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Unread 10-04-2013, 16:32
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AKA: Andrew Palardy (Most people call me Palardy)
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Re: Talons, Jaguars and Victors - where do you stand?

The update rate really doesn't matter if you are running code slower than the update rate you are running (e.g. we run our code at the relatively fast rate of 10ms/iteration, so the standard Victor update rate of 10.1ms vs a Jaguar or Talon at 5.05ms would make no difference)

I also played with (psudo-accidentally) updating the Victor 884's at 5.05ms and it worked fine. The new 888's appear to be spec'd down to 2.1ms cycle time (with a max pulse width of 2ms) but using a cycle time that isn't a multiple of 5.05ms requires some additional timing calculations (it's not hard, if I were to try to run my code at 7ms and update the PWMs at 3.5ms it would be possible).

BUT since the code still calculates the pulse width at 10ms the update frequency doesn't matter at all below that. In fact, the default code updates at somewhere around 20ms in the main loop in LabVIEW (not exactly sure, it's not timed well) so the 10.1ms vs 5.05ms update rate wouldn't affect anything.

We ran Talons on our test chassis in late December without fans and were so happy we ran them on all of our 2013 motors (there are 11 on our robot) without any fans.


Edit: I see absolutely no reasons to use a Jaguar in FRC. The reliability history is poor (in my time on 33 we've blown ~3x more Jaguars than Victors, yet used ~6x more Victors on robots), although the changes by IFI should help that, the CAN implementation is poor (synchronous blocking) and increases single point failures, and they're freaking huge.
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Last edited by apalrd : 10-04-2013 at 16:35. Reason: Jaguars