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Unread 06-02-2011, 12:56
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Re: CAN LabVIEW help

Quote:
Originally Posted by compwiztobe View Post
Is this how you would control multiple motors going into a single gearbox? It seems it would be a good way to avoid asyncronous PID loops on the different controllers, which may result in breaking stuff (unless your integral and derivative coefficients are zero, which seems kind of stupid)...

If so, is this all embedded in Robot Drive when started with the CAN Jaguar overload of Drive Open? How does it do all the sync group assignment? I see an Update Sync Group block in Tank Drive.vi, but it somehows picks the 8th sync group (b 10000000, x 80, d 128)... Which it looks like it also feeds to the Set Output blocks, which works, I guess?

Edit: oops, didn't see new posts before posting... Question still stands though, I suppose.
Yes, the Robot Drive uses sync group #8 (decimal 128).
You'll also notice those "set output" functions happen in PARALLEL, which takes advantage of the space between when the message is sent to the Jaguar, and when the Jaguar sends a response.

Sync group is not something that is "assigned" to the motor (though I suppose this could be done through a modified motor devref). Sync group is sent with each individual message.
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