x681. WITHOUT the $NODEID part as with PDO1-4.
    Other CANOpen devices use "$NODEID+0x180 + 0x40" often.

    Is it possible to make the "Generic cob-id" depend on the $NODEID. (So the "Settings cob-id" is has a good value, when multiple devices are used. And not both 0x681.)

    A second remark:
    The "Generic cob-id" is fixed and cannot be changed! (The "Settings cob-id" can be changed of course. But that is extra work.)
    It would be really nice if the "Generic cob-id" is user changeable. So an own "cob-id algorithm" can be used.


    IMG: CoDeSys_PDO5_cob

  • timvh

    timvh - 2011-11-30

    This is CANOpen related. You cannot freely use COB IDs for PDO's.
    CANOpen defines only 4 PDO's for sending and 4 PDO's for receiving (each node).
    Cob id 681 is not pre-defined and therefore you might be able to use it, but I doubt your CAN node accepts this.

  • chab

    chab - 2011-12-13

    The Cob id 681 is CoDeSys' standard value for PDO5.
    (0x681 is the free range after the SDO area.)


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