en
16 | DCU 100 | User information
2.5
Wireless link
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DCU 100 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 network. Like Bluetooth,
WLAN provides a wireless link on the free 2.4 GHz ISM
band (ISM: Industrial, Scientific, Medical). This frequen-
cy range is subject to state legislation, can however be
used without a license in most countries. Consequently
a large number of applications and devices employ this
frequency band for transmission. This can result in fre-
quency interference.
Depending on ambient conditions, the WLAN link may
therefore deteriorate, e.g. in the case of Bluetooth links,
cordless telephones, radio-controlled thermometers,
radio-controlled garage door openers, radio-controlled
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 wire-
less systems, as proper functioning of these items
could be impaired.
Pay attention to the following to ensure the best possi-
ble connection:
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The WLAN signal always tries to find the most direct
path. When setting up the PC/Laptop and access
point (see Sec. 2.5.2), make sure there are as few
obstacles as possible (e.g. steel doors and concrete
walls) which could interfere with the signal from and
to the DCU 100.
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Inside buildings, the range of the WLAN is also great-
ly influenced by the construction materials used.
Conventional masonry, wooden walls and various
types of dry construction wall scarcely impair the
propagation of radio waves. Thin gypsum walls are
however problematic, as considerable amounts of
moisture may accumulate in the gypsum and result
in the absorption of radio signals. Metal walls and
concrete (in particular reinforced concrete) large-
ly block out radio waves. Cellar ceilings are often
impenetrable. Generally speaking, walls with a lot
of installed metal (e.g. pipes, wires) obstruct radio
waves.
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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 radio tele-
phones, motion detectors and microwave ovens.
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Human beings are also an obstacle to wireless trans-
mission. It must therefore always be ensured that
no-one stands between the transmitter and receiver.
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1 689 989 174
2015-03-25
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We advise having the network infrastructure installed
and maintained by a network specialist.
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Keep the SSID and the codes for the wireless 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 100 works properly and where the operat-
ing limits are.
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If the DCU 100 is used inside a vehicle (Faraday
cage), wireless communication may be severely
impeded.
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The wireless link is affected by weather conditions.
The reception signal may therefore vary.
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Please contact your network specialist for any que-
ries.
2.5.2
Notes on access point (WLAN)
An access point is an electronic device which acts as
an interface between a wireless network and a ca-
ble-connected computer network. It provides a wireless
connection between the DCU 100, the PC/Laptop and
a printer.
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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.
Heed the following:
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The access point should be located as centrally and
high up as possible, ideally under the ceiling. The
access point is not to be installed behind any me-
tallic objects, such as radiators or in a metal switch
cabinet.
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If there is only one access point antenna, this should
face downwards towards the floor. If an access point
has several antennas, these should be in three-di-
mensional arrangement.
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The best and highest transmission rates are always
achieved if there is visual contact between the
DCU 100 and the access point.
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In the event of a weak link it may be useful to change
the channel set on the access point. Where possible
avoid employing channels adjacent to those already
in use.
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It is advisable to configure wireless communication
encoding at the access point.
Robert Bosch GmbH