Siemens SIMATIC 277 IWLAN, Getting Started

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2 Configuring the
WLAN
8
HMI Device Mobile Panel 277 IWLAN
Getting Started, 04/2008, A5E01004533-01
• Plant control system
The PLC transmits the process data to the access point via Ethernet and
receives the operating data about the Mobile Panel from it.
How it works
WLAN uses electromagnetic waves for wireless data transmission.
The IEEE 802.11 process used for WLAN transmits on the frequencies 2.4 GHz
and 5 GHz which are available license-free to all countries. Only one station can
transmit at any one time on each of a frequency's channels (simplex mode).
Security
SIEMENS access points support all the current measures to secure your WLAN.
Take the following steps to avoid unauthorized access to the WLAN:
1. Select a secure encryption process.
All SIEMENS access points support WPA2 with AES and TKIP, which is
currently regarded as the most secure encryption process.
2. Password-protect the access point.
3. Select an SSID (service set identifier) which does not indicate the
hardware used.
A transmitter's range at
2.4 GHz is between 30 and
100 m. The range depends on
the antenna, on objects in the
way indoors, on surfaces and
on materials. Operation at
5 GHz has a lower range,
although it is more resistant to
radio interference. All
SIEMENS access points are
designed for industrial use.
The access points support
MAC address filters as well as
the encryption processes
WEP, WPA2 with AES and
TKIP, EAP-TLS and EAP-
PEAP. You can find additional
information about the individ-
ual security processes in the
system manual entitled
“SIMATIC NET, Basics of
Industrial Wireless LAN”.