IEC 60870-104 Protocol SCADA

IEC 104 Protocol

IEC 60870-104 Protocol

IEC 60870-104 is a widely used protocol for communication between supervisory control and data acquisition (SCADA) systems and remote terminal units (RTUs). IEC 60870-104 is a modern and more advanced protocol compared to IEC 101. It is designed to address the limitations of IEC 101, such as its security vulnerabilities and performance limitations.

IEC 104 Protocol
IEC 60870-104 Protocol Master/Slave

Key features and components of IEC 104:

  • Asynchronous serial communication: Similar to IEC 101, IEC 104 uses asynchronous serial communication for data transmission.
  • Master-slave architecture: It also follows a master-slave architecture, where the SCADA system is the master and controls the RTUs.
  • Event-driven data transfer: Unlike IEC 101, IEC 104 uses an event-driven data transfer mechanism. This means that data is only transmitted when there is a change in the status of the remote equipment, rather than on a periodic basis. This improves efficiency and reduces network traffic.
  • Message types: IEC 104 defines various message types for different functions, including:
    • Initialization messages: Used to establish communication between the master and slaves.
    • Control messages: Used to send control commands to the slaves.
    • Data messages: Used to transmit measurement data from the slaves to the master.
    • Status messages: Used to report the status of the slaves and their connected equipment.
  • Error detection and correction: IEC 104 includes mechanisms for error detection and correction, similar to IEC 101.
  • Security features: IEC 104 incorporates security features, such as encryption and authentication, to protect data transmission.

Advantages of IEC 104:

  • Improved performance: The event-driven data transfer mechanism and security features make IEC 104 more efficient and secure than IEC 101.
  • Scalability: IEC 104 is designed to handle larger and more complex SCADA systems.
  • Modern features: It offers modern features, such as support for different data types and protocols.
  • Compatibility: IEC 104 is compatible with IEC 101, allowing for gradual migration.

Disadvantages of IEC 104:

  • Complexity: IEC 104 is a more complex protocol than IEC 101, requiring more specialized knowledge and skills.
  • Higher costs: Due to its advanced features, IEC 104 equipment may be more expensive than IEC 101 equipment.

Overall, IEC 104 is a superior protocol to IEC 101, offering improved performance, security, and scalability. It is particularly suitable for large and complex SCADA systems that require high levels of reliability and data integrity. However, its complexity and higher costs may be factors to consider when making a decision.