This may be redundant information for some, but there is a really detailed guide for using the LabVIEW PID controls on NI.
http://www.ni.com/pdf/manuals/372192b.pdf
It’s a good mix of Description, Explanation and fundemental math.
You can ignore the math and still get a lot from this manual. Likewise if you’re good at math, it explains what PIDs do.
I went looking for this because I wanted to see if I could use the Auto-tuning version of the PID control. We are using wheel encoders and I wanted to get the best possible speed control to implement constant acceleration rates. Now I feel comfortable trying it out.
One key thing I learned was that all the PID ins/outs assume 0-100 = full scale so you need to scale your control inputs/outputs into this range to get the most out of the VI.
Phil.