I use one at work to monitor the field stuff from the plant I operate. Learned about it in school (gots me a degree in instrumentation and electrical electronics at Okmulgee) and we created a small system in the lab setting. Currently where I'm working we have a contract crew installing a fancy new Foxboro DCS control system. This is going to be a MAJOR upgrade from our super outdated Texas Instrument PLC (late 1970s I think) control with Labview.