Hello,
I take part in commissioning of process station with lobe pump. Speed of the pump is controlled by PowerFlex 525. A customer requirement is to set a desired setpoint of flow for a pump. But there is no flow meter, there is only an encoder mounted on a shaft of a drive. Depending on a shaft gear ratio and pump efficiency (assumed that a dose per revolution is constant) I compute flow. To control this flow I want to use embeded PID control. Everything is cotrolled with PLC over Ethernet network so I set parameter A459 [PID 1 Ref Sel] to "Ethernet/IP" and parameter A460 [PID 1 Fdback Sel] as well. There is no problem with PID Reference signal - I can add parameter A464 [PID 1 Setpoint] to data structure and set it from PLC over Ethernet. But how can I connect actual value of flow computed in PLC to PID Feedback signal? I can't find this option anywhere.
I will be very thankful for any remarks.
I take part in commissioning of process station with lobe pump. Speed of the pump is controlled by PowerFlex 525. A customer requirement is to set a desired setpoint of flow for a pump. But there is no flow meter, there is only an encoder mounted on a shaft of a drive. Depending on a shaft gear ratio and pump efficiency (assumed that a dose per revolution is constant) I compute flow. To control this flow I want to use embeded PID control. Everything is cotrolled with PLC over Ethernet network so I set parameter A459 [PID 1 Ref Sel] to "Ethernet/IP" and parameter A460 [PID 1 Fdback Sel] as well. There is no problem with PID Reference signal - I can add parameter A464 [PID 1 Setpoint] to data structure and set it from PLC over Ethernet. But how can I connect actual value of flow computed in PLC to PID Feedback signal? I can't find this option anywhere.
I will be very thankful for any remarks.