Industrial Maintenance Technician Practice Test 2025 – 400 Free Practice Questions to Pass the Exam

Discrete outputs in a Programmable Logic Controller (PLC) are used to control devices that can operate in an on/off manner rather than providing continuous signals. Relay and contactor coils are a prime example of devices connected to PLC discrete outputs, as they require a binary signal to either energize or de-energize, thus controlling the power supply to motors, lights, or other loads.

When the PLC sends a signal to the relay or contactor coil, it can switch the connected circuit on or off, enabling various automation tasks. This control mechanism is essential in industrial applications, where the ability to switch larger electrical loads with a low-power signal is critical.

Understanding the role of relay and contactor coils highlights how PLC outputs facilitate the operation of other devices in an industrial environment. This connection allows for effective automation and control processes, making the discrete output configuration vital for industrial systems.