How to scan CAN bus to detect available nodes

[hvazquez]

Hello Forum, I have a VI to communicate with multiple CAN based modules using an IXXAT device. At present I have to provide the number of nodes (CAN devices) that I want to control. Question, instead of providing the number of nodes, how can I scan for available node IDs in the CAN bus?

Thanks!

[Sam_Sharp]

How do you know if the node is on the CAN bus? You should be able to read the frames from the CAN network and get the Message ID/data - it would be quite easy to build up an array/lookup table of the Message IDs that are present on the bus and use that to determine what nodes are there?

I haven't used IXXAT devices...so without you posting your VI and more detail, I can't really offer much more assistance.

[nathand]

If your devices are strictly CAN (and not some higher-level protocol on to of that such as CANOpen) then no, this isn't possible. Nodes on a CAN network don't have a single ID assigned to them, any node is allowed to send a message with any ID. If all your devices are using some higher-level protocol then you'll have to see if it supports a device search. The fact that you are using an IXXAT device is in this case irrelevant.

[Bonged]

out of several nodes, how would u identify which node has what canID

[nathand]

You cannot. CAN doesn't work that way. Nodes on a CAN network do not have unique IDs; any device can send a message with any ID. It's up to the higher-level protocol to determine how those IDs are used.