A construction of RTU assembly having a number of independently operational cells for systems functions is provided. Each cell is formed from a configurable component and effectively could be of the same construction as a conventional RTU that would be used for a particular function. There is inter-cell communication for the continuous downloading of information between cells. Ideally the information is controlled in such a way that each cell is aware of all the information that is being transferred, but only receives that information that it requires. In this way all the functions can be performed and the cells operate as equal peers and no one cell has priority over the other cells, such that the failure of one cell will cause the failure of all the others. There can be duplication of function in the cells and various "redundancy" of power, and I/O ports is built into the system.