Practical applications of peer-to-peer messaging in industrial facilities

Various communication protocols are used within a typical industrial facility including Modbus RTU, DeviceNet and Profibus. These protocols used over the years have been in a Master-Slave configuration. Intelligent Electronic Devices (IEDs) are slaves to single or multiple masters with one-way communication with the IED acting as a data/controlled node to the master device. Control is implemented in the IEDs, but only after commands are issued by the master computer. Both serial RS485 and Ethernet have been used for device communications. A new standard, defining protocols has been evolving since 1997, called IEC61850. This standard enables several industrial benefits when using an Ethernet network, such as high speed device-to-device communications (i.e. peer-to-peer communications both digital and analog values) within cycles and between different vendors, high-speed processing of analog signals and a common database naming format and structure. This paper will review the fundamentals of IEC61850 protocol including network requirements. It will also discuss four practical applications of IEC61850 protocol such as zone interlocking protection scheme, main-tie-main bus transfer scheme, load shedding scheme and client-server communications.