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Rockwell Automation Publication 450L-UM001F-EN-P - March 2022
Chapter 6 Installation and Wiring
Figure 48 - Terms to Help Define Safety Distance to Avoid the Possibility of Standing between the
Protective Field and the Point of Operation
Mount Multiple 450L GuardShield Safety Light Curtains
When two or more 450L safety light curtain pairs are mounted closely, the
following possibilities can happen:
1. Optical interference: The receiver of one pair “sees” sporadically infrared
light from the transmitter of another pair. Optical interference between
neighboring 450L safety light curtain systems can affect light curtain
system reliability by the sporadic switching off of the OSSDs.
2. Optical crosstalk (see
): The receiver of one pair
communicates continuously with the transmitter of another pair. Optical
crosstalk between neighboring 450L safety light curtain systems causes
holes in the protective field and is therefore an unsafe installation.
Optical crosstalk can only occur if:
a. Both systems have the same resolution and the same height of the
protective field.
b. The height of the protective field is smaller than the minimum
separation distance S provided in
.
c. The space between both pairs is smaller than the minimum separation
distance S provided in
.
IMPORTANT
Confirm that an operator is not able to stand between the protective
field and the point of operation (hazard). EN ISO 13855 requires a
minimum distance X at an installation height of 300 mm (11.9 in.). Check
EN ISO 13855 for other installation heights.
ATTENTION:
Cross talking between adjacent installed pairs can cause an
unsafe situation.
X
Middle of Depth of
Protective Field
Safety
Distance Ds
Point of Operation
Top of Tool
Machine
Stop Time
Protective Height
Middle of Depth of
Protective Field
