128 Fieldbus Communication
WAGO I/O SYSTEM 750 XTR
750-333/040-000 FC PROFIBUS G2 12MBd XTR
Manual
Version 1.4.0
10
Fieldbus Communication
PROFIBUS (
Pro
cess
Fi
eld
Bus
) was developed as an open fieldbus. It was
standardized in DIN 19245 and then later merged into the International standard
IEC 61158.
PROFIBUS DP (
D
ecentralized
P
eripheral) is a version of PROFIBUS that is
configured to meet the demands of a quick, efficient data exchange between a
controller (PLC/PC) and decentralized (local) peripheral devices.
The devices can include sensors and actuators as well as digital or analog input
and output modules.
A DP system consists of a DP master and up to 125 slaves:
Master:
A DP master exchanges data with the DP slaves via PROFIBUS DP and
monitors the data traffic. It transmits data between the superior controller and the
decentralized peripheral.
Slave:
The DP slaves form the link to the field. They prepare the input data of the
peripheral for communication to the master and output the output data from the
master to the peripheral.
The PROFIBUS uses the master-slave mode of operation for data transmission.
The master reads the input data cyclically from the slaves and writes the output
data to the slaves. Among other things, PROFIBUS DP/V1 also supports acyclic
data exchange. PROFIBUS DP uses a transfer rate of 9.6 kBaud up to
12 MBaud.
Characteristics of PROFIBUS DP:
•
Short response times
•
High interference resistance
•
Master and slave diagnostics
•
Individual slaves can be disconnected or switched off without disrupting the
ongoing bus operation.
•
The complete configuration is stored in the DP master.
•
Each slave has a manufacturer-specific identifier, which is assigned
through the PNO.
•
The slaves are described in the generic station description (GSD file). This
file is imported to the configuration software and facilitates the slave
configuration.