Installation
C-NET topology and connection
5
38 | 62
Building Technologies
A6V10211094_f_en_--
Fire Safety
2015-12-15
Stub connection example
● Max. 32 line devices per stub
● Total of max. 64 line devices per line connection (4 terminals)
Figure 12: C-NET stub circuit
Loop extension
The loop extension (C-NET) can be used to double the number of lines, but the
total number of C-NET devices which can be connected is not increased (max. 252
or 504). The line devices can be spread over several loops or stubs.
The loop extension (C-NET) is mounted onto the periphery board. Installation of
the two loop extensions is identical on both periphery boards. The two connections
(X13/X14) on the loop extensions are not electrically isolated.
Depending on the control panel type (2 or 4 loops), up to 4 C-NET loops or 8 stubs
can be connected.
Cable types
As a result of national standards and requirements, installation may require a
particular cable type. The relevant requirements and planning documents should
be taken into account here. The following cable types can always be used for
cabling the detector line:
● twisted, with and without shielding (recommended)
● untwisted, with and without shielding
Cable shielding
When using shielded lines (e.g. fire detection cable J-Y(St)Y, n x 2 x 0.8 mm),
ensure that the cable shielding is only connected on one side. The fire control
panel's function may be impaired by a missing or incorrect cable shielding
connection. The 'shield connection terminal blocks' option is available for the
shielding connection. Depending on the installation environment and requirements
of relevant standards, cable shielding may have to be connected and merged at
one central connection point.
Limitations
● The following restrictions apply if more then 126 devices are connected to a
loop (a maximum of 252 may be connected):
– No support for ’turbo isolation’
– Restricted loop length (see outline quantities tool FX7210 )
– A total of 252 addresses are possible per line card
– Line tester only supports a maximum of 126 addresses
In accordance with EN 54, a maximum of 32 detectors may fail in one fire sector in
the event a simple fault (e.g. wire breakage, short-circuit).
Details of the cable specification for the C-NET can be found in the system
documentation.
a
b
d
e
1
2
3
j
l
n o
4
5
6
g
h i
u
7
8
9
p
q r
0
#
C
Cerberus
TM
+
+
