[ksafin]

I love that thing. My team has the exact same one.

Each piston has a valve at the bottom and top. One that's filled with air, and one that's exhausted of it. Hook up each end to the two connectors on one of the solenoids. Then you hook up the actual solenoids with a connector to the bumper on the cRIO (from which you control the solenoids).

Lastly, this whole thing should be connected to your entire pneumatics circuit (featuring compressor, air tanks, pressure gauge, release valve).

So, essentially, what happens is, there's always pressured air accessible to the unit. Whenever one of these solenoids receives a signal from the cRIO to open up, one of the valves will open and allow the pressured air to enter the piston.

If the piston goes in reverse direction of what you expected (extend rather than retract), just change which valve the pneumatic tubing is leading into on the solenoid.