Motion Control and Motor Drives

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Why write express vi does not work while line do?



I'm using NI9514 to control a motor drive. When I was building the VI I found that the straight line move works while the write(with either velocity or position) won't do anything. I've read about the detailed help about it and still have no idea, and there's no such example in my LabVIEW example library as it suggested. Does anyone have idea? Thanks for any help!


Best Regards

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Message 1 of 5

Make sure that your drive is enabled (software- & hardware-), that no limit switches are set or activated. Some axis furthermore may require setting the type of resolver/encoder & the resolution per revolution. Also consult the help to see how setpoint values are scaled interpeted (some motors require a number between -1000 and +1000 during torque control mode instead of physical quantity like Nm. The same might apply for velocity or position)

Message 2 of 5

Thank you for the advice! I will try these settings. Also is there any difference using line and write? Do they both use generated trajectory to control the motor?


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Message 3 of 5

Hi Lysandros,


I just read about some instruction here In my situation I'm using NI9514 to give output to Kollmorgen drive, which then controls the motor. So it's probably only for users who's using EtherCAT drive, though I'm not 100% sure.


Best Wishes

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Message 4 of 5


maybe you are right. I assign the Setpoint VI's only over EtherCAT, so perhaps the NI-9514 does not support this command logic.

Best regards


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