Hi
You can use a PID Toolkit which is oferred to the LabVIEW. There is meny PID examples you only need to search ni.com or your LabVIEW package (click find examples).
Specially for you:
examples\daq\solution\control.llb\Simple PID Demo.vi
examples\control\pid\prctrlex.llb\General PID Simulator.VI
and etc.
bogdani