Run FRC pneumatics with VEX Cortex

[superbotman]

I have been taking some of my team's old robots that we removed the C-Rio from and hooked them up to VEX Cortex microcontrollers. Although I was able to get the motors running easily, I am uncertain how to run the pneumatics electrical wiring (if it is possible). The vex pneumatics uses three pins, but the FRC solenoids have only two. Does anyone know how to wire them?
Thanks.