Compare senor level input to setpoint and automatically adjust gate motor to keep output at set point.

[Paul B]

Customer has input from remote senor via radio rtu, they want to enter a setpoint then compare it to existing flow rate, then automatically set gate motor to achieve flow rate. Gate motor is controlled by digital output. I need to update or change level after each poll to maintain this level. any suggestions or sample expressions? PID loop will not work with no analog output available.

[Khalid]

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Hello Paul,

Can you give some more details of the issue.. If your motor is controlled by a digital output, you'll have to basically implement an ON/OFF controller. Am I right in understanding this?

Do you want this control scheme to be more sophisticated and turn On/Off the motor for a computed amount of time only? How often do you poll the RTU and get the current reading?

Rgds,

Khalid


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[Paul B]

Thanks for the input, I need for the operator to enter a setpoint in Cubic feet per second and this will regulate a gate to keep flow within a certain tolerance,also it needs to raise or lower gate according to setting, ie. current flow from sensor is 300CFS and need to go to 350cfs, the gate must lower to produce 50cfs more to match set point and same other way to raise and decrease flow.I know this would be next to impossible because of the polling cycle, which will probably be about every 15 minutes. Thanks for any help Paul B