How to activate Slider with ag and retract it

@DUNIAN Yup, that's the way to do it with Vizzy. I would suggest using a while loop with no condition instead of the repeat loop which will only work a finite number of times. Also you can simplify your code using the "Zero on Deactivate" property in the Piston Input part properties settings (you have to enable "Show Hidden Properties" option in the tinker panel in order to see this).

Like This? @sflanker

You cannot change the value of the Slider 1 or Slider 2 inputs using an activation group without using Vizzy. If you want to use Vizzy you just have to wait until the activation group expression returns true, and then set the desired slider input. However, if you don't want to use Vizzy, there are ways to use activation groups to articulate moving parts. The easies thing to do is to set the Input value for your input controller to fixed number between -1 and 1, and then set the part's activation group to the one you want to use. If you enable hidden properties in the tinker panel you can also toggle whether the part goes back to its default position when the AG is deactivated or not. There's lots more fancy stuff you can do with input controllers, so in reality you probably won't need Vizzy.