[x-post from Control System] We are having problems with lab =views.

Technical NI LabVIEW
#1

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.

#2

I would definitely check your termination resistors. When flashing firmware and assigning ID’s this year, we noticed something interesting. Every device was fine when adding them in one by one. When adding the ninth, however, CAN errors started popping up everywhere. Someone then realized the resistor wasn’t in all the way, and they instantly disappeared. This could amount to the lag you see.

#3