Cody Anderson
Member
Hello all,
I am using a temposonic R series linear transducer for positioning of a lower ram on a hydraulic powdered metal press. The transducer part number is RPS0180UD601A01 and it is connected to the analog input on a 1769-L24ER-QBFC1B processor. There is an HMI where we can set a fill position. When we get to the fill position the lower ram should stop moving up. I am using a 1769-OW16/A relay output card to send the signal to the solenoid valve that controls the upward movement. When I get to the fill position it does not stop right at 4.9 inches, it keeps overshooting, but not consistently. Sometimes I stop at about 5.6 inches. Sometimes it stops at 5.4 inches. Sometimes at 5.35. It would not be an issue if I could get it to stop consistently, but I cannot get it to. So we ended up wiring a limit switch for a test. I did not hook the switch up to my plc, just brought power to the switch and straight to the valve afterwards and the lower ram would stop in the same position every single time with the switch, so I am thinking it has something to do with the PLC causing some kind of inconsistent delay when trying to stop the lower ram. The RPI setting for my analog input is at 80 ms, would lowering this value help at all? Should I try a different output card? Not sure exactly where the issue is yet.
I am using a temposonic R series linear transducer for positioning of a lower ram on a hydraulic powdered metal press. The transducer part number is RPS0180UD601A01 and it is connected to the analog input on a 1769-L24ER-QBFC1B processor. There is an HMI where we can set a fill position. When we get to the fill position the lower ram should stop moving up. I am using a 1769-OW16/A relay output card to send the signal to the solenoid valve that controls the upward movement. When I get to the fill position it does not stop right at 4.9 inches, it keeps overshooting, but not consistently. Sometimes I stop at about 5.6 inches. Sometimes it stops at 5.4 inches. Sometimes at 5.35. It would not be an issue if I could get it to stop consistently, but I cannot get it to. So we ended up wiring a limit switch for a test. I did not hook the switch up to my plc, just brought power to the switch and straight to the valve afterwards and the lower ram would stop in the same position every single time with the switch, so I am thinking it has something to do with the PLC causing some kind of inconsistent delay when trying to stop the lower ram. The RPI setting for my analog input is at 80 ms, would lowering this value help at all? Should I try a different output card? Not sure exactly where the issue is yet.