What is redundancy in PLC architecture?

Redundancy in PLC architecture refers to the duplication of critical components within the system to ensure that if one component fails, another can take over, thus preventing system failure and enhancing overall reliability. This practice is vital in industries where system downtime can lead to significant financial losses or safety hazards.

For example, if a primary PLC controller fails, a redundant controller can immediately assume control without affecting the operation of the machinery or process. This strategy improves the system's resilience and availability, which are critical in mission-critical applications such as manufacturing, power generation, and process control systems.

In contrast, the other options focus on different aspects of PLC maintenance or operation. Streamlining communication might enhance efficiency but does not address reliability. The use of alternative programming languages pertains to software flexibility rather than hardware reliability. Finally, limiting the number of PLCs in a network relates to network design and efficiency and does not contribute directly to redundancy.