32
3.3.7.8
Falling Trip Point
Z 1 G r o u p 1 N O 2
F a l l i n g : 1 . 0 p p m
Figure 3-48 Falling Trip Point Entry
The default falling trip points are:
Description
Carbon
Monoxide
Nitrogen
Dioxide
Combustible
Gas
Ammonia
Hydrogen
Sulfide
Refrigerants
Carbon
Dioxide
Oxygen
Type
CO
NO2
EX
NH3
H2S
REF
CO2
O2
Falling Level
15ppm
1.2ppm
5%
10ppm
3ppm
50ppm
800ppm
20.6%
3.3.7.9
Multiple Sensor Mode
Z 1 G r o u p 1 N O 2
M o d e : 2 V o t i n g
Figure 3-49 Sensor Mode Selection
When multiple sensors are being monitored by a group, the output decision can be based on either voting, as shown here, or the
average of all sensors in the group. Valid modes are:
–
1 Average
–
2 Voting
(default)
When the configuration is Average, the gas concentrations from all sensors in the group are averaged and if the average is greater
than or equal to the rising trip point the zone outputs(s) are activated. When the average is less than or equal to the falling trip point the
zone output(s) are de-activated. If the average is between the two trip points, the outputs remain in their previous state.
When the configuration is Voting, the number of sensors in the group indicating a value greater than or equal to the rising trip point is
counted. If the count is greater than or equal to the quorum then the zone output(s) are activated. If the count of sensors indicating less
than or equal to the falling trip point is greater than or equal to the quorum the zone output(s) are de-activated. Activating the output(s)
is given priority if a group has an equal number of sensors with gas readings greater than or equal to the rising trip point and sensors
with readings less than or equal to the falling trip point.
3.3.7.10
Multiple Sensor Quorum
Z 1 G r o u p 1 N O 2
Q u o r u m : _ 2
Figure 3-50 Quorum Entry
It is up to the installer to ensure that the quorum entry is appropriate for the configuration. Valid entries are one to twelve, but a value
greater than the number of sensors being monitored by the group, stops the group from controlling the outputs. The default quorum
value is 1.
3.3.8
Configure Signals Submenu
The DVP-120 can drive the buzzer, horn and strobe with different sound patterns to indicate the severity of the current conditions.
These patterns are selectable by the installer using this group of submenus. Once again, the left and right keys will scroll through the
signal types and the up and down keys will scroll to the signal sources.
3.3.8.1
Alarm Signal Summary
The alarm signals are in response to one or more sensors indicating gas levels at or above the sensors’ configured alarm level.
