SIEMENS
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Siemens IK PI · 2015
Industrial Wireless Communication
Industrial Wireless LAN (IWLAN)
Introduction
6
■
Overview
SCALANCE W – wireless communication with Industrial
Wireless LAN
The SCALANCE W products provide a combination of reliability,
ruggedness and security in a single product:
•
For use by industrial and automation customers
•
For outdoor use under demanding climatic conditions
•
For low-cost integration in the control cabinet or in devices
The Industrial Wireless LAN (IWLAN) technology provides an
extension to the IEEE 802.11 standard that is particularly suited
to demanding industrial applications with real-time and redun-
dancy requirements. This provides customers with a unique
wireless network, both for process-critical data and for uncritical
communication. SCALANCE W products distinguish themselves
by the reliability of their radio channel and the rugged type of
construction with high requirements with respect to mechanical
durability for which SIMATIC is known. To protect against
unauthorized access, the products have modern standard
mechanisms for user identification (authentication) and data
encryption, and can at the same time be easily integrated into
existing security concepts.
Wireless infrastructure
Instead of copper cables and fiber-optic cables, wireless trans-
mission techniques use radio waves. The propagation charac-
teristics of the electromagnetic waves can differ considerably
and depend on the spatial environment with the installed wire-
less infrastructure.
SCALANCE W modules use techniques such as MIMO, high-
quality receivers, and fault-tolerant modulation procedures to
improve signal quality and to prevent interruption of wireless
communication. Extensions to the IEEE 802.11 standard also
permit reliable, wireless transmission from PROFINET, form the
basis for wireless safety applications and the transmission of
video data with extremely short reply and update data.
Network solution with IWLAN
Mobile end devices, for example, allow a continuous information
flow from the management level down to the production level.
The IE/PB Link PN IO with SCALANCE W client modules
(e.g. W722) is available for wireless-based connection of
PROFIBUS devices.
This means that information can be provided quickly, reliably
and easily at the right place and at the right time by wireless.
Ruggedness and industrial suitability
The SCALANCE W products can be exposed to fluctuations in
the extended temperature range, or to continuous contact with
dust and water. Rugged enclosure and mechanical protection
against shock and vibration allow use in harsh industrial environ-
ments.
EEC (Enhanced Environmental Conditions) series devices are
also specially strengthened (coated printed circuit boards resist
condensation, increased temperature range) and can also be
used in railway applications. Accessories such as antennas,
power supply units and cabling are also part of this concept and
are suitable for use in industry.
Power and data are transferred over one cable with Power-over-
Ethernet (PoE), saving investment and maintenance costs.
The C-PLUG (configuration plug) swap medium stores engineer-
ing and configuration data, making device replacement possible
in a short time and without specially trained personnel. This
minimizes downtimes and saves training costs.
In addition to the functions of the C-PLUG, the KEY-PLUG
swap medium allows additional features to be enabled on
SCALANCE W78x/W74x and W77x/W73x.
Reliability of data communication
The international standard IEEE 802.11n makes wireless
communication via IWLAN even more robust. The greatest
advantage is the use of multiple path propagation (
M
ultiple
I
nput,
M
ultiple
O
utput (MIMO)). This allows the devices parallel
use of multiple antennas. A higher data transfer rate is achieved
and susceptibility to interference in environments with a lot of
reflections is reduced.
SCALANCE W products with IWLAN in accordance with
IEEE 802.11n support up to three streams each in both the send
and receive directions.
© Siemens AG 2014