PIR-018
PASSIVE INFRARED DETECTOR
2824-00005 Page 4 of 10
Sensitivity Settings
The various settings of the PIR-018 are made by means of multiple DIP - switches on the connector board.
The
DIP – Switches 1 and 2
are for
sensitivity setting
depending on the required detection performance. If the maximum
required range is less than the nominal range of the detector, it is recommended to reduce the overall sensitivity to reduce
nuisance alarms.
*) With the DIP - switches 1 and 2 both set to „on“, the overall sensitivity is 100% factory setting but can be changed with the
installation software (see annex 3 for details).
If the sensitivity is adjusted with the installation software, the programmed value will remain active also following a power
off.
Operation of the PIR-018 with overall sensitivity set to more than 100% is not recommended in outdoor applications as
the nuisance alarm rate could increase significantly.
Adaptive Threshold Discrimination (ATD)
The background noise is constantly averaged and used to adjust the threshold levels for the alarm. This special feature is
reducing the probability of nuisance alarms caused by wind, moving vegeta tion or objects that have a thermal contrast
although usually weaker than a person.
Each signal exceeding a certain minimum value will activate the ATD and increase the threshold levels depending on its
strength. The time constants for increase and decrease are chosen in a way to adapt to gradual changes. Signals generated
by a person moving within the specified speed range, however, are fast enough for detection.
Repeated movement of any kind within the field of view is therefore activating the ATD, reducing the overall sensitivity. This
has to be noted particularly when walk testing the PIR-018 following installation.
The
DIP – Switch 3
is used to activate or deactivate the
ATD
(Adaptive Threshold Discrimination), for details of the ATD
function see below.
*) Operation of the PIR-018 in this mode is possible but not recommended in outdoor applications as the nuisance alarm
rate could increase significantly as a result of turbulences.
Pulse Count
The
DIP – Switch 4
is used to set a pulse count delay for the alarm activation. This means that the alarm output is only
activated after a pre-set number of pulses having reached the alarm criteria within a certain period of time. If DIP – switch 4 is
set to “on” the pulse count delay is 3.
The programmed setting adds the defined number of pulses to the one pulse required without pulse count (e.g. pulse count
3 results in 1 + 3 = 4 pulses for alarm).
If software settings are used the pulse count delay can be programmed to any value of 0 … 10 (see annex 3 for details).
Switch
1 and 2
Overall
Sensitivity
off – off
40 %
off – on
75 %
on – off
100 %
on – on
Software Settings
*) 20 … 140 %
Switch 3
ATD
off
„off“
*)
on
„on“
Switch 4
Pulse Count
off
„off“
on
„on“
*) Factory setting: 3
