Variate stepper motor speed dynamically

[thitchen007]

Hi all,

I'm using PCI 7330 with P70530 to control a legacy stepper motor CTP10xxx10.

I want to variate the speed of the motor without stopping the motor.

I saw what you can do is, preset all the parameters and then start the motor, nowhere mentions that one can change those "parameters" on the go,

Please advise and thanks in advance.

-chen

[mikeporter]

Check the "programmable" examples. With this structure, you call VIs that essentially write a program that runs on the controller. The program can get operating parameters (like speed) from variables that you create during the programming process. While the motion program is running you can change the variable value to change the motion.

Mike...

[thitchen007]

Thanks for your reply.

From this thread I understand that, the control of the velocity of stepper motor is actually realized by sending position setpoints at a controlled rate. 

And here is where the "real-time" comes into play. Correct me if I'm wrong, the real-time module deals more with high frequency implementation, but what I need is with far lower rate, say several Hz maximum. So is it possible that I can use software to send position setpoint at the slow rate, in order to control the speed of the motor? Plus there can be some finite speed error tolerance here. Please advise. May thanks.

-chen