PLC Guard
PLC Guard™ provides deterministic, policy-governed monitoring and protection of industrial network communications, with a specific focus on communications involving PLCs and other critical control devices.
Rather than relying on implicit trust or static packet filtering alone, PLC Guard evaluates communications against explicitly defined asset roles, approved communication paths, and authorised operational conditions.
This section describes PLC Guard's operational capabilities and the categories of risk it addresses. Detailed configuration, policy tuning, and architecture design are intentionally out of scope for this manual and are covered separately through specialised technical guidance and advanced training.
PLC Guard Philosophy
Human-Governed Network Protection
PLC Guard™ is designed around a fundamental principle of industrial operations:
Network visibility and deterministic policy enforcement must support engineering authority — not replace it.
Industrial networks, especially those involving PLCs, are highly sensitive environments where incorrect blocking or restriction can have immediate and unintended operational consequences. For this reason, PLC Guard does not function as an autonomous or heuristic decision-maker.
Instead:
- It provides comprehensive, structured visibility into industrial communications
- It evaluates traffic against explicitly defined, engineer-approved policies
- It enforces only those restrictions that have been formally defined and authorised
Structured Communication Visibility
PLC Guard continuously collects and organises detailed information about network communications, including:
- Which assets communicate with PLCs
- When communications occur
- Frequency and timing characteristics
- Protocol usage and command types
This structured visibility forms the technical foundation for informed policy design and deterministic enforcement.
Engineering judgment defines the rules. PLC Guard enforces those rules consistently and predictably.