B
I am doing a project where I have a steady water flow that changes no more than 200,000 gallons a day. There is a clorine analyzer that I am controlling with a 3705 Tele PLC using PL7 software. The specs are 0 to 10mgd of water flow and 0 to 10 mg/L of clorine. I get a 4-20 mA signal input from the flow transmitter and I put out a 4-20 mA signal to control the pump. I have written PID loop using the water flow and another using the clorine flow as the process varible but they will not pay for a start up I can not be there to tune the loop. So the analog output wanders and never settles as I would suspect since there is very little change in water flow. I want to rewrite the program not using a PID loop. I want to do a 1 to 1 ratio proportional program that would look at the water flow and adjust the analog out set point to match the rise or fall of water flow. At this time 3mg/l is where they want it to track but I have it adjustable from 0 to 10 mg/l just incase they need to add more of less. Has anyone written a program simular to this? Can anyone help?