LINK Systems Max Presence Sensing Device - Manual (Page 11)

Link Lite Black Max Section 3 - Installation
3-6
3. The mounting location or method must
leave access for work pieces, tool changes,
and other operational requirements.
4. The main transmitter and receiver must
be mounted so that the indicator lights and
warning messages on their enclosure doors
are clearly visible to operators and supervi-
sors and so that the enclosure door can be
opened.
5. The main transmitter and receiver
may be mounted directly to the machine, on
brackets attached to the machine, or on floor
stands as long as safety distance and
operational requirements are met.
Mounting brackets must be sturdy to
provide a rigid mounting support that is not
easily knocked out of alignment. When
prefabricated brackets are not provided, the
installer must design and make suitable
mounting brackets.
6. When Black Max light curtains are to
be installed on two or more machines that
are arranged in a row, alternate the trans-
mitter and receiver units (as to which unit
is mounted on the left and which on the
right side of the machine) on each adjacent
machine as shown in Figure 3.4 to reduce
the possibility of crosstalk. Crosstalk
occurs when light pulses from transmitter
unit mounted on one machine are "seen"
not only by the intended receiver unit, but
also by receiver units on other machines.
For many infrared light curtains on the
market today this creates a danger to
operators because their receiver units
accept crosstalk pulses just as they accept
pulses from the correct transmitter. An
operator may have a hand or arm in a light
curtain sensing field, blocking light pulses
from the transmitter on his machine, and a
transmitter on another machine can pass
over or under his arm, "fooling" the re-
ceiver into not providing a stop signal to
the machine control as required. The
Black Max is designed to detect crosstalk
from other light curtains and to provide a
stop signal if it occurs. It is important to
install Black Max light curtains in such a
manner as to avoid nuisance machine stops
caused by crosstalk.
Figure 3.4: Mounting scheme to minimize
crosstalk.
The scheme shown in Figure 3.4 should
also be followed when infrared light
curtains other than the Black Max are used
on adjacent machines.
7. Mount the Black Max main transmitter
and receiver units on the rubber shock
mounts provided in the shipment box using
one of the two mounting methods shown in
Figure 3.5.
Figure 3.5: Use of rubber shock mounts.