Wiring a limit switch.

[mtnteam]

Originally Posted by Jon Stratis

You have two options with limit switches:

1. Wire it into a Digital Input on the Digital Sidecar. This allows your software to read it and take appropriate action (such as turning off the motor). Doing this, you only need to wire it to signal and ground (there's an internal pull-up resistor on the digital inputs).

2. Wire it into a Jaguar that is using CAN (per R61, nothing else can be attached to a Jaguar using PWM except for the coast/break port). For these, there are 4 pins - two control forward direction, two reverse. There are jumpers in there when its shipped. If you go this route, make sure you wire the limit switch so it's "Normally Closed" - in other words, you should be able to measure 0 (or near 0) resistance when the switch is NOT being pressed, and infinite resistance when it is. That way, the Jaguar will automatically stop when the switch is pressed.


Regardless of which way to wire it up, make sure you add some sort of mechanical stop to ensure the arm won't go past the limit switch. Even with it turning off as soon as the switch is pressed, often an arm will continue moving a bit before it fully stops - a mechanical stop will prevent this.

So in order to wire the limit switch to the Digital I/O who wire it to a PWM cable to only the signal and GND?