0

I decided to connect my can device using serial port. I want to know could I use multiple salves with only one object dictionary in master at the same time or I have to use an object dictionary for each of them in master?

I'll be grateful for your responses.

samini
  • 195
  • 11

1 Answers1

2

Strictly speaking, each node on a CANopen network will have its own Object Dictionary, in order to be compliant with the standard. But sometimes it is not feasible to implement a full-blown CANopen stack for each node, in which case it is common to implement non-compliant slaves that only have the bare minimum of functionality. See this.

As for master/slave, please note that CANopen is a de-centralized protocol and master/slave has nothing to do with data transmission, nor with the presence of an Object Dictionary. A NMT (network management) master in CANopen is simply a node with the task of supervising other nodes. It sends the NMT start remote node message to put other nodes in operational, and it acts as Heartbeat consumer etc.

Lundin
  • 195,001
  • 40
  • 254
  • 396
  • I am a bit confused. I know that I should use an object dictionary for each slave node . but in master node, I don't know if I can use one dictionary for all slaves! – samini Mar 12 '18 at 08:39
  • 1
    @samini The master has its own OD, and every slave has its own. That's it. Not quite sure what you are asking, if you can use the same PDO mapping or COBID for all slaves? – Lundin Mar 12 '18 at 11:49
  • just SDO and PDO mapping should be added according to address of data in master and slaves – samini Jul 23 '18 at 11:29