Which action is commonly performed by a programming device?

• A. Loading a new program into the PLC
• B. Replacing the PLC CPU hardware
• C. Reconfiguring I/O hardware in the field
• D. Providing plant-wide network security

Answer: (A)

The main idea is that a programming device's job is to deliver and deploy software to the PLC so it can run new or updated control logic. You typically write or edit the program on a computer, connect to the PLC, and download that program into the PLC’s memory. Once loaded, the PLC’s CPU executes the new logic, allowing you to implement changes in how the plant is controlled and tested safely before going live.

Replacing the PLC CPU hardware is a hardware maintenance task, not the standard programming workflow. Reconfiguring I/O hardware in the field involves changing physical connections or module configurations, which is hardware-focused and not the primary function of loading software. Providing plant-wide network security spans IT/OT security responsibilities and uses broader tools beyond simply loading a program.

So, loading a new program into the PLC is the action a programming device is primarily used for.