Andrés_Ariza_From-Colombia

Hello Dear Experts,

I'm working in a temperature control, I'm using a 1200 CPU DC-DC-DC, a RTD module, the process have six PT100 and six valves, through the valves hot oil flows ,

I have a problem with the valves functionality, because I don't know, how Do I use the PID with them?,

Basically the valves having a motor with a screw conveyor, so if, I feed the line voltage in one direction, motor turns clockwise until end switch is activated, and so if, I feed the line voltage in the opposite direction, motor turns anti clockwise until end switch is activated,

The screw move the mechanism, this mechanism opens and closes the valve,

I need configure the PID system,the motor rotates in one direction, the motor is activates with digital output, for example Q0.0, when the temperature set point is surpassed, the motor should rotates in the opposite direction, the motor should be activated with digital output, for example Q0.1 (different at the first) and the valve is closed a little and then temperature is lowered.

How I can use two digital outputs for control direction of rotation in a PID?

Thank you so much, for you attention and your collaboration,

I will be grateful if you help me...