Compact programmable logic controller and central unit of a modular programmable logic controller

摘要

A compact, modular SPC has a number of units, each with a micro-based control unit (6) that connects to and controls a number of input units, output units and intelligent peripherals. The interconnection with these units is made by a bus (10) via a microcontroller stage (23). The interconnection between the groups of control systems is via a second bus (5) coupled by an interface (13) to the main microcontroller (22). A microprocessor (14) processes the user programme held in memory (16). Programming and monitoring units access the controllers via the bus (5). IMAGE