Restart Interlock (Res) - SICK LE20 Instrucciones De Operación

Operating Instructions
LE 20
Note
Note
WARNING
8 008 685/Q913/2007-05-21
Product description
active when the TEST/NON input is open with 24 V. If a fault
occurs, the two OSSD 1 and OSSD 2 supply connections of the
evaluation unit assume the OFF status. The test does not affect
the protective functions of the connected photoelectric switches
and photoelectric switch cascade.
The two OSSD 1 and OSSD 2 outputs of the evaluation unit must also
be configured as two-channel outputs in the machine control unit.
Since the C 2000 and M 2000 are self-testing units, only the OSSD 1
and OSSD 2 outputs of the C 2000 and M 2000 are connected to
SENSOR A and SENSOR B of the LE 20. The test input of the C 2000
and M 2000 unit must be connected to TEST A or TEST B of the
LE 20.
External test
Since the LE 20 system is a self-testing unit, an external test is
unnecessary and the TEST EXTERN input must be connected to
24 V. If, however, the machine control unit has been designed for
an external test, the LE 20 system can be configured for the
external test. A NC contact is connected to the TEST EXTERN input
of the evaluation unit for this purpose. The device self-test function
is active when a 24 V signal is applied to this input. If the 24 V
signal is deactivated for at least 30 ms by an NC contact, the
evaluation unit carries out an additional test cycle in which the
evaluation unit and photoelectric safety switches are tested.
The two OSSD outputs of the evaluation unit assume the OFF
status to confirm that the self-test has been successfully
completed. The NC contact must then reconnect 24 V to the TEST
EXTERN input. If the test lasts longer than 150 ms, the restart
interlock must be activated.
No emergency-stop switch connected to TEST EXTERN!
No emergency-stop switch must be connected to the TEST EXTERN
input.
3 . 3 . 2

Restart interlock (RES)

If a light beam has been broken, the restart interlock stops the
machine from being restarted using the restart pushbutton –
connection to RES terminal (restart interlock) – has been pressed
and released after the light beam is clear again. The restart
pushbutton also has to be pressed then the device has been
switched on. The function can be activated/deactivated.
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