Use the built-in PID vi to regulate the timing of a solenoid valve

[8kaho]

Hi, I'm trying to create a cooling system for a box using a solenoid valve. The valve is only able to open and close, and I'd like to implement a PID control to regulate the amount of time it's open for based on the current temperature of the box.

I'm using LabVIEW 2010, and I have the PID and fuzzy logic toolkit, but I have very little experience with LabVIEW or PID controls.  The built in PID.vi has 2 output branches, "output" and "dt (out)", but I don't understand exactly what those are, or what I should be wiring them to. If anyone could give me a basic overview of the steps I'll need to take to set up the system, it would be very very much appreciated!

[nathand]

Have you searched this forum already?  You are looking to couple the PID output with a PWM (Pulse Width Modulation) generator, which will cycle your valve on and off.  If the board controlling the valve has a built-in timer output, you can do PWM in hardware.  If not, you can do it in software as demonstrated here.

I wrote up a long explanation of the PID VI here (spread across many messages), but there are many other good examples already posted on this forum as well.

[8kaho]

Ok wonderful, I'll look at those, thank you so much! I had searched the forum, but I didn't really know what I was looking for so I found it somewhat overwhelming.