text: <s>[INST] CIP Axis with PF755 and MP Series motor that is oscillating Summary: CIP Axis with PF755 and MP Series motor that is oscillating when it stopsHello I have just started a project using PowerFlex755 using CIP motion, the connected motor is a Servo Motor with Absolute Feedback MPL-B680F-M and the processor is a 1756-L73 Revision 24.12. I have setup another axis that is using a PowerFlex755 and an MPL-B4560F-M and I have had no problems with this one. I have set it all up and I am just using the Motion Commands in Studio 5000 to test the motor before I program it. Problem I am having is I will run the motor (MAJ) and then when I do a Motion Axis Stop (MAS) the motor seems to have a hard time stopping, it oscillates violently and then it faults on OvertorqueLimitFault (in the Quick View Window) and on the VFD I get a shear pin alarm. I have also tried a MAM and when it gets to its Position, I get the same problem and fault. I have gone over the parameters and I am not sure what is causing this. I thought it might be because I did not have a Brake Resistor connected so I connected one and it has not made a difference. Maybe I need too manual tune it? Before I do I just wanted some feedback Thanks in advance! [/INST] In our experience, all CIP motion 755 applications need a brake resistor. Some basic questions, but sometimes a thing gets missed. Are you sure you configured the axis to use the resistor properly? Did you do an auto-tune on the axis? Our experience is that the Auto-Tune results tend to be rather hot. Try NOT using the rigid setting for load coupling, and no more than medium response. If you're already there, then yes, you may need to manually detune the axis. If the motor starts normally, runs at constant speed normally, then only goes bad when trying to decelerate, it's likely tuned too hot. One experiment to try is to issue the MAJ command, and then issue an MCD to lower the speed slightly, to see if the motor goes unstable. \\n </s>