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# twathit

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1. ## How to keep the angular velocity constant?

Option 1) This is exactly why PMAC has kinematic axis definitions available. Look in the User Manual for the section dealing with forward and inverse kinematics. As you already understand (by asking the question), the relationship is not linear and will depend on the actual position of the mechanism at any given point in time. So the task is to develop a non-linear relationship that will define the actuator position as a function of the desired axis position. This allows you to program desired axis motion and allow PMAC to transform into actuator motion. Equally important is a relationship that will define the axis in terms of known actuator position. This allows PMAC to properly initialize the axis by reading the actuator position. For a single axis as you describe, this should be fairly easy. Option 2) If this is a simple, single axis task you could use a linearization table (cam function) to 'correct' for the geometry changes through the range of motion. Not as good as #1 in my opinion, but with cubic interpolation turned on will do the job smoothly. Option 3) Again, if the application is simple.... You could even program your motion into a loop that solves the trig relationship each iteration. The 'While Loop' would need to execute fairly often. This is essentially a crude & limited way of doing #1, and not very good. Option #1 allows you to utilize all of PMAC's built in capabilities. With #3 method, your motion program will become more complex, and there will be greater error. I have some program idea about option #3,in every loop calculate the next position.But I not sure how to program option #1 and #2,could you give me some example?Thanks.
2. ## How to keep the angular velocity constant?

Option 1) This is exactly why PMAC has kinematic axis definitions available. Look in the User Manual for the section dealing with forward and inverse kinematics. As you already understand (by asking the question), the relationship is not linear and will depend on the actual position of the mechanism at any given point in time. So the task is to develop a non-linear relationship that will define the actuator position as a function of the desired axis position. This allows you to program desired axis motion and allow PMAC to transform into actuator motion. Equally important is a relationship that will define the axis in terms of known actuator position. This allows PMAC to properly initialize the axis by reading the actuator position. For a single axis as you describe, this should be fairly easy. Option 2) If this is a simple, single axis task you could use a linearization table (cam function) to 'correct' for the geometry changes through the range of motion. Not as good as #1 in my opinion, but with cubic interpolation turned on will do the job smoothly. Option 3) Again, if the application is simple.... You could even program your motion into a loop that solves the trig relationship each iteration. The 'While Loop' would need to execute fairly often. This is essentially a crude & limited way of doing #1, and not very good. Option #1 allows you to utilize all of PMAC's built in capabilities. With #3 method, your motion program will become more complex, and there will be greater error. I have some program idea about option #3,in every loop calculate the next position.But I not sure how to program option #1 and #2,could you give me some example?Thanks.

4. ## How to keep the angular velocity constant?

For example,in a triangle,the real move is a straight line x,the pole is L,so there will be a angle θ,x=L*sinθ,when I make the x move in straight line, I want the angular velocity of θ is constant,how could I code this? Anyone can help?
5. ## how to run motion program

I am curious about why the initial value of motor[x].status[0] is 30004000, why the motor reach the minus and plus hardware limits before it run? Since I don't use encoder, so I need the minus and plus limit to be the reference position. By set Motor[x].pLimits to 0, I can run motion program, but can't monitor the motor[x].pluslimit or motor[x].minuslimit change, is there any other way? Thanks.
6. ## how to use position compare

I’m using 24E2S to output PFM signal to control stepper motor, and I don’t use encoder, so I set Gate1[6].Chan[j].EncCtrl to 8. I know I need to “bracket” my starting position. So I setup Gate1[6].Chan[0].CompA=400,Gate1[6].Chan[0].CompB=-400,Gate1[6].Chan[0].CompAdd=1600, and it work fine. I can see the Gate1[6].Chan[0].Equ toggled. Now I want the starting position isn’t 0, so I think I should change the element in the motion program, here is a simple program, open prog 2 // Open buffer for entry linear; // Linear interpolation move mode abs; // Absolute move mode ta500; // 1/2-second accel/decel time ts0; // No S-curve accel/decel time f100; // Speed of 500 axis units per time unit X10000; // Move X-axis to position of 10 units if(Gate1[6].Chan[0].PhaseCapt==1000){ Gate1[6].Chan[0].CompA=800; Gate1[6].Chan[0].CompB=1200; Gate1[6].Chan[0].CompAdd=800; } dwell2000; // Sit here for 1/2-second X0; // Move X-axis to position of 0 units dwell2000; // Sit here for 1/2-second close but the three element doesn’t change, if I use them right? Thanks
7. ## how to run motion program

I’m using 24E2S to output PFM signal to control stepper motor,I don't need encoder, so I connected the controller to driver then the step motor.I attach my setup below. Now I can only make the motor run use open loop mode. But the question is I want to run some motion program,so it should be run under close loop mode,I tried #n J+, #n J/,#n J=100,I monitor motor[x].status[0],It change from \$30004000 to \$30007800,but there are no PFM signal output(I monitor it from oscilloscope).Do I need more setup?I have been stuck in this for quite a long time, hopefully I can get some answer. Motor[1].ServoCtrl=1 Motor[2].ServoCtrl=1 Motor[3].ServoCtrl=1 Motor[4].ServoCtrl=1 Motor[1].pAmpEnable=0 Motor[2].pAmpEnable=0 Motor[3].pAmpEnable=0 Motor[4].pAmpEnable=0 Motor[1].pAmpFault=0 Motor[2].pAmpFault=0 Motor[3].pAmpFault=0 Motor[4].pAmpFault=0 Motor[1].Servo.Kvfb=0 Motor[2].Servo.Kvfb=0 Motor[3].Servo.Kvfb=0 Motor[4].Servo.Kvfb=0 Motor[1].Servo.Kp=40 Motor[2].Servo.Kp=40 Motor[3].Servo.Kp=40 Motor[4].Servo.Kp=40 Motor[1].Servo.Kvff=40 Motor[2].Servo.Kvff=40 Motor[3].Servo.Kvff=40 Motor[4].Servo.Kvff=40 Motor[1].Servo.Ki=0.001 Motor[2].Servo.Ki=0.001 Motor[3].Servo.Ki=0.001 Motor[4].Servo.Ki=0.001 Motor[0].PhaseCtrl=0 // No phase commutation active Motor[2].PhaseCtrl=0 // No phase commutation active Motor[3].PhaseCtrl=0 // No phase commutation active Motor[4].PhaseCtrl=0 // No phase commutation active Gate1[6].Chan[0].OutputMode=3 //CH1A and CH1B ouputs will be DAC and CH1C output will be PFM Gate1[6].Chan[1].OutputMode=3 //CH2A and CH2B ouputs will be DAC and CH2C output will be PFM Gate1[6].Chan[2].OutputMode=3 //CH3A and CH3B ouputs will be DAC and CH3C output will be PFM Gate1[6].Chan[3].OutputMode=3 //CH4A and CH4B ouputs will be DAC and CH4C output will be PFM Gate1[6].Chan[0].EncCtrl = 8 //Simulated feedback for channel 1 Gate1[6].Chan[1].EncCtrl = 8 //Simulated feedback for channel 2 Gate1[6].Chan[2].EncCtrl = 8 //Simulated feedback for channel 3 Gate1[6].Chan[3].EncCtrl = 8 //Simulated feedback for channel 4 // Create encoder conversion table entries for all motors EncTable[1].Type=3 EncTable[1].pEnc=Gate1[6].Chan[2].ServoCapt.a EncTable[1].pEnc1=Gate1[6].Chan[2].TimeBetweenCts.a EncTable[1].index1=0 EncTable[1].index2=0 EncTable[1].index3=0 EncTable[1].index4=0 EncTable[1].MaxDelta=0 EncTable[1].ScaleFactor=1/512 EncTable[2].Type=3 EncTable[2].pEnc=Gate1[6].Chan[2].ServoCapt.a EncTable[2].pEnc1=Gate1[6].Chan[2].TimeBetweenCts.a EncTable[2].index1=0 EncTable[2].index2=0 EncTable[2].index3=0 EncTable[2].index4=0 EncTable[2].MaxDelta=0 EncTable[2].ScaleFactor=1/512 EncTable[3].Type=3 EncTable[3].pEnc=Gate1[6].Chan[2].ServoCapt.a EncTable[3].pEnc1=Gate1[6].Chan[2].TimeBetweenCts.a EncTable[3].index1=0 EncTable[3].index2=0 EncTable[3].index3=0 EncTable[3].index4=0 EncTable[3].MaxDelta=0 EncTable[3].ScaleFactor=1/512 EncTable[4].Type=3 EncTable[4].pEnc=Gate1[6].Chan[2].ServoCapt.a EncTable[4].pEnc1=Gate1[6].Chan[2].TimeBetweenCts.a EncTable[4].index1=0 EncTable[4].index2=0 EncTable[4].index3=0 EncTable[4].index4=0 EncTable[4].MaxDelta=0 EncTable[4].ScaleFactor=1/512 // Point motors to encoder conversion table entries Motor[1].pEnc=EncTable[1].a Motor[2].pEnc=EncTable[2].a Motor[3].pEnc=EncTable[3].a Motor[4].pEnc=EncTable[4].a Motor[1].pEnc2=EncTable[1].a Motor[2].pEnc2=EncTable[2].a Motor[3].pEnc2=EncTable[3].a Motor[4].pEnc2=EncTable[4].a Motor[1].pDac=Acc24E2S[6].Chan[0].Pwm[2].a //Command output to CH1A address (default address + 2) for Stepper Motor[2].pDac=Acc24E2S[6].Chan[1].Pwm[2].a //Command output to CH2A address (default address + 2) for Stepper Motor[3].pDac=Acc24E2S[6].Chan[2].Pwm[2].a //Command output to CH3C address (default address + 2) for Stepper Motor[4].pDac=Acc24E2S[6].Chan[3].Pwm[2].a //Command output to CH4C address (default address + 2) for Stepper
8. ## position compare function on power brick

I am using Power Brick LV, I know it has the position compare function, but I can't find any setup about it on Power PMAC users manual or Power Brick LV User manual.So which manual could I find the setup about the position compare function?
9. ## basic question about motion program

I am using POWER UMAC to control stepper motor,i just learn this controller for not too long.Based on the file,i use PFM signal,here is my configure: Gate1[6].Chan[0].OutputMode=3 //CH1A and CH1B ouputs will be DAC and CH1C output will be PFM Gate1[6].Chan[1].OutputMode=3 //CH2A and CH2B ouputs will be DAC and CH2C output will be PFM Gate1[6].Chan[2].OutputMode=3 //CH3A and CH3B ouputs will be DAC and CH3C output will be PFM Gate1[6].Chan[3].OutputMode=3 //CH4A and CH4B ouputs will be DAC and CH4C output will be PFM Gate1[6].Chan[0].EncCtrl = 8 //Simulated feedback for channel 1 Gate1[6].Chan[1].EncCtrl = 8 //Simulated feedback for channel 2 Gate1[6].Chan[2].EncCtrl = 8 //Simulated feedback for channel 3 Gate1[6].Chan[3].EncCtrl = 8 //Simulated feedback for channel 4 Motor[1].pDac=Acc24E2S[6].Chan[0].Pwm[2].a //Command output to CH1A address (default address + 2) for Stepper Motor[2].pDac=Acc24E2S[6].Chan[1].Pwm[2].a //Command output to CH2A address (default address + 2) for Stepper Motor[3].pDac=Acc24E2S[6].Chan[2].Pwm[2].a //Command output to CH3C address (default address + 2) for Stepper Motor[4].pDac=Acc24E2S[6].Chan[3].Pwm[2].a //Command output to CH4C address (default address + 2) for Stepper By this configuration, the controller can output PFM signal,I just need the controller to finish an easy move,so I didn't use encoder,so i put .EncCtrl = 8.Now before i run the motion program,should i must use encoder and close the loop?or i still don't need to use encoder and just close the loop is fine.Sorry about my poor english, i am just a begginer,so my question maybe stupid,but i still looking for some help,thanks
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