OPERATION
31
5.8
FAULT AND OPM SIGNALLING
The FV300 detector has a number of external interfaces. A fault condition is signalled on these
interfaces as follows:
Fault relay:
The fault relay will open. (Hardware, window and OPM faults)
4-20mA:
The current (source or sink) become 0mA for hardware and window
faults or 2mA for OPM faults.
Modbus:
The appropriate fault bit will be set in the status register and is available
at the next read of the unit. Hardware faults, window obscured and
window dirty are separately identified.
Video:
A fault banner will be superimposed on the CCTV image with an
information field to specify the fault type.
Each output will remain activated until the reason for the fault has cleared (non-latching mode)
when it will return to normal status. In latching mode the detector will also need to be reset, see
section 5.9.
5.9
DELAY TO ALARM
The FV300 processes the array and sensor signals to identify a potential alarm event twice a
second. The detector takes 9 cycles, 4.5 seconds, to confirm that there is an event to report. The
detector considers each report and will indicate and signal an alarm if several alarm event reports
are produced within a time window. The number of reports to consider is selectable and defines the
response time. The detector response time consists of the initial 4.5 seconds followed by the
selectable delay.
The FV300 detector provides 4 selectable alarm response times. These are set on the DIP switches,
see Section 7.2.2.
The default setting requires that in an 8 second window the event should be reported for at least 4.5
seconds to put the detector into alarm. This gives an overall response time of 9 seconds. The
minimum time from the presentation of a detectable fire to activation of the outputs is 6 seconds
(short delay). The alarm delay response times are also used for the pre-alarm response.
The selected response time also defines the alarm clearing time in non-latching mode. An alarm is
cleared when a number of reports of no alarm are produced. The default setting requires that 20
reports (10 seconds) are detected. Thus a detector will remain in alarm for at least 10 seconds.
SW
1-2
SW
1-3
Delay
Description
Alarm / Prealarm
ON condition
Alarm / Prealarm
OFF condition
0
1
SHORT
1.5 seconds over threshold
in any 4 second period
10 seconds under
threshold
0
0
MEDIUM
(Default)
4.5 seconds over threshold
in any 8 second period
10 seconds under
threshold
1
0
LONG
9 seconds over threshold in
any 12 second period
12 seconds under
threshold
1
1
EXTRA LONG
12 seconds over threshold in
any 15 second period
15 seconds under
threshold
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