Hi! What exactly are you looking? Mitsubishi has DCS for power plants
called DIASYS Netmation (
http://www.diasys-netmation.com/ ).
Also Mitsubishi has redundant PLC solution QnPRH with PXDeveloper
process configuring and run-time environment. On the top of
PXDeveloper, Wonderware Intouch may act as HMI.