Unexplained intermittent CAN / 2CAN Jaguar problems at GSR

[John Heden]

I would like to thank everybody for their thoughts on our CAN issue and all the suggestions you have offered. Our team crafted a custom dashboard that saves all of our data to disk including any UDP NetConsole data that it happens to catch and I’ve started to work way through this information looking for possible clues. Our freeze in our first quarter final match did yield some interesting results that I’m still trying to fully understand but certainly looks like a complete loss of CAN integrity through some mechanism. The following is part of the recorded error sequence (it goes on quite a bit longer) that shows a total of 16 InitCANJaguar() calls. The only call I can find to InitCANJaguar, however, is in the constructor for CANJaguar() so I a bit perplexed at this point given we have only 5 CANJaguars. After this initialization like sequence there is a litany of getTransaction() errors before we eventually do a reset and regain control.

At this point I’m partial to the startup race condition theory of some type. I would also add that we do launch a status monitoring thread that does read information from CANJaguar at the end of our robot constructor well before the autonomous loop is initiated. This seems to work but I wonder if the 2CAN occasionally needs a bit more time to settle down before it is called upon for status and CAN transactions…

Thanks again,

John

Code>-44087 ERROR: status == -44087 (0xFFFF53C9) in getTransaction() in C:/windriver/workspace/WPILib/CANJaguar.cpp at line 425

<Code>-63194 ERROR: status == -63194 (0xFFFF0926) in InitCANJaguar() in C:/windriver/workspace/WPILib/CANJaguar.cpp at line 47

<Code>-44087 ERROR: status == -44087 (0xFFFF53C9) in getTransaction() in C:/windriver/workspace/WPILib/CANJaguar.cpp at line 425

<Code>-63194 ERROR: status == -63194 (0xFFFF0926) in InitCANJaguar() in C:/windriver/workspace/WPILib/CANJaguar.cpp at line 47

<Code>-44087 ERROR: status == -44087 (0xFFFF53C9) in getTransaction() in C:/windriver/workspace/WPILib/CANJaguar.cpp at line 425

<Code>-44087 ERROR: status == -44087 (0xFFFF53C9) in setTransaction() in C:/windriver/workspace/WPILib/CANJaguar.cpp at line 392

<Code>-44087 ERROR: status == -44087 (0xFFFF53C9) in setTransaction() in C:/windriver/workspace/WPILib/CANJaguar.cpp at line 392

<Code>-44087 ERROR: status == -44087 (0xFFFF53C9) in getTransaction() in C:/windriver/workspace/WPILib/CANJaguar.cpp at line 425

<Code>-63194 ERROR: status == -63194 (0xFFFF0926) in InitCANJaguar() in C:/windriver/workspace/WPILib/CANJaguar.cpp at line 47Etc. etc. etc...