I am in the process of building a new vacuum system at work and instead of using the usual assortment of dedicated controllers for pumps,pressure gauges and relays I was thinking of maybe using an OPLC. However, the only experience I have when it comes to "programming" hardware is using Labview Realtime to program a NationaL Instruments FPGA-DAQs in a PXI system (I also have some experience with Atmels AVR microcontrollers, but that is of course quite different). Although I should perhaps mention that I have a lot of experience controlling hardware from a PC using GPIB, RS232, USB etc, usually via Labview (which I use a lot) but also via Matlab,C, BASIC etc... Anyway, my question is this: How difficult is it to program e.g. one of Unitronics OPLCs (with built in display)? I've had a look at some of the videos at the Unitronics website and it looks fairly straightforward using their graphical IDE, but I have zero experience of ladder logic. I don't want to spend several days just learning how to do the programming... I should perhaps mention that in addition to the usual IO for relays and gauges I would also need to be able to control a couple of units via RS232 or RS485, I don't know if that makes it more complicated.