AnsweredAssumed Answered

Any reason not to use CAN identifier as node ID?

Question asked by f-stop on Jul 31, 2017
Latest reply on Jul 31, 2017 by f-stop

Preamble for the uninitiated:

CAN identifiers are usually associated/related with/to the content of the message rather than as an identification mechanism for a specific participant on the bus.


The question therefore:

In an automation environment with approximately 30 CAN bus nodes, would there be any reason NOT to use the 11-bit identifier as a node ID and set up filter masks on the F0 bxCAN peripheral to pass to FIFO only that node ID with RTR set?


The design features a CAN/ethernet gateway that relays requests from a monitoring system to CAN nodes. The gateway always requests data from a specific node with RTR set and the node always responds without.


If the CAN id is used as a node id, the higher order bytes of the payload can be used for an instruction/request and the lower order bytes for parameters/data.


The parameter/data is always less than 2 bytes all the permutations of varying requests can be done in 2 bytes, so payload length is not an issue.


Any thoughts from the more experienced?