It has the software for programming it built into the on board GUI. Depending on what you want to do you might not need a plc. It does have a few timers. Not much for math functions though. The newer version due out soon should have serial ports on it. It already has an interface for X-10.What do I need to interface this with the PLC ?
The HMI would be the PC, and would need a software to control the PLC functions.