Qing Xie

Thank you Martins, I will try to track the Motor[x].New[i] structure. I designed the filter, followed the steps in manual, cutoff freq. = 100, damping = 0.7 sample rate = 20k

I use an analog sensor (load cell) as the position feedback, so the motor's actual velocity can not be exact zero, even PMAC send no pulse to motor. And here is another question, how does pmac determine Motor[0].DesPos, why does not the value keep equal to actual position.

Hello everyone: My motor desired position (Motor[0].DesPos) may jump randomly and sharply when motor servo on by orders like "jog/", "jog0:0". I use a load cell voltage(-10V ~ +10V) as my motor position value, the corresponding code is shown as bellow. ---------------------------------------- // use encode convert table to right move adc raw data EncTable[3].Type = 1 EncTable[3].pEnc = Gate3[2].Chan[0].AdcAmp[0].a // feedback source. AdcAmp: adc EncTable[3].index1 = 0 EncTable[3].index2 = 16 // input raw data(type 1: WORD) right move bits EncTable[3].ScaleFactor = 1 // use encode convert table to track filte data EncTable[8].Type = 1 EncTable[8].pEnc = ect_ss_actor.PrevEnc.a // feedback source. AdcAmp: adc EncTable[8].index1 = 1 EncTable[8].index2 = 245 // input raw data(type 1: WORD) right move bits EncTable[8].ScaleFactor = 1 Motor[0].pEnc = ect_ss_actor_flt.a Motor[0].pEnc2 = ect_ss_actor_flt.a ---------------------------------------- The value of desired position (Motor[0].DesPos) is equal to the actual position value when the servo loop is disabled. But once I close the servo loop by using "jog/", "jog0:0", etc. the value of Motor[0].DesPos will change to a random value immediately, and then change to actual position gradually. The sharply position jump may cause great possition error and ServoOut. How can I avoid this position jump?