Rockwell Automation 442L SafeShield Safety Light Curtain Hardware - Manual (Page 16)

SafeShield Safety Light Curtain Hardware User Manual
16
Table 10. For this reason the moving area must always be
greater than the effective resolution at the edges of the
area.
If you configure a blanked area without positional and
without size tolerance, the movement of the object within
the area is very limited before the light curtain may change
to red.
The maximum selectable tolerance values depend on the
size of the blanked area: The actual tolerance expansion in
millimetres differs. It depends on the physical resolution of
the device.
Device symbol SafeShield safety light curtain Host
(receiver), context menu Configuration draft, Edit,
file card Blanking of the appropriate system, option Type
of blanking = fixed. Here you can also set the positional tolerance
and size tolerance directly in millimetres.
Increased Size Tolerance
Figure 11: Schematic layout of the fixed blanking with increased size
tolerance
You can configure an increased size tolerance of the fixed blanking.
In this way objects can pass through the protective field on one side
of the fixed blanking, e.g. for material feed on a conveyor belt (
➦
and
➨). Configure fixed blanking for the conveyor, for the material
input an increased size tolerance above the fixed blanking.
Figure 12: Example of mechanical protection of fixed or floating blanking
!
➦ ➨ !
Blanked area, sides
protected by
mechanical barriers
Unlike the normal size tolerance for blanking, the increased size
tolerance allows the blanked object on a specific side of the area to
be larger than the blanked area.
In the area of the increased size tolerance, the object can penetrate
the protective field if it does not exceed the increased size
tolerance defined.
Notes The increased size tolerance must not cover the last
beam.
On fixed blanking with increased size tolerance, you
cannot configure a positional tolerance or a normal size
tolerance in addition.
You can expand the increased size tolerance to the next blanked
area as a maximum, or to the second or second last beam of the
light curtain.
➢ After modifying the blanking, check the protective field with the
test rod. Instructions can be found in the “Daily Functional
Checks of Protective Device” on page 31.
➢ Also pay attention to the warnings in the related chapter.
ATTENTION: Blanked areas require a
separate risk analysis!
A blanked area is in principle a hole in the
protective field. Check in detail whether and
where blanking is actually required. You must
protect the blanked area in another way, e.g.
mechanically. Otherwise you must take the
blanked area into consideration in the
calculation of the safety distance and mount
the safety light curtain appropriately.