7354 output power per channel

[varmih]

Hello there,

Does anybody know what the output power per channel in PCI-7354 and PCI-7352 boards is?

I have several motors that require 4 W or less, and wonder whether I can drive them directly with the NI motion controller boards without the need of additional drivers. Please advise.

Thank you.

[ahillinaustin]

Hi Varmih,

Thanks for posting on the discussion forums to get an answer to your motion question. The boards themselves should be able to drive 4W motors, but you cannot drive them directly with the 7354. You need to have a UMI connector block, normally a NI UMI 7774 or 7764. This connects to the 7354 or 52  and then the motors will connect to the motors. As far as drivers, to use the 7354 you have to use the NI-Motion driver. 

What are the specs of your motor? Do you have a data sheet for them? Also, what OS are you running and are you using LabVIEW or NI MAX? Were you hoping to drive the motors directly from the PCI card?

Thanks!

[Buechsenschuetz]

As already mentioned, the outputs of the NI cards might have sufficient power to drive your motors. However, usually stepper motors are driven with constant current, and the current has to be set to a certain value in order not to destroy the motor. 

In case you connect a motor directly to an output rather designed to drive a control device, there will be no current control and/or current limit. The current limit will be set by the circuitry of the board and usually is NOT a design spec. Also, you will not be able to use microstepping. 

I would also recommend using a special motor driver which allows for setting some more parameters, such as motor current and microstepping modes. 

[varmih]

Hi Austin,

Thank you very much for your response. Of course, I am going to use a connector block. I was interested in whether the power specs of 7352/4 allow to drive small motors without special drivers.

I would like to drive the following servo motors: (a) micro-translation stage M-111.1DG (power 1.75 W), (b) linear actuator with DC motor M-227.10 (power 1.25 W) and (c) linear actuator with DC motor M-235.2DG (power 4 W).

The application will work with Win 7, in LabVIEW environment. Yes, I am hoping to drive the motors directly from PCI-7352/4 card, that has a power consumption of 18 W, which seems suitable.

So what do you say based on the above data? Is that possible?

Thank you.

[varmih]

Hi Buechsenschuetz,

Thank you for your response. I am going to drive servo motors (see their specs in my response to Austin), so probably the information about step motors does not apply.

What do you say about servos? Will the PCI-7352/4 will work directly with small motors without drivers?

Thank you.

[ahillinaustin]

Hi Varmih,

Based on the specs of your system, you should be able to perform the motion control with the 7354. You don't need any additional drivers on the software side of things, but you will need a motor drive that has the power outputs your servos require. Using LabVIEW and NI-Motion, you should be able to generate commands and velocity profiles to drive your motors. These commands are sent through the 7354, into the UMI, and then to a motor drive, which converts the commands into the actual current/voltage levels appropriate for the motor attached. The best bet would be for you to reach out to Physik Instrumente, the motor manufacturer, or the reseller who has the motors to spec out an appropriate drive for your application.

Hope this helps!

[varmih]

Hi Austin,

Thanks for the answer. My question was about the hardware side of things and your answer is negative, so to speak: my motors cannot be driven directly by 7354. I was hoping that your motion control boards work like this one that can drive small DC motors with no external power amplifier. Probably you can cosider making them in the future.

Kind regards.

[ahillinaustin]

Hi Varmih,

I'm glad I could answer your question, and I'm sorry that the 7354 won't work for you application directly. Our NI-Motion hardware is an older line that doesn't necessarily have all of the capabilities of our newer Motion hardware, particularly our C-Series drive modules used on the RIO platform. As far as the PI PCI board you referenced, I'm sure it will work great for your application that also uses PI's motors.

Good luck!