Siemens F IWLAN Operating Instructions Manual page 31

For stable PNIO communication, a WLAN client should be located at all times in a radio cell
with a signal strength > 60% or > -65 dBm. This can be checked by switching the various
segments on and off.
This does not mean that the client needs to change over at a signal strength < 60% or < -65
dBm. Make sure that a segment is available with a sufficiently powerful signal.
Limitations due to iPCF-MC
iPCF-MC is an in-house development of the Siemens AG that will only work with participants
in which iPCF-MC has been installed.
Operating principle of iPCF-MC
iPCF-MC uses both radio interfaces of the access point differently: One interface works as
management interface and sends a beacon every five milliseconds. The other interface
transmits the user data.
The following requirements have to be met to use iPCF-MC:
● All "RR" versions of the SCALANCE W-700 access points with at least two WLAN
interfaces can be used as access point. The HMI device and all SCALANCE W-700 "RR"
versions are suited as clients.
● You have to operate the management interface and the data interface in the same
frequency band; they also have to match in their radio coverage. iPCF-MC will not work if
both radio interfaces are equipped with directional antenna the cover different areas.
● The management inferfaces of all access points that a client is to access must use the
same channel. A client will only scan this one channel to find all available access points.
● You cannot use the transmission method to IEEE 802.11h for the management interface.
802.11h is possible for the data interface.
Wireless Teach Pendant F IWLAN V2
Operating Instructions, 08/2010, A5E02453837-01
PRELIMINARY II
1.7.2010
Overview
1.12 Rapid roaming
31