Design & development of soft-core processor based remote terminal units for nuclear reactors

Remote Terminal Units (RTUs) are single board, real time remote data acquisition & control systems that are used in Fast Breeder Reactors to acquire analog/digital signals [like voltage, signal inputs from surface thermocouple, leak detector & limit switches], sends digitized data packets over Ethernet to the nearest Local Control Centre (LCC) and generate control outputs in the form of potential free contacts during all states of the reactor operation. The design implementation concepts of soft-core processor based RTUs where TSK51 (a processor IP core from Altium) is used in place of conventional microcontroller along with other glue logic coded in VHDL thereby implementing complete digital logic of the embedded system in a FPGA is being discussed in this paper. This has enabled to overcome the problem of obsolescence of components along with the added advantage of improved reliability and reduced power consumption, which is proven in the last part of the paper. This paper also demonstrates the use of Altium designer software and Altium Nanoboard [Development Kit], which is used in the entire development process, starting from IP cores based development on FPGAs, embedded software development for the IP cores and overall PCB designing.