OUMAN WL-Base Manual

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PC in internal network
FIGURE 1 structure of wireless sensor network
The mesh structure of the wireless network improves network reliability. The signal has multiple routes, from
which the system automatically selects the strongest. The larger the number of routers in the coverage area,
the more routing options the signal has. One wireless base station can monitor data from up to 100 sensors.
Base station connections:
– Direct connection to base station with browser. (over the Internet/locally)
– Ounet connection directly from the base station. (over the Internet)
– local Modbus RTU connection.
(Connections can be utilised simultaneously)
Initial engineering in network construction:
• Building structures are crucial in network engineering. Metal structures weaken the signal, which is also the case for
lift wells, electrical power centres, fire doors, etc.
• Old concrete buildings are easier in regard to networks than buildings constructed in the 2010s, where the amount
of steel in the structures is higher.
• From the base station, the network should be built by first finding a suitable "backbone" for the network and applying
the operating voltage to the sensors, so that they will act as routing elements in the network. See FIGURE 1.
• Once the network is operational in this regard, battery-operated sensors are placed as part of the network.
• The positioning of room sensors must take into account that the sensor should never be exposed to direct sunlight.
It must also be ensured that no other external sources of heat affect the sensor, such as refrigerators, television sets,
ventilation windows, water radiators, etc.
• It is often the easiest way to place the base station to the same space with the automation substation (heat distribu-
tion room, AHU room), but due to the weak 3G signal the optimal location can also be in the other parts of the build-
ing. Centrally selected location for the base station can improve the functionality of the sensor network, because
more sensors can be directly connected to the base station without routers.
• It is able to select external antenna to the base station which improves reception of the sensor network when need-
ed to achieve better signal levels.
• The base station requires a separate housing, e.g. K118 which also includes the needed power supply. (must be ap-
plied when certain IP protection class is needed)
Internet / Ounet
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= Base station
Internet
connection
= Routing wireless sensor
= Wireless sensor
Wireless sensor system
General description
The wireless Ouman sensor system
enables a quick and easy reading of
precise room temperature data in a
building without the laborious laying of
cables and drilling of walls. The sensor
system comprises a base station, sen-
sors that act as routers and are con-
nected to the mains, and battery-op-
erated wireless sensors. A predefined
register list makes it easy to connect
the wireless sensors to a SCADA sys-
tem. In the event of failure, a damaged
sensor can be replaced without chang-
ing the register list. This makes the
installation of the replacement sensor
quicker and easier.