Which DAQ board to choose?

[TJ Culliton]

I am trying to set up a test machine that monitors incoming pulses from DC motor's and then through external relays controls movements of that motor. Such as CW rotation vs CCW rotation. I am attempting to control 6 motors at once. Any suggestions on which DAQ board would best suit my needs? What type of connector block should I tie into.....Maybe a SCB-68? I will be using Labview 7.1 to program this.

[bushman]

Sooooooooo many questions before this can be answered.

A DC motor doesn't generate pulses, so what are these pulses from?
Are they the PWM signal into the motor to drive it?
Is an encoder attached to the motor shaft to give velocity or position feedback?
Are the pulses TTL referenced to ground or are they floating?
What type of relays are you using? Mechanical SSR ....
What type of response time are you expecting?
Is that response time critical ? Should you be thinking of using a RT system?
Are these relays controlling a drive?

[TJ Culliton]

I believe the pulses are coming form either an encoder on the shaft of the motor or a hall effect sensor. We will use these pulses to figure out positioning of the mechanism. A regular voltage through a relay will drive the motor(12V). We would like to use SSR relay's but are not sure if there is a chassis that will allow 12 digital IO's. We would like to use only one board but could use two, one for the counter and one for input monitoring of voltage & current. Response time is not critical so I don't think an RT system is needed. Thanks for the input.

[LA 75]

Hello,

An M-series board is ideal if you want to do a very simple application with your motor. As the current that can be output is very limited, you will need to use a power amplifier to drive your motor. The quality of the speed control of your motor will be very limited with this method.

For a more complex application, you might want to take a look at our motion boards which are specifically designed for these purposes (http://www.ni.com/motion/). For example, the 733x devices are low-cost stepper motion controllers for point-to-point applications. These low-cost motion controllers provide new solutions for machine builders who need simple, straightforward motion control without a lot of extra features. Unlike other low-cost motion controllers, NI 733x controllers still have a variety of powerful features including: (1)linear interpolation for coordinating multiple axes; (2)real-time system integration for directly communicating with data acquisition or image acquisition boards; and (3)high-performance stepper generation for ensuring smooth motion at high velocities.

Hope this helps,

LA

[TJ Culliton]

I think I plan on using a PCI-7356 for the card and a UMI interface. I still need to figure out what Motion amplifier I need to use. I think this will be the best way. Any other suggestions would be appreciated.

[Dan_Quinn]

TJ,

The easiest way to do this with your 7356 is actually with an MID-7604 stepper drive. It incorporates the amplifier (with adjustable settings for your motor's power specs) with easy direct cabling fromt he 7356 to the drive. You can then easily connect stepper signals and encoder feedback signals as well.

Regards

Dan
National Instruments