text: <s>[INST] Kinetix 300 for web tension control Summary: K300 in analog velocity mode following +-10VDC signal from tension controller; advise please Hi, I am using a Kinetix 300 Servo Drive (2097-V33PR3) with a MPL-A1520U-EJ72AA servo motor in a web tension control application as a driven unwind. I am operating the K300 in analog velocity mode, where the speed of the servo follows a -10 to +10 VDC signal from a closed loop tension controller. The tension controller allows the operator to enter a tension set point and monitors feedback from a tension transducer roll that is mounted in my web path. Based on the entered set point and the feedback from the tension transducer roll, the tension controller uses a PID loop to regulate the -10 to +10 VDC signal to run the servo at just the right speed to create the desired tension. This is the first time I have used a servo for this purpose, and I am trying to get my tuning as good as I possibly can. As far as the servo is concerned, I just followed the tuning instructions (Tune the Axis) in the Kinetix 300 User Manual (2097-UM001D-EN-P). I tuned the servo with my unwind shaft empty (no spool of material in place). The tuning procedure completed with success almost immediately (I didn’t even see the motor turn). It came up with the following settings: Velocity P-Gain = 15137.504, Velocity I-Gain = 3558.289, and Gain scaling = -9. After doing this, I threaded a web and tested my tension control with the K300 controlled by my tension controller. The default PID settings in the tension controller seemed to be too aggressive and caused the servo to oscillate even at zero web speed. I played with these settings to make the tension controller PID loop less aggressive until I was able to maintain tension at set point a zero web speed with no oscillation on the servo. After doing this, I started running web at different speeds throughout my required range, and I was quite happy with my tension control. It’s not perfect, but I have some mechanical and other issues on my test machine that I believe to be creating some transients in my signal from the tension transducer roll. I have a feeling that these issues will impose a limitation on how good I’ll be able to get this working on this test machine, but I am hoping to learn as much as I can in my own shop before I ship these components to my customer and try to get it working in the field. (At my customer, I do not expect to have the same issues I have with my test machine, so I expect to be able to get much better results there). I was just wondering if anyone here has done this sort of thing with a K300? I was just wondering if you basically used default settings in the K300 and did a standard tuning with an empty shaft like I did? Or did you find it helpful to change any settings in the K300? Or do you think I should have done the tuning procedure with a spool of material in place (so that there would be more of a load?) Any advice you can give me would be greatly appreciated. thanks in advance, Paul [/INST] Paul, I suggest repeating your tuning process with a load on the shaft. I also suggest you look at the values used to tune the axis - make sure you have them such that the axis does in fact move (torque and velocity limits high enough, position limit large enough to permit motion). The autotune usually has a small but noticeable motion. \\n </s>