Servo Axis Position Error Too High

[bin mulyadin]

Dear Expert,

Currently I am working on a machine that get strange fault. Here are the hardware:
1. Servo Controller Kollmorgen MMC-A4 Plus
2. Servo Drive Indramat DDS02 Series analog input
3. Servo Motor Indramat MDD Series (4 axis)

In Axis 1 (main Drive), during speed-up or in steady speed let say 80 %, the following error is not more then 50. But during speed-down from 80 to 30 following error is too high (above 5000). The limit is previously is only 1800, but I increase to 5000 just for troubleshooting but it still happened.

Original setting of Kp is 1001, Ki and Kd is 0.

If I disconnect the motor from the load, everythings is fine. I test from 100 to 10 it's fine.

Please advice

[theplcgeek]

So then it sounds like you have an inertial load problem. Are you to the max on your current limit already? If not, crank it up. Are braking resistors available for this servo? If so, then consider that.