Problems with Labview, Unexplainable lag

[Retro Frost]

We are having massive issues with Labview and possibly CAN bus, however it isn't anything we can specifically identify.

We have a version of code deployed to run as startup which works flawlessly, but when we added one more jag (in code, it was already physically in the CAN bus) we started getting huge amounts of lag and jerkiness in any control. Including things not on the CAN bus.

We removed the offending code, and the problem persisted. We thought, and still think, that we are causing some sort of error cascade (handling one error takes long enough that it can cause a timeout error, which is handled, etc) but commenting out all the error handling helps only intermittently. (It worked once, and for a while afterwords, but then we had the errors again.)

Any help would be appreciated.

[Joe Ross]

Originally Posted by Retro Frost

We are having massive issues with Labview and possibly CAN bus, however it isn't anything we can specifically identify.

We have a version of code deployed to run as startup which works flawlessly, but when we added one more jag (in code, it was already physically in the CAN bus) we started getting huge amounts of lag and jerkiness in any control. Including things not on the CAN bus.

We removed the offending code, and the problem persisted. We thought, and still think, that we are causing some sort of error cascade (handling one error takes long enough that it can cause a timeout error, which is handled, etc) but commenting out all the error handling helps only intermittently. (It worked once, and for a while afterwords, but then we had the errors again.)

Yes, LabVIEW has trouble with cascading errors. Additionally, many of the CAN VIs block until a response is received. If it blocks in teleop, it can cause timeouts.

How many CAN messages are you sending per loop? The black jaguar serial bridge is very limited in how many it can handle. The 2CAN is much better.

Some VIs, like the set motor VIs have an isochronous option which causes them to send the command and not wait for a response. This is much better to use if you are setting a command every loop.

Have you asked for help from the CSA at your event?