Rockwell Automation 442L SafeShield Safety Light Curtain Hardware - Manual (Page 15)

SafeShield Safety Light Curtain Hardware User Manual
15
Figure 9: Example of mechanical protection of fixed or floating blanking
➢ After modifying the blanking, check the protective field with the
test rod. Instructions can be found in the “Daily Functional
Checks of the Protective Device on page 31.
➢ Also pay attention to the warnings in the related chapter.
Properties of Blanked Areas
• The SafeShield safety light curtain is capable of blanking a total of
four areas simultaneously.
• Fixed and floating blanking can be mixed.
• A minimum of one beam spacing must exist between two blanked
areas. The SCD software automatically ensures that this is the
case during the configuration. Exception: It is not necessary to
maintain any distance between an area of floating blanking with
partial object monitoring and an area of fixed blanking without a
positional tolerance. In this case the effective resolution for the
overlapping is equal to the sum of the effective resolutions in the
two areas (see Table 10 and Table 11).
• The first beam of the light curtain (closest to the 7-segment
display) cannot be blanked. It is needed for the synchronization
between sender and receiver.
• With fixed blanking, the 7-segment display indicates r as soon as
sender and receiver are aligned.
Blanked area, sides
protected by
mechanical barriers
Fixed Blanking
Figure 10: Schematic layout of the fixed blanking
The SafeShield safety light curtain is capable of fixed-blanking one
or several adjacent beams, e.g. to allow continued operation in
spite of an obstruction such as a table placed permanently in the
light path.
The blanked area will no longer be part of the protective field.
Objects to be blanked out must therefore be permanently located
inside the blanked area (1). As soon as the object is removed from
the beam path, the light curtain will send a signal to stop the
dangerous movement (2). Protection is otherwise no longer
guaranteed.
Notes On devices with a physical resolution of 14mm, you can
set an area positional tolerance for the fixed blanking of
maximum ±2 beams. This is e.g. helpful when blanking
vibrating objects. The effective resolution of the light
curtain does not change due to the positional tolerance.
In addition you can define a size tolerance of –1 beam, i.e.
the blanked object is allowed to be a maximum of 1 beam
smaller.
Depending on the size tolerance configured, the effective
resolution reduces at the edges of the blanked area as per