I have a spacecraft which has a docking port with a cover over top it. How I do this is I attach my docking port to my command pod, then I temporally move the port out of the way to attach the piston to the command pod as well. Once the piston is connected, I then connect the port cover onto the piston itself, then move the docking port back into it's original position. The result is a hidden docking port that I can easily access by removing the cover. At the moment, I can only remove the cover by using the slider. What I would like to do is configure the piston's settings so that it responds strictly by activation group 2. I know there's a way to pull it off, but I'm not sure how exactly. I'm hoping somebody can explain it for me.