Which step helps ensure data integrity when programming a PLC?

• A. Confirm the program version matches the target hardware before loading
• B. Load any random program
• C. Change I/O wiring after loading
• D. Remove the PLC from the system

Answer: (A)

Ensuring data integrity involves making sure the program you load is meant for that specific PLC hardware. Before loading, confirming the program version matches the target hardware helps guarantee that the code, addressing, and configuration data align with the device’s firmware and I/O map. If the versions or hardware IDs don’t match, loading could overwrite data in a way the hardware can’t interpret, leading to corruption or unsafe behavior. This pre-load check acts as a safeguard to keep the PLC’s data and configuration consistent with what it expects.

Loading a random program would bypass this safeguard and could corrupt data or cause incorrect operation. Changing I/O wiring after loading doesn’t address data integrity and can lead to misreads or hardware damage. Removing the PLC from the system stops operation but doesn’t protect the integrity of the programmed data during loading.