Tracking down a stuttering JAG/CAM drive.

[PhilBot]

I continue to try to get my drive working with encoders/Cam etc.

I currently have a problem in that my drives Stutter as I drive.

By this I mean that when they should be driving smoothly they seem to freeze momentarily on a semi regular basis... eg once a second.

To track this down, I dropped back to a raw Robot Project (LabVIEW) and just switched the Open Drive to a CAN version with ID's 11 and 12 (to match my Jags).

Result.... it rans a smooth as a baby's.... you get the idea.

So I slowly started stripping code out of my own app untill the stutter went away (boy I wish I undserstod the safety code)

Bottom line is very interesting. When I took out the Compressor code, my drive went smooth.

I have replicated the problem with the Basic Robot code. If I open a compressor VI in Begin (and save the ref nin a global) and then in Teleop I just do two calls.... one to read the Compressor status, and one to Stop the Compressor (normally used in response to a compressor on/off switch on the DS)

With these two VIs called once per teleop cycle, my motors go back to stuttering once a second.

How is it possible for these two simple calls to cause this problem? I've attached my simplified test code. Only chanages are to Begin and Teleop.