Reer JANUS Quick start guide

TYPE 4 SAFETY LIGHT CURTAIN
JANUS
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8540573 • 16/09/2016 • Rev.20
1
TYPE 4 SAFETY LIGHT CURTAIN
JANUS
SUMMARY
INTRODUCTION ............................................................................................................................................... 3
PRINCIPLE OF OPERATION........................................................................................................................... 4
LIGHT CURTAIN............................................................................................................................................ 4
MUTING FUNCTION ..................................................................................................................................... 5
SERIES "ML" - PREASSEMBLED KIT OF JANUS LIGHT CURTAIN AND SENSOR ELEMENT “Ml
S” Integrated Muting sensors –only for one-way openings with pallet exit......................................... 5
SERIES "MT" - KIT PREASSEMBLED OF JANUS LIGHT CURTAIN AND SENSORS ELEMENTS
“MT SI” and “MT SE” Integrated Muting sensors – for two-way openings with pallet entrance/exit. .. 6
SERIES "MT S4" - KIT PREASSEMBLED OF JANUS LIGHT CURTAIN AND SENSORS
ELEMENTS “MT S” Integrated Muting sensors – for two-way openings with pallet entrance/exit. .... 6
SERIES "ML S2" - KIT PREASSEMBLED OF JANUS LIGHT CURTAIN AND SENSORS
ELEMENTS “ML S” Integrated Muting sensors – for one-way openings with pallet exit. ................... 7
MODEL "MI" –external sensors 3 selectable methods of Muting....................................................... 7
MI models used with “l” operational logic.............................................................................................. 9
INSTALLATION ................................................................................................................................................ 9
POSITIONING.............................................................................................................................................. 11
POSITIONING OF THE MUTING SENSORS ("MI" SERIES)............................................................ 11
POSITIONING AND ADJUSTMENT OF SENSOR ELEMENTS FOR "ML" and "MT" SERIES:...... 13
CALCULATION OF THE SAFETY DISTANCE.................................................................................. 14
VERTICAL POSITIONING OF THE LIGHT CURTAIN....................................................................... 15
MULTIPLE SYSTEMS........................................................................................................................ 17
DISTANCE FROM REFLECTIVE SURFACES.................................................................................. 17
LIGHT SIGNALS.......................................................................................................................................... 19
Emitter SIGNALS................................................................................................................................ 19
Receiver SIGNALS............................................................................................................................. 20
ELECTRICAL CONNECTIONS AND CONNECTORS................................................................................ 22
EMITTER Connections (Male Connector)......................................................................................... 22
RECEIVER CONNECTIONS (Main Connector - Male)...................................................................... 23
Connections CONNECTOR M12 n. 1 (for muting sensor) ("MI" MODELS) (Female Connector)...... 24
Connections CONNECTOR M12 n. 2 (for muting sensor) ("MI" MODELS) (Female Connector)..... 24
RECEIVER CONNECTIONS J LR M12 MODELS............................................................................. 25
SELECTION OF CONFIGURATION AND OPERATING MODE................................................................. 25
SELECTION FEEDBACK EXTERNAL CONTACTORS K1/K2.......................................................... 25
SELECTION OF MANUAL/AUTOMATIC FUNCTIONING................................................................. 26
SELECTION OF THE MAXIMUM DURATION AND TYPE OF MUTING .......................................... 27
OVERRIDE CONFIGURATION.......................................................................................................... 27
MUTING OVERRIDE FUNCTION (“M” MODELS) ............................................................................. 28
"SYSTEM STATUS" OUTPUT (“M” MODELS) .................................................................................. 29
TEST FUNCTION............................................................................................................................... 29
SAFETY MODULES MJB1 - MJB2 - MJB3 - MJB4 ........................................................................... 29
EXAMPLE OF CONNECTION WITH EXTERNAL CONTACTORS K1/K2 WITH start/restart interlock
activated.............................................................................................................................................. 30
EXAMPLE OF CONNECTION WITH AD SR0 WITH start/restart interlock activated....................... 31
MUTING STATUS AND LIGHT ("M" MODELS).............................................................................. 31
CONFIGURATION AND OPERATION MODES J LR M12......................................................................... 32
AUTOMATICO MODE........................................................................................................................ 32
MANUAL MODE................................................................................................................................. 33

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DIMENSIONS.................................................................................................................................................. 34
JANUS "MI" - "J" .......................................................................................................................................... 34
JANUS "ML"................................................................................................................................................. 35
JANUS "MT"................................................................................................................................................. 35
JANUS "ML S2" - "MT S4"........................................................................................................................... 36
TECHNICAL DATA......................................................................................................................................... 37
CHECKOUTS AND MAINTENANCE........................................................................................................... 41
TROUBLESHOOTING................................................................................................................................. 42
ACCESSORIES ........................................................................................................................................... 44
GUARANTEE.................................................................................................................................................. 45

8540573 • 16/09/2016 • Rev.20 3
INTRODUCTION
This symbol indicates an important personal safety warning. Failure to comply with the
warning may result in very high risks for exposed personnel.
The JANUS safety light curtain is a multi-beam opto-electronic safety system of the Type 4
category of electro-sensitive devices (in accordance with IEC 61496-1,2; EN 61496-1) –if
necessary equipped with MUTING function (“M” models) - for the protection of persons exposed
to dangerous machines or plants.
The two PNP auto-controlled static outputs permit connection of the light curtain to a control
system complying with the requirements and level of safety required for the application.
The light curtain integrates the start/restart interlock and EDM functions (control of external relays
K1 and K2). In this way, the light curtain can be connected to a simple pair of relays or external
safety contactors without having to install additional modules.
A diagnostic display on the Emitter and Receiver provide the information required for correct use
of the device and to check for any operating faults.
The diagnostic output (see TROUBLESHOOTING, page 42) makes it possible to obtain weak
signal and light curtain status information from a single wire.
JANUS is ideal for protecting:
automatic palletizing/depalletizing systems
materials handling and storage systems;
packing and packaging machines;
assembly lines;
industrial automatic warehouses;
AGV transit openings;
metal, wood, marble and glass tool machines;
presses, die cutting machines.
For problems regarding safety, if necessary, consult the competent safety authorities of
your country or the related industrial association.
For applications in the food industry, consult the manufacturer to check compatibility
between the materials of the light curtain and the chemical agents used.
The guarding function of opto-electronic safety devices is not effective in the case in
which the machine cannot be electrically controlled and is unable to stop the dangerous
movement immediately at any time during the work cycle.

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PRINCIPLE OF OPERATION
LIGHT CURTAIN
If the area guarded is clear, the two outputs on the Receiver are active and permit normal
functioning of the machine connected to these.
When an object larger than or equal to the resolution of the system interrupts the sensing field of
one or more beams, the Receiver de-activates its outputs.
This condition makes it possible to block the dangerous movement of the machine (using a
suitable machine stop circuit).
Resolution is the smallest diameter object that will be reliably detected by at least one of the
optical beams generated by the light curtain (Figure 1).
Figure 1- Light curtain resolution
Resolution is constant regardless of working conditions as it depends only on the geometrical
characteristics of the lenses and the center distance between two adjacent lenses. The height of
the guarded area is the height effectively protected by the safety light curtain.
If the curtain is positioned horizontally, this value indicates the depth of the guarded zone. The
useful range is the maximum operating distance that can exist between the Emitter and Receiver.
JANUS is available with the following resolutions (MODEL "MI") :
30mm (protected heights from 300mm to 1200mm) ("MI" models):
PROTECTION OF THE HANDS.
40mm (protected heights from 300mm to 1800mm) (“MI”, "MILR" and “JLR” models):
PROTECTION OF THE HANDS.
90mm (protected heights from 300mm to 1800mm) ("MI" models):
PROTECTION OF THE LIMBS.
JANUS is also available in a Multibeam version ("MI", "MT" and "ML" models)with a pitch
between the lenses of:
500mm (2 beams), 400mm (3 beams), 300mm (4 beams only models "MI"), "MILR"
”J” and “JLR”. PROTECTION OF THE BODY.
P = Pitch bewteen two lenses
D = Diameter of one lens
R = Resolution = P+D
Emitter
Receiver
Opaque Object

8540573 • 16/09/2016 • Rev.20 5
MUTING FUNCTION
The Muting function is a temporary suspension of the safety light curtain’s protective
function. Carefully check your risk analysis in order to assess whether the Muting function
is compatible with your application and what additional measures have to be taken.
The Muting function generates a temporary, automatic interruption of safety light curtain
functioning in order to permit normal transit of material through the guarded opening.
The Muting function is activated when the system detects the object that interrupts the opening
protected. In other words, when the system recognizes the material and distinguishes between
this and any operator (in a potentially dangerous situation), it is enabled to bypass the light
curtain temporarily, allowing the material to pass through the opening.
The Muting sensors –which can be integrated in the light curtain (models "ML" and "MT") or be
external (model "MI") –form the sensing system that decides whether the Muting function is to
be activated (or not). Control of the dangerous opening can be de-activated only by a correct
sequence of interruption of the beams of the Muting sensors.
The JANUS system is available in the “ML" and "MT” models (with 2 integrated opto-electronic
sensors) and "MI" models to which 2 or 4 sensors of various type can be connected (proximity,
optical, capacitive etc).
SERIES "ML" - PREASSEMBLED KIT OF JANUS LIGHT CURTAIN AND SENSOR ELEMENT “ML S”
Integrated Muting sensors –only forone-way openings with pallet exit.
In this model, the sensors 1 and 2 are on the same side of
the vertical light curtain and are placed in front of the
guarded opening (Figure 2).
This model is one-way and is useful for protecting pallet exit
openings.
The Muting function is activated following concurrent
interruption (within max. 4 sec) of sensors S1 and S2. The
Muting function remains active as long as both sensors
remain occupied.
When the first of the 2 sensors is cleared, the material has
four seconds to abandon the guarded area delimited by the
light curtain. The Muting condition will be disabled as soon
as the protected area is cleared.
After 4 seconds, if the light curtain is still occupied, the
OSSD outputs are disabled, interrupting functioning of the
machine. For this model, the maximum duration of the
Muting condition (timeout) can be set to 30 seconds or 90
minutes.
To guarantee the safety operation of the ML
series, the horizontal muting sensor must be
mounted INSIDE the dangerous area
(dashed on Figure 2).
When using a ML series JANUS, the minimum
distance between two consecutive pallet must
be less than 10cm or more than 32cm.
Figure 2
Emitter
Receiver
Sensor 1
Sensor 2
D
DA AN NG GE ER RO OU US S
A
AR RE EA A

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SERIES "MT" - KIT PREASSEMBLED OF JANUS LIGHT CURTAIN
AND SENSORS ELEMENTS “MT SI” and “MT SE”
Integrated Muting sensors –for two-way openings with pallet entrance/exit.
In this model, the Muting sensors are the first on one side
and the second on the other in relation to the vertical light
curtain (Figure 3).
This model is therefore two-way and is useful for
protecting pallet entrance/exit openings.
The point of intersection of the two muting
sensors (Figure 11) must be inside the
dangerous area in order to avoid accidental
actuation of the Muting function.
The Muting function is activated following concurrent
interruption (within max. 4 sec) of sensors S1 and S2.
The Muting function remains active as long as both
sensors remain occupied.
When the first of the two sensors is cleared, the Muting
function is disabled.
Also for this model, the maximum duration of the Muting
condition (timeout) can be set to 30 seconds or 90
minutes.
Figure 3
SERIES "MT S4" - KIT PREASSEMBLED OF JANUS LIGHT CURTAIN AND SENSORS ELEMENTS “MT S”
Integrated Muting sensors –for two-way openings with pallet entrance/exit.
This model is two-way and is useful for protecting pallet
entrance/exit openings (Figure 4).
Using this model, two methods of operation are possible:
Concurrent
The Muting function is activated following concurrent
interruption of sensors S1 and S2 (within maximum
4sec) (or S4 and S3 with material transiting in the
opposite direction). Muting status ends after clearing
of the opening and of S3 (or S2 with material
transiting in the opposite direction).
Sequential
The Muting function is activated following sequential
interruption of sensors S1 and S2, of the opening and of
sensors S3 and S4. It is important to remember that,
for correct actuation of the Muting function, the
sequence indicated in Figure 8 and Table 1 is
required (without time restrictions).
The MT S4 models have two
available timeouts: 1) 30 sec;
2) infinite (Sequential operation).
The pallet minimum length (in both
operation modes) must be 70cm (all
the 4 sensors have to be
simultaneously occupied).
Figure 4
Emitter
Receiver
Sensor 1
Sensor 2
Sensor 3
Sensor 4
D
DA AN NG GE ER RO OU US S
A
AR RE EA A
Emitter
Receiver
Sensor 1
Sensor 2
D
DA AN NG GE ER RO OU US S
A
AR RE EA A

8540573 • 16/09/2016 • Rev.20 7
SERIES "ML S2" - KIT PREASSEMBLED OF JANUS LIGHT CURTAIN AND SENSORS ELEMENTS “ML S”
Integrated Muting sensors –for one-way openings with pallet exit.
In this model, the sensors 1 and 2 are on the same side of the
vertical light curtain and are placed in front of the guarded opening
(Figure 5).
This model is one-way and is useful for protecting pallet exit
openings.
The Muting function is activated following concurrent interruption
(within max. 4 sec) of sensors S1 and S2. The Muting function
remains active as long as both sensors remain occupied.
When the first of the 2 sensors is cleared, the material has four
seconds to abandon the guarded area delimited by the light curtain.
The Muting condition will be disabled as soon as the protected area
is cleared.
After 4 seconds, if the light curtain is still occupied, the OSSD
outputs are disabled, interrupting functioning of the machine. For
this model, the maximum duration of the Muting condition (timeout)
can be set to 30 seconds or 90 minutes.
To guarantee the safety operation of the ML S2
series, the horizontal muting sensor must be
mounted INSIDE the dangerous area (dashed in
Figure 5).
When using a ML series JANUS, the minimum distance
between two consecutive pallet must be 40cm.
Figure 5
MODEL "MI" –external sensors
3 selectable methods of Muting.
The "MI" model can use 2 or 4 sensors that must be connected to
the M12 connectors on the front part of the vertical light curtain.
These sensors may be of various types (proximity, optical,
capacitive with PNP or electromechanical type output and with
DARK-ON switching (i.e. output active when material is present).
If 4 sensors are connected, it is possible to choose two methods of
operation: 1) Concurrent; 2) Sequential.
CONNECTION WITH 2 EXTERNAL SENSORS (Figure 6)
This model is two-way and is useful for protecting pallet
entrance/exit openings.
The point of intersection of the two sensors must be
located inside the dangerous area to prevent accidental
and dangerous activation of the Mutingfunction.
The Muting function is activated following concurrent interruption
(within max. 4s) of sensors S1 and S2. The Muting function
continues as long as both sensors are occupied. When the first of
the two sensors is cleared, the Muting function is disabled.
Also for this model, the maximum duration of the Muting condition
(timeout) can be set to 30 seconds or 90 minutes.
Figure 6
Receiver
Emitter
Sensor 2
Sensor 1
D
DA AN NG GE ER RO OU US S
A
AR RE EA A
Emitter
Receiver
Sensor 1
Sensor 2
D
DA AN NG GE ER RO OU US S
A
AR RE EA A

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CONNECTION WITH 4 EXTERNAL SENSORS
Using 4 sensors, two methods of operation are possible:
Sequential (figure 7)
The Muting function is activated following sequential interruption of
sensors S1 and S2 and of sensors S3 and S4. It is important to
remember that, for correct actuation of the Muting function,
the sequence indicated in Figure 8 and Table 1 is required
(without time restrictions).
It is also possible to enable a control of the activation time of the 4
sensors.
Concurrent
The Muting function is activated following concurrent interruption
of sensors S1 and S2 (within maximum 4sec) (or S4 and S3 with
material transiting in the opposite direction).
Muting status ends after clearing of the opening and of S3
(or S2 with material transiting in the opposite direction).
The MI models connected with 4 external
sensors, have two available timeouts:
1) 30 sec; 2) infinite.
Figure 7
sensor1
sensor2
sensor3
sensor4
Muting
30 s/
Figure 8
Sequential muting: activation sequence.
SENSOR 1
SENSOR 2
SENSOR 3
SENSOR 4
LIGHT CURTAIN STATUS
0
0
0
0
LIGHT CURTAIN ACTIVE
1
0
0
0
LIGHT CURTAIN ACTIVE
1
1
0
0
MUTING
1
1
1
0
MUTING
1
1
1
1
MUTING
0
1
1
1
MUTING
0
0
1
1
MUTING
0
0
0
1
LIGHT CURTAIN ACTIVE
0
0
0
0
LIGHT CURTAIN ACTIVE
Table 1
LEGEND:
0 = SENSOR FREE; 1 = SENSOR ENGAGED
SENSOR 1
SENSOR 2
SENSOR 3
SENSOR 4
MUTING
ENGAGED
CLEAR
Emitter
Receiver
Sensor 4
Sensor 3
Sensor 2
Sensor 1

8540573 • 16/09/2016 • Rev.20 9
Both operating modes with 4 sensors are TWO-WAY.
The correct Muting sequence can start either from sensor 1 or from sensor 4.
MI MODELS USED WITH “L” OPERATIONAL LOGIC
In this model the sensors 1 and 2 are on the same side with respect to the vertical curtain and are positioned
in front of the dangerous opening (Figure 9 and Figure 10). This model is unidirectional and is useful for
protecting openings with pallet exit.
The activation of the Muting function takes place following the simultaneous interruption (within max. 4 sec)
of sensors S1 and S2. The Muting function remains while both sensors are occupied.
On release of the first of the 2 sensors, the material will still have 4 seconds available to abandon the
protected area delimited by the curtain. The Muting condition will be disabled as soon as the protected area
is released.
If the curtain is still occupied after the 4 seconds, the OSSD outputs are disabled, interrupting machine
functioning.
For this model, the maximum duration of the Muting condition (timeout) can be selected in 30 seconds or 90
minutes (Table 13).
It is indispensable that a Muting sequence is completed (release of controlled area) in order to
guarantee the correct activation of the successive sequence.
For safe functioning of the MI series (with L logic), it is necessary that the muting sensors
are positioned inside the dangerous area (traced in Figure 9 and Figure 10).
Figure 9 - Crossed sensors
Figure 10 - Parallel sensors
INSTALLATION
Before installing the JANUS safety system, check that:
The safety system is used only as stopping device and not as machine control device.
The machine can be controlled electrically.
Any dangerous action of the machine can be promptly interrupted. In particular, the
stopping time of the machine must be known, if necessary measure this.
The machine must not cause dangerous situations due to flying or dropping of material;
otherwise, additional mechanical guards are required.
The minimum size of the object that must be detected must be greater than or equal to the
resolution of the model selected.
D
DA AN NG GE ER RO OU US S
A
AR RE EA A
Emitter
Receiver
Sensor 2
Sensor 1
D
DA AN NG GE ER RO OU US S
A
AR RE EA A
Emitter
Receiver
Sensor 2
Sensor 1

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Knowing the shape and dimensions of the dangerous area, it is possible to assess the width and
height of its access area:
Compare these dimensions with the maximum useful range and the height of the area
protected of the model used.
Before positioning the safety device, take into account the following general indications:
Check that the temperature of the environments where the system is installed is
compatible with the temperature operating parameters indicated in the technical data.
Do not position the Emitter and Receiver close to sources of bright light or high intensity
flashing lights.
Particular environmental conditions may impair the detection efficiency of light curtains. In
places with the possibility of mist, rain, fumes or dust, for correct functioning of the
equipment it is advisable to apply suitable correction factors Fc to the values of useful
operating range.
In these cases:
Pu = Pm x Fc
where Pu and Pm are respectively the useful and maximum operating range in meters.
The recommended Fc factors are indicated in the table below.
ENVIRONMENTAL
CONDITION
CORRECTION FACTOR Fc
Mist
0,25
Vapors
0,50
Dust
0,50
Dense fumes
0,25
Table 2
If the device is installed in areas liable to sudden changes in temperature, suitable
measures must be taken in order to avoid formation of condensation on the lenses which
could impair detection efficiency.
If JANUS light curtains are used with palletizers, depalletizers and stacking/destacking
machines for empty pallets, refer to European standard EN 415-4.

8540573 • 16/09/2016 • Rev.20 11
POSITIONING
Protection of the guarded opening by JANUS must be integrated with suitable mechanical
guards.
While the "MI" model permits various types of installation (2, 4 sensors, one- or two-way), the
"ML" and "MT" have been designed for "dedicated" use.
In particular, "ML" manages the muting function in one-way mode (normally for
pallet exit); in this case, the horizontal arms must be positioned between the
dangerous area and the light curtain.
The "MT" model manages the muting function in two-way mode using four horizontal
arms. This model is useful when the pallets, once the process has been carried out
by the dangerous machine, must be returned outside using the same palletizer.
POSITIONING OF THE MUTING SENSORS ("MI" SERIES).
2 sensors The Emitter and receiver of the light curtain must be positioned so as to permit access to the
dangerous area from above, from below and from the sides without first of all intercepting at least
one of the optical beams.
Indications for correct positioning of the light curtain are provided in the figure below.
Figure 11
For correct positioning of sensors 1 and 2, i.e. those that manage enabling and disabling of the
Muting function, take into account the following:
the two beams must be crossed and pass diagonally through the zone guarded by
the light curtain;
the point of intersection of the two beams must be in the dangerous area beyond
the light curtain;
the angle between the two Muting beams must be calculated according to the size of
the pallet and its speed, taking into account that the Muting function is activated only
if the interception delay between the two sensors is less than 4 seconds;
the pallet must interrupt the two beams before intercepting the light curtain;
the two beams must be interrupted continuously by the pallet for the entire period
during which the pallet passes between the sensors;
make sure that the two beams are effectively intercepted by the material on the pallet
and not by the empty pallet;
the zone identified by the points of interception and clearing of the beams of sensors
1 and 2 by pallet must be limited as far as possible (or suitably protected) so as
S1 = Sensor 1
S2 = Sensor 2
R1 = Reflector 1 (or Receiver 1)
R2 = Reflector 2 (or Receiver 2)
B = Light curtain
Material
Dangerous area

12 8540573 • 16/09/2016 • Rev.20
to avoid the possibility of accidental passing through the light curtain with Muting
active (Figure 12).
Figure 12
4 sensors
For correct positioning of sensors 1, 2, 3 and 4, i.e. those that manage enabling and disabling of the
Muting function, take into account the following:
Figure 13
SEQUENTIAL (Figure 8, Figure 13 Table 1):
the distance between the first and the
last sensor must never exceed the length
of the pallet (in one of the phases of
the sequence, the 4 sensors must all
be intercepted simultaneously);
the pallet must interrupt sensors S1 and
S2 (or S4 and S3 in the opposite
direction) before intercepting the light
curtain;
make sure that the two beams are
intercepted by the material on the pallet
and not by the empty pallet
Figure 14
CONCURRENT (Figure 14):
The Muting function is activated following
concurrent interruption (within max. 4
sec) of sensors S1 and S2 (or S4 and
S3 in the opposite direction).
also in this operating mode, for correct
activation of the Muting function, for a
short period of time, all 4 sensors
must be intercepted simultaneously.
Dimension to be reduced to a minimum
Mechanical guards
Material
DANGEROUS
AREA
Mechanical guards
DANGEROUS
AREA
Material
Mechanical guards
DANGEROUS
AREA
Material

8540573 • 16/09/2016 • Rev.20 13
POSITIONING AND ADJUSTMENT OF SENSOR ELEMENTS FOR "ML"AND "MT" SERIES:
As already mentioned, the pre-assembled JANUS "ML" and "MT" kit consist of a vertical light
curtain and of one ("ML" series) or two ("MT" series) horizontal sensor element in which the
Muting sensors are integrated.
The system is equipped with a VERTICAL adjustment of the sensor elements to solve the
following problems:
Incorrect and non-continuous sensor beam interception by the material in movement.
Need to reduce the beam intensity when transparent objects (i.e. glass, plastic, etc)
are detected.
At the operating range limits (1 ÷ 2,5m) or in dusty environments, it would be necessary to use
the ANGULAR adjustment to reach the maximum signal intensity. (REER advise against this
operation with transparent materials).
Figure 15 shows the two axes (horizontal and vertical) on which to operate.
To make the adjustment:
loosen the Allen screws;
operate on the arms to make the adjustments;
tighten the Allen screws.
Figure 15
NOTE: For installations that do not require any particular adjustments, the ML and MT
models are pre-aligned and do not require further regulation.
MAXIMUM VERTICAL
ADJUSTMENT
PERMITTED:
+ 70mm
MAXIMUM
ANGULAR
ADJUSTMENT
PERMITTED:
+ 8°

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CALCULATION OF THE SAFETY DISTANCE
The light curtain must be positioned at a distance exceeding or equal to the minimum safety
distance Sso that a dangerous point can be reached only after stopping the dangerous action of
the machine (Figure 16).
Referring to European standard EN999, the minimum safety distance Smust be calculated
according to the following formula:
S = K (t1+ t2) + C
where:
S
minimum safety distance
mm
K
speed of approach of the body to the danger area.
mm/sec
t1
total response time in seconds of the safety light curtain
sec
t2
response time of the machine in seconds, i.e. the time taken by the machine
to interrupt the dangerous action from the moment in which the stop signal is
transmitted
sec
C
additional distance
mm
Failure to comply with the safety distance reduces or defeats the protective function of the
light curtain.
If the position of the light curtain does not exclude the possibility of the operator
accessing the danger area without being detected, the system must be equipped with
additional mechanical guards.
Figure 16

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VERTICAL POSITIONING OF THE LIGHT CURTAIN
Models with resolution 30, 40mm.
These models are suitable for detecting the hands
The minimum safety distance Sis calculated according
to the following formula:
S = 2000 (t1+ t2) + 8(D-14)
(D=resolution)
This formula is valid for distances Sbetween 100 and
500 mm. If, according to the calculation, Sexceeds 500
mm, the distance can be reduced up to a minimum of
500 mm using the following formula:
S = 1600 (t1+ t2) + 8 (D-14)
Where, due to the particular configuration of the
machine, it is possible to access the danger area from
above, the highest beam of the light curtain must be at a
height Hof at least 1800 mm from the resting surface G
of the machine.
Figure 17
Models with resolution 90mm.
These models are suitable for detecting the arm or legs
and must not be used to detect the fingers or hands.
The minimum safety distance Sis calculated according
to the following formula:
S = 1600 (t1+ t2) + 850
In any case, the height Hof the highest beam
from the reference surface Gmust not be less
than 900 mm while the height of the lowest
beam Pmust not exceed 300 mm.
Figure 18
Light
curtain
Dangerous
point
Reference surface
Direction
of approach
Light
curtain
Dangerous
point
Direction
of
approach
Reference surface

16 8540573 • 16/09/2016 • Rev.20
Mutlibeam Models
These models are suitable only for detection of the
entire body.
The minimum safety distance Sis calculated
according to the following formula:
S = 1600 (t1+ t2) + 850
The recommended height H from the
reference surface G (ground) is as follows:
Figure 19
MODEL
BEAMS
Recommended height H
(mm)
2B
3B
4B
2
3
4
400 –900
300 –700 –1100
300 –600 –900 - 1200
For applications on packaging machines (palletizers and depalletizers), comply with the
indications of European standard EN 415-4, which are repeated below.
Figure 20
Protection of the opening with JANUS light curtain and mechanical side guards.
From low level (floor)
Device with minimum 3 beams
Above the conveyor (roller bed)
Device with minimum 2 beams
Type of access
Dimensions in m
Light
curtain
Dangerous point
Direction
of
approach
Reference surface

8540573 • 16/09/2016 • Rev.20 17
MULTIPLE SYSTEMS
When several JANUS systems are used, these must not interfere optically with each other.
Position the elements so that the beam emitted by the Emitter of a system is received only by the
respective Receiver.
Figure 21 provides various examples of correct positioning of two photo-electric systems.
Incorrect positioning could generate interference and possibly result in irregular functioning.
Figure 21
DISTANCE FROM REFLECTIVE SURFACES
The presence of reflective surfaces close to the light curtain may cause spurious reflections that
prevent detection. Referring to Figure 22, object Ais not detected because of surface Swhich,
reflecting the beam, closes the sensing field between the Emitter and Receiver. A minimum
distance dmust therefore be maintained between any reflective surfaces and the protected area.
The minimum distance dmust be calculated according to the distance lbetween Emitter and
Receiver and taking into account that the angle of projection and reception is equal to 4º.
Figure 22
Figure 23 indicates the values of the minimum distance dto be complied with as the distance l
between Emitter and Receiver varies.
Side by side systems: A
Adjacent positoning of the
two projectors
Systems one above the other: B
Emitter
Receiver
Direct beam
Reflected beam

18 8540573 • 16/09/2016 • Rev.20
Figure 23
After installation, check for any reflective surfaces, intercepting the beams first of all at the center
and those close to the Emitter and Receiver.
During this procedure, the red led on the Receiver must never switch off.
SENSITIVE AREA
EMITTER
RECEIVER
JANUS
JANUS Long Range

8540573 • 16/09/2016 • Rev.20 19
LIGHT SIGNALS
EMITTER SIGNALS
At power-on, all the leds are ON for a period of 5 seconds.
Subsequently, the leds display functioning condition.
"ML" - "MT" MODELS "J"-"LR"-"MI" MODELS
Figure 24
LED
MEANING NORMAL
FUNCTIONING (LED ON)
COLOR
Test
Light curtain under test
YELLOW
Light curtain functioning
GREEN
Fault detected
RED
High range selected *
ORANGE
Table 3
If a fault is detected, the led will indicate the type of alarm (ref. "TROUBLESHOOTING").
* The value of the selected range depends on the JANUS model. (Refer TECHNICAL DATA - page 31).
RANGE