USB CAN 8473 goes crazy

[aworld]

Hi, guys, my CAN USB8473 goes crazy.

I use CVI  8.5  to communicate with USB 8473. The software done by using CVI works all right before, when i use another USB 8473.

However, now, when i just try to initialise the CAN0, i find that the USB CAN is keeping sending CAN frames, then i open the NI-Spy, there is no action observed in spy,which means my soft doesnt give the order to send messages, but the CAN port just keep sending messages(i use a very good scope to get the active can activity). When i call the function to reset the CAN, it stop sending frames, but after i try to send just another frame, it starts  sending frames endless which always goes with ACK error.

from what could i know if is my hardware problem? I dont want to believe the problem is my hardware, because it is a quite new USB 8473. 

What is wrong?

[DirkW]

Hi,

If you send a Frame and there is no receiver connected acknowledging the frame the can controller would transmit the frame over and over again until it becomes acknowledged or the driver closes the handle for the port. 

The re-transmit ishandled by the can controller onboard automatically and it doesn't require api call, thus it doesn't show up in NI-SPY.

But you should be able to stop this, by closing the handle.

DirkW