stepper motor

[Jochen]

As already stated and described in the linked documents above, P-command mode is the commonly used technical term for controlling servo motors with step and direction signals. Only some special motion drives provide this feature. These drives run the closed loop servo control onboard and you can use a more simple motion control board (e. g. the PCI-7330 or the PCI-7390), that doesn't provide PID control.

From my own experience I'm not sure if P-command mode is a big advantage compared to +/- 10 V control. You still have a servo system and you still need to tune the PID parameters. The major difference is that in P-command mode you need to do the tuning on the drive with the tools of the drive's vendor and with a +/- 10 V interface (e. g. a PCI-7340) the tuning is done on the controller board with the tools of the controller board's vendor (e. g. NI). With this said, P-command mode doesn't seem to be a big deal to me.

When programming your application, there is no difference anymore. If you use NI-Motion (driver for PCI-73xx boards) it doesn't matter if you are using a stepper, servo or P-command servo.

Jochen

[AliT]

Hi, I'm not sure whether this is the right place for asking this question or not and if not, then please guide me to the right place for asking such question. Thanks.

I have a stepper motor with the Vector Network Analyzer Anritsu MS4623B. I got it up and running with the LabWindows/CVI. I need to sync the motion of the stepper motor with my data acquisition. Basically, I have to acquire the data in a way that in the start the motor will come back to home position wherever it was and then I want to move it to the specific position to do the measurements (For Example, I want to measure the 40 GHz channel between 1m to 3m movement of a stepper motor on a linear positioning system (ball-screw)). I've interfaced the VNA with the PC using LabWindows/CVI and I've controlled the clockwise and anti-clockwise movements of the stepper motor using LabWindows/CVI but I'm unable to sync the system in a way that whenever I run the code, the motor will run back to the home position and then move to a specific measurement start position and move till the end position and in between do the increment and stop and acquire the data. Is there any one to help me please? It's really urgent please and I'm doing this thing first time so please guide me in a proper way. I shall really apprecaite that and will be highly obliged with you. Thanks for your time and concern.

Thanks and Regards.

[Jochen]

Hi AliT,

I have seen, that you have posted this question to mulitple other boards in this forums, so I won't post another technical comment to your question.

Still in order to get the best results from this forum and to keep contributors motivated I kindly ask you to follow standard discussion forum rules, especially these two:

1. Don't hi-jack existing discussion threads with issues, that are not directly related to these threads. This is considered as quite rude behavior as it mixes topics and makes it hard to find focused information in the forums. Additionally it triggers a lot of personal email notifications. Always open a new thread for a new topic!
   
   
2. Don't post your questions multiple times. This results in multiple people answering your questions in parallel, which wastes a lot of time of people who volunatrily contribute to the forums. If you don't know to which board to post, you may post to maybe two boards but make sure, that you crosslink to your other thread, so people know, that you have created a duplicate post.

Thank you for following these rules.

Kind regards,

Jochen Klier