Thermocouple VI and Digital I/O VI

[Shack]

I need a VI that takes the voltage/temperature from a thermocouple and in turn controls the on/off switch of a heater.  Basically the heater will return a fluid to its original temperature after being altered.  From the examples in Labview, I was able to find a thermocouple VI and digital VI, but I need help in linking the two VI's together.  Thanks.

- Shack

[Otis]

Hi Shack,

Unfortunately there's not just a single VI that has all of the functionality that you are looking for.  LabVIEW is a programming language, so while you may be able to find some already existing VIs that have some of the functionality you desire, you will still have to create the application on your own.

It sounds like you are fairly new to LabVIEW.  If that's the case, then I definitely recommend that you take a look at the LabVIEW Fundamentals page, particularly the 3 Hour Introduction to LabVIEW Course.

That being said you can really break your application into 3 parts:

1. Read the Temperature from a Thermocouple - You can use the DAQ Assistant (if you have LabVIEW 7.0 or higher) to quickly begin taking Temperature measurements from a Thermocouple.
2. Have some sort of logic to determine On/Off State - You might want to just use a Greater Than function to say if a temp is greater than Y to turn something off.
3. Write Values to Digital Port - You can probably use the digital port and write the values that you determined in step 2 and write those values (as an array of 1D Boolean Data or something like that) to the digital port on your board.

LabVIEW can help you do just about everything you want to do, but you first have to break things into smaller pieces and then assemble the pieces that you want to use into a larger application for your use.

Regards,