→PLC - programmable logic controller

definition according to EN 61131-1: A digitally operating electronic system, designed for use in an industrial environment, which uses a programmable memory for the internal storage of user-oriented instructions to implement specific functions such as logic, sequencing, timing, counting and arithmetic, to control, through digital or analogue inputs and outputs, various types of machines or processes.
Both the PC and its associated peripherals are designed so that they can be easily integrated into an industrial control system and easily used in all their intended functions.

extract from http://en.wikipedia.org/wiki/Programmable_logic_controller: A programmable logic controller, PLC or Programmable Controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures.

A PLC is also identified as →target system. The PLC built-in into logi.CAD 3 is the →PLC runtime system of logi.cals.