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© Carlo Gavazzi A/S
The above described 1-segment system manages an area of the parking facility and provides local guidance for
that area with its displays and indicators� In order to extend the system to provide guidance at a more “global”
level as well, it is necessary to link all the CPMs from the various system segments together�
Segments Linked Together via L2 Bus for Totalizing
The L2 bus is used to collect data from all the segments (L1 buses) and distribute the data to displays
that show the numbers of available spaces� The CPM module GP34829091 which is programmed in
master mode has the possibility of showing numbers of available spaces from specific segments in
numerical order, e�g� ID5, ID6, ID7 etc� Also the CPM modules are able to show the total number of
available spaces in a Parking Guidance System system� Then all segment ID numbers must be select-
ed to accomplish this� The number of CPM modules installed in “master Indicator mode” is unlimited�
The module does not use or occupy addresses but collects only data from the L1 busses (segments)�
On the L2 bus there must always be one CPM module programmed as “master”� The master has the
same function as the “master Indicator” but it also functions as a provider of multiplex signals in the
system� Only one “master” can be present on the L2 bus�
The two busses, L1 and L2 are galvanically separated from each other, which means if one or sev-
eral segments (L1 busses) are suddenly malfunctioning, the rest of the system will continue working
without any problems� When the defective segments have been repaired they will automatically be
integrated in the system again without the need of resetting or restarting the system� This will not in
any way affect the user�
If the L2 bus is malfunctioning, only the displays will be affected� All the segments (L1 busses) will
con tinue working without any problems� The software will also continue working because all the infor-
mation to the software is provided from the GP34960005700 Dupline
®
master module on the L1 bus�
Fig. 25: LED indicators powered by bus or sensor