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BCU 560, BCU 565 · Edition 02.16
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8 Profinet
Profinet is a manufacturer-independent, open standard for
industrial Ethernet. It covers the requirements for automation
technology (manufacturing automation, process automation,
drive applications with or without functional safety).
Profinet is a bus variant for fieldbus communication, optimized
for speed and low connection costs.
1
2
3
BCU 56x
BCM
BCU 56x
BCM
BCU 56x
BCM
PROFINET
L1
BUS
FCU
P
HT
PLC
The basic function of Profinet is the exchange of process and
required data between an IO controller (e.g. PLC) and several
distributed IO devices (e.g. BCU/FCU).
The signals from the IO devices are read into the IO controller
cyclically. There, they are processed and are then output to
the IO devices again.
In addition to cyclic data exchange, Profinet also provides
acyclic data exchange for events which are not constantly
repeated such as sending parameter settings and configu-
ration data when the IO devices start up or sending a diag-
nostic message from the IO device to the IO controller during
operation. The data read or written acyclically by read/write
services are specified by an index, see page 48 (Indexes
The technical properties of an IO device are described by the
manufacturer in a device master data file (GSD file). The GSD
file contains the device image, the communications properties
and all fault messages from the IO device in text form which
are important for the configuration of the Profinet network
and the data exchange. The configuration is completed using
an engineering tool which is supplied by the manufacturer
of the IO controller. Modules defined in the GSD file may be
selected for configuration to include them in the system, see