What is the IEC standard for RTU?

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What is the IEC standard for RTU?

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Remote Terminal Units (RTUs) are designed to comply with various international standards to ensure interoperability, reliability, and security in SCADA and power system automation. The key International Electrotechnical Commission (IEC) standards applicable to RTUs are:

1. IEC 60870-5 (Protocol for SCADA Communication)

This standard defines protocols for telecontrol applications, ensuring reliable communication between RTUs and SCADA master stations. The two most relevant protocols are:

  • IEC 60870-5-101: Used for serial communication in SCADA systems.
  • IEC 60870-5-104: Used for Ethernet-based TCP/IP communication, enabling faster data exchange.

2. IEC 61850 (Communication for Substation)

  • Defines protocols for communication between RTUs, Intelligent Electronic Devices (IEDs), and SCADA systems in substation automation.
  • Provides real-time data exchange, ensuring interoperability between multi-vendor equipment.

3. IEC 61131 ( PLCs)

  • Applicable to RTUs that integrate PLC-based control logic for automation and process control.
  • Defines programming languages such as Ladder Logic, Structured Text, and Function Block Diagram for RTU-based control applications.

4. IEC 62351 (Cybersecurity for Power System Communication)

  • Establishes security measures to protect SCADA, RTU, and IED communications from cyber threats.
  • Ensures data integrity, authentication, and encryption for secure communication over IEC 60870-5-101, IEC 60870-5-104, and IEC 61850 protocols.

Extra RTU Requirements as per IEC Standards:

  • Time Synchronization: RTUs must support time synchronization with SCADA using IEC 60870-5-101/104.
  • Automatic Restart: After power restoration, RTUs must automatically start up and reinitialize without manual intervention.
  • Multiple Protocol Support: RTUs should support simultaneous communication over multiple serial and Ethernet ports, using IEC 60870-5-101, IEC 60870-5-104, MODBUS, and IEC 61850.
  • Data Concentration: RTUs can act as data concentrators, collecting data from slave RTUs and exercising supervisory control.
  • Sequence of Events (SOE) Support: Ensures accurate event logging for fault analysis and reporting.