SIEMENS
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Siemens NC 62 · 2016
5
SINAMICS S120 drive system
Communication
PROFIBUS
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Overview
What is PROFIBUS?
PROFIBUS is the most successful open fieldbus used for auto-
mation technology which can be used for a wide range of appli-
cations. Standardization according to IEC 61158/EN 50170
secures your investments for the future.
PROFIBUS defines the technical and functional features of a se-
rial fieldbus system, with which the distributed field automation
devices in the lower area (sensor/actuator level) can be net-
worked up to the mid performance range (cell level).
The requirements of users for an open, non-proprietary commu-
nication system have resulted in the specification and standard-
ization of the PROFIBUS protocol.
Multi-vendor installations
Using the conformity and interoperability test performed by the
test laboratories authorized by PROFIBUS & PROFINET Interna-
tional (PI) and the certification of the devices by PI, users have
the security that the quality and functionality is guaranteed, even
in multi-vendor installations.
PROFIBUS versions
PROFIBUS FMS (Fieldbus Message Specification) – The univer-
sal solution for communication tasks on the field and cell level of
the industrial communication hierarchy.
PROFIBUS PA (Process Automation) – The version for applica-
tions in process automation. PROFIBUS PA uses intrinsically
secure data transfer technology defined in IEC 61158-2.
PROFIBUS DP (Distributed Peripherals) – This version, which is
optimized for speed, is tailored especially for the communication
of automation systems with distributed I/O stations and drives.
The outstanding features of PROFIBUS DP are
•
very short response times
•
high interference immunity
PROFIBUS DP replaces cost-intensive parallel signal transmis-
sion with 24 V and the measured value transmission with 0 mA
or 4 mA to 20 mA technology.
PROFIBUS and SINAMICS
SINAMICS uses the PROFIBUS DP protocol.
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Design
Bus nodes
PROFIBUS DP distinguishes between two different master
classes and one slave class:
DP master Class 1
For PROFIBUS DP, DP master Class 1 is the central component.
In a defined message cycle that always repeats itself, the central
master station exchanges information with distributed stations
(DP slaves).
DP master Class 2
Devices of this type are used (programming, configuration or
control devices) during start-up, for configuring the DP system,
for diagnostics or controlling the plant during normal operation.
A DP master Class 2 can be used, for example, to read the input,
output, diagnostic and configuration data of the slaves.
DP slave
A DP slave is an I/O device, which receives output information or
setpoints from the DP master, and as response, returns input in-
formation, measured values and actual values to the DP master.
A DP slave never sends data automatically, but only when re-
quested by the DP master.
The quantity of input and output information depends on the
device, and for each DP slave in each send direction can be a
maximum of 244 bytes.
G_D211_XX_00049
© Siemens AG 2016