NI XNET J1939 Network Management messages

[Cabman]

I've written an Active-X server to send and receive messages use NI-XNET USB-8502. All is working fine, except my UUT sends out an address claim message using PGN 0xEE00 on power up which is not captured by the software.  According to http://www.ni.com/example/31215/en/#toc4 this is a special message (Network Management) and therefore handled differently.

I also noticed the NI-XNET Bus Monitor application also filters out this message in J1939 mode. In CAN mode; it is displayed.

My software is using "Frame In/Out Streams". Is there any way to display the 'special messages'?

LabVIEW 2013

NI-XNET 16.1

[TyVo]

Hey Cabman,

To see these messages, you will need a non-J1939 stream. See this documentation: http://zone.ni.com/reference/en-XX/help/372841P-01/nixnet/addressclaimingprocedure/

-TyVo 

[Cabman]

The article referenced is talking about the NI-XNET claiming procedure. I don't need to monitor that.

What I want to see is the address claim message from the unit I am testing. Since this is a valid J1939 message shouldn't I be able to observe it in software designed to test the functionality of a unit? My current tool shows the message, but I want to use the dual channel functionality of the USB-8502.

[TyVo]

Hi Cabman,

XNET's implementation of the J1939 Address Claiming procedure does not pass the frames to J1939 Input Sessions. 

"The frames transmitted during address claiming are not passed to the J1939 input session. To see those frames, open a non-J1939 CAN session, which can be running parallel with a J1939 session on the same interface." 

When a J1939 input session is running and the interface sees a valid Address Claim message it does not make that message available as an output of XNET Read for that Session because XNET knows to respond with the Address Claiming procedure and assumes the User does not want to see this message as part of their data transfer. This is not true for CAN input sessions which do not know that it is a J1939 Address Claim and will output the special message when XNET read is called on the CAN input session.

There is no functionality within the XNET driver for a J1939 input session to make the Address claim messages available to the user from XNET Read. The workaround is to use a CAN input session which does not recognize the message as an Address Claim because the CAN session thinks its base CAN and not J1939. 

If this is still unclear, let me know. You should still be able to do exactly what you want. You just run a CAN input stream in parallel on the same interface as your J1939 input stream. Calling XNET read on the CAN input stream should return the Address Claim message that is being sent by your device.

[Cabman]

I understand but did not implement. Noted for future use, thanks.