e1276e
10
Siemens Building T
echnologies
Cerberus Division
09.2000
3.7
Functions in operation with interactive system
3.7.1
Emergency operation
If the DLO1191 can no longer be polled by the control unit, for example, due to a
µ
P fail-
ure, it switches automatically to emergency operation. In the event of a fire this detector is
still able to trigger a collective alarm.
3.7.2
Line isolation function
If a short circuit occurs on the detector bus line, detectors with separator prevent failure of
the entire bus line because only the defective portion of a line is isolated. The DLO1191
features such a isolation function. Before and after the detector an electronic switch
(FET) is installed in the bus line. This switch opens automatically in the event of a short
circuit and the defective portion of the detector line is disconnected.
3.7.3
Diagnostic facilities
A detector can transmit four events to the control unit:
Danger level 0 (quiescent value)
Danger level 1 (possible danger)
Danger level 2 (probable danger)
Danger level 3 (highly probable danger)
Danger level 1
For early warning where installation locations are critical, the number of times the thresh-
old to danger level 1 is exceeded is counted by the control unit. When the counter reaches
a preset value an information «application warning» is displayed. This information is reg-
istered in the event memory of the basic parameterization of the control unit.
Danger level 2
The occurence of danger level 2 causes the actuation of an information «Warning» in the
basic parameterization of the control unit. This information is also actuated in the event
memory of the basic parameterization of the control unit.
Danger level 3
As a rule, this is a precondition for direct alarm actuation. Dual or multiple cross-zoning is
possible through corresponding programming of the control unit.
Response threshold 1...3 corresponds to danger levels (G1 ... G3) for standard sensitivity
Time
Signal [%]
0
10
20
30
40
50
60
70
80
90
100
110
0% compensation value
100% response threshold 3 (G3)
85% response threshold 2 (G2)
70% response threshold 1 (G1)
Signal
NF = Compensation
max. NF