(...) How about using a diode in each wire, (assuming single acting solenoid), then connecting both to one output. One opens when power is one direction, the other one opens on the other direction (reversed polarity). James P (25 years ago, 8-Feb-00, to lugnet.robotics)
(...) Aha, yes, that should do it. Essentially a reversing switch just like the Lego pneumatic valve. -- C S Soh (URL) where air is power (25 years ago, 9-Feb-00, to lugnet.robotics)