Controlling a 24V, .2A servo motor

[Bob_Y.]

I had no answer on getting a MID-7654 to control a 24V, .2A servo from the Motion Control and Motor Drives board, so I thought I would ask here.

Is there any way at all to control a 24V, .2A servo through LabVIEW? I have found quite a few sites with stand alone controller/drivers, and others for much smaller servos, but I have not run across anything that will work for controlling this servo with LabVIEW. Granted I could probably control one of those stand alones with serial commands, but I think that may be too slow for my application.

Another idea was to use a UMI-7774. Will the UMI-7774 do it alone or do I still need a driver/amplifier. If I do, any suggestions as to which one?

As you might have guessed, motion control is very new to me and this servo was requested by my customer, so I need some help making it work. Also budget is a consideration, but I will accept any suggestions.

Thanks,
Bob

[LV_Pro]

Good Morning,
The UMI-7774 is just an interface between the motion control boards and the power amplifier. The MID-7654 is basically just the power amplifier part of the list. Depending on your motor's requirements a controller out of the NI-73XX category might be a good fit with the 7654. The third party controller/drives can frequently be used, some, as you say, are serial communication, some are parallel (both interfaces are becoming harder to find). Remember, as to speed of communications, that motion controllers do some/most of the work. With many you specify a direction, distance and speed, and then they go off doing it, signalling when they're done with that motion. In some cases a series of complex motions can be downloaded and then initiated. There isn't a straight forward answer without more info on the application.

Sorry if this doesn't shed much more light!

Putnam Monroe
Senior Engineer, Certified LabVIEW Developer
North Shore Technology, Inc.

[nickbike]

Bob,

I saw your post in the Motion Control and Motor Drives board also, so we'll link them together and try to get a solution. For other users in the community, here is the link:
http://forums.ni.com/ni/board/message?board.id=240&message.id=2375

As LV-Pro said, the Universal Motion Interface (UMI) devices are just interfaces to a drive or amplifier. So the answer is Yes, you still need an amplifier/driver. If you look at the tutorial below, a UMI would fit in right between the Motion controller and Amp/Drive in figure 1. Think of it as a break out board on steroids with a little bit of built in circuitry.
http://zone.ni.com/devzone/conceptd.nsf/webmain/722ecf56222aad5086256f7b007072c4

In terms of your motor only handling 0.2 Amps and our drive putting out a minimum continuous value of 0.5 Amps, you can do 1 of 2 things. You can add inductance to your motor as mentioned by Jochen in the post linked above. Or you can use a 3rd party drive. Even if you use a third party drive, it will probably still work with one of our motion boards meaning you can still easily integrate your motion control with LabVIEW.

In terms of the 24V limit of your motor, you should be ok based on the knowledgebase below.

http://digital.ni.com/public.nsf/websearch/AA46780BEF038CC4862565EF00512D7D?OpenDocument

Nicholas C
National Instruments
Applications Engineering