Sending a Message to channel on one arbitration id and then reading messages from channels on other arb id

[jgkempen]

Hi,
I need to send some configuration data to various channels  on one arbitration id and then after this recieve messages from several other channels with a different arbitration id and display the values for these channels in realtime.  Can anyone point me in the right direction to start?  The device will not send any info untill i send the config data so I guess that would be a good place to start.

[Robert M]

What development environment are you working in?  If LabVIEW, have you tried using one of the examples?  "Channel Monitor.vi" is a good one to start with.  What CAN hardware do you have?  Have you tested communication to your device in the Measurement & Automation Explorer test panels?

Hope this helps,

[jgkempen]

Im using Labview, but for some reason i don't think all the examples are installed on my computer because i don't recall a channel monitor and i remember reading that elsewhere in the forums.  Ill have to check that computer next time im in the lab. Im using a high speed can pci card.  I have tried max but i did not seem to get anything.  I think I am battling both connection and programming problems

Message Edited by jgkempen on 02-08-2006 09:36 AM

Message Edited by jgkempen on 02-08-2006 09:37 AM

[elmo]

First make sure you have the recent version of NI-CAN since if you dont upgrade, then you will be missing functions in LabVIEW and MAX.

I would first use MAX to see that you can read and write some CAN messages with a specific arbitration ID.  Check your settings such as baud rate etc.  Dont forget your 120ohm termination as this is a common cause of communication problems.

If that works then you need to decide whether to use Channel of Frame API functions.  You need to look at examples or read the NI-CAN manual to get started.

Sorry I cant give more help as I did this stuff quite a while ago and I dont look at it unless I really have to.

[jgkempen]

Does NI-CAN Version 2.3 download include Channel Monitor.vi? I recently reinstalled NI-CAN software but i cannot remember what version i had.  I don't recall seeing Channel Monitor.vi in when i was looking at examples, but i will download and install version 2.3 to be safe.  Will the channel monitor allow me to send some configuration data first to a few channels and monitor channels or will it only let me monitor channels.  What I am using this for is a radar from an active cruise control system.  In the active cruise control system a control module sends a signal to the radar unit to command a scan and then radar begins transmitting data.  I need to duplicate the command normally sent by the control module so I can get the radar to start transmitting data.

[elmo]

Im only using NI CAN 2.2 and LabVIEW 7.1 and i use the complete installation option.  You can check your software versions from MAX under "Software".

I have the example Channel Monitor.vi under the examples/NI CAN/Channel Advanced.llb.

I would make sure that everything works under MAX using bus monitor, then if you are confident that your CAN bus can send and receive messages, you can start developing your application.