2.5
Wireless radio link
!
DCU 220 users are responsible for compliance with
the applicable directives and restrictions in the
country concerned.
2.5.1
Important information on WLAN and Bluetooth
WLAN (Wireless Local Area Network) is the term used
to describe a wireless local radio network. With WLAN,
there is a radio link in the free 2.4 GHz ISM range
(ISM: Industrial, Scientific, Medical) or 5 GHz range.
We recommend using the 5 GHz range where possi-
ble, as Bluetooth connections (e.g. mobile phone, KTS
module) limit the WLAN communication in the 2.4 GHz
range. This frequency range is subject to state legisla-
tion, can however be used without a license in most
countries. Consequently a large number of applications
and devices employ this frequency band for transmis-
sion. This can result in frequency interference.
Depending on ambient conditions, the WLAN link may
therefore deteriorate, e. g. in the case of Bluetooth
links, cordless telephones, radio-controlled thermome-
ters, radio-controlled garage door openers, radio-con-
trolled light switches or radio-controlled alarm systems.
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Extreme caution is to be taken if wearing pacemak-
ers or other vital electronic devices when using radio
systems, as proper functioning of these items could
be impaired.
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If the DCU 220 is operated within a frequency range
of 5150 MHz to 5350 MHz, it may only be used for in-
terior rooms.
Pay attention to the following to ensure the best possi-
ble connection:
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The WLAN radio signal always tries to find the most
direct path. When setting up the PC/Laptop and ac-
cess point (refer to Section 2.5.2), make sure there
are as few obstacles as possible (e. g. steel doors
and concrete walls) which could interfere with the
radio signal from and to the DCU 220.
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Inside buildings, the range of the WLAN is also
greatly influenced by the construction materials
used. Common masonry, wooden and dry walls have
little dampening effect on the spread of radio waves.
Thin gypsum walls can however cause problems,
as considerable amounts of moisture may accumu-
late in the gypsum and result in the absorption of
radio signals. Metal or concrete walls (in particular
steel-reinforced concrete) present a strong barrier to
radio waves. Cellar ceilings are often impenetrable.
Generally speaking, walls with a lot of installed metal
(e.g. pipes, wires) obstruct radio waves.
Robert Bosch GmbH
Symbols used | DCU 220 | 19
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Radio reception is also impeded by large metal
objects such as radiators and window frames as
well as active sources of interference such as mobile
phones, motion sensors and microwave ovens.
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The human body also impedes radio transmission.
For this reason, always make sure that there are no
people stood between the transmitter and receiver.
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We recommend having network infrastructure in-
stalled and maintained by a network specialist.
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Keep the SSID and the codes for the radio link in a
safe place. Make sure these data are readily to hand
in case faults occur.
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We recommend a thorough inspection of the premis-
es on commissioning: Establish where in the building
the DCU 220 works properly and where the operat-
ing limits are.
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If the DCU 220 is used inside a vehicle (Faraday
cage), radio communication may be severely imped-
ed.
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The radio link is affected by weather conditions.
The reception signal may therefore vary.
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Please contact your network specialist with any
queries.
2.5.2
Notes on access point (WLAN)
An access point is an electronic device which acts as an
interface between a radio network and a cable-connect-
ed computer network. This allows DCU 220, PC, laptop
and a printer to be wirelessly connected.
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We recommend using WLAN standard IEEE 802.11n
(data transmission rate max. 600 Mbps) for the
access point. The "extended range" function is not
supported.
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The WLAN configuration always depends on the con-
figuration of the access point available.
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1 689 989 221
2014-11-26