toddp65
Member
Introduction: I'm tasked with created a rslogix program to communicate with a SCADA based PH monitoring and equalization project for our wastewater.
The contractor is doing the SCADA programming.
In the chemical pump dosing routine they're asking the following:
For the dosing pump repeat cycle timer the operator shall be able to enter a dosing time (TON preset variable) for open and one for closed. In the reaction repeat timer ON time is active, the dosing time shall be initiated and the air supply open and remain open until dosing time expires at which time the valve shall close. The closed time shall be based upon a "Lookup Table' such that when the difference between measured PH and PH set point is large, the valve closed time shall be shorter; when the diff between the measured PH and PH setpoint is small, the Valve closed time longer.
I'm confused with some of their thought process, especially with the Lookup table.
Thoughts?
TIA
The contractor is doing the SCADA programming.
In the chemical pump dosing routine they're asking the following:
For the dosing pump repeat cycle timer the operator shall be able to enter a dosing time (TON preset variable) for open and one for closed. In the reaction repeat timer ON time is active, the dosing time shall be initiated and the air supply open and remain open until dosing time expires at which time the valve shall close. The closed time shall be based upon a "Lookup Table' such that when the difference between measured PH and PH set point is large, the valve closed time shall be shorter; when the diff between the measured PH and PH setpoint is small, the Valve closed time longer.
I'm confused with some of their thought process, especially with the Lookup table.
Thoughts?
TIA