using DAQ to supply voltage to a bridge?

[atomicalex]

I would like some guidance on developing a block diagram to supply voltage (AO?) to the excitation end of a bridge which I plan to read using the AI functions.

I would like to drive the bridge only when collecting data. I am not grasping how to do this in the block diagram. :kind of exasperated:

Thanks!
-aa

[Matthew C]

Hi,

Thank you for contacting National Instruments.

From what you have described, it sounds like you are trying to supply an excitation voltage to a bridge circuit, possibly as part of a strain gauge application.

If you are simply interested in supplying the bridge with a steady voltage using the analog output of your DAQ card, I have attached a small example VI that illustrates how to do this with DAQmx. There are also numerous examples included with LabVIEW that demonstrate how to perform various I/O functions using both DAQmx and Traditional DAQ. Just go to Help >> Find Examples, and with the browse tab selected, go to Hardware Input and Output.

You can incorporate this basic analog output structure into your code such that it only executes w
hen you begin collecting data. This can be done a number of ways, from data flow programming to using case structures.

I would also like to mention that if you are in fact driving a bridge as part of a strain gauge application, National Instruments provides hardware specifically designed for this kind of application.

I hope this helps! Let me know if you have further questions.

Matthew C
Applications Engineer
National Instruments

[atomicalex]

Thank you very much, Matt. LabView 7 is a lot more complex that the older versions!

I will work with the VI you sent and keep working on this.

I am driving an LVDT position sensor, which I was assured by the sales rep could be done with the combination of PCI-6036E and LV7. Actually, it is not going that badly. I am mostly hanging up on the little information feeders for all of the controls.

Thanks,
-aa