Compare processor-based sensor systems with discrete (hard-wired) sensor logic.

• A. Processor-based systems rely solely on hard-wired relays.
• B. Processor-based systems use software only for data collection, with no logic.
• C. Processor-based systems use software to process data (PLCs or microcontrollers), enabling complex logic; discrete systems rely on hard-wired relays/contacts for simple logic.
• D. There is no difference between them.

Answer: (C)

The key distinction is how decisions are made: processor-based systems rely on software running on a processor (like a PLC or microcontroller) to read sensors, process data, and implement logic, which allows complex conditions, sequencing, timing, and easy changes by editing software. Discrete, hard-wired logic uses physical relays, contacts, and gates to implement simple logic, so the behavior is fixed by the wiring and changes require altering hardware. This makes processor-based systems far more flexible and scalable for complex tasks, while discrete systems remain straightforward and robust for straightforward, fixed logic.