Recently, the thermal power plants save grown to larger capacity, higher temperature and pressure and utilize more advanced technology such as the integrated coal gasification combined cycle. As these plants grow, the control & monitor systems, which operate and control the plant, are goring to play an important part answering the needs of higher control performance and automation. We developed the "DIASYS-UP/V series", which is an integrated plant control system that incorporates our wealth of experience as a total manufacturer using the latest micro-electronics technology, we have achieved satisfactory results.