Periodic Task (vi) - Thoughts?

[Ether]

Originally Posted by Greg McKaskle

Doug Norman and I will be giving a presentation in St Louis which covers this in a bit more detail. I'm assuming the slides will be available afterwards.

Thank you Greg. I think there's a real need for this information, especially for teams with no mentors who have experience with realtime control.

[cabbagekid2]

Thanks Greg. I look forward to your presentation. Do you know what the topic of the other tbd NI presentation is?

[Greg McKaskle]

The title is something like -- Making the Most of LabVIEW for FRC : Performance, Debugging, and Architecture.

The performance section covers the performance goals of the different VIs, shows different measurements you can make to determine if you meet those goals, and if not, why not.

Debugging covers understanding errors, determining where they come from, why they are being reported, and what to try to get them to stop.

Architecture covers determining where to put different code elements, and how to coordinate them.

And of course, if you ask other questions, we'll try to answer them. Doug and I will also be in the NI booth in some form of Genius Bar. We'll have computers and robot, so you can drop by and we'll do our best to answer whatever questions you may have.

Greg McKaskle

[Richard100]

Greg - Does this apply to Autonomous as well? Should a while loop in autonomous (say, iterating while waiting for a drive encoder to reach a certain distance) - be moved to periodic tasks? Is there any difference in a loop running within periodic tasks and one running in autonomous?

We're getting performance issues (drive motors stop intermittently) while running this autonomous and the concurrent vision processing loop. We have a 50 ms delay in the autonomous loop and 20 ms delay in the vision loop.

[Greg McKaskle]

The only thing special about the autonomous VI is that it is dynamically launched and aborted after the autonomous is over. If you would like to distribute some of the processing into other loops, that is fine. The parallel loops can be in periodic.vi or even in the autonomous.

Another thing to consider is whether you would like to use the exact same periodic loop code for a mechanism. Use it during tele and during auto. This should allow for more consistent control.

Greg McKaskle