Design of Interface Circuits for Industrial Process Control

The correct design of the I/O-ports used in industrial process control is very important. The susceptibility against conducted interference without the use of expensive filtering and shielded interconnection lines is possible if the design of the circuits is adequate to the properties of the disturbances. In this paper suitable precautions for analog and digital circuits are described and realized interfaces are presented. The use of simulation during the design process is shown. Models for ESD, Burst and Surge generators are presented. The behaviour of the generators and tested circuits in the simulation is compared with measurements.