IEC 61508 is an international standard that defines the functional safety requirements for electrical, electronic, and programmable electronic systems. The standard focuses on ensuring that safety-related systems operate correctly in response to potential hazards, thereby preventing accidents or damage. This is achieved through the application of rigorous safety lifecycle processes, including hazard analysis, risk assessment, and the implementation of specific safety functions.

    Communication relays are used in industrial automation to transmit information between different system components, often over various communication protocols such as Modbus, Profibus, or Ethernet. When these relays are IEC 61508 compliant, they adhere to safety integrity levels (SIL), a key concept within the standard. SIL determines the reliability of a safety system and is assigned based on the level of risk reduction required to ensure safety. For IEC 61508 compliant communication relays, meeting these SIL levels is essential for maintaining the integrity of safety-critical communication in industrial processes.