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Functional principle of the joker² light barrier system
Copyright eltima electronic 2022
The cross barrier
Symbol:
, Level:
In order to increase the selectivity, the cross barrier can be used. It is formed
by the light barriers 1 and 2, which are linked by a logical AND. This means
that the action mode is met if both light barriers are interrupted at the same
time (1 AND 2).
The light beams are typically ar-
ranged crosswise and in one plane.
The action mode is met, when the
subject interrupts both light barriers
at the crossing point. Thus it is possi-
ble to have more precision on the
subject location and arrange the ar-
tistic composition of a picture
The point or rather the "sensitive"
area in which the action mode can be
met depends on both the size of the
subject and the angle that the two
beams form. If the light beams cross
at an angle of 90°, the area is the
smallest. Furthermore, the larger the
subject, the larger the sensitive area.
However, the light beams do not necessarily have to be arranged crosswise
in one plane. They can be arranged anywhere in space. The action mode will
be met when both light beams are interrupted at the same time.
Once the action mode is met, both beams must be reset before a new action
can be triggered.
The directional barrier
Symbol:
, Level:
The directional barrier is formed by the light barriers 1 and 2. The action
mode is met if at first the light barrier 1 and subsequently the light barrier 2
is interrupted.
When light barrier 1 is interrupted, the system is activated and waits for light
barrier 2 to be interrupted. If this happens, the action mode is deemed to be
met and the status is reported to the digital part as a trigger.
If an object first moves through light barrier 2 and then through 1, i.e. in the
opposite direction, no trigger is issued.
Once the action mode is met, both beams must be reset before a new action
can be triggered.
When setting up the direction barrier, care must be taken to ensure
that the objects move through both beams. If an object only inter-
rupts light barrier 1 and not light barrier 2 (e.g. because it stops or
changes direction) the system will still be activated. If an object then
comes from the "wrong" direction, i.e. from 2 to 1, the action mode
will be met and the trigger set when light barrier 2 is interrupted. If
the object continues to move and now also interrupts light barrier 1,
the system will be reactivated. So the direction becomed reversed!
To get back to the initial direction an object must cross the barriers
from 1 → 2.
Subjects
Light beams
Sensitive area