Technical / Programming Manual
FT128 Rev 2.2
100
14 Functions / Services / Features
Some Functions / Services / Features require programming via EBLWin, see chapter PC
software (S/W), page 14.
How to connect the PC and more information, see chapter "Download SSD" page 157 and
"Download software (S/W)" page 160.
Notes: The information in the following sections from 14.1 - 14.7 is valid for the analogue
smoke detectors 430x / 440x in NORMAL mode.
Chapter 14.5 is valid for the analogue heat detectors 3308 / 3309 in NORMAL mode.
For the analogue detectors 440x in Advanced mode, see chapter “Advanced
Mode”, page 127.
14.1 Sensor Value
An analogue smoke detector is like a "sensor". It detects its environment at all times. Each
detected analogue value is converted in the detector to a digital "sensor values", which is
continuously picked up and evaluated by FT128 for each individual detector. In Figure 34
the (digital) sensor values (during a certain time) are represented by the graph "Working
level".
14.2 Week Average Sensor Value
Each hour, one sensor value is stored in a special memory (in FT128) and each week,
these stored sensor values are used to calculate a "week average sensor value".
This
is done for each analogue smoke detector individually. In Figure 34 the (digital) week
average sensor values are represented by the graph "Week average sensor value" (B).
Each analogue smoke detector has a default sensor value = 0.1 %/m and a week average
sensor value = 0.1 %/m (i.e. at Time = 0).
A "Fire Alarm Offset" (value) is added to the week average sensor value to get each
detector's "Fire Alarm Level", i.e. the fire alarm level will be adjusted in relation to each
new week average sensor value in order to keep the detector's fire alarm sensitivity
constant. The fire alarm level is in Figure 34 represented by the graph "Fire alarm level"
(C) - parallel with the graph "Week average sensor value" (B).
In Figure 34 (at Time = 0):
The week average sensor value (B) is 0.1 %/m and the fire alarm offset is 3 %/m, i.e.
the fire alarm level (C) is 0.1+3=3.1 %/m.
Service signal will be given when the week average sensor value for a detector has
reached the service signal level (1.8 %/m), i.e. the detector is "dirty" and has to be
replaced. See "Service level" (D) Figure 34. The week average sensor value will now stay
on 1.8 %/m, i.e. the detector will be more sensitive until it is replaced with a new one.
"Sensor Information" is available via menu H4/U4. Via EBLWin and a PC connected to
FT128 you can also get continuous "Sensor Information" for one or several detectors.
Also via the Web-server II 1598 you can get "Sensor Information" for one or several
analogue detectors on a COM loop.
The smoke detector sensor values are presented as obscuration in % per meter (%/m).
(Heat detector values as °C.)
The very first week average sensor value will be calculated within 2½ minutes after any restart, i.e. also after SSD
download. During this "2½ min. period" all analogue smoke detector fire alarms are suppressed.
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