Siemens MICROMASTER 420 Reference Manual page 69

3.5 PROFIBUS Module
This option allows the MICROMASTER 420 to be controlled via a PROFIBUS-DP
serial bus (SINEC L2-DP).
PROFIBUS-DP is a cost-effective high-speed serial communication system
optimized for the actuator/sensor area where very short system reaction times are
critical. It operates as a decentralized I/O system whereby the traditional wiring to
the sensors and actuators is replaced by an RS485 serial bus system linking the
stations together.
The suitability of the system for such applications has been recently enhanced by
the extension of the bus speed up to 12 MBd. The protocol is defined as
DIN19245 and also as EN50170 guaranteeing open, multi-vendor communications
between PROFIBUS-DP stations.
Up to 125 stations can be networked together using this single bus system and a
very flexible data structure allows the system to be optimized to exactly match the
requirements of each device.
PROFIBUS-DP lies at the heart of the new generation of SIMATIC S7 automation
systems offered by Siemens. Using this single bus system, all engineering,
visualization and PLC control operations can be integrated. To configure a
SIMATIC based automation system, all that is required is the associated STEP7
configuration tool running on a PC. Bus configuration is performed by using a drag
and drop technique in a graphically displayed PROFIBUS-DP network.
Some of the advantages of automating a system with PROFIBUS-DP are detailed
in the following list:
•
Only one single network for operator panels, drives, sensors, actuators,
PLCs.
•
Cost savings in installation time and cabling.
•
Ease of commissioning with the SIMATIC S7 PLC system and STEP7
software.
•
Flexibility to expand or modify the automation system at a later date.
•
Simple integration into higher level process visualization systems such as
PCS7.
•
Remote diagnostics reduce the down-time in the event of a problem.
3.5.1 Features of PROFIBUS Module
•
Permits fast cyclic communications via a PROFIBUS connection.
•
Supports all PROFIBUS baud rates up to 12 MBd.
•
Control of up to 125 inverters using PROFIBUS-DP protocol (with
repeaters).
•
Conforms with EN50170 guaranteeing open communications on a serial
bus system. It can be used with other PROFIBUS-DP/SINEC L2-DP
peripheral devices on the serial bus. Data format conforms to the VDI/VDE
directive 3689 "PROFIBUS Profile for Variable Speed Drives".
•
Acyclic communications channel for connecting SIMOVIS or other service
tools.
•
Support for the PROFIBUS control commands SYNC and FREEZE.
•
Can be easily configured using the S7 Manager software, or any
proprietary PROFIBUS commissioning tool.
•
Simple integration into a SIMATIC S5 or S7 PLC system using specially
designed functional blocks (S5) and software modules (S7).
MICROMASTER 420 Reference Manual
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