The memory of a PLC is organized by types.
The memory space can be divided into two broad categories:
Program and Data Memory:
Advanced ladder logic functins allow controllers to perform calculatins, make decisions and do other complex tasks. Timers and counters are examples of ladder logic functions. They are more comples than basic inputs contacts and output coils and relay heavily upon data stored in the memory of the PLC.
The user program will account for most of the memory of a PLC system.
Program files contain the logic controlling machine operation.
This logic consistes of instructions that are programmed in a ladder logic format.
DATA FILES:
The data file protion of memory stores input and output status, processor status, the status of various bits and numerical data.
