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Field Bus Communication
PROFIBUS
4 Field Bus Communication
4.1 PROFIBUS
4.1.1 Description
PROFIBUS is an open field bus standard, laid down in the European Standard
EN 50 170, Vol. 2 (also IEC).
PROFIBUS DP has been designed for a fast and efficient data exchange
between a control (PLC / PC) and decentralized peripheral equipment, for
example sensors and actuators, digital or analog input and output modules.
A DP System consists of a master and up to 124 slaves:
Master: A DP Master exchanges the data with the slaves via PROFIBUS DP
and controls the bus. It transfers the data between a supervisory control and
the decentralized peripheral equipment.
Slave: DP Slaves are the link to the field side. They edit the input data of the
peripheral equipment for the communication with the master and output the
Master data to the peripheral equipment.
PROFIBUS uses the master/slave method for data transmission. The master
cyclically reads the input data from the slaves and cyclically writes the output
data to the slaves. PROFIBUS DP V1 also supports an acyclic data exchange.
PROFIBUS DP has baud rates from 9.6 kbaud up to 12 Mbaud.
PROFIBUS DP features:
• fast system response times
• high immunity to interference
• master and slave diagnostic
• single slaves may fail or be turned off without the field bus operations
• Every configuration is stored in the master.
• Every slave has a manufacturer-specific identifier that has been assigned
• The slaves are described in the GSD files. The GSD file is imported into
being interrupted
by the PNO (PROFIBUS Nutzerorganisation).
the configuration software which makes the configuration of the slave
easier.
WAGO-I/O-SYSTEM 750
Bus System
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