LINK Systems Max Presence Sensing Device - Manual (Page 19)

Link Lite Black Max Section 3 - Installation
3-14
paths in special interfaces between the
Black Max and the machine controls
designed by Link Systems.
Link Systems will evaluate existing
machine controls as to their suitability for
use with the Link Lite Black Max upon
customer request and provision of schemat-
ics, and will mark schematics for intercon-
nection with the Black Max when such
controls are suitable for use with the Black
Max.
In some cases, Link Systems may have to
provide an interface circuit to accomplish
proper interconnection of the Link Lite
Black Max with a customers existing
control circuit.
On linearly stroking machines such as
mechanical power presses, hydraulic power
presses, power press brakes, etc., OSHA
and ANSI allow presence sensing devices
such as the Link Lite Black Max to be
interconnected or interfaced with the
machine control so that the protective
function is bypassed (muted) during the
non-hazardous portion of the stroking cycle
only. Never simply use unmonitored limit
switch contacts to mute the Black Max in
the non-hazardous part of a machine cycle.
Interfacing to maintain "control reliability"
in the event of a component fault in the
muting circuit is necessary.
Some machine controls are designed to
require cycling of light curtain output
relays on each cycle of the machine even if
the sensing field is not interrupted.
Terminals 1 and 2 on the eight position
terminal/connector provide an input to
cycle the output relays. To activate the
relay cycle circuit a jumper must be re-
moved on the receiver logic board in the
receiver unit. See Figure 3.15. When the
jumper is removed, a voltage must be
supplied between terminals 1 and 2 to
energize the output relays in each receiver
unit (but only when the Black Max trans-
mitter and receiver are properly aligned
and no obstruction is in the sensing field).
Switching this voltage off at least 35
milliseconds will cause relays LC1 and
LC2 to de-energize. If both relays switch
off and the voltage is switched back onto
terminals 1 and 2, the relays will again
energize. This relay cycle is normally done
during the non-hazardous portion of the
machine stroke when the Black Max is
muted to avoid stopping the machine when
the relays are de-energized.
As shipped, a voltage of 12VDC to 30VDC
may be used for the relay cycle input to
terminals 1 and 2 when the jumper is
removed. Removing jumpers J2 and J3 on
the receiver Relay Board as
WARNING! Never use the normally
closed contact path only to provide a
stop signal to the machine control. A
loose connection or broken wire would
result in no stop signal being supplied
to the control by the Black Max even
though the Black Max itself was
operating properly.
WARNING! When Link Systems
provides machine controls or marks
existing machine control schematics for
interconnection with Black Max units,
always wire as shown by Link on
schematics. Improper connection of
Black Max units to the machine control
may result in failure of the machine to
stop even though the Black Max
component is functioning properly with
possible serious injury or death to
personnel.