What is a PLC?
A Programmable Logic Controller (PLC) is a specialized industrial computer designed to control manufacturing processes, robotic devices, or any activity requiring high reliability and real-time control. PLCs are widely used in industries such as automotive manufacturing, food processing, energy, and water treatment.
Key Characteristics
- Ruggedized design for harsh industrial environments
- Real-time operation with deterministic response times
- Modular I/O for connecting to sensors and actuators
- Ladder logic and other IEC 61131-3 programming languages
- High reliability with mean time between failure (MTBF) of decades
Security Considerations
PLCs are increasingly targeted by sophisticated cyber attacks. Notable examples include attacks that have targeted industrial control systems. Securing PLCs requires network segmentation, access control, firmware integrity verification, and monitoring for anomalous behavior.
Relevance to IEC 62443
Under IEC 62443 Part 4-2, PLCs and other embedded devices must meet specific technical security requirements based on the target Security Level for their zone.
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