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The time set jumper can be installed in any of three positions to
alter the factory set trailing edge delay of four seconds. The drawing
to the right shows the three choices. Four seconds is right for most
i
mmediately exit but moves around in front of the door, they will
continue to retrip the
AL-85851
. Persistant retripping of the
85851
will cause the Lock Control and REX Relay to remain latched until no movement is sensed for a
time greater than the set 1/2 second. It is important to note that this device has a “trailing
edge” delay – i.e. the device Lock Control and REX Relay will remain latched until a time
greater than the set time has expired since the last detected movement. If you used the
four second setting on the XMS for integration with an access control system, you would risk the
following problem. On initial detection, the access system starts timing for 10 seconds (as an
example) But the person does not immediately exit but moves around in front of the door
so that the
AL-85851
signal does not change but stays closed because of the four
second timing function. This allows the access system’s 10 second timer to time out and if
the door is then used, a “forced door” alarm signal will result. So the 1/2 second setting is
right for integration with access control systems.
Another application where you should employ the 1/2 second setting is when the
AL-85851
is employed to initiate delayed exit when you are using
a
model XDT timer.
The eight second setting is rarely used unless there is strong concern for maximum time being
allocated for egress even when movement is not maintained. The problem with an eight second
trailing edge delay is that entry security begins to be compromised by the door remaining open
for this length of time following exit.
6.
DETECTION PATTERN SET-UP
At this point in the installation, the unit should be physically mounted and wired.
You should have also considered changing the jumper settings. Your final step is to
adjust the detection pattern for the optimum combination of egress safety and entry
security. Before doing this, set the time set jumper to the 1/2 second position
(shown in the drawing to the right). As you are adjusting the pattern, you will make
many quick tests of the unit and this will be most efficient if you don’t have to wait for a four or
eight second trailing edge timer to expire.
The
AL-85851
provides two means of adjustment. First, the entire
barrel assembly rotates 90 degrees so that the unit can look “out” or
“down”. Second, aiming screws (see Figure 2) are provided to laterally
control the pattern. To access the aiming screws, the barrel
assembly must be rotated so that the unit looks “out” so while
you are making these adjustments, you will need the barrel locking
screw (see Figure 2) to be loose.
In most applications, the unit is set to look “down”. The exception would
be if the
AL-85851
was mounted on a wall perpendicular to the door
rather than parallel to it. As the detection pattern proceeds outward
from the XMS it spreads. We are talking here about spreading in
the same direction as the barrel rotation rather than lateral
spreading which is
constrained by the aiming screws.
A
B
A
B
A
B
FOUR SECONDS
FACTORY SET
applications. 1/2 second is used for pattern set-up (see Section 6)
and certain applications where an external timer should replace the
1/2 SECOND
XMS timer. For example, when the
AL-85851
is integrated with
an access control system (see Section 3.4), the
85851'
s REX relay
will
trigger the access system’s lock control relay and the magnetic lock
will release for the same amount of time that is programmed for entry.
If the set jumper is installed for the 1/2 second setting and
assuming
8 SECONDS
A
B
constrained by the aiming screws. The drawing on the right provides an
example of this spreading. Assuming the
AL-85851
is mounted seven feet
above the floor, the pattern will spread out roughly three feet by the time it reaches the floor.
Maximum detection distance is approximately 20 feet.
The aiming screws are used as follows. They control internal louvers that point the same way
as the slots in the screws. When adjusting these screws, do not turn them past the point where
7 FT. (2.1 M)
a person is initially sensed by the
AL-85851
, then does not
3 FT. (1 M)
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