SIEMENS
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Siemens IK PI · 2015
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Application
(continued)
Industrial Wireless Communication
IWLAN – Access Points IEEE 802.11n
Overview
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Application examples:
•
Automated guided vehicle systems and suspended
monorails;
prevents wear and offers high flexibility for traffic routing
thanks to the wireless transfer of data to the vehicles. It is also
possible to transfer PROFIsafe via IWLAN.
• Cranes;
high flexibility due to access to data communication with the
moving unit independent of the location
•
Mobile control console;
reliable intervention in the process thanks to data communi-
cation over IWLAN with mobile units (e.g. Mobile Panel 277(F)
IWLAN); the number of operator panels is therefore deter-
mined by the number of personnel and no longer by the
number of control desks.
•
Wireless access to field devices for configuration and testing
•
Passenger transportation systems;
transmission in passenger information systems, e.g. high-
quality video streams between the control center and buses or
trains
•
Tunnel application;
reliable wireless link since the devices can handle multiple
path propagation better by using the MIMO technology.
•
Communication with moving stations (e.g. mobile controls and
devices), container logistics, storage and retrieval machines,
conveyor systems, conveyor belts, rotating machines, trucks
•
Wireless coupling of communication segments and bridging
of large distances for fast commissioning and cost-effective
networks in applications where cable routing would be
extremely expensive (e.g. on public roads, rivers, lakes, train
lines)
•
Localization of personnel and machines using WLAN tags and
localization software from AeroScout
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Function
A simple RF field can be established with a single access point
(infrastructure mode). The access point provides at least one
Industrial Ethernet interface for connection to the wired network.
Nodes, such as mobile controllers or a Field PG can move freely
within the RF field and exchange data with other nodes via this
access point.
If the RF field of a single access point (wireless cell) is insuffi-
cient, it can be expanded by further access points. The individ-
ual wireless cells must overlap so that moving nodes can be
handed over seamlessly from one access point to the next
(roaming).
This is transparent for the application. The access
points must be able to exchange data via Industrial Ethernet or
a Wireless Distribution System (WDS).
If the access points are not connected to Industrial Ethernet us-
ing a wired connection (e.g. no cable tray available for a data
line), the "Wireless Distribution System" mode must be selected.
An access point from the SCALANCE W700 product line can
communicate via WDS with several other access points that are
not connected to the data network by a direct wired connection.
Remote directional antennas can be used to achieve ranges of
several thousand meters outdoors.
Apart from a reliable radio link, the SCALANCE W700 Access
Points are characterized by their support of IT mechanisms:
•
IEEE 802.11a/b/g/n for different frequency ranges
•
IEEE 802.11e for Wireless Multimedia (WMM)
•
IEEE 802.11i for security
•
Construction of redundant networks with the Spanning Tree
Protocols (RSTP, MSTP)
•
Virtual networks (VLAN) for example to logically separate
different user groups
•
Sending the log entries of the SCALANCE W devices to a
Syslog server
•
Modern security mechanisms (e.g. network security such as
IEEE 802.1x, RADIUS, EAP mechanisms)
Security
A high degree of data security is achieved by means of the
WPA2/IEEE 802.11i mechanisms. These define modern proce-
dures that control a regular exchange of the complete 128-bit
key as well as performing the access check (authentication) of
a node. The Advanced Encryption Standard (AES) is available
for data encryption.
On top of this, access to the devices (HTTPS) is encrypted and
a secure logon (SSH) is possible. If a security concept in combi-
nation with SCALANCE S is required, the security requirements
can be increased using Virtual Private Networks (VPN).
© Siemens AG 2014