pcmcia-CAN/2 no ack

[glstill]

Hi,

I am working with a NI PCMCIA CAN/2 Series 2 Card.  I have an application which sends commands to a Freescale microcontroller and receives responses using the Frame API. The card will sucessfully send the message every time I instruct it to, however after getting a few valid responses, the card no longer acknowledges the next received frame which forces the microcontroller to transmit the same message over and over again. The message that is not getting acknowledged has the valid arbitration ID and valid data.

I am verifying all CAN traffic using Intronix Logic Port Logic Analyzer.  I am almost certain it has nothing to do with the way the Labview application is written because this is also occurring with some of the CAN examples.

I am not sure who to contact at NI, because the FAE in our area is not very helpful.  I have a PCI and another PCMCIA card being shipped here next week, but I would like to figure out why the card I have is doing this.

Thanks,

Gary

[DirkW]

Not many FSE's are so familiar with CAN Bus to answer this kind of question. But you could call your branch support and they would certainly love to help you out.

Make sure all connected devices are having the same kind of transceiver. (High speed, Low Speed or Single Wire). Additionally based on your transceiver type make sure the cabling is terminated correctly. For High Speed for example both ends of the cable should be terminated with 120 ohm resistors.

Hope that helps.

DirkW

Message Edited by DirkW on 09-08-2008 09:05 AM