Rockwell Automation 442L SafeShield Safety Light Curtain Hardware - Manual (Page 14)

SafeShield Safety Light Curtain Hardware User Manual
14
Table 7: Overview of the blanking function
Notes If you are using the weld shields (see page 45) available as
an accessory, the overall scanning range will be reduced by
8% per shield.
Mirrors, available as accessories (see page 45) reduce the
usable scanning range as a function of the number of
mirrors in the light path (see Table 7). When using
mirrors, you must configure the light curtain for a long
scanning range.
Table 8: Scanning Range when using 1 or 2 mirrors
The information in the table relates to 90° beam deflection per
mirror and a protective field height of 900mm.
Blanking
Notes The SafeShield safety light curtain offers various ways of
blanking the protective field. In this way in many
applications a higher level of safety and availability can be
assured than would be possible without the usage of the
blanking function. This requires the careful analysis of the
usage of blanking as part of a risk analysis for these
Fixed Blanking Floating Blanking
Fixed blanking Fixed blanking with increased size
tolerance Floating blanking with complete
object monitoring Floating blanking with partial object
monitoring
An object of fixed size must be at a
specific point in the protective field. On one side of the fixed blanking an
object of limited size is allowed to
move through the protective field. An object of fixed size must be within
a specific area of the protective field.
The object is allowed to move. An object of limited size is allowed in a
specific area of the protective field.
The object is allowed to move.
Mirror 14mm 20, 30 or 40mm
1 5.4m 17.0m
2 4.8m 15.2m
ATTENTION: Do not use mirrors if the
formation of droplets or heavy
contamination of the mirrors is to be
expected.
The formation of drople1ts of heavy
contamination can be detrimental to the
reflection behavior. The protective function
of the system will be affected and the system
will thus become unsafe. This would mean
that the operator is at risk.
applications. Only if the analysis produces advantages in
reliability and thus advantages in safety when the blanking
function is used the usage of the function is
recommended.
The person responsible for the machine has the
responsibility to decide whether or not to use the
blanking function and to undertake the installation,
mounting and configuration of the light curtain such that
• The necessary safety is achieved on the machine
and
• Access to the hazardous area through the light curtain in
conjunction with the blanking function is prevented by
other guards.
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.