• ControlLogix memory types; program and data

• Data types; output, input, status, bit, timer, counter, integer, floating point, etc.

• Memory addresses; words, bits, data files, expressions, literal values and indirect.


• To know the basic memory types available

• To be able to use addresses for locations in memory

Advanced ladder logic functions such as timers and counters allow controllers to perform calculations, make decisions and do other complex tasks. They are more complex than basic input contacts and output coils and they rely upon data stored in the memory of the PLC. The memory of the PLC is organized to hold different types of programs and data. This chapter will discuss these memory types. Functions that use them will be discussed in following chapters.