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© Carlo Gavazzi A/S
The elements of the structure are the following:
The Dupline
®
master Module with DC Power Supply
This unit generates the Dupline
®
carrier signal and DC power supply synchronization needed to create
the 3-wire bus linking all the sensors and CPM’s in the segment together� In a given segment you will
always find one - but only one - master module� A Dupline
®
3-wire bus at segment level is referred to
as an L1 bus�
Sensors and Indicators
Each parking space belonging to the segment needs one sensor and one indicator (unless the sensor
with built-in indicator is used)� Each sensor needs to be connected to the 3-wire bus and it must have
one of the 120 addresses in the range A1���O8 assigned to it for transmission of the sensor status
(occupied / not occupied) on the bus� The 8 Dupline
®
addresses in group P are reserved for system
purposes and cannot be used for sensors� The sensor is mounted in the middle of the parking space
and the indicator is mounted at the entry to the parking space, where it will clearly indicate to the driv-
ers if the parking space is available or not� The two units are connected with 2 wires�
Car Park Monitor(s) (CPM) with Display(s)
Each display is controlled by a CPM, which must always be configured to operate in slave mode
when it is connected to a segment bus (L1)� In slave mode, the CPM monitors a user-defined range
of parking spaces within one segment, which essentially means a range of sensor addresses (e�g� A1,
A2, and A3���A7)� By reading the status of these sensor addresses, the CPM calculates the number of
open parking spaces� It sends via RS485 the result to the display, which then displays the number and
shows a dynamic green arrow� Unless of course the number is “0”� In that case red crosses will be
shown� It is possible to have several CPM modules with displays within one segment�
Another example of a 1-segment system is when we are using the 3-coloured sensor or 3-coloured
LED indicator� The 2 and 3-coloured sensor types are in general equal to each other but the 3-colour-
ed LED indicator is different compared to the 2-coloured LED Indicator� The 3-coloured LED indicators
are Dupline
®
bus powered just like the sensors�
The function of the 3-coloured LED is equal to the 2-coloured LED but the new indicator/sensor allows
the customer to use part of the Carpark for special parking, like for instance VIP, guest and perhaps
family parking�
This is done by using Carpark software to book these areas for special purposes� Then the drivers are
in position to find the parking places by navigating by the colors of the sensors/LED indicators�