Interfacing between SCADA systems and substation communications networks

There is a growing interest in the use of computer systems within substations to provide the control and monitoring facilities previously done by individual equipments e.g. event loggers. The standard approach to system control and data acquisition (SCADA) has been to use a separate outstation or remote terminal unit (RTU) to provide the information link between the substation equipment and the control room. The link between the RTU and the other substation equipment has been by conventional wiring. Where computer systems are used to provide the local control and monitoring, the potential exists to use the same computer to carry out the SCADA functions, as all the data relating to the status and operation of the substation is available in the computer. Therefore the proposal to use a substation computer system to carry out the SCADA function is now gaining ground