Your still going to need some type of timer. I use animation maestros to control nearly all my pneumatics. Even if all you need it to do is extend the cylinder once and then retract it you still need the delay before the prop can reset and be ready to trigger again. The animation maestro allows you to program a delay right after the animation.
The animation maestros are pretty resonable for all that they can do. And there is still the option to have multiple animations where with a simple timer, all you can do is turn an effect on and the turn it off.
Animation Maestro 1