The capability of convention relay systems for complex operations is ___________ that of the PLCs.excellent thanpoor thanas good asunpredictable as

The most appropriate way to complete the sentence is: "The capability of conventional relay systems for complex operations is poor than that of the PLCs."

Explanation:

1. Conventional Relay Systems: These systems primarily rely on electromechanical relays, which are limited in terms of flexibility and complexity. They require manual rewiring for modifications and are typically used for simpler applications.

2. Programmable Logic Controllers (PLCs): PLCs are designed for complex and versatile applications. They are programmable and can handle multiple inputs and outputs with ease. PLCs are more efficient when it comes to operations that require logic, sequences, and real-time processing.

3. Comparison: When comparing the two systems, it is clear that PLCs have capabilities that far exceed those of conventional relay systems, especially in complex operations. This includes features such as easier programmability, troubleshooting capabilities, and adaptability to new tasks without hardware changes.

In summary, conventional relay systems fall short when it comes to handling complex operations compared to PLCs, making the answer poor than the PLCs.