Kuhnke Electronics Instruction Manual

Introduction
1.3 From Stand-alone Controllers to
Distributed Networks
For mainly three reasons, programmable logic controllers
and PCs play a key role in industrial automation:
� they are universally applicable,
� programming them is both simple and clear,
� extensive utilities for testing and commissioning are
available.
Standard programming utilities compliant to EN 61131-3
further reduces the effort to be put into programming. The
latest generation of Kuhnke PLCs therefore deploys
CoDeSys for programming.
The PLC has become a universal automation tool in a
wide range of application requirements.
Networkable control systems have emerged in response
to the ever increasing requirements of the complexity and
flexibility of machines and process control systems. The
"old" allround PLC for all aspects is being replaced with a
notion of task separation. Every part system just does
what it can do best.
For example, PCs are the perfect tool for computing and
managing large volumes of data at the control level or for
visualisation and operation.
PLCs are responsible for real-time control tasks and, if a
suitable field bus is available, for the process interfacing
level.
The process signals go through remote I/O units located
somewhere near the sensors and actuators.
The field bus focusses on the speed and reliability of data
transfer and the design as an open system. PROFIBUS-
DP and CANopen currently have the greatest market
awareness.
12 E 700 GB