©
CIAS Elettronica S.r.l.
Ed. 2.4
4 The masking thresholds are positioned one above and one below the field signal level
memorised during the working parameter acquisition phase (SW1 in Position 2 phase “j”).
They verify if there is a variation in the received field that could alter the detection capability
of the barrier. These variations can be created, for example, by progressive accumulation of
snow along the protected area or they could be produced deliberately in an attempt to
overcome the protection. The sensitivity to the detection of these variations is set during
manufacture to the
default value of “2”
, using switch
SW4
. To reduce this sensitivity move
SW1 to position 3 and set SW4 to a lower value, such as:
“1”, “0” and press S1
. NB.
Setting the value to “0” effectively disables this function. If an increase in sensitivity is
required move SW1 to position 3 and set SW4 to a higher value, such as:
“3”, “4”, “5”,
“6”, “7”, “8”, “9”, “A”, “B”, “C”, “D”, “E”, “F” an press S1.
NB. Setting this value too
high will create more possibilities of false alarms from the MW barrier.
5 After completing the IR alignment phase (described in the next section) it is possible to
select the operating scenario most suitable to the requirements of the site to be protected.
The choice of scenario is made using switch SW1 and selecting one of the following
positions:
“9”, “A”, “B”, “C”, “D”, “E”, “F”, “0”.
The scenarios are as follows:
Scenario “0” : AND with 2 techno priority Filters
Selecting this option will produce an alarm only if at least one pair of barriers of different
technologies reach alarm with the following sequence: first MW and then IR. For example:
MW + low IR = alarm, MW + high IR = alarm, MW + middle IR = alarm, low IR + MW =
No
Alarm
, bottom IR + middle IR =
No Alarm
, middle IR + MW =
No Alarm
, high IR + MW =
No
Alarm
, high IR + middle IR =
No Alarm
, middle IR + bottom IR =
No Alarm
.
The use of this scenario allows to reduce drastically false alarms due to the reaction of the
different technologies used in critical environmental conditions, such as heavy fogs or rain,
narrow corridors and closed and loosen fences. The consequent reduction in probability of
detection must be always evaluated for the specific site requirements.
Note:
middle IR is optional.
Scenario “9” : AND with 2 technologies Filter
Selecting this scenario will produce an alarm if at least two of barriers of different technologies,
regardless to the sequence (priority), detect an alarm condition. For example, first low IR and
then MW = alarm, first MW and then low IR = alarm, while the sequence first low IR then high IR
=
No Alarm
.
This scenario will filter alarms created by the IR barriers when, for example, two of them, just
before to go into disqualification, produce the alarm condition.
Scenario “A” : AND with Priority Filter
Selecting this scenario will produce an alarm if at least one single pair of barriers detects an
alarm condition as per scenario “0” but the alarm sequence of first IR barrier and then MW
barrier is discarded. For example, first low IR and then MW = No alarm while the sequence first
MW then low IR = Alarm.
This scenario will filter alarms created by the IR barrier when for example it is about to go into
disqualification and when interference is present on the MW it will produce one alarm condition.
Installation Manual
Page
47
of
56
PYTHAGORAS
