SIEMENS
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Siemens IK PI · 2015
PROFIBUS
Optical networks with OLM
OLM Optical Link Module
3
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Overview
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Construction of optical PROFIBUS networks (line, star, ring)
with glass, PCF and plastic fiber optic cables
•
High availability can be achieved using a redundant power
supply and redundant cable routing
•
Function monitoring by means of signaling contact
•
All PROFIBUS data transmission rates from 9.6 Kbit/s to
12 Mbit/s inclusive 45.45 Kbit/s for PROFIBUS PA
•
Monitoring of the fiber optic cable routes on LEDs for channel
monitoring or using a voltmeter across measurement terminals
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Benefits
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High availability of the network thanks to redundant optical
ring
•
Fast fault localization due to signaling of the fiber-optic line
quality to LEDs and signaling contact (e.g. import of the level
value of the fiber-optic line quality via an analog module into a
programmable logic controller)
•
Large range due to use of glass fiber optic cables in lengths
of up to 15 km
•
OLM/G12-EEC for outdoor use down to -25 °C
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Application
With the PROFIBUS OLM (Optical Link Modules), optical
PROFIBUS networks can be established in linear, star and
redundant ring topologies.
The data transfer rate of a fiber optic line is independent of the
distance and can be up to 12 Mbit/s.
Possible applications for OLMs include:
•
System buses based on PROFIBUS
•
Networking between buildings using glass fiber optic cable
•
Mixed networks with electrical and optical segments
•
Networks covering a wide area (road tunnels, traffic control
systems)
•
Networks with high availability requirements (redundant ring
networks)
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Design
The OLMs have a compact metal housing. It is suitable for
mounting on a standard rail or for wall mounting with a mounting
plate.
The 24 V power supply is fed in through a terminal block and can
be redundantly connected.
The signaling contact allows a digital signal to be transferred to
PLCs or HMI systems for evaluation.
OLMs can be combined with each other and individual stations
or complete electrical segments can be integrated into the
optical PROFIBUS network through an electrical interface. With
the PROFIBUS OLM P22 and OLM G22, two electric PROFIBUS
segments can be connected separated from each other.
OLMs are available with one or two fiber optic interfaces with
BFOC connectors for different types of fiber optic cables:
•
Plastic fiber-optic cables (980/1 000 μm) can be used for
single lengths of up to 80 m. They can also be assembled with
BFOC cable connectors on site.
•
PCF fiber-optic cables (200/230 μm) can be used for single
lengths of up to 400 m. They are offered preassembled with
four BFOC plugs and an insertion tool.
•
Glass fiber multimode fiber-optic cables (62.5/125 μm) such
as the SIMATIC NET Fiber Optic cables can be used for long
distances of up to 3000 m. They must be ordered preas-
sembled with 4 BFOC plugs or as a FastConnect FO system
for assembly on site.
•
Singlemode fiber-optic cables (10/125 μm or 9/125 μm fibers)
can be used for extremely long distances up to 15 km.
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Function
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Automatic detection of all PROFIBUS data transmission rates
9.6 Kbit/s to 12 Mbit/s inclusive 45.45 Kbit/s (PROFIBUS PA)
•
Construction of the following network topologies: Line, star,
redundant ring
•
High availability due to media redundancy. The distance
between two OLMs in the redundant ring is only limited by the
optical range of the modules
•
RS485 interface with segment capability (Sub-D female
connector)
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Unrestricted multimaster operation: Expanded segmentation
functions for localization of faults to fiber optic and RS485
segments
•
Fast localization of faults:
- Indication of module status through floating signaling
contact
- Checking the fiber optic cable route quality on LEDs
- Checking the fiber optic cable route quality Measurement
output for optical receiver for logging and plausibility
checking of the fiber optic path attenuation with a voltmeter
•
High cascading depth: Line and redundant ring up to
124 OLM (only limited by monitoring times)
© Siemens AG 2014