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Functional principle of the joker² light barrier system
Copyright eltima electronic 2022
Functional principle of the jok
e
r
²
light barrier system
Functionally, the light barrier system consists of an analog and a digital part.
The analog part controls and monitors the light barriers, the digital part con-
trols the outputs.
The analog part
The analog part controls and monitors up to the three light barriers con-
nected to the system. It captures their status and, if one has been inter-
rupted, it passes this information as a trigger to the digital part.
The reflex barrier
The light barriers of the jok
e
r
²
system are designed as reflex light barriers.
The transmitter and receiver are in the same housing.
The transmitter emits fast successive infrared light pulses, which are re-
flected by a reflector and sent back to the receiver. The strength of the re-
flection is shown by the reflection bar, see Figure 11.
If at least one pulse is missing, or is
received very weakly, e.g. because
an object is in the beam, the light
barrier is considered to be inter-
rupted. This status is reported as a
trigger to the digital part, which will
now control the outputs a to d. At
the same time, the interruption is in-
dicated with a dot next to the reflec-
tion bar, see Figure 12.
The subject itself can also serve as a
reflector. In this case, the light bar-
rier acts as a light sensor. This oper-
ating mode can be selected in the
basic parameter level. It can be set
individually for each of the three
light barriers. In this mode, how-
ever, the range is much smaller in
comparison with using a reflector.
The range essentially depends on
the reflective properties of the sub-
ject.
Figure 10: Reflex barrier
Figure 12: Light barrier interrupted
Figure 11: Reflexion bar