nastybitofcode
Member
Opening post
Greetings All J
Its been a while since I have been on. Someone hacked my email account and was able to create some serious havoc on me. I had to create a new user on the forum because of it. Never the less I have still been reading all the great informative post, but now it is time to post my own.
I currently have a waste treatment project that I am working on. It was kind of shoved my way if you will, in the name of trying to save money. This is my first project working with PID loops and I have to say it’s kicking me around. I have read many posts, on this forum from a lot of the experts here but still I am having issues. I think I need some help at this point. I have worked with analog for speed references and valve positioning but I have never programmed a PID before.
I am going to try and supply all the information required so that you may have a good picture. Also more importantly maybe I can leave something behind here for the next guy to find and it may help his journey too.
PROCESS DESCRIPTION
1. Intent of control system is to limit the influent flow of industrial waste (IW) from the equalization (EQ) tank to the Dissolved Air Flotation (DAF) tank to 25 gpm but if the EQ tank becomes full override the control valve to a full open position.
2. Influent Sump Pump from the factory is operated by an on/off level float( high and low floats) with an internal dead-band to prevent short cycling.
3. On rising level on the Influent Sump Pump, the Influent Sump Pump turns on and fills the EQ tank. At the same time the Feed Pump from the EQ Tank turns on and feeds the waste to the DAF through the Flow Control Valve.
4. As IW flows to the DAF, the magnetic flow meter controls the modulating control valve to a set-point of 25 gpm. On rising level in the EQ tank , FIC-101 will increasingly close the control valve to limit the flow. On falling level, FIC-101 will increasingly open the control valve to maintain the set-point flow.
5. If the EQ tank becomes totally full, the control loop between FIT-101 and FIC-101 will be overridden and the modulating control valve will be fully opened to prevent overflow/damage to the EQ tank. EQ Tank level is read by ultrasonic transmitter.
I know the above description will raise some questions J
Devices:
PLC
1. 1762-L40BWAR MicroLogix 1200
2. 1762-OF4 4 Channel Current/Voltage Analog Output Module
3. 1762-IF4 4 Channel Current/Voltage Analog Input Module
Analog
1. LVU832 Ultrasonic Level Transmitter 4-20mA
2. Siemens Magflo Meter MAG5000
3. Triac Electric Actuator WE series 4-20mA in and out
I am trying to run my pid off the 4-20mA that I receive from the flow meter. I currently have the analog input configured for scaled for pid. I also have the output for the valve configured the same. I thought that since I was not trying to totalize. This would not be to terribly bad. But I have a ton of questions at this point. Things related to scaling, filters, etc.
If anyone has time and your bored. I would like the educationJ
Greetings All J
Its been a while since I have been on. Someone hacked my email account and was able to create some serious havoc on me. I had to create a new user on the forum because of it. Never the less I have still been reading all the great informative post, but now it is time to post my own.
I currently have a waste treatment project that I am working on. It was kind of shoved my way if you will, in the name of trying to save money. This is my first project working with PID loops and I have to say it’s kicking me around. I have read many posts, on this forum from a lot of the experts here but still I am having issues. I think I need some help at this point. I have worked with analog for speed references and valve positioning but I have never programmed a PID before.
I am going to try and supply all the information required so that you may have a good picture. Also more importantly maybe I can leave something behind here for the next guy to find and it may help his journey too.
PROCESS DESCRIPTION
1. Intent of control system is to limit the influent flow of industrial waste (IW) from the equalization (EQ) tank to the Dissolved Air Flotation (DAF) tank to 25 gpm but if the EQ tank becomes full override the control valve to a full open position.
2. Influent Sump Pump from the factory is operated by an on/off level float( high and low floats) with an internal dead-band to prevent short cycling.
3. On rising level on the Influent Sump Pump, the Influent Sump Pump turns on and fills the EQ tank. At the same time the Feed Pump from the EQ Tank turns on and feeds the waste to the DAF through the Flow Control Valve.
4. As IW flows to the DAF, the magnetic flow meter controls the modulating control valve to a set-point of 25 gpm. On rising level in the EQ tank , FIC-101 will increasingly close the control valve to limit the flow. On falling level, FIC-101 will increasingly open the control valve to maintain the set-point flow.
5. If the EQ tank becomes totally full, the control loop between FIT-101 and FIC-101 will be overridden and the modulating control valve will be fully opened to prevent overflow/damage to the EQ tank. EQ Tank level is read by ultrasonic transmitter.
I know the above description will raise some questions J
Devices:
PLC
1. 1762-L40BWAR MicroLogix 1200
2. 1762-OF4 4 Channel Current/Voltage Analog Output Module
3. 1762-IF4 4 Channel Current/Voltage Analog Input Module
Analog
1. LVU832 Ultrasonic Level Transmitter 4-20mA
2. Siemens Magflo Meter MAG5000
3. Triac Electric Actuator WE series 4-20mA in and out
I am trying to run my pid off the 4-20mA that I receive from the flow meter. I currently have the analog input configured for scaled for pid. I also have the output for the valve configured the same. I thought that since I was not trying to totalize. This would not be to terribly bad. But I have a ton of questions at this point. Things related to scaling, filters, etc.
If anyone has time and your bored. I would like the educationJ