Rockwell Automation 445L GuardShield Micro 400 Safety Light Curtain User Manual - Manual (Page 14)

R
GuardShield™ Micro 400 Safety Light Curtain User Manual
12
Original instructions
Figure 9: Multiple GuardShield Micro 400 alignment options
Cascaded GuardShield Micro 400
Configuration of Operating Modes in Cascading Systems
All of the operating modes of a cascaded GuardShield Micro 400
can be configured at the MSR42 control unit.
Two Segment Cascading GuardShield Systems
When the safety distance calculation requires that a GuardShield
pair is vertically mounted at a distance that would allow a person
to stand between the vertical pair and the machine hazard, a
means of detection of that person is required.
There are a few methods of detecting the presence of a person
who could be standing in front of the machine hazard but inside
of the light curtain; installing a safety mat or safety laser scanner
are possible solutions, however, they are costly solutions as these
are separate safety systems that need to be integrated to the
safety circuit. The most cost-effective solution is to interconnect
an additional light curtain in series to the vertical pair. This is
accomplished by first selecting a cascading pair of GuardShield
Micro 400 safety light curtains with a protective height and
resolution based upon the results of a risk assessment. It is then
necessary to select the horizontal protected height of the pair of
GuardShield Micro 400 light curtains. This pair should provide
detection from the vertical pair to the front of the machine
hazard. In most cases this pair of GuardShield Micro 400 can be 30
mm resolution as their purpose is to detect the presence of a
person, not a person’s fingers or hands.
The next step is to select the interconnect patchcords for the
transmitter and receiver. These patchcords are offered in a variety
of lengths (“Table 6: Available cable types” on page 14). The final
cascading segment which is not connected to another pair of
GuardShield Micro 400 light curtains is equal to a standard
GuardShield Micro 400 light curtain.
Figure 10: “L-shaped” two segment GuardShield Micro 400 cascading systems offer
protection when it is possible to stand between the vertical light curtain and the machine
hazard
Three Segment GuardShield Cascading Systems
When the use of corner mirrors is not practical or possible, three-
sided guarding of a machine hazard is possible using cascading
GuardShield Micro 400 light curtains.
Figure 11: Top and bottom mounting of three GuardShield Micro 400 segments is possible,
which will provide three-sided machine guarding without the use of corner mirrors
Transmitters emit in
opposite direction. Each
receiver receives only the
beams of the appropriate
transmitter.
Transmitters emit in same
direction:
Optical (physical) barrier
necessary
Positioning of the light
curtain: Transmitters emit in
opposite direction.