Solenoids - quasics/quasics-frc-sw-2015 GitHub Wiki

A solenoid is a valve used to (electronically) turn a pressurized air line "on" or "off". They are controlled by the robot's Pneumatics Control Module (PCM), which is connected to the roboRIO via CAN.

A solenoid's state can usually be visually checked via a small red LED on the unit, and they can be manually actuated (triggered) when not under control by the RIO via the small button adjacent to the LED.

Solenoids come in two varieties: "single acting" and "double acting" (or just "single" and "double").

  • Single acting solenoids:
    • Use single output port to vent/apply pressure.
    • Are typically used either (a) when something else (a spring, gravity, etc.) will provide the force required to return the cylinder to its initial position or (b) in pairs to act as a double solenoid.
    • Are controlled in software using the Solenoid class.

Single Solenoid

  • Double solenoids:
    • Switch air flow between two output ports. (Many also have a center position where neither output is vented or connected to the input, allowing the cylinder to be held at a given place.)
    • Are commonly used when you wish to control both the extend and retract actions of a cylinder using air pressure (i.e., to move something "out" and "back").
    • Have two electrical inputs, which connect back to separate channels on the solenoid breakout.
    • Are controlled in software using the DoubleSolenoid class.

Double solenoid