Control System for a Windtunnel

[ByInspection]

My project is to implement a control system for a wind tunnel

- Labview 2014 to do user interface and control system

- 2 load cells to gauge Lift and Drag.

- a Linear Servo to change vertical elevation of the object.

- 2 amplifier circuits to increase voltage of load cells for reading.

This is all to be control by a USB 6008 board. Current problems stem from the linear servo which needs a PWM signal to control position. To contol it we need a variable duty cycle with about 500 Hz and 5V.

Linear Servo - https://www.servocity.com/hdls-6-50-12v 

My question is can USB 6008 do a PWM signals? If yes can it also preform all these other tasks? If Not what Board could do this at a budget of close to $800

[Bob_Schor]

I assume this is a "real project" and that the data from the Wind Tunnel might be important.  So whether or not the USB-6008 can handle the PWM or not (have you read the manual?), why would you use a Legacy device when NI has come out with the 6001, faster, more bits of A/D, etc.?  It may even be less expensive ...

Bob Schor

[Alexander_Sobolev · Accepted solution]

For servo you need PWM signal changing from 1 ms to 2 ms. 6008 can not do it. The first usb that can is 6210, it fits the budget (654).

It also has analog outputs, 125 kS/s/ch with 2 active channels, 16 bit should be enough

Having something like Arduino to position servo and 6008 to read position will be a cheaper (if analog speed, resolution enough) but more time consuming solution, depends on your experience and exact task.

[joej]

If you knew analog ICs, you'd find the "timerblox pwm"; http://www.linear.com/product/LTC6992-1  This would take up one analog out of the 6008 and convert it to PWM...  I've done PWM with 8 channels using a 6009 - at 10 Hz through.

[ByInspection]

Thanks for your replies!

I neglected to mention a couple of things about the project

-We are doing data aquisition by saving lift and drag to an excel file.

-We what to control wind speed which needs voltage of 0 to 10V

I have been looking at the 6210 and it seems to have just about all the qualities I desire, with one exception. It does not have any analog out ports. We want to have a virtual potentiometer to control wind speed, but the only way I know how to do that in LabVIEW is with a DAQ Assists Voltage output which is connected to an analogy out port. Do you know of any ways to do this from a digital port?

Also the Arduino is a good idea and one that worked, but we are only allowed National Instrument devices for the control systems.

[DiegoH214 · Accepted solution]

Hello ByInspection

Have you checked the USB 6212?

http://www.ni.com/en-us/support/model.usb-6212.html

That one includes 2 AO.

Diego H

National Instruments.