IEC 60870 part 6 in electrical engineering and power system automation, is one of the IEC 60870 set of standards which define systems used for telecontrol (supervisory control and data acquisition) in electrical engineering and power system automation applications. The IEC Technical Committee 57 (Working Group 03) have developed part 6 to provide a communication profile for sending basic telecontrol messages between two systems which is compatible with ISO standards and ITU-T recommendations. Related Standards These standards include: IEC 60870-6-1 Application context and organization of standards IEC 60870-6-2 Use of basic standards (OSI layers 1–3) IEC 60870-6-501 TASE.1 Service definitions IEC 60870-6-502 TASE.1 Protocol definitions IEC 60870-6-503 TASE.2 Services and protocol IEC 60870-6-504 TASE.1 User conventions EC TR 60870-6-505 TASE.2 User guide IEC 60870-6-601 Functional profile for providing the connection-oriented transport service in an end system connected via permanent access to a packet switched data network IEC 60870-6-602 TASE transport profiles IEC 60870-6-701 Functional profile for providing the TASE.1 application service in end systems IEC 60870-6-702 Functional profile for providing the TASE.2 application service in end systems IEC 60870-6-802 TASE.2 Object models National Networks A typical national power grid includes a hierarchy of control centres to manage the generation, transmission, and distribution of power throughout the grid: one or more system control centres, responsible for scheduling of power generation to meet customer demand, and for managing major network outages and faults. generation control centres, responsible for managing the operation of generating plants (coal-fired, natural gas, nuclear, solar, wind, etc.), and for adjusting the power generated according to the requirements of the system control centre. transmission control centres, responsible for the transmission of power from generating stations to network distributors. distribution control centres, responsible for the distribution of power from the transmission networks to individual consumers. Prior to the development of electronics and telecommunications networks all co-ordination between control centres was carried out by telephone. However, the development of SCADA (supervisory control and data acquisition) systems allowed remote control and monitoring of electrical plant from centralised control centres. Initially individual SCADA manufacturers developed their own proprietary "closed" protocols for communicating from a control centre to electrical equipment in the field. These were followed by the development of "open" industry-standard protocols such as DNP3 and IEC 61850. However, none of these communication protocols were suited to the requirements of communicating between control centres. To meet these special requirements for communication and co-ordination