Fotoelektrik Pauly – Light barriers
E_52692 Ref. 2019-29
12/24
Fotoelektrik Pauly GmbH, Wahrbrink 6, D-59368 Werne, T: +49 2389/402 27-70, F: +49 2389/402 27-77
http://www.fotoelektrik-pauly.de, eMail: info@fotoelektrik-pauly.de
4.3.3 Continually self-testing
During the entire operation the light reflected by the reflector is reproduced by each external test
unit. Each external test unit generates a modulated light signal and shines through the receiver
lens and onto the own receiver. The modulated test signal received is evaluated by the highly
dynamic signal processing procedure. In this manner, a functional check of all optical and
electronic construction elements is conducted simultaneously. The light barriers performs self-tests
continuously.
If the reflector is not sighted and if no optical or electronic faults are present, the NO contact of two
separate and mutually monitored switching relays for releasing the travel movement are switched
on. The design has resulted in relays that are specially qualified. Positively driven contacts here
ensure a high degree of reliability. The power via the contacts has to be limited by an overcurrent
protection device.
4.3.4 Possible movement of the crane
Prerequisite: The reflector is undetected. The actual distance between the cranes is greater than
the set clearance distances. The beams of the reflex light barriers goes past the reflector. There
are no optical or electronic faults.
Effect: The crane is cleared for movement. For each system, two safety-related relays are switched
on and these signal the clearance for crane movement through the closed NO contacts. 2 green
status LEDs are switched on directly with the relays and visualize the clearance for crane travel.
4.3.5 Movement of the crane is stopped
Prerequisite: The set clearance distance is reached during the approach travel. The reflector edge
of the other crane moves into the beam of the first or second system of the reflex light barrier.
Effect: The reflex light barrier detects its emitted light signal and switches the system associated
two safety-related relays off. The green status LEDs darken. The travel movement is stopped.
REMARK:
Switching off the safety-related relays, depending on the task, can be used either to reduce the
speed or stop the travel movement.
In accordance with its purpose, the two systems serves to influence the cranes movement by
means of a pre-disconnection and a main disconnection.
Once the first distance has been reached, the pre-disconnection typically slows down the crane
movement while the crane movement is stopped once the main disconnection is reached.
