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Unread 23-04-2012, 10:46
mjcoss mjcoss is offline
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Re: URGENT: CAN Jag error code 1 - dequeue element in acquire semaphore

Quote:
Originally Posted by legogeek24 View Post
Hey all,
...
I get this:
"error code 1:
Dequeue element in acquire semaphore.vi:1->WPI_CAJaguar_SetTransaction.vi:28->WPI_MotorControlSetOutput.vi:9->Periodic Tasks.vi->Robot Main."
Note: Labview isn't my forte but ...
The error message to me implies that your code is accessing something that wasn't properly initialized, probably the CANJaguar controller. I'll take a quick look at the WPI_CANJaguar_SetTransaction vi and see if I can get a sense of what could have gone wrong. The CAN bus uses messages to update the Jaguars. The message are queued and dequeued and I suspect a semaphore is used to protect access to the queue.

Took a quick look at the vi, and it was as I suspected, it tries to acquire the semaphore, and then sends the command. The semaphore is part of the CANJaguar reference that is passed in. I would suspect that the CANJaguar reference is bad in some way. Without seeing the project that fails, I'm not sure what else to tell you.

Last edited by mjcoss : 23-04-2012 at 13:29. Reason: Updated
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