If the memory of a PLC is described by a map, what does the map primarily define?

• A. How addresses are organized
• B. The speed of memory
• C. The amount of memory
• D. The protection scheme

Answer: (A)

The memory map shows how addresses are arranged in the PLC’s memory. It defines which regions hold different types of data (inputs, outputs, data blocks, timers, counters, internal flags, etc.) and which address ranges correspond to each region. This organization lets the program read and write the correct data by referencing the right addresses and understanding what each address represents. It doesn’t determine memory speed, total capacity, or protection features—the speed is a hardware property, capacity comes from the overall address space, and protection is handled by the system’s security mechanisms.