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© Carlo Gavazzi A/S
robust bus system has been proven in more than 150,000 installations worldwide in a wide range of
building automation applications such as water distribution, mining, railways, parking systems and
many other areas�
Dupline
®
Bus Features
The strength of the Dupline
®
system lies in a unique set of features that enables elegant, flexible and
cost-effective solutions� Most of these features originate from the effective time-division multiplex
technology used� The efficiency of the protocol allows a low carrier frequency of 1 kHz, providing long
transmission distance and superior noise immunity� Hence, Dupline
®
is capable of transmitting
multiple digital and analogue signals over distances of up to 10 km via a non-shielded, non-twisted 2-
wire cable, without using repeaters� These unique Dupline
®
features provide considerable cost savings
in many installations�
Dupline
®
Basic Elements
A Dupline
®
network consists of 4 basic elements: The master module, input modules, output modules
and a 2-wire cable� The master module controls the communication on the Dupline
®
bus� It sends out
the Dupline
®
carrier signal and coordinates all transmission between input and output modules�
In-
put modules connect to contacts, voltages and analogue signal sources etc� and transmit this
information via the 2-wire cable� In the parking system the ultrasonic sensors can be regarded as input
modules because they use the Dupline
®
bus to send status information to the CPMs�
Output modules connect to loads like lights, roller blinds, motor contactors, valves etc� In the parking
system, the CPM can be regarded as an output module controlling the display based on the informa-
tion received from the sensors via the Dupline
®
bus�
Dupline
®
Bus Including a 3’rd wire
The parking guidance system is using an expanded version of Dupline
®
in which a 24 VDC power
supply is included as a 3’rd wire� The reason being that a power supply is needed for the sensors on
the bus� The power supply needs to be synchronized with the Dupline
®
bus, and this is taken care of
by the specific master module for the parking system�
Fig. 17: Example of a basic Dupline
®
system
