I have a motorized valve which controls the gas to a furnace. When I put 24V on one terminal it starts to open. When I remove the 24V the valve stays where it was. When I put 24V on the other terminal it starts to close. It has limit switches at the 'maximim open' and 'maximum closed' positions to prevent overtravel. It does not have any position feedback signal output.
How do I connect this valve to a PID temperature controller that has one 4-20mA analog output (I am not sure what the voltage is at the output)?