Banner MULTI-BEAM Series - Manual (Page 21)

LM4-2 one-shot (retriggerable)
The LM4-2 provides a one-shot ("single shot") output pulse each time there is a transition from
LIGHT to DARK (jumper installed) or from DARK to LIGHT (jumper removed). The output
pulse time range is adjustable from 0.1 to 1 second. The duration of the pulse is independent of
the duration of the input signal. The timing of the LM4-2 is restarted each time the input signal
is removed and then recurs. This is referred to as a "retriggerable" one shot, and this feature may
be applied to some rate sensing applications (use LM6-1 for true rate sensing).
LM1 is an on-off logic module that causes the power block output to "follow the action" of the
scanner block: when the scanner block sees a LIGHT signal, the output is energized; when the
scanner block sees a DARK signal, the output is de-energized. This is referred to as the LIGHT
operate mode. If the application calls for DARK operate mode, the LM1 may be used with
normally-closed type power blocks such as PBAQ or PBT2. LM1 on-off
LM3 on-off
LM2 alternate action
Specifications, 3- and 4-wire Logic Modules
The logic module interconnects the power block and scanner block both electrically and
mechanically using a unique blade-and-socket connector concept. It also provides the
LIGHT/DARK operate function (except in the LM1) and the timing functions, all of which
are fully adjustable.
In the diagrams below, the "signal" represents the light condition (in LIGHT operate) or
the DARK condition (in DARK operate), and the "output" represents the energized
condition of the solid-state output switch (power block). "Delay" refers to the time delay
before the output operates, and "hold" refers to the time that the output remains "on" after
the event has occurred.
The photo (left) shows a typical logic module for 3- or 4-wire operation. Note that all 3-
& 4-wire logic modules are color-coded red. The time ranges listed for the logic modules
in the table below are standard time ranges. Other time ranges are available; see page 23
for information.
The LM2 provides "flip-flop" or toggling action of the power block output, such that each time
the scanner block changes from a DARK state to a LIGHT state, the output changes state. The
output remains in the last state until another change occurs. The LM2 is frequently used to operate
a diverter gate that splits a production line into two lines. It may also be used to operate room
lighting by breaking a photoelectric beam: if the lights are OFF, breaking the beam turns them
ON; if the lights are ON, breaking the beam turns them OFF.
The LM3 is an on-off logic module that has the ability to be programmed for either LIGHT
operate or DARK operate. It comes with a jumper wire installed: with the jumper in place, the
output is DARK operated; with the jumper removed, the output is LIGHT operated. The LM3
is the most commonly used logic module when no timing function is desired, particularly if it is
not known at the time of ordering which mode (LIGHT or DARK operate) will be needed.
Description of Logic Model and Function
MULTI-BEAM
3- & 4-wire Logic Modules
CONSTRUCTION: molded VALOX ® housing; electronic components epoxy encapsu-
lated. Gold plated blade connectors.
OPERATING TEMPERATURE: -40 to +70 degrees C (-40 to +158 degrees F).
TIMING ADJUSTMENT(S): one or two single turn potentiometers with slot for blade-
type screwdriver adjustment. NOTE: when turning time adjustments fully clockwise or
counterclockwise, avoid excessive torque to prevent damage to potentiometers.
TIMING REPEATABILITY: plus or minus 2% of maximum range under constant power
supply and temperature conditions; plus or minus 5% of maximum range under all
conditions of supply voltage and temperature.
TIMING RANGE: useful range is from maximum time down to 10% of maximum (e.g.-
from 1 to 0.1 seconds, or from 15 to 1.5 seconds). When timing potentiometer is set fully
counterclockwise, time will be approximately 1% of maximum. RESPONSE TIME: response time will be that
for the scanner block (plus power block) plus the
programmed delay (if the logic includes a delay
function).
Functional Schematic
OUTPUT
SIGNAL
OUTPUT
SIGNAL
OUTPUT
SIGNAL
OUTPUT
SIGNAL
Pulse Pulse
Hold
Setable time range: .1 to 1 second.
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