Micro Switch Limit?
 

Can we hard wire the limit switch in our design or does it need to go through a PWM?

Re: Micro Switch Limit?
 

I believe the limit switch must be through PWM since the current motor controllers push to motors would burn the switch out. You may be able to find switched rated for a significant amount of amps but you probably won't pass inspection unless you route through PWM

Re: Micro Switch Limit?
 

I suggest that you take a pretty good look at R71. Limit switches are considered to be custom circuits.

If by "hard wire" you mean running power through it, and using it to turn power on and off when tripped and not tripped, I would say that technically that's impractical.

Re: Micro Switch Limit?
 

I would recommend wiring the limit switches to the DIO on the sidecar and program the function that you desire.

Re: Micro Switch Limit?
 

PWM is out put only. It is also illegal to wire it in series with a motor. The two legal implementations include using either the DIO or the Analog breakout, I would recommend DIO.

Re: Micro Switch Limit?
 

The rules say that you MUST use the cRio to control anything. So a switch to supply & remove power to (something) is not allowed.

Use a Digital I/O on the Digital Sidecar to signal the cRio that the switch is tripped, and then use (somehting, maybe a PWM or a Relay) to make whatever it is, happen.

Re: Micro Switch Limit?
 

jdh,
I hope what you have gathered from the above posts is that only approved motor controllers (Victors, Jaguars, Talons, or Spikes) may be used to control motors. If you are using Jaguars, you may wire limit switches to the limit inputs on the Jaguar. Most people (as above) will recommend you wire a limit switch to a DIO on the digital sidecar and have it implement in software. This allows you to also pass the switch state to your driver's station if you want. It is also recommended that an electrical limit be backed up with a mechanical stop if the parts that move should be capable of exceeding the perimeter limit of the Frame + 20 inches.