Industrial Communication Guide

BASICS OF AUTOMATION

Control level Within the control level are all automation computer systems (func- tion) that control the process. The controllers are connected to the sensors / actuators of the field level and each control a part of the system. The controllers are also connected to each other and to the higher level. At this level, information is transferred in size from a few bytes to a few kilobytes. The latency is a fraction of a second. MES/ERP Level Since the Manufacturing Execution System (MES) level is directly linked to the control level, the current production data, such as the quantities produced, are read out of the control units, and based on the current availability of the machines, in order to be executed is coordinated. The Enterprise Resource Planning (ERP) level allows you to control and plan a company’s resources, such as material re- quirements planning. At this level, information is transferred in size from a few megabytes to gigabytes. The latency is several seconds.

Data volume Latency

MES/ERP level

Mbytes - Gbytes 2-20 s

Control level

Bytes - Kbytes 0,2 s

Field level

Bytes 0,002 s

A

S

A A

Field level As the lowest level, this level contains all sensors (input) and ac- tuators (output) of the machines / plants of a manufacturing com- pany. Here, only a few bytes are transmitted at the same time, for example, to control an actuator or to receive a sensor signal. At the same time, however, high demands are placed on the maximum latency: in order to be able to control the processes correctly, the control signals must be transmitted within a few milliseconds.

7