| FC510x - PCI Cards for CANopen |
Identifier distribution
Default identifier
CANopen provides default identifiers for the most important communication objects, and these are derived from the 7-bit node address (the node ID) and a 4-bit function code in accordance with the following scheme:
For broadcast objects the node ID is set to 0. This gives rise to the following default identifiers:
Broadcast objects
Object | Function | Function code | resulting COB ID hex / dec | Object for comm. Parameter / mapping |
|---|---|---|---|---|
NMT | Boot-Up | 0 | 0x00 / 0 | - / - |
SYNC | Synchronization | 1 | 0x80 / 128 | 0x1005 + 0x1006 / - |
Peer-to-peer objects
Object | Function with I/O devices | Function code | resulting COB ID hex / dec | Object for comm. Parameter / mapping |
|---|---|---|---|---|
Emergency | Status / error | 1 | 0x81 - 0xFF/ 129 - 255 | - / - |
PDO1 (tx) | dig. inputs | 11 | 0x181 - 0x1FF / 385 - 511 | 0x1800 / 0x1A00 |
PDO1 (rx) | digital outputs | 100 | 0x201 - 0x27F/ 513-639 | 0x1400 / 0x1600 |
PDO2 (tx) | analog inputs | 101 | 0x281 - 0x2FF/ 641-767 | 0x1801 / 0x1A01 |
PDO2 (rx) | analog outputs | 110 | 0x301 - 0x37F/ 769-895 | 0x1401 / 0x1601 |
PDO3 (tx) | analog inputs* | 111 | 0x381 - 0x3FF / 897 - 1023 | 0x1802 / 0x1A02 |
PDO3 (rx) | analog outputs* | 1000 | 0x401 - 0x47F/ 1025 - 1151 | 0x1402 / 0x1602 |
PDO4 (tx) | analog inputs* | 1001 | 0x481 - 0x4FF/ 1153 - 1279 | 0x1803 / 0x1A03 |
PDO4 (rx) | analog outputs* | 1010 | 0x501 - 0x57F/ 1281 - 1407 | 0x1403 / 0x1603 |
SDO (tx) | Parameter | 1011 | 0x581 - 0x5FF/ 1409-1535 | - / - |
SDO (rx) | Parameter | 1100 | 0x601 - 0x67F/ 1537-1663 | - / - |
Guarding | Life/node guarding, Heartbeat, Boot-up message | 1110 | 0x701 - 0x77F/ 1793-1919 | (0x100C, 0x100D, 0x100E, 0x1016, 0x1017) |
* For historical reasons, the Beckhoff default mapping applies to PDOs 3 and 4 in Beckhoff I/O devices. In most configurations, PDOs 3+4 contain data related to analog inputs and outputs, but there can also be "excess" data from digital I/Os, or data from special terminals. Details may be found in the Bus Coupler documentation.
Up until version 3 of the CANopen specification, default identifiers were assigned to 2 PDOs at a time. The Beckhoff Bus Couplers up to firmware status BA correspond to this issue of the specification. After firmware version C0 (CANopen version 4), default identifiers are provided for up to 4 PDOs.