GuardShield™ Safe 4 and Safe 4 PAC
Safety Light Curtains
User Manual
Important User Information
Because of the variety of uses for the products described in this publication, those responsible for the
application and use of this control equipment must satisfy themselves that all necessary steps have been
taken to assure that each application and use meets all performance and safety requirements, including
any applicable laws, regulations, codes and standards.
Reproduction of the contents of this copyrighted publication, in whole or part, without written permission
of Rockwell Automation, is prohibited.
Throughout this manual we use notes to make you aware of safety considerations:
The illustrations, charts, sample programs and layout examples shown in the guide are intended solely for
purposes of example. Since there are many variables and requirements associated with any particular
installation, Rockwell Automation does not assume responsibility or liability (to include intellectual property
liability) for actual use based upon the examples shown in this publication.
Rockwell Automation publication SGI-1.1, Safety Guidelines for the Application, Installation and
Maintenance of Solid-State Control (available from your local Rockwell Automation sales oce), describes
some important dierences between solid-state equipment and electromechanical devices that should be
taken into consideration when applying products such as those described in this publication.
It is recommended that you save this user manual for future use.
Identies information about practices or circumstances that can cause an explosion in
a hazardous environment, which may lead to personal injury or death, property
damage, or economic loss.
Identies information that is critical for successful application and understanding of
the product.
Identies information about practices or circumstances that can lead to personal
injury or death, property damage, or economic loss. Attentions help you identify a
hazard, avoid a hazard, and recognize the consequences.
SHOCK HAZARD
Labels may be on or inside the equipment (for example, drive or motor) to alert people
that dangerous voltage may be present.
BURN HAZARD
Labels may be on or inside the equipment (for example, drive or motor) to alert people
that surfaces may reach dangerous temperatures.
WARNING
IMPORTANT
ATTENTION
GuardShield™ Safe 4 Safety Light Curtain User Manual
R
Conditions required for proper use of the
GuardShield Safe 4 Safety Light Curtain
Please make sure you read and understand these requirements before you select and install the
GuardShield Safe 4 safety light curtain. GuardShield safety light curtains are point of operation
and perimeter access safeguarding devices. These safety light curtains are intended to be used to
to provide point of operation and perimeter access safeguarding of personnel on a variety of
machinery.
GuardShield Safe 4 safety light curtains are presence sensing devices and will not protect
personnel from heat, chemicals, or ying parts. They are intended to signal a stop of hazardous
machine motion when the sensing eld is broken.
The GuardShield Safe 4 family of safety light curtains are general purpose presence sensing
devices which are designed to protect personnel working on or near machinery.
It is the responsibility of the employer to properly install, operate and maintain the product as
well as the machinery on which the GuardShield Safe 4 presence sensing device is installed.
The installation of GuardShield Safe 4 safety light curtains must comply with all applicable
federal, state, and local rules, regulations, and codes.
GuardShield Safe 4 safety light curtains must be properly installed by qualied personnel.
GuardShield Safe 4 safety light curtains can only be used on machinery which can be stopped
anywhere in its stroke or cycle.
GuardShield Safe 4 safety light curtains should never be used on full revolution clutched
machinery.
The eectiveness of the GuardShield Safe 4 safety light curtains depends upon the integrity
of the machine control circuit. The machinery on which the GuardShield Safe 4 presence sensing
device is installed should have control circuitry that is fail safe in design.
All stopping mechanisms for the machinery should be inspected regularly to ensure proper
operation. The protected machinery must have a consistent reliable and repeatable stopping
time.
ATTENTION
Failure to read and follow these instructions can lead to misapplication or
misuse of the GuardShield Safe 4 safety light curtains, resulting in personal
injury and damage to equipment.
Original instructions
1
GuardShield™ Safe 4 Safety Light Curtain User Manual
Save these instructions for use at a future
time.
Generally recognized technical regulations and quality
assurance system ISO 9000 are carefully applied during
the development and production of Allen-Bradley/
Guardmaster products.
This technical description must be followed when
installing and commissioning the GuardShield Safe 4.
Inspection and commissioning must be carried out by a
qualified person.
Table of Contents
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Principles for Safe Use and Symbols Used. . . . . . . . . . . . . . . . . . 3
Specialist Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Range of Uses of the Device. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Proper Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
General Protective Notes and Protective Measures . . . . . . . . . 4
Product Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Special Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Principles of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Perimeter Systems (PAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Examples of Range of Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Safety Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Determining the Safety Distance. . . . . . . . . . . . . . . . . . . . 6
US Safety Distance Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
OSHA Safety Distance Calculation Formula . . . . . . . . . . . . . . . . 7
The ANSI Safety Distance Formula . . . . . . . . . . . . . . . . . . . . . . . . . 7
European Safety Distance Formula . . . . . . . . . . . . . . . . . . . . . . . . 7
Installation and Mounting. . . . . . . . . . . . . . . . . . . . . . . . . . 8
Alignment Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Correct Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Incorrect Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Multiple GuardShield Safe 4s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Mounting Brackets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
This manual covers the operation and installation of the:
• GuardShield Safe 4 POC and PAC safety light curtains and
• GuardShield Safe 4 special configurations in the appendix
IMPORTANT
Rockwell Automation reserves the right to make changes or
revisions to the material contained in this publication and cannot
be held liable for incidental or consequential damages resulting
from the furnishing, performance or use of this material.
Electrical Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Typical Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Trouble Shooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Safety Instructions—Maintenance . . . . . . . . . . . . . . . . 17
Daily Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Six-Month Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Date Code and Label. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Catalog Number Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Dimensional Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
GuardShield Safe 4 Specials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Systems without an Integrated Laser Alignment System. . . 27
Systems with Connector Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Cascaded Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Systems with Separated Controller . . . . . . . . . . . . . . . . . . . . . . . 29
Special Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Part List Safe 4 Specials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Certificate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
EC Declaration of Conformity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2
Original instructions
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Introduction
These installation instructions are designed
to address the technical personnel of the
machine manufacturer and or the installer of
the safety system regarding the proper
mounting, configuration, electrical
installation, commissioning, operation and
maintenance of the GuardShield Safe 4 safety
light curtain. These installation instructions
do not provide instruction for the operation
of machinery to which the GuardShield Safe
4 safety light curtain is, or will be, integrated.
Only qualified personnel should install this
equipment.
ATTENTION
ATTENTION
Potentially hazardous situation, which, if not
prevented, might lead to serious or deadly
injury.
Failure to observe may result in dangerous
operation.
ATTENTION
The GuardShield Safe 4 must not be used
with machines that cannot be stopped
electrically in an emergency.
The safety distance between the GuardShield
Safe 4 and a dangerous machine movement
has to be maintained at all times.
Additional mechanical protective devices have to be
installed in a way that hazardous machine elements cannot
be reached without passing through the protective field.
The GuardShield Safe 4 has to be installed in a way that
operators can only operate within the sensing area.
Improper installation can result in serious injury.
Never connect the outputs to +24V DC. If the outputs are
connected to +24V DC, they are in ON-state and cannot stop
hazardous spots at the machine/application.
Never expose the GuardShield Safe 4 to flammable or
explosive gases.
Regular safety inspections are imperative (see maintenance).
Do not repair or modify the GuardShield Safe 4. The
GuardShield Safe 4 safety light curtain is not field repairable
and can only be repaired at the factory. Removal of either of
the GuardShield Safe 4 endcaps will void the warranty terms
of this product.
The GuardShield Safe 4 family of safety light curtains are general
purpose presence sensing devices, designed for use on hazardous
machinery providing point of operation (POC), as well as,
perimeter access (PAC) detection.
It is a self-contained, two box, Type 4 ESPE (Electro Sensitive
Protective Equipment).
The GuardShield Safe 4 is offered in a number of configurations
based on a standard Type 4 safety light curtain platform.
In addition to the standard GuardShield Safe 4 POC and Safe4
PAC, the GuardShield Safe 4 are offered in special configurations
described in the appendix at the back of these instructions.
IMPORTANT
GuardShield™ Safe 4 Safety Light Curtain User Manual
Safety Precautions
Principles for Safe Use and Symbols Used
The following instructions are preventive warnings to ensure the
safe and proper operation of the GuardShield Safe 4 light curtains.
These instructions are an essential part of the safety precautions
and therefore have to be observed at any time.
Throughout this manual we use the labels ATTENTION and
IMPORTANT to alert you to the following:
Failure to observe may result in dangerous
operation
ATTENTION: Identifies information about practices of
circumstances that can lead to personal injury or death, property
damage, or economic loss.
ATTENTION helps you
• Identify a hazard
•Avoid a hazard
• Recognize the consequences
IMPORTANT: Identifies information that is especially important for
successful application and understanding of the product.
Specialist Personnel
The GuardShield Safe 4 safety light curtain must be installed,
commissioned and serviced only by a qualified person. A qualified
person is defined as a person who:
• Has undergone the appropriate technical training
and
• Who has been instructed by the responsible machine
operator in the operation of the machine and the currently
valid safety guidelines
and
• Who has read and has ongoing access to these installation
instructions
Range of Uses of the Device
The GuardShield Safe 4 safety light curtain is classified as electrosensitive protective equipment (ESPE). The physical resolution of
the POC is 14 mm (0.55 in.) or 30 mm (1.18 in.). The maximum
protective field width of GuardShield Safe 4 POC is:
• 0…9 m (29.5 ft) for the 14 mm (0.55 in.) resolution,
• 0…18 m (59.1 ft) for the 30 mm (1.18 in.) resolution
• 5…30 m (16.4…98.4 ft) for the 30 mm (1.18 in.) resolution
Original instructions
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GuardShield™ Safe 4 Safety Light Curtain User Manual
Safety Notes
Please observe the following items in order
to ensure the proper and safe use of the
GuardShield Safe 4 safety light curtain.
The protective field height is between 120 mm (4.7 in.) and 1920
mm (75.6 in.).
The maximum protective field width of GuardShield Safe 4 PAC (2,
3, and 4 beam) is 5…30 m (16.4…98.4 ft).
All standard GuardShield Safe 4 POC and PAC light curtains have
Integrated Laser Alignment.
The device is a Type 4 ESPE as defined by IEC 61496-1 and CLC/TS
61496-2 and is therefore allowed for use with controls in safety
category Type 4 in compliance with EN ISO 13849, SIL CL3 in
accordance with EN62061 or up to PLe in accordance with EN ISO
13849. The device is suitable for:
• Point of operation protection (finger and hand protection)
• Hazardous area protection
• Access protection
Access to the hazardous point must be allowed only through the
protective field. The machine/system is not allowed to start as
long as personnel are within the hazardous area. Refer to the
“Examples of Range of Use” on page 6 for an illustration of the
protection modes.
Depending on the application, mechanical protection devices
may be required in addition to the safety light curtain.
Proper Use
The GuardShield Safe 4 safety light curtain must be used only as
defined in the “Range of Uses of the Device.” It must be used only
by qualified personnel and only on the machine where it has been
installed and initialized by qualified personnel.
If the device is used for any other purposes or modified in any
way, warranty claims against Allen-Bradley/Guardmaster shall
become null and void.
General Protective Notes and Protective Measures
IMPORTANT
The national/international rules and regulations apply to the
installation, use and periodic technical inspections of the safety
light curtain, in particular:
• Machine Directive 2006/42/EC
• Low Voltage Directive 2006/95/EC
• Use of Work Directive (2009/104/EC)
• The work safety regulations/safety rules
• Other relevant health and safety regulations
Manufacturers and users of the machine with which the safety
light curtain is used are responsible for obtaining and observing
all applicable safety regulations and rules.
The notices, in particular the test regulations of these installation
instructions (e.g. on use, mounting, installation or integration into
the existing machine controller) must be observed.
The tests must be carried out by specialist personnel or specially
qualified and authorized personnel and must be recorded and
documented to ensure that the tests can be reconstructed and
retraced at any time.
The installation instructions must be made available to the user of
the machine where the GuardShield Safe 4 safety light curtain is
installed. The machine operator is to be instructed in the use of
the device by specialist personnel and must be instructed to read
the installation instructions.
Product Description
This section provides information on the special features and
properties of the safety light curtain. It describes the structure
and functions of the unit.
Please read this section before mounting, installing and
commissioning the unit.
Special Features
• Integrated laser alignment
• Large range with a compact profile
14mm resolution: 0…9 m
30mm resolution: 0…18 m or 5…30 m
• Tolerant to dust and pollution
• Short-circuit protected semiconductor outputs
• Built-in-diagnostic LEDs
• Optical synchronization, no electrical cable needed
between transmitter and receiver
• Maintenance-free and cost effective
Principles of Operation
The GuardShield Safe 4 safety light curtain consists of a nonmatched pair of optic units, i.e., transmitter and receiver with the
same protected height and resolution. The transmitter and
receiver operate on +24V DC. The maximum distance between
transmitter and receiver is referred to as the protective field width
or range. The protective field height is the distance between the
first and last beam in the device.
The transmitter emits sequential pulses of infrared light which are
received and processed by the GuardShield Safe 4 receiver. The
synchronization of the timing of the emission and reception of
infrared light pulses is accomplished optically by the first beam
adjacent to the GuardShield Safe 4 status LEDs. This beam is
referred to as the synchronization beam. Because the GuardShield
Safe 4 transmitter and receiver are optically synchronized, no
electrical connection is required between the transmitter and
receiver.
The GuardShield Safe 4 receiver has two safety outputs, Output
Signal Switching Devices (OSSDs). When the GuardShield Safe 4
transmitter and receiver are properly powered and aligned, all
OSSDs are current sourcing +24V DC with a switching capacity of
300 mA. The two safety OSSDs are cross monitored and shortcircuit protected. Interruption of the sensing field causes the
receiver to switch the sourced current OFF (0V DC).
4
Original instructions
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Restoring the GuardShield Safe 4 sensing field causes all outputs
Transmitter Receiver
300
900
Reference plane (e.g. ground)
0
300
1200
Reference plane (e.g. ground)
0
600
900
(OSSDs) to switch to the active high state (resume current
sourcing +24V DC with a switching capacity of 300 mA).
GuardShield Safe 4 operates in the guard only mode with
automatic restart. Other modes of operation e.g. PSDI mode
(break mode), muting, external relay monitoring (EDM) can be
realized using external safety devices.
The GuardShield Safe 4 safety light curtain consists of a
transmitter and a receiver.
Figure 1: Components of the GuardShield Safe 4
GuardShield™ Safe 4 Safety Light Curtain User Manual
The protective field and the active elements respectively, are
clearly recognized as black surfaces with the integrated optical
lenses.
The width of the protective field is derived from the length of the
light path between sender and receiver and must not exceed the
maximum rated width of the protective field
• (0…9 m (22.9 ft) for 14 mm (0.55 in.) resolution, or
• 0…18 m (59.1 ft) for 30 mm (1.18 in.) resolution, or
• 5…30 m (16.4…98.4 ft) for 30 mm (1.18 in.) resolution.
Perimeter Systems (PAC)
Perimeter systems are usually produced by means of several
single-beam light barriers. But the flexibility of the GuardShield
Safe 4 system allows also the production of vertical entry
safeguarding according to the standard EN ISO 13855 [2010].
Such systems are composed of active and passive elements in one
compact profile. The element length of each is 120 mm (variations
are given in the appendix).
The protective field and the active elements respectively, are
clearly recognized as black surfaces with the integrated optical
lenses. The areas not monitored (passive elements) are also clearly
indicated as yellow surfaces.
1100
300
700
0
Reference plane (e.g. ground)
Figure 2: Perimeter systems (2-, 3-, and 4-beams) according to EN ISO 13855 (2010)
Original instructions
5
GuardShield™ Safe 4 Safety Light Curtain User Manual
Additional measures may be necessary to
ensure that the ESPE does not fail to danger
when other forms of light radiation are
present in a particular application (i.e., use of
cableless control devices on cranes, radiation
from weld spatter or effects from strobe
lights).
Class 2 Laser
To prevent exposure to laser radiation, do
not expose your eyes to the laser. Turn ILAS
off if not in use.
The protective system must be tested for
proper operation after each and every
change to the configuration.
IMPORTANT
Determining Stop Time: The measurement of
stopping time (Ts) must include the stopping
times of all devices in the stop circuit. Not
including all device and control system
elements when calculating Ts will result in an
inaccurate safety distance calculation.
ATTENTION
The GuardShield Safe 4 safety light curtains
must be mounted at a sufficient distance
from the pinch point or point of operation
hazard to help ensure that the machine stops
before a person’s finger, hand, arm(s), or body
reaches the hazard.
IMPORTANT
Regardless of the calculated safety distance,
GuardShield Safe 4 safety light curtains
should never be mounted closer than six
inches from the point of operation or pinch
point hazard.
Examples of Range of Use
The GuardShield Safe 4 safety light curtain operates as a proper
protective device only if the following conditions are met:
• The control of the machine must be electrical.
• The controlled machine must be able to be stopped any
where in the machines stroke or cycle.
• The transmitter and receiver must be mounted such that
access to the hazard is only through the light curtain’s
protective field.
• The restart button must be located outside the hazardous
area such that it cannot be operated by a person working
inside the hazardous area.
• The statutory and local rules and regulations must be
observed when installing and using the device.
IMPORTANT
GuardShield Safe 4 Laser Alignment
The laser light source in the Integrated Laser Alignment system of
the GuardShield Safe 4 light curtains is a Class 2, eye safe laser
diode with a wavelength of 630 nm.
This Class 2, eye safe laser is switched from a low output power
state to a high output power state (and back again) by means of
control circuitry which detects reflected laser light from a
temporary blockage of the emitted laser light. This is most
commonly accomplished by a person’s finger placed over the
laser overlay window. There is also an automatic shutdown
feature that switches the laser diode from the high power state to
the low power state if there is no finger or other interruption
detected for a period of five minutes.
During the high output mode of operation, the laser is pulsed at a
rate of approximately 2 Hz in order to facilitate finger detection in
high ambient light conditions.
System Testing
The GuardShield Safe 4 performs a complete system self-test at
power up and switches to the ON state if the system is properly
aligned and the protective field is unobstructed.
External Test (Machine Test Signal)
Normally the test input at the transmitter is installed with a shortcircuit jumper to activate the transmitter. A test cycle of the
system can be triggered by an external test signal to the
GuardShield Safe 4 transmitter. Supplying or removing a signal
(+24V DC) via a N.C. or N.O. switch at the test input deactivates
the transmitter for the duration of the test signal, simulating an
interruption of the protective sensing field (see also page 11).
Response Time
The response time of the GuardShield Safe 4 safety light curtain
depends on the height of the protective field, the resolution, and
the number of light beams (see table on page 20).
Determining the Safety Distance
The light curtain must be mounted with proper safety distance
• From the point of danger
• From reflecting surfaces
US Safety Distance Formula
Safety Functions
All GuardShield Safe 4 safety light curtains operated as on/off
devices, meaning the OSSD outputs switch off/on according to an
obstruction or clearing of the detection field.
IMPORTANT
6
Original instructions
This distance, referred to as the safety distance, must be properly
calculated prior to determining the safety light curtain protective
height and mounting the light curtains on the machine. Failure to
properly calculate this safety distance may result in operator
injury.
In the United States there are two formulas that are used to
properly calculate the safety distance. The first, the OSHA formula,
is the minimum requirement for the calculation of the safety
distance. The second formula, the one recommended by Rockwell
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GuardShield™ Safe 4 Safety Light Curtain User Manual
Safety distance S (Ds)
Protective field height
Point
Distance to avoid standing behind
of
danger
the safety curtain 75mm
Automation, is the ANSI formula, which incorporates additional
factors to be considered when calculating the safety distance.
OSHA Safety Distance Calculation Formula
The OSHA safety distance formula as specified in CFR Subpart O
1910.217 is as follows:
Ds = 63 X T
S
Ds Safety Distance in inches
63 Is the OSHA recommended hand speed constant in inches
per second
Ts Is the total stop time of all devices in the safety circuit,
measured in seconds. This value must include all
components involved in stopping the hazardous motion of
the machinery. For a mechanical power press it is the
stopping time measured at approximately the 90º position
of the crankshaft rotation.
number must include the response times of all devices,
The T
S
including the response time of the safety light curtain, the safety
light curtain controller (if used), the machine’s control circuit and
any other devices that react to stop the hazardous motion of the
machinery. Not including the response time of a device or devices
in the stop time calculation will result in insufficient safety
distance for the application. This may result in operator injury.
The ANSI Safety Distance Formula
The ANSI safety distance formula, which is the Rockwell
Automation recommended formula, is as follows:
= K x (TS + TC + Tr + Tbm) + D
D
S
Ds Minimum safety distance between the safe guarding device
and the nearest point of operation hazard, in inches.
K Hand speed constant in inches per second. The ANSI
standard value is 63 inches per second when the operator
begins reaching toward the point of operation hazard from
rest. NOTE: ANSI B11.19 1990 E4.2.3.3.5 states “The value of
the hand speed constant, K, has been determined by
various studies and although these studies indicate speeds
of 63 inches/second to over 100 inches/second, they are not
conclusive determinations. The employer should consider
all factors, including the physical ability of the operator,
when determining the value of K to be used.”
Ts Stop time of the machine tool measured at the final control
element.
Tc Response time of the control system
and Tc are usually measured by a stop time measuring device.
T
s
Tr Response time of the presence sensing device (safety light
curtain) and its interface, if any. This value is generally stated
by the device manufacturer or it can be measured by the
user.
Tbm Additional time allowed for the brake monitor to
compensate for variations in normal stopping time.
pf
Dpf Depth penetration factor. It is an added distance to allow for
how far into the protective field an object, such as a finger
or hand, can travel before being detected. D
is related to
pf
the object sensitivity of the safety light curtain. Object
sensitivity is the smallest diameter object which will always
be detected anywhere in the sensing field.
Example:
In opto-electronic safeguarding, such as with a perpendicular
safety light curtain applications with object sensitivity (effective
resolution) less than 2.5 inches, the D
can be approximated
pf
based on the following formula:
(inches) = 3.4 × (Object Sensitivity – 0.276),
D
pf
but not less than 0.
European Safety Distance Formula
A safety distance must be maintained between the light curtain
and the point of danger. This safety distance ensures that the
point of danger can only be reached after the dangerous state of
the machine has been completely removed.
The safety distance as defined in EN ISO 13855 and EN ISO 13857
depends on:
• Stopping/run-down time of the machine or system. (The
stopping/run-down time is shown in the machine
documentation or must be determined by taking a
measurement.)
• Response time of the protective device, e.g. GuardShield
Safe 4 (for “Response Time” see page 6).
• Reach or approach speed.
• Resolution of the light curtain and/or beam separation.
Figure 3: Safety distance from the point of danger
How to Calculate the Safety Distance S for GuardShield Safe 4 Systems
with a resolution 40 mm. According to EN ISO 13855 and EN ISO 13857:
-> First, calculate S using the following formula:
S = 2000 × T + 8 × (d – 14) [mm]
Where …
T = stopping/run-down time of the machine
+ response time of the protective device [s]
Original instructions
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GuardShield™ Safe 4 Safety Light Curtain User Manual
Distance D (meters)
IMPORTANT
The installation of the GuardShield Safe 4
safety light curtain must be such that access
to the hazard is only possible through the
sensing field of the GuardShield Safe 4.
Auxiliary safe guarding may be required in
conjunction with the GuardShield Safe 4 to
meet this requirement.
d = resolution of the light curtain [mm]
S = safety distance [mm]
The reach/approach speed is already included in the
formula.
-> If the result S is 500 mm (19.6 in.), then use the determined
value as the safety distance.
-> If the result S is > 500 mm (19.6 in.), then recalculate S as
follows: S = 1600 × T + 8 × (d – 14) [mm]
-> If the new value S is > 500 mm (19.6 in.), then use the newly
determined value as the minimum safety distance.
-> If the new value S is 500 mm (19.6 in.), then use 500 mm
(19.6 in.) as the safety distance.
Example:
Stopping/run-down time of the machine = 290 ms
Response time = 30 ms
Resolution of the light curtain = 14 mm (0.55 in.)
T = 290 ms + 30 ms = 320 ms = 0.32 s
S = 2000 × 0.32 + 8 × (14 – 14) = 640 mm (25.1 in.)
S > 500 mm, therefore:
S = 1600 × 0.32 + 8 × (14 – 14) = 512 mm (20.1 in.)
How to Calculate the Safety Distance S for
GuardShield Safe 4 PAC Systems
In the case of perimeter systems or light curtains with a resolution
d > 40 mm, the safety distance is calculated for vertical mounting
light curtains and horizontal approach, according to the formula:
S = 1.6 mm/ms x T + 850 mm
More detailed information regarding safety distance and safety
heights can be found in standard EN 13855 (2010).
• Read the minimum distance a [mm] from the graph:
Figure 5: Graph, minimum distance from reflecting surfaces
The effective aperture angle for the GuardShield Safe 4 system is
±2.5° at a mounting distance of > 3.0 m (9.8 ft). Calculate the
minimum distance to reflecting surfaces depending on the
distance between the transmitter and the receiver, using an
aperture angle of ±2.5°, or take the appropriate value from the
following table:
Distance Between
Transmitter and Receiver
(Range D) [m (ft)]
0…3.0 (0…9.8) 135 (5.31)
4.0 (13.1) 175 (6.88)
5.0 (16.4) 220 (8.66)
6.0 (19.6) 265 (10.43)
7.0 (22.9) 310 (12.2)
10.0 (32.8) 440 (17.32)
16.0 (52.4) 700 (27.55)
Minimum Distance
a [mm (in.)]
Minimum Distance from Reflecting Surfaces
The infrared light from the sender may be reflected off of shiny
surfaces and be received by the system’s receiver. If this condition
occurs, it can result in an object not being detected when it enters
the GuardShield Safe 4 sensing field.
All reflecting surfaces and objects (e.g. material bins) must
therefore be located at a minimum distance a from the protective
field of the system. The minimum distance a depends on the
distance D between sender and receiver.
Figure 4: Minimum dist ance from reflecting sur faces
How to Determine the Minimum Distance from the Reflecting Surfaces:
• Determine the distance D [m] sender-receiver
8
Original instructions
Formula: a = tan 2.5° x D [mm]
a = minimum distance to reflecting surfaces
D = distance between transmitter and receiver
Installation and Mounting
This section describes the preparation, selection and installation
of the GuardShield Safe 4 safety light curtain. Mount and connect
both transmitter and receiver.
Determine if the machinery, on which the GuardShield Safe 4 is to
be mounted, meets the requirements as specified in the
beginning of this manual, i.e., machinery must be able to be
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GuardShield™ Safe 4 Safety Light Curtain User Manual
On optimal alignment of the light
curtain, the ILAS light point can deflect
from the ILAS target point. The
maximum deflection adds up to the
following value due to the operating
distance:
2 m
6 m
9 m
18 m
30 m
R = 7 mm
R = 20 mm
R = 30 mm
R = 60 mm
R = 99 mm
D = 7 mm
D = 21 mm
D = 32 mm
D = 63 mm
D = 105 mm
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D
Operators cannot reach hazardous
machine parts without passing through
the protective field.
Operators must not step between
protective field and hazardous machine
parts (by-pass prevention).
stopped anywhere in its stroke or cycle, consistently and
repeatedly.
Alignment Procedure
Standard GuardShield Safe 4
The GuardShield Safe 4 is offered with an integrated laser
alignment system which has a constantly powered Class 2, eye
safe laser located in the bottom of the GuardShield Safe 4
transmitter and in the top of the GuardShield Safe 4 receiver. Each
laser emits a low level of visible light. Simply blocking this light
below the finger symbol causes the light to be reflected back to a
photo sensor which changes the condition of the laser light. If this
light is at a low level, interrupting it will cause the laser to emit a
highly visible level of light. Interrupting the visible light in the
same location will cause the laser to switch to a low level of
emission. The emission of visible light will also change to a low
level after five minutes of activation.
GuardShield Safe 4 with Integrated Laser Alignment
Cycle power to assure that the system powers up and goes to the
ON state.
1. Properly locate the GuardShield Safe 4 pair from the point of
operation hazard after performing the safety distance
calculation.
2. Using the GuardShield Safe 4 mounting brackets, mount the
transmitter and receiver so that they are facing one another
and are positioned in the same direction. A reference would be
that the indicator LEDs are opposite one another. They must be
parallel to each other and be positioned at the same height.
Turn on power to GuardShield Safe 4 system.
opposite each laser. A small deviation around the target is
allowable and are harmless as long as they are within the
aperture angle.
5. Tighten all screws firmly.
6. Switch the ILAS off when aligned.
When mounting Perimeter Systems adjust the heights according
to the recommendations in the local standards and regulations
(Europe: EN ISO 13855 [2010]) (see Figure 2).
The GuardShield Safe 4 safety light curtain is suitable for most
operating environments (IP65 environmental rating). Proper
safety distance as well as adequate protective height must be
observed.
Remarks to ILAS
Due to dimensional tolerances the visible ILAS laser beam may be
located “off center” from the target when the light curtain is
aligned optimally in the center of the operating range. The
optimal operating point can be found after alignment with ILAS
when moving the axis in X- (left, right) and Z- (up, down)
direction. The optimal operating point is in the middle of the two
end points, where the receiver output switches from active to
inactive condition.
Transmitter
Transmitter
Figure 6: Layout of the transmitter/receiver
3. Turn on each laser by placing a finger or hand in front of each
laser (close to the finger symbol ).
4. For optimal alignment, adjust the transmitter and receiver in
such a way that both visible laser beams hit the laser targets
Incorrect
Correct
Figure 7: Adjustment with ILAS
Correct Installation
Receiver
Receiver
Original instructions
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GuardShield™ Safe 4 Safety Light Curtain User Manual
Operators can reach hazardous machine
parts without passing through the
protective field.
Operators can step between protective
field and hazardous machine parts.
Middle of Depth of Protective Field
Safety Distance
Point of Operation
Top of tool
Bottom of tool
To avoid the possibility of
standing between the protective
field and the point of operation,
the distance must be
maintained.
Protective Field Marking
Machine stop
time
Transmitter
Receiver
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.
Incorrect Installation
The GuardShield Safe 4 must be mounted at the proper distance
from the point of operation hazard. This distance is referred to as
the Safety Distance.
Multiple GuardShield Safe 4
When two or more GuardShield Safe 4s are mounted in close
proximity to one another, it may be possible for the receiver of
one GuardShield Safe 4 pair to receive infrared light from the
transmitter of another GuardShield Safe 4 pair.
There are various techniques to prevent or eliminate the
possibility of optical interference from GuardShield Safe 4 light
curtains mounted in the same plane. The simplest method is to
alternate transmitter and receiver pairs so that the receiver from a
second pair is facing away from the transmitter of another
GuardShield Safe 4 pair in close proximity. It is also possible to
place a physical barrier between pairs to prevent the infrared light
from reaching another GuardShield Safe 4 pair.
Figure 8: Determining machine stopping time and safety distance
After installation and alignment of the GuardShield Safe 4 safety
light curtain, the protection field has to be tested with the test rod
for the corresponding resolution (14 or 30 mm) according to
Figure 9.
Figure 9: Correct testing of the protective field using a test rod
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Figure 10: Multiple GuardShield Safe 4 alignment options
Mounting Brackets
The GuardShield Safe 4 is mounted using brackets which attach to
the side of both transmitter and receiver. It may be necessary to
use additional brackets to mount the GuardShield Safe 4 at a
proper safety distance from the machinery hazard.
Original instructions
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