VESDA by Xtralis
VESDA VLC-400 Product Guide
www.xtralis.com
13
2.5.5
Apollo Protocol
Apollo protocol utilizes digital values of counts allocated for faults, Pre-alarms and Fire Alarms.
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Count 0 = Default Configuration Values
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Count 1 = Default Head Calibration
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Count 2 = Normalizing
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Count 3 = Not Assigned (Reserved)
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Count 4 = Laser Low
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Count 5 = Filter Fault
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Count 6 = Flow Fault
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Count 7 = Any other fault
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Count 23 to 45 = Normal (optical type)
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Count 12 to 45 = Normal (aspirating type)
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Count 45 to 55 = Pre-alarm depending upon FACP
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Count 55 = Fire Alarm
2.5.6
Sensitivity modes
The VESDA VLC-400 uses five sensitivity modes (see Table 2-3), which also allows delay times to be
configured. The user may select a sensitivity and delay mode that best suits their application, providing for the
best sensitivity while minimizing the likelihood of nuisance alarms.
Sensitivity Threshold Modes
Threshold Setting Range
Delay Time
Mode 1
0.05%/m (0.015%/ft)
15 secs
Mode 2
0.1%/m (0.03%/ft)
10 secs
Mode 3 Factory Default Setting
0.2%/m (0.06%/ft)
10 secs
Mode 4
0.5%/m (0.15%/ft)
10 secs
Mode 5
1.0%/m (0.31%/ft)
10 secs
Table 2-3: Default Sensitivity Modes
Where the FACP supports timed mode selection (i.e. selecting different modes at different times of day), the
modes may be used to support day/night settings, e.g. to provide increased sensitivity at night and selecting
normal sensitivity during the day.
Each mode is alterable via Xtralis VSC. The factory default mode is Mode 3. When the VESDA VLC-400
communicates with the fire panel, the message contains the sensitivity mode being used.
The selected mode information is stored on an EEPROM so that the value is remembered each time the
VESDA VLC-400 detector is powered-up.
When the VESDA VLC-400 is connected to an XP95 compatible panel, the mode used is not selectable from
the panel. In this case the active mode may only be set through a command from Xtralis VSC.
To configure custom alarm thresholds and delays for the 5 sensitivity modes using Xtralis VSC software
select the Smoke Thresholds tab in the corresponding detector screen. Select the appropriate Band and enter
the required obscuration percentage and/or the delay time for the selected Band. Refer to Figure 2-6 for further
information.
