Can I use LabVIEW to control voltage?

[Blackavar]

I am at the company I work for due to co-op, and I have a short amount of time to automate a testing process for valves invovling applying voltage to the valve and measuring its volumetric flow with a flow meter. I have very little LabVIEW experience, and even less NI-DAQ experience. Is it possible to control voltage flow from LabVIEW? If so, a bit of example code would be VERY helpful, if it's not too much trouble. I have the choice of using a DIO-24 card with a CB-40LP or a 6020E with an SCB-68. Any help at all would be greatly appreciated, and I thank you for your time.

[Dennis_Knutson]

The DIO-24 is digital I/O only so unless you have a digital to analog convertor on the valve, that card won't help. The 6020E has 16 12-bit analog inputs and 2 analog outputs. There are numerous shipping examples for both. In LabVIEW 6 or higher, go to Help>Find Examples>Hardware Input and Output>DAQ and either Analog Input or Analog Output. You don't mention the interface to the flow meter. What do you need to do to read that?

[Blackavar]

That was set up before I arrived. It gets its power from and communicates through the serial port, so that shouldn't be a problem. If I run into trouble, I'll post about that, too.

[Blackavar]

My problem, though, is that I'm running LabVIEW 5.1, not version 6. I'll check and see if I have those examples, though. Thanks!

[Blackavar]

Alright, I have examples to browse, but is there a way to do it through input data rather than a waveform? Also, to be sure, output means input from the computer fed to the device, right?

[Dennis_Knutson]

You output a constant voltage i.e. Generate 1 Point on 1 Channel.vi example. Or just use AO Update Channel on the Data Acquisition>Analog Output palette. Output means output from the daq board to some device. Input is input from some device to the daq board. Output is a source and Input would be a measurement.

[Blackavar]

Thank you very much! It gets confusing when you're just starting out, what with all the acronyms thrown about as if you knew them coming in... SCXI, VISA, GPIB, etc... It's difficult to know what to do when you're starting out, having not been exposed to any of this previously.