Rockwell Automation 442L SafeShield Safety Light Curtain Hardware - Manual (Page 17)

SafeShield Safety Light Curtain Hardware User Manual
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Device symbol SafeShield safety light curtain Host
(receiver), context menu Configuration draft, Edit,
file card Blanking of the related system, option Type of
blanking = fixed + increased size tolerance. Here you can adjust
the position of the increased size tolerance and the size of this area
in millimeters directly.
Floating Blanking
Figure 13: Schematic layout of the floating blanking
The SafeShield safety light curtain is capable of blanking an area of
two or more adjacent beams (
➦). In contrast to fixed blanking, the
blanked area is allowed to move (
➨) without the light curtain
changing to red. The safety light curtain detects whether the object
is in the blanked area or not (!, so-called Object Monitoring, see
below in chapter).
Notes You cannot combine the function Floating blanking with
partial object monitoring with the function Reduced
resolution (see page 18).
For each floating area with complete object monitoring
you must choose a size tolerance of –1 or –2 beams, i.e.
the blanked object is allowed to be a maximum total of 1
beam or 2 beams smaller.
Figure 14: Example of mechanical protection of fixed or floating blanking
Depending on the size tolerance configured, the effective
resolution reduces at the edges of the blanked area as per
!
➦ ➨ !
Blanked area, sides
protected by
mechanical barriers
Table 10. For this reason the moving area must always be
greater than the effective resolution at the edges of the
area.
The size of the blanked area for floating blanking with
complete object monitoring must be at least equal to the
effective resolution.
The size tolerance of –2 beams can be used only in devices
with a physical resolution of 14mm.
Device symbol SafeShield safety light curtain Host
(receiver), context menu Configuration draft, Edit,
file card Blanking of the related system, option Type of
blanking = floating (full) or floating (partial). With the help of the
selection fields, the size of the area can be selected directly (in
millimeters).
Object Monitoring
Despite the floating blanking of the area, the safety light curtain
monitors whether there are objects in the area with floating
blanking. For areas with floating blanking you must configure which
type of object monitoring is to apply to the areas:
!
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.