epos pdo read on RT system

[mschoenwald]

I am trying to get the PDO to work on a PXI-RT system. I have tried all the examples that I can find and have not had any luck. The SDO communications is not a problem.

I Start my vi and there are not errors, but never receives any data from the controller. Does anyone have an example that works with the EPOS and RT?

Any help would be great.

[AndreasStark]

Hi mschoenwald,

did you set your device into operational mode using NMT commands? PDO communication is only available if the CANopen device is in operational state whereas SDO communication is also available in pre-operational.

Best Regards,

[mschoenwald]

Yes I use the module control vi and set it to start remote node. But it does respond like it is actully going into operational mode. Do you know what index and sub-index this is actually sending?

[AndreasStark]

The NMT commands use Arbitration ID 0, Datalength = 2. Start Remote nodes sends "1" in byte 0 and the Node ID of your CANopen device in byte 1.

Are you sure you set up the PDOs correctly in preoperational mode?

[mschoenwald]

Sorry for the delay, but we have the reads working now. we had the start listening vi in the wrong location. We are still having problems with the write though. The EPOS card just ignores all the PDO requests that we give it.

[AndreasStark]

Hi mschoenwald,

could you post some more details please:

- bus log

- epos spec

- your VI

Best Regards,

[mschoenwald]

Well we finally got it to work last night. The problem with the read was that you have to make a change of state on index 1400 subindex 1 bit 31. I will post the vi once we have it finalized and cleaned up. This might be a couple of days before I c an get to this.

[Vincent_R.]

Hi,

I've a similar application, could you, please, post the VI?

Regards

Vincent

[mschoenwald]

This Vi should work. It goes through and sets up both a SDO and PDO connection. Motor parameters are also set. I ran in to a limitation of setting up read and writes for the PDO at 16 motors. Hope this helps.