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Unread 09-05-2012, 15:40
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Re: TI and future Jaguars

Quote:
Originally Posted by Al Skierkiewicz View Post
Those are not First's limits. Those were chosen by the original manufacturer. The only FIRST limits are the safety issues of stopping all output when commended by the field. What are you calling "in-band field disable"?
For the purpose of the RFP/RFQ provided to manufacture the Jaguars essentially FIRST seems to have adopted those limits. Luckily that's only serving as a template at this point not an absolute. FIRST KOP did indicate they would be flexible about the current limit and that's great because I'm good letting currents flow up to 90As often even with the 40A breaker. I'd also love a nice latched visual indication that any current limit within the controller was exceeded for quick troubleshooting.

The CAN functions implement not only FIRST's protocol to check that the FRC firmware is present (BTW that's been totally hacked so it would be dead easy to slip some other firmware in there...we don't use Jaguars on Team 11 any more so I don't feel concerned pointing it out) and in effect implement the field disable in-band on the CAN bus. Not that anything would know if you hacked the Jaguar firmware anyhow if you used PWM.

PWM is not much of a bus so I don't consider the absence of signal in-band. That could happen sitting on a bench all by it's lonesome.

If we do make the 'custom circuit module' I suspect it'll just use a digital I/O as a global disable/enable, so that would be out-of-band disable.

Last edited by techhelpbb : 09-05-2012 at 15:44.
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