SNK
Member
People,
I have used the PID function previously in AB applications, but this is the first for the ML1200 Series. I need help in interfacing the PID to a DISCRETE OUTPUT signal, RATHER than the traditional Analog output.....if possible.
Here is the application....
I need to meet a specific setpoint set in the program. (lets say 20 PSI) I have a validated range (say for ex. +/- 5 PSI) which would make the limits 15 and 25 respectively. I am using an analog transducer to read the value into the analog input card, and moving the data to an integer.
In this application, I am drawing a vacuum....
I have a motor/pump combo, and some solenoid valves.
The problem is that I don't have an analog output device (IE motor or porportioning valve) to control the output to the vacuum motor, so the vacuum will always be on. If the vacuum gets too high, I need to keep the analog value in the correct range.
I first thought the best way to do this is to cycle the solenoid valve that is connected to the vacuum tube.....(as the output of the PID).
Has anyone ever used a DO on the output of the PID loop successfully?
Any help would be appreciated.
I have used the PID function previously in AB applications, but this is the first for the ML1200 Series. I need help in interfacing the PID to a DISCRETE OUTPUT signal, RATHER than the traditional Analog output.....if possible.
Here is the application....
I need to meet a specific setpoint set in the program. (lets say 20 PSI) I have a validated range (say for ex. +/- 5 PSI) which would make the limits 15 and 25 respectively. I am using an analog transducer to read the value into the analog input card, and moving the data to an integer.
In this application, I am drawing a vacuum....
I have a motor/pump combo, and some solenoid valves.
The problem is that I don't have an analog output device (IE motor or porportioning valve) to control the output to the vacuum motor, so the vacuum will always be on. If the vacuum gets too high, I need to keep the analog value in the correct range.
I first thought the best way to do this is to cycle the solenoid valve that is connected to the vacuum tube.....(as the output of the PID).
Has anyone ever used a DO on the output of the PID loop successfully?
Any help would be appreciated.