And since I had gutted the controls on the other system and replaced the motor on the roots blower with a 3 phase motor I had no way to control the system. So I decided to build a controller using labview. Used a 16in/16out PCI card and a USB data acquisition unit to control valves and get feedback from devices like the turbo pump. The USB device handled analog in from the vacuum sensors. Took a couple weeks of programming and building the control box that has the power supplies, VFD, contactors, and solenoid valves. So far it seems to work. Still attaching all the cables I made to connect to the various parts of the system.
LabView is interesting, you can get the 2014 version for $50. Its a graphical programming system that makes it pretty easy to build GUI controls for all sorts of different equipment. I needed to control one of the valves through it's serial interface and within probably an hour I had a sequence programmed to handle the serial communication. Everything is controlled through the touchscreen on this old P4 industrial PC I scrounged up.
IMG_6306 by Jerry Biehler, on Flickr
IMG_6305 by Jerry Biehler, on Flickr
IMG_6304 by Jerry Biehler, on Flickr