How does a hard-wired control circuit differ from PLC-based control?

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Multiple Choice

How does a hard-wired control circuit differ from PLC-based control?

The main idea is how the control logic is implemented: with fixed hardware or with software in a programmable device. In a hard-wired setup, the sequencing is built directly into the circuit using relays, contactors, pushbuttons, limit switches, timers, and fixed wiring. Changing the behavior means rewiring or replacing components, which is rigid and manual. In a PLC-based system, a programmable controller reads inputs, runs a software program (often ladder logic), and drives outputs. The logic lives in the program, not in the physical wiring, so you can change how the system behaves by editing the software rather than rewiring. A PLC can also replace many discrete components and provide easier diagnostics, scalability, and flexibility while still driving the same kinds of actuators. So, the correct description is that hard-wired control uses relays, switches, and fixed wiring, while PLC control uses a programmed controller.

The main idea is how the control logic is implemented: with fixed hardware or with software in a programmable device. In a hard-wired setup, the sequencing is built directly into the circuit using relays, contactors, pushbuttons, limit switches, timers, and fixed wiring. Changing the behavior means rewiring or replacing components, which is rigid and manual.

In a PLC-based system, a programmable controller reads inputs, runs a software program (often ladder logic), and drives outputs. The logic lives in the program, not in the physical wiring, so you can change how the system behaves by editing the software rather than rewiring. A PLC can also replace many discrete components and provide easier diagnostics, scalability, and flexibility while still driving the same kinds of actuators.

So, the correct description is that hard-wired control uses relays, switches, and fixed wiring, while PLC control uses a programmed controller.

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