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IMPORTANT
This manual must accompany the product throughout its workinglife. Those persons responsible for the product must ensure thatall persons involved in the installation, commissioning, operation,maintenance and servicing of the product have access to all theinformation supplied by the manufacturers of the machine and itssafety system.
WARNING
Guardscan photo-electric safety systems are intended to protectoperators working at or near dangerous machinery. They canonly perform this function if they are correctly fitted to a suitablemachine. It is essential that the full contents of this manual andall the authoritative documents referred to herein are fullyunderstood before any attempt at installation is made. If in doubtcontact your authorised Guardscan distributor.
GUARDSCANGS120
LIGHT CURTAINS &MULTI-BEAM SYSTEMS
TECHNICAL MANUAL 343351-00English
2
Guardscan Light Curtain Products are manufactured by:
Tapeswitch LtdUnit 38 Drumhead RoadChorley North Industrial ParkChorleyPR6 7BXEngland
Tel : +44 (0) 1257 249777Fax : +44 (0) 1257 246600Email : [email protected] : www.tapeswitch.co.uk
The Tapeswitch Group
Tapeswitch Corporation100 Schmitt BoulevardFarmingdaleNew YorkNY 11735USA
Tel : +1 631 630 0442Fax : +1 631 630 0454E-mail : [email protected] : www.tapeswitch.com
Tapeswitch Ltd635 Newbold StreetLondonOntarioCanadaN6E 2T8
Tel : +1 519 681 2980Fax : +1 519 685 9318Email : [email protected]: www.londonmat.com
Tapeswitch Japan5-11-23 Nakakasai - Hirano Bldg.Edogawa-ku,TokyoJapan 134-0083
Tel : + 81 3 5676 5421Fax : + 81 3 5676 5422Email : [email protected] : www.tsjapan.co.jp
Tapeswitch GmbHPostfach 10 20 23Walter-Bruch-Straße 13D-30982 PattensenGermany
Tel : +49 (0) 5101 14490Fax : +49 (0) 5101 14499Email : [email protected] : www.tapeswitch.de
3
CONTENTS
1. GENERAL
2. SYSTEM DESCRIPTION
2.1 CURTAIN2.2 INDICATORS
3. INSTALLATION
3.1 GENERAL3.2 SEPARATION DISTANCE3.3 ELECTRICAL INSTALLATION3.4 INITIAL CHECKING AND ALIGNMENT
4. PERIODIC CHECKING, SERVICING AND MAINTENANCE
4.1 PERIODIC CHECKING4.2 SERVICING4.3 MAINTENANCE
5. TECHNICAL SPECIFICATION
5.1 GS120 LIGHT CURTAIN SYSTEM5.2 ORDER CODES AND MODEL NUMBERS
4
Guardscan GS120 light curtains and grids arethrough-beam photo-electric machineguarding devices, designed to protectoperators working at or near dangerousmachinery. They meet the requirements forEN61496 Type 2 light curtains andCategory 3 safety control units as defined inEN954-1.
When correctly installed on a suitable machine,the system will detect a person (or part of aperson) entering a dangerous area in thevicinity of the machine and will causedangerous motion to cease before that personcan reach a position where injury couldoccur.
Guardscan GS120 light curtains and gridsuse infra-red technology. A curtain ofinfra-red light is projected across thedangerous area. Intrusion into this curtain bya person, or part of a person, will be detectedby the system. This will cause safety outputsignals to be generated which will stop thedangerous motion of the machine.
WARNING
The information in this manual relates tothe use of the GS120 light curtain, toprovide a basic safety switching device.
In some applications a GS120 light curtainmay be used together with otherGuardscan equipment to provideadditional functions and features. Theadditional information necessary for thecorrect use of a GS120 light curtain whenused with other Guardscan equipment isprovided with the equipment concerned.
In such cases, some installationparameters, notably the mountingposition of the light curtain in relation tothe dangerous parts of the machine, canbe affected and close attention must bepaid to all the information supplied withall equipment.
1. GENERAL
5
2. SYSTEM DESCRIPTION
2.1 CURTAIN
A GS120 system consists of an arrangementof infra-red emitting devices, which send outpulses of infra-red light (emitter), and anarrangement of infra-red receiving devices,which detect the pulses (receiver). Botharrangements are identical in shape and size,and are enclosed in a robust extrudedaluminium section with aluminium end covers.
The emitter and receiver units togethergenerate a curtain of infra-red light betweenthem. This curtain is mounted in such aposition in relation to the dangerous parts ofa machine that a person or part of a personapproaching those dangerous parts must firstpenetrate the curtain. This penetration isdetected by the light curtain system and, bymeans of its output switching devices, thelight curtain system causes the dangerousparts to go to a safe state (e.g. by stoppingmoving parts) before the person can reachthem.
IMPORTANT
From the above it can be seen that safe useof a light curtain relies not only on thesafety integrity of the curtain itself butalso on its proper mechanical andelectrical interfacing to the machine.
The safety integrity of the light curtainitself is the responsibility of Tapeswitchand the remainder of this section describesthe features of the design by which safetyintegrity is ensured.
Proper mechanical and electricalinterfacing is the responsibility of theuser. Information for this purpose isprovided in section 3 of this manual. Theuser should also refer to relevantapplication standards.
6
2.1.1 GS120 BASIC SYSTEM
The curtain dimensions are defined by theprotected height and the range (i.e. the distancebetween the sender and receiver units). Theprotected height must be selected to suit theapplication.
All the dimensions relating to the curtain, foreach detection characteristic of a basicGS120 system, (or basic slave) are shown inFigure 1. The upper and lower boundaries ofthe curtain are indicated by arrows on thefront window labels of each unit.
Figure 1
X = Nominal curtain length (e.g. 200, 400, 600 etc.)
48X
+ 8
X +
80
24
36
45
Range
7
2.1.2 GS120 MULTI-BEAM SYSTEM
All the dimensions relating to the curtain, foreach of the Multi-beam systems (or multi-beamslave systems) are shown in Figure 2.
Figure 2
Range
Bea
m S
paci
ng +
180
9585
36
2 be
ams
- 500
mm
cen
tres
3 be
ams
- 400
mm
cen
tres
4 be
ams
- 300
mm
cen
tres
45
8
2.1.3 GS120 CASCADED SYSTEM
Additional flexibility to facilitate guarding inmore than one plane is provided, by thecapability to connect slave units to a basic ormulti-beam master system.
The slave units can be basic, or multi-beamsystems, with either of the defined detectioncharacteristics of 30mm or 70mm.
The dimensions relating to the curtains, foreach slave unit are as defined in the previoussections for each model. The upper andlower boundaries of each curtain are indicatedby arrows on the front window labels of eachunit.
A maximum of two slave units can beconnected to a master system. Master andslave units can be assembled up to a maximumof 240 beams. Where:
30mm detection - 12 beams per 200mm curtain70mm detection - 4 beams per 200mm curtain
E.g. GS120 / M / 1000 / 30 + GS120 / A / 0400 / 70 = 68 beams
Note:
When master/slave columns have detectioncharacteristics which have different rangecapabilities, these must be respected whensystems are configured.
Important:
When master/slave columns have differentdetection capabilities the separation distancemust be calculated and adhered to for eachcolumn separately.
Figure 3
Range
300
max
.30
0 m
ax.
ReceiverTypeGS120 / M
ReceiverType GS120 / D
ReceiverTypeGS120 / A
EmitterType
GS120 / A
EmitterType
GS120 / D
EmitterType
GS120 / M
Note:
When master/slave combinations are used,the total response time of the system iscalculated by adding the response time of themaster unit to the response time of the slaveunit.
9
tinU ruoloC noitpircseD
/dradnatSretsaMrettimE
rebmA .tinuotdetcennocsirewopnehwtiL
wolleY .deilppasitupnitsetnehwydaetstiL.melborpastcetedtinurettimenehwgnihsalftiL
/dradnatSretsaMrevieceR
rebmA .tinuotdetcennocsirewopnehwtiLneerG .raelcsiniatrucnehwtiL
deR morftupnitsetnehwrodetcurtsbosiniatrucnehwtiL.deilppasirettime
wolleY .tratserarofgnitiawsitinureviecernehwydaetstiL.melborpastcetedtinureviecernehwgnihsalftiL
evalSrettimE rebmA .tinuotdetcennocsirewopnehwtiL
evalSrevieceR rebmA .tinuotdetcennocsirewopnehwtiL
Table 1
2.2 INDICATORS
2.2.1 LED OPTION
The standard/master receiver unit has fourindicators as shown in Figure 4. Thestandard/master emitter unit has two indicatorsas shown in Figure 5. The slave emitter/receiver has one indicator as shown inFigure 6. A description of each indicator is given inTable 1.
Figure 5
Figure 6
AmberYellow
Amber
Figure 4
Red Green
Yellow Amber
10
2.2.2 DIAG OPTION
The LED indicators on the standard/masteremitter unit and all slave units are the same asfor the previous section (2.2.1). The receiverunit contains a scrolling 4-digit alphanumericdisplay for diagnostic purposes as shown inFigure 7.The various displays and their meanings areshown in Table 2 below.
noitarepolamronnisyalpsiD
APNP edomtratserotuAPNP
MPNP edomtratserlaunaMPNP
RSS edomyalereerf-tloV
MDErofgnitiaW lanretxemorfkcabdeefehtesuacebffoerastuptuo,edomtratserotuAnI.tneserptonsignirotinomecived
tratseRrofgnitiaW sahlangistratserehtesuacebffoerastuptuo,edomtratserlaunaMnIdeviecerneebton
xxxB nekorbmaebtsrifehtsixxxrebmunmaebdnadetcurtsbosiniatrucehT
sesuaclanretxeelbissophtiwstluaF
niatrucetelpmocnI tonsiniatrucehtnimaebtsalehtmorflangisgnimitehttahtswohSniatrucretsama,elpmaxerof,fideyalpsidebdluowsihT.deviecergnieb
.detcennocevalsondah
iHAP/O cdV42+otAtuptuOmorftiucric-trohselbissopA
oLAP/O V0otAtuptuOmorftiucric-trohselbissopA
iHBP/O cdV42+otBtuptuOmorftiucric-trohselbissopA
oLBP/O V0otBtuptuOmorftiucric-trohselbissopA
stluaFlanretnI
XXRORRE .riaperrofrodnevotnruteR.dleifehtnielbaecivrestontluaF
Figure 7
Table 2
Red Green
DiagnosticDisplay
11
3.1 GENERAL
WARNINGGuardscan GS120 systems are designed to protect operators working at or neardangerous machinery. They can only perform this function if they are correctly fittedand interfaced to a suitable machine. Those persons responsible for the machine mustensure that all persons involved in the installation of the photo-electric safety systemhave the necessary knowledge, training and experience and that they are fully awareof all laws, rules, regulations and codes of practice pertaining to their task.
EN999 gives guidance on the dimensions andpositioning of photo-electric safety devicesfitted to industrial machines. The mainconsiderations are described below.
The attention of the installer is drawn tofollowing general requirements for theinstallation of a GS120 system:
(a) The dangerous motion of the machinemust be electrically controllable.
(b)The machine response/stoppingperformance must be adequate and consistent.
(c) It must be possible to stop the dangerousmotion of the machine at any point in itsoperation, in any operating mode.
(d) The control system as a whole must bedesigned and constructed to provide theappropriate category of safety integrity as definedin EN954-1 'Safety of machinery: Principles forthe design of safety related control systems'.The appropriate category should be as prescribedin the relevant C type EN standard for the typeof machine concerned. In the absence of sucha standard the appropriate category of safetyintegrity should be determined by performing arisk assessment as described in EN1050 'Safetyof machinery: Risk assessment'.
3. INSTALLATION
(e) At power on, after a power interruption orafter the curtain has been actuated, it must notbe possible for the machine to start (orrestart) until a manual control has beenoperated. This is known as “start/restartinterlock”. The GS120 can provide thisfunction (See section 3.3.3) but if it is notinstalled, it must be provided elsewhere withinthe safety system
(f) Steps must be taken to prevent access tothe dangerous parts of the machine from anydirection not covered by the photo-electriccurtain. Such steps could include fixed orinterlocking fences or screens, additionalphoto-electric devices or pressure sensitivemats. Similar steps should be taken to preventa person standing between the curtain and thedangerous parts.
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(g) The correct minimum separation distancemust be observed. The curtain must bemounted in the correct position in relation tothe dangerous parts of the machine to takeaccount of the stopping performance of themachine, the curtain format used and thedetection capability of the curtain.
(h) The curtain must be of sufficient heightsuch that access to the dangerous parts, fromthe direction of approach of the operator, isonly possible by obstructing the curtain takinginto account all possible operator positions.
(i) No devices other than those specified inthis manual should be connected to theinternally generated power supply of thesystem.
(j) After installation the machine/guard systemmust be commissioned in accordance withthe requirements of section 4.1.1 of thismanual.
(k) Any covers removed during installationmust be replaced as soon as possible.
(l) To avoid nuisance tripping, if a fluorescentlamp with an electronic ballast is fittedwithin 1,5 metres of the receiver unit it mustbe fitted outside a 20º field of view from thereceiver unit (±10º about the centre line). Ifthis is not practical, a mains frequencyfluorescent light fitting should be used.
3.1.1 MOUNTING BRACKET OPTIONS
There are 3 types of mounting bracket optionsavailable for the GS120 Systems:
3.1.1.1 MOUNTING BRACKET TYPE AB
The adjustable mounting bracket - Type ABcombines a robust design with quick releasefacility, the adjustable bracket promotesspeedy installation and also allows for easyinterchange of a light curtain unit without theneed for re-alignment. This option is specifiedas 'AB' in the order code.
3.1.1.2 MOUNTING BRACKET TYPE CB
The Clamp Bracket - Type CB offers a neatand compact design to provide versatileinstallation. In addition, the Clamp BracketMounting Plate has been specially designed toallow angular adjustment of the light curtain.This option is specified as 'CB' in the ordercode.
3.1.1.3 MOUNTING BRACKET TYPE EB
The Endcap Bracket - Type EB is designed tobe used in situations where space is limited,the slimline nature of the Endcap Bracketallows the light curtain to be easily mounted ina confined space such as on the external edgeof a fixed structure or adjacent to a floor post.This option is specified as 'EB' in the ordercode.
For installation instructions regarding thesemounting bracket options please see theinstallation sheets supplied with each kit.
13
3.1.3 REFLECTIVE SURFACES
There should be no reflective surfaces withinthe ‘field of view’ of the curtain units. Reflectivesurfaces within the field of view can lead tonon-detection of an obstruction. The field ofview of each of the emitter and receiver unitsis approximately 5 degrees either side of theoptical axis.
A minimum distance from the optical axis toany reflective surface must be observed. Thisdistance depends on the actual operatingdistance and must take into account possiblemisalignment. This is illustrated in Figure 9.The distance should be determined as follows:
Operating distance L<3m: X>260mm
Operating distance L>3m: X>0.0874Lmm
3.1.4 SYSTEMS IN CLOSE PROXIMITY
In order to avoid nuisance interferencebetween adjacent systems, whenever twosensing units are used within each other'ssensing range, ensure that the front window ofany unit is not within the field of view of unitsof the opposite type from other systems.
This can be achieved by ensuring that units ofthe same type are mounted facing in oppositedirections. See Figure 10.
Figure 9
3.1.2 OPTICAL ALIGNMENT
The emitter and receiver units should bemounted facing each other at the same heightwith their axes aligned. Misalignments asillustrated in Figure 8 should be avoided.
Figure 8
MinimumDistance
Reflectivesurface
ReceiverEmitter
Operating Distance L
X
5º 5º5º5º
14
Figure 10
EN999 provides guidelines on how todetermine the minimum separation distancefor a given application.
Figure 11 provides a methodology fordetermining the separation distance of aGS120 system, which is as follows:
(a) Identify the hazards and assess therisks (see EN292-1 and EN1050).
(b) If a type C standard exists for themachine, use the distance specified by thatstandard.
(c) If there is no type C standard, or if theC standard does not specify a minimumdistance, then use the formulae in EN999(reproduced in the following sections)to calculate the separation distance.
(d) Incorporate the distance in the machinedesign.
(e) Ensure that the device has been installedin such a manner that access to the dangerzone is not possible without detection.
(f) If the positioning of the curtain allowspersons to be in a position between thecurtain and and the danger zone,supplementary measures may be requireddepending on the risk.
Emitter 1 Receiver 2
Emitter 2Receiver 1
INCORRECT
INCORRECTEmitter 1
Receiver 2
Emitter 2Receiver 1
CORRECTEmitter 1 Receiver 1 Receiver 2 Emitter 2
3.2 SEPARATION DISTANCE
Any machine, regardless of the efficiency ofits braking system, will take a certain time tocome to rest after a stop signal is generated.
The time from the instant that the curtain isbroken to the instant that dangerous motionactually ceases is called the overall systemresponse time. The dangerous parts willobviously continue to move during this time.The curtain must therefore be positioned at acertain minimum distance from the dangerousparts to prevent a person who has obstructedthe curtain from reaching the dangerous partsbefore they have stopped.
This distance is the minimum separationdistance and is defined as the distance, in thedirection of approach, between the physicalpoint at which the curtain detects anobstruction and the nearest dangerous parts.
15
Figure 11
Calculate
minimum distance
the danger zoneallow persons to be within
without being
Use this minimumdistance together
with supplementarymeasures depending
detected?
on the risk
YES
Does the
minimum distanceUse this
distance bethe minimum
minimum distance byformulae in EN999
NO
YES
achieved?
NO
Can
Select appropriateprotective equipment
using Type-A andType-B standards
for the machine?Type-C standard
NO
Is there a
Assess the risksIdentify the hazards
Determine minimum
bereduced?
Use additionalor alternative
protective equipment
NO
or can parameter Ctime be reduced
Canoverall response
reduce parameter C(See clause 5)
response time and/orReduce overall
YES
minimum distanceUse this
standardto the Type-C
distance according
Type-C standardas specified in
Select appropriateprotective equipment
minimum distancesgiven in Type-C
formulae orAre specific
standards?
NO
YES
YES
16
The minimum separation distance should berecorded on the machine information label orplate.
The general formula for calculating theminimum separation distance, S, inmillimetres, for GS120 light curtains is asfollows:
S = K x T + C
3.2.1.1 NORMAL APPROACH
Normal approach format is shown inFigure 12. For normal approach format theinner edge of the front window of each unit(i.e. the edge which is nearest to the machine)should be considered to be the point at whichan obstruction is detected. See plane X inFigure 12.
(a) For a normal approach application wherethe curtain has a detection capability, d, of<= 40mm:
S = K x T + C
where K = 2000 andC = 8(d - 14), but not less than 0;
If this formula gives S greater than 500mmthen S can be recalculated K = 1600 but in thiscase S must not be less than 500mm.
If it is foreseeable that the guard will be usedin a non-industrial environment, eg, in thepresence of children, the minimum distanceshall be increased by at least 75mm and abody part speed of 2000mm/s must be used.
3.2.1 GS120 SYSTEMS
The separation distance depends on theapplication and the following factors:
- the curtain format used. - the detection capability, d. - the overall system response time, T. - the curtain penetration figure, C. - the derived body part speed, K.
The overall system response time, T, is aperiod, in seconds, given by the sum of theresponse times of the safety device and themachine control system. The response timeof the GS120 system is between 20ms and44ms. ( See section 5.1 for specific data). Theresponse time of the machine control systemshould be measured using a suitable deviceand the highest value recorded, plus a suitableallowance for brake deterioration, should beused in the calculation of the minimumseparation distance. It is recommended thatthe overall system response time is recordedon the machine information label or plate.
The curtain penetration figure, C, is adistance, in millimetres, representing thedistance by which part of a person penetratesthe plane of detection of the safety devicebefore actuation of the sensing unit occurs.This figure is a function of the detectioncapability.
The derived body part speed, K, is aspeed, in millimetres per second, derivedfrom measurement data of speeds ofmovement of various parts of the humanbody. This figure represents the derived speedof that part of the body which will obstruct thesensing unit.
17
Figure 12
(b) For detection capability, d, of 30mm:
S = K x T + C
where K = 2000 andC = 8(d-14)
i.e. S = (2000 x T) + 128
(c) For detection capability, d, of 70mm(when d is greater than 40, C = 850):
S = K x T + C
where K = 1600 andC = 850
i.e. S = (1600 x T) + 850
Plane of detectionof curtain
Direction of approach
Separation distance
Nearest dangerous parts
X
18
3.2.1.2 PARALLEL APPROACH
Parallel approach format is shown inFigure 13. For parallel approach format theouter curtain detection limit (as shown on thefront window of each unit) minus the detectioncapability, should be considered to be thepoint at which an obstruction is detected.See Plane X in Figure 13.
S = K x T + C
where K = 1600 mm/sC = 1200mm - 0.4H, but not lessthan 850mm, where H is the heightof the detection zone above thereference plane, in mm.
i.e. S = (1600 x T) + 1200 - 0.4 x H
For this type of protective equipment, theheight H of the detection zone shall notexceed 1000mm. If H is greater then 300mm(200mm for non-industrial applications), therisk of undetected access beneath thedetection zone shall be considered.
The lowest allowable height of the detectionzone shall be calculated using the formula:
H = 15(d - 50mm).
Therefore, for a given height of the detectionzone, the detection capability, d, is:
d = H/15 + 50mm
Figure 13
Nearest dangerous parts
Separation distance
Direction of approach Plane of detectionof curtain
H
X
19
3.2.1.3 ANGLED APPROACH
If it is necessary to install the curtain,at anangle to the direction of approach as shownin Figure 14, then the following requirementsapply:
An angle within ± 5° of normal or horizontal,need not be considered to be angled, and therelevant formula used.
For detection zones which are positioned atangles greater than ±5°, to the direction ofapproach, account shall be taken of the risksassociated with the direction of approach,and the most appropriate formula used.
3.2.1.4 APPROACH TO 'L' INSTALLATION
If vertical and horizontal master/slave GS120light curtains are used together as in Figure 15,where the vertical curtain is the main tripcurtain and the horizontal curtain performspresence sensing inside it, the separationdistance calculations for the vertical curtainare used. However, the detection capabilitycalculations of the horizontal curtain withrespect to its height should also be observed.
Note: Where master/slave combinations areused:
Total Master Unit Slave UnitResponse = Response + ResponseTime Time Time
Figure 14
H
X
Figure 15
HH
XDirection ofapproach
Nearest dangerous parts
Separationdistance
Nearest dangerous parts
Separationdistance
Plane of detectionof curtain
Plane ofdetectionof curtain
Direction ofapproach
20
3.2.1.5 POSITIONING OF GS120
EN999 gives guidance on the dimensions andpositioning of photo-electric safety devicesfitted to industrial machines. The mainconsiderations are described below and areillustrated in figure 16.
(a) The appropriate protected height must beselected. The curtain must be of sufficientheight such that access to the dangerousparts, from the direction of approach of theoperator, is only possible by obstructing thecurtain taking into account all possible operatorpositions.
(b) The correct minimum separation distancemust be observed. The curtain must bemounted in the correct position in relation tothe dangerous parts of the machine to take
Figure 16
account of the stopping performance of themachine, the curtain format used and thedetection capability of the curtain.
(c) Steps must be taken to prevent access tothe dangerous parts from any direction notcovered by the curtain and prevent an operatorfrom standing between the curtain and thedangerous parts without obstructing thecurtain. Additional mechanical guarding willusually be necessary to acheive this.
The physical parameters affecting thepositioning are the dimensions of the detectionzone of the light curtain (i.e. the protectedheight and the range) and the minimumseparation distance. These are described inthe following sections.
Incorrect!Access to dangerousparts possible beneaththe curtain
Incorrect!Access to dangerousparts possible abovethe curtain
Use additional fencesto prevent access todangerous partsaround the curtain
Use a slave guard toprevent a personstanding between thecurtain and dangerousparts
21
3.2.2 GS120 MULTI-BEAM SYSTEM
The separation distance depends on theapplication and the following factors:
- the curtain format used. - the overall system response time, T.
The overall system response time, T, is aperiod, in seconds, given by the sum of theresponse times of the safety device and themachine control system. The response timeof the GS120 multi beam system is 20ms inall cases. The response time of the machinecontrol system should be measured using asuitable device and the highest value recorded,plus a suitable allowance for brakedeterioration, should be used in the calculationof the minimum separation distance. It isrecommended that the overall systemresponse time is recorded on the machineinformation label or plate.
The minimum separation distance should berecorded on the machine information label orplate.
The calculations for minimum separationdistance , S, in millimetres, for GS120 Multi-beam light curtains used in normal format areas follows:
S = (1600mm/s x T) + 850mm
the system has to be mounted with the bottombeam set at a height from the floor as shown:
GS120/2: 400mmGS120/3: 300mmGS120/4: 300mm
3.2.3 MULTI-SIDED GUARDING
By using mirror columns the beams can bedeflected around corners to form two andthree sided guard configurations. It shouldbe borne in mind that for each mirror used therange is reduced by approximately 20%.Also the alignment of systems with mirrorscan be difficult especially where the mountingsurfaces are uneven. It is thereforerecommended that no more than two mirrorsare used between any pair of emitter andreceiver units. See Figures 17 and 18.
Note: The arrangement shown in Figure 19 isnot recommended, as it is very difficult todetermine that the safety distance S is correct.
22
Figure 17 - Guarding a two sided area Figure 18 - Guarding a three sided area
Figure 19 - Incorrect use of two sidedguarding
Power drivenmachinery
s
s
Mirror Receiver
Emitter
DangerArea
Power drivenmachinery
Emitter
Receiver
Mirror
Mirror
s
DangerArea
ss
DangerArea
Power drivenmachinery
Receiver
Mirror
Emitter
s
23
3.3 ELECTRICAL INSTALLATION
3.3.1 GENERAL
Both units must be supplied with 24V d.c.±20%. This d.c. supply must be an isolatedsupply from a safety transformer which meetsthe requirements of IEC61558-2-6 and whichcan maintain a minimum of 18V d.c. outputduring a 20ms dip in the mains supply. The-ve side of this supply should be earthed, andthe cables should be routed separate frompower/motor drives.
IMPORTANT
The screen is to be connected to thesystem PE in the control cabinet.
If the moulded connection cable is to beextended, screened cable is to be used witha minimum wire cross sectional area of0,5mm². Care must be taken to ensure that thecontinuity and protection provided by thescreen is maintained.
The power consumption is dependant on theprotected height of the system but is less than12VA.
3.3.2 EMITTER UNIT
3.3.2.1 GENERAL
The emitter unit uses five terminals, two forthe d.c. supply, two for the test input(see 3.3.2.2) and one for the protective earth,as shown in Figure 20.
3.3.2.2 TEST INPUT
On some machines a test input is used tocheck the interface between the photo-electricsafety device and the machine. The inputsimulates the obstruction of the curtain inorder to cycle the output relays and therebyexpose any fault before the next machinecycle. This input is applied during a safe partof the machine cycle or at the end of the cycle.
If this function is used a normally closedcontact should be connected as shown inFigure 20.
Figure 20 - Emitter Unit Connections
1 = BROWN /BN2 = WHITE / WH3 = BLUE / BU4 = BLACK / BK5 = GREY / GY
1
234
5
NormallyClosedContact
Protective Earth PE
0V
Link OR
+24V
24
1 = WHITE / WH2 = BROWN / BN3 = GREEN / GN4 = YELLOW / YE5 = GREY / GY6 = PINK / PK7 = BLUE / BU8 = RED / RD
This contact must open for a minimum of100ms. When this contact is opened the lightcurtain safety outputs will be switched off andwill remain off until the test contact closesagain and the curtain self-tests have beensuccessfully performed (assuming that thecurtain is not obstructed).
If test input is not used then these terminalsshould be linked together.
3.3.3 RECEIVER UNIT
3.3.3.1 GENERAL
The GS120 is available with two output modes,PNP and SSR, as shown in the order code. ThePNP version has cross-monitored 24Vdc PNPoutputs, start/restart interlock and the ability tomonitor contacts from external devices (EDM).The SSR version has volt-free contacts whichare closed when the curtain is clear, but does nothave any start/restart interlock function. Thismust be provided elsewhere in the safety system.
The 24Vdc supply must have a 2A quickblow in-line fuse fitted.
Figure 22 - PNP Version Safety Outputs
3.3.3.2 PNP VERSION
3.3.3.2.1SAFETY OUTPUTS
The unit has two 24Vdc PNP outputs. Thetwo output signal switching devices (OSSDs)should be wired to independent switchingdevices in the machine control circuit. TheOSSDs are solid-state devices and aremonitored and short-circuit protected.
The maximum current is 0.1A
The output voltage, UA, of each OSSD isdependent on the supply, UV, and the loadwhich is given by the following expression:
UA > UV - 2V
Figure 21 - Receiver Unit Connector
+24V
Protective Earth PE
0V
0V 0V
RL RL
1
3
6
8
45
2
7
2A
25
Figure 23 - Auto Restart
Figure 24 - Auto Restart with EDM
Figure 25 - Manual Restart
Figure 26 - Manual Restart with EDM
Figure 27 - SSR Version Safety Outputs
1
3
6
8
45
2
7
1
3
6
8
45
2
7
EDM
1
3
6
8
45
2
7
RESETSWITCH
EDM
RESETSWITCH1
3
6
8
45
2
7
3.3.3.3 SSR VERSION
The unit has two volt-free solid-state outputs.It operates in automatic mode and so theoutputs will be on whenever the curtain is clearand off whenever the curtain is obstructed.See Figure 27.
3.3.3.2.2 START/RESTART ANDEXTERNAL DEVICE MONITORING (EDM)
In the PNP mode the GS120 can be used asa manual or automatic start/restart system.The function is determined by the connectionsto the unit. In manual mode, the outputs willonly switch on when the curtain is clear anda reset switch is closed and then opened. Inautomatic mode the outputs will be on wheneverthe curtain is clear and off whenever thecurtain is obstructed.
The GS120 also has the ability to monitorexternal devices. This is achieved by usingnormally-closed contacts of the external deviceand monitoring that they are closed beforeallowing the outputs to switch from off to on.The possible configurations are shown inFigures 23 to 26.
Earth PE
Output 1
0V
Output 2
1
3
6
8
45
2
7
2A+24V
26
GS120 Receiver Unit
5
Reset MPCE 1 K1
24V DC
Fuse 2A
- +
L N
SupplyPower
1 2 3 4-
WH+BN GN YE
K2 MPCE 2
GS120 Emitter Unit
if requiredTest input
BU
6 1 2 3
PKGY BN+
WH-
4 5
BK GY
3.3.4 INTERFACING TO A MACHINE
The interfacing of a light curtain to a machinecan be achieved by using discrete componentsor by means of an interface unit such as theGuardscan SRUB or the Pilz PNOZ 8.
All the relays shown are safety relays withpositively guided contacts. If this circuit isimplemented using discrete ciomponents it isessential that this type of relay is used.
3.3.4.1 PNP VERSION MANUAL RESET
It may be possible to connect the GS120directly to the Machinery Primary ControlElements (MPCE). The GS120 provides theStart/Restart function necessary to avoidunintended initiation of the machine.
Note N/C contacts of K1 and K2 are used formonitoring purposes. If EDM is carried outelsewhere the reset switch should be connectedbetween pin 2 and pin 6 of the Receiver unit.
IMPORTANT
A number of manufacturers produce unitscontaining circuits of this type. Care shouldbe taken to ensure that the inputs of these unitscan accept the PNP outputs of the lightcurtain.
Figure 28
27
T12
K2
GS120 Receiver Unit
5
A2(-)
-+
SRUB
K1 K2
K2
K3
K1 K1
24V DC
Fuse 2A
A1(+)
- +
L N
SupplyPower
1 2 3 4
T34
-
T11Reset
X1 X2
WH+BN GN YE
K2
control circuitto machine
Safety outputs14 24
K1
gnK3
K3
gn
K1
K3
K2
K1
K3
K2
42
K3
GS120 Emitter Unit
WH-
1 26 7
T22T44 PE
PKGY BU
13 23
BN+
53 4
41
if requiredTest input
BKBU GY
3.3.4.2 PNP VERSION AUTO RESET
The GS120 can be used in Auto Restartmode. If this mode is selected, the ManualRestart function must be provided elsewherein the machine safety control system (forexample, in the SRUB interface unit).
Note: The connection through 41 and 42 isused for external monitoring (EDM). If analternative safety relay is used which does nothave N/C contacts for monitoring, thenconnect pin 2 to pin 6 on the Receiver unit.
Figure 29
IMPORTANT
A number of manufacturers produce unitscontaining circuits of this type. Care shouldbe taken to ensure that the inputs of these unitscan accept the PNP outputs of the lightcurtain.
28
3.3.4.3 SSR VERSION
The interfacing of a GS120 light curtain to amachine can be achieved by means of aninterface unit such as the Pilz PNOZ 8. Thecircuit diagram for the PNOZ 8 and the typicalconnections to the GS120 light curtain andthe machine are shown in Figure 30 below.
IMPORTANT
A number of manufacturers produce unitscontaining circuits of this type. Care shouldbe taken to ensure that the inputs of these unitscan accept the volt-free outputs of the lightcurtain, and that the outputs of the lightcurtain are wired with one channel "pull up"and one channel "pull down" so as to maintainthe failure mode integrity.
Figure 30
6
GY
PNOZ 8
GS120 Receiver Unit
Reset
S11
A1 S52
N
+
24V DCSupply
Fuse 2A
-
Power
L
WH
1-
2
BN+
3
GN
4 5
YE
Y36
Y37
*Safety Contacts
Auxiliary N/C
for safety contactscontacts, unsuitable
positive-guided
14
13
Y1 Y2 A3
S12 S22 S21
3424 42
3323 41
A2
WH
GS120 Emitter Unit
BUPK
7
BN
1+
2-
Test inputif required
BKBU
3 4 5
GY
29
3.3.5 CONNECTIONS TO AS-i SYSTEM
The connection of a GS120 system to anAS-i Safe system is accomplished as shownin Figure31 below, using standard AS-i SafeI/O modules.
The connection of the Emitter and Receiverunits to the system is simply achieved byplugging into standard AS-i components usingthe cables supplied.
Receiver Unit
3RK1205-0AQ00-0AA3Siemens:
Safety InputModule
PowerConnector
AS-iCable
Cable B
Receiver Connection CableTapeswitch Part No.321352
GS120
Connector
Cable A
Power
Tapeswitch Part No.321351Emitter Connection Cable
Emitter UnitGS120
Figure 31
Note: The power supply leads of the GS120system should not be connected directly tothe YELLOW AS-i cable as this may causeAS-i data transmission problems. It isrecommended that this connection be madeusing a decoupling network.
Alternatively the guard can be connected to theBLACK AS-i cable ( the auxiliary power cable).
30
Using the test piece provided, obstruct thecurtain. On the receiver unit the green indicatorshould go off and the red indicator come on.Move the test piece in and out of the curtainseveral times and check that the indicatorschange state appropriately each time.
See section 4.2 of this manual if the systemdoes not function as described above.
The installation of the machine can now becompleted. Before putting the machine intouse the complete system (i.e. the machine andall its safeguarding devices) should becommissioned by qualified personnel and asa minimum the commissioning checksdescribed in section 4.1.1 of this manualshould be performed.
Periodic checks in accordance with section4.1.2 should be carried out at the prescribedintervals. Daily checks to be performed onthe GS120 system are detailed in section4.1.3 of this manual. In some cases there arespecific statutory requirements concerningthe examination, inspection and test of amachine and its safety devices. It is for theuser to determine if such requirements existfor the machine in question and to ensure thatthose requirements are met.
3.4 INITIAL CHECKING AND ALIGNMENT
The procedure for alignment is describedbelow.
Apply power to the GS120 system.
The amber indicators on the emitter and thereceiver units should be lit. If either of theindicators are not lit, check the wiring.
The yellow indicators on the emitter and thereceiver units should be in the off state. Ifeither of these two indicators are flashingthere is a fault, contact your Guardscandistributor. If the yellow indicator on theemitter unit is on constantly, check the wiringas described in section 3.3.2
The green indicator on the receiver unit shouldbe lit, if not, adjust the units into generalalignment until the green indicator comes on.
Adjust the units to optimum alignment asfollows:
1. Slowly turn the emitter unit clockwise untilthe green indicator on the receiver unit goesoff and the red indicator comes on. Note thisposition.
2. Then turn the emitter unit anti-clockwise,again until the green indicator goes off and thered indicator comes on. Note this position.
3. Fix the emitter unit at the centre of the twonoted positions.
4. Repeat steps 1, 2 and 3 but this time turningthe receiver unit.
31
4.1 PERIODIC CHECKING
4.1.1 COMMISSIONING CHECKS
The commissioning examination should becarried out by persons who are competentand who possess all the information suppliedwith the machine and its safety equipment.The results of the examination should berecorded and copies of this record should bekept by the user and the employer of theperson performing the examination. Theperson carrying out the examination shouldensure that the following general standard ofperformance is met:
(a) It should not be possible for the dangerousparts of the machine to be set in motion whilethe light curtain is penetrated.
(b) Penetration of the light curtain during adangerous phase of the operation of themachine should result in the dangerous partsbeing arrested or, where appropriate, assumingan otherwise safe condition, before any partof a person can reach them. It should not bepossible for the dangerous parts to be set inmotion until the curtain has been cleared, thesafety system has been restored to its normalcondition and the machine controls havebeen re-operated.
The person performing the examinationshould also:
(c) Inspect the position of the light curtain toensure that it is set at the correct distance fromthe dangerous parts of the machine as recordedon the machine information label or plate.
4. PERIODIC CHECKING, SERVICING AND MAINTENANCE
(d) Ensure that additional safeguardingmeasures have been provided wherenecessary to prevent access to the dangerousparts of the machine not protected by thesensing unit.
(e) Where appropriate, test the overall systemresponse time using a suitable device andensure that it is the same or less than thatrecorded on the machine information label orplate.
(f) Test the detection capability of the sensingunit as described in section 4.1.4 of this manual.
(g) Examine the machine controls andconnections to the GS120 system to ensurethat the requirements described in this manualand in the machine manual have been met.
(h) Examine the stopping performance monitor(if fitted) to ensure that it is fitted and functioningcorrectly. Ensure that the means whereby thestopping performance can be assessed by theoperator is indicating correctly.
(i) Test the muting arrangements (if fitted).
(j) Examine brakes or clutches (if fitted) asrecommended.
NOTE: No stopping performancemonitor or muting facility is providedwith the basic GS120 system and there isno means provided for the connection ofsuch devices to the system. These devicesmay however have been providedelsewhere in the machine control system.
32
4.1.3 DAILY/SETTING EXAMINATION
The following tests should be carried outdaily and after setting by a designated personappointed by the machine user. The resultsshould be recorded and a copy should bekept on or near the machine. Specific statutoryrequirements may apply to certain types ofmachine. The designated person should:
(a) Check that access to the dangerous partsof the machine is not possible from anydirection not protected by the sensing unitand that side and rear guards are in order.
(b) Check that the minimum distance from thedangerous parts of the machinery to the sensingunit is not less than the distance stated on themachine information label or plate.
(c) Check that it is not possible for a personto stand between the dangerous parts of themachine and the sensing unit.
(d) Check that when the muting facility(if fitted) is operative the moving parts are nolonger dangerous.
(e) Check that the stopping performancemonitor (if fitted) is in use and is set up andfunctioning correctly.
(f) Check that electrical enclosures are closedand locked and that any keys have beenremoved for retention by a designated person.
(g) Check for external signs of damage toequipment or to electrical wiring.
(h) Check the detection capability of theGS120 as described in section 4.1.4
4.1.2 6 OR 12 MONTHLY CHECKS
These examinations should be carried outby competent persons. The results shouldbe recorded and a copy kept by the user.
The person should ensure that the generalstandard of performance as described insection 4.1.1 (a) and (b) is achieved.
The person should perform thecommissioning inspections and tests detailedin the section 4.1.1. When checking thestopping performance monitor, item (e), anyequally effective means of determining thatthe overall system response time, as recordedon the machine information label or plate, isnot exceeded, is acceptable.
In addition the person should:
(a) Examine all switching elements in theswitching paths controlled by the light curtainoutputs to ensure that they are functioningcorrectly and are not in need of maintenanceand/or replacement.
(b) Inspect the machine to ensure that thereare no mechanical or structural aspects whichcould prevent the machine from stopping orassuming an otherwise safe condition whencalled upon to do so.
(c) Examine and inspect the machine controlsand the connections to the GS120 system toensure that no modifications have been madewhich could adversely affect the system andthat suitable modifications have been correctlyperformed and properly recorded.
33
(c) Repeat the above test with the test pieceinserted close to the front of the receiver unitand with the test piece inserted at the midpointbetween the emitter and receiver units. Theindicators should behave as describedpreviously whenever the test piece is betweenthe arrow markers.
WARNING
At no time while the test piece is obstructingthe curtain should the green indicatorcome on. If it does the machine must beisolated and must not be used until thecause has been investigated.
(d) If the system passes the above testsproceed as follows. Initiate a cycle of themachine and then insert the test piece into thecurtain. Upon insertion of the test piece duringdangerous motion, the dangerous parts shouldcome to rest without apparent delay.
WARNING
If the machine does not stop or there is anydelay in its response the machine must beisolated and must not be used until thefault has been rectified.
4.1.4 CHECKING DETECTION CAPABILITY
Figure 32
The detection capability of the light curtainshould be checked as required in the previoussections using the method described belowand as shown in Figure 32.
4.1.4.1 GS120 SYSTEM
(a) With power applied to the GS120 systemand with the machine at rest, check that thelight curtain is functioning by observing thestate of the appropriate indicators. The greenindicator should be on, the red indicatorshould be off.
(b) Insert the test piece provided into thecurtain with the axis of the test pieceperpendicular to the plane of the curtain.Starting at the top of the emitter unit with thetest piece less than 150 millimetres from thefront of the emitter unit, pass the test pieceslowly down the front of the emitter unit.While the full diameter of the test piece iswithin the area defined by the two arrowmarkers on the front window, the greenindicator should GO OFF AND REMAINOFF and the red indicator should BE LITAND REMAIN LIT.
Test piece
<150 <150
Prot
ecte
d he
ight
34
!
(c) Repeat the above test for each of thebeams. The indicators should behave asdescribed above whenever the beams areobstructed.
WARNING
At no time while a beam is obstructedshould the green indicator come on. If itdoes the machine must be isolated andmust not be used until the cause has beeninvestigated.
(d) If the system passes the above testsproceed as follows. Initiate a cycle of themachine and then insert your hand into thecurtain. Upon insertion of your hand duringdangerous motion, the dangerous parts shouldcome to rest without apparent delay.
WARNING
If the machine does not stop or there is anydelay in its response the machine must beisolated and must not be used until thefault has been rectified.
Figure 33
4.1.4.2 GS120 MULTI-BEAM SYSTEM
The operation of the light curtain should bechecked as required in the previous sectionsusing the method described below and asshown in Figure 33.
(a) With power applied to the GS120 systemand with the machine at rest, check that thelight curtain is functioning by observing thestate of the appropriate indicators. The greenindicator should be on, the red indicatorshould be off.
(b) To test the curtain is operating correctly,insert your hand in between the emitter andreceiver units and obstruct one of the beams,see Figure 33. While the beam is obstructed,the green indicator should GO OFF ANDREMAIN OFF and the red indicator shouldBE LIT AND REMAIN LIT. Move yourhand in and out of the beam several times andcheck that the indicators change state eachtime as appropriate.
35
4.3 MAINTENANCE
There are no mechanical, electrical or opticaladjustments necessary. Apart fromoccasionally cleaning the windows of theemitter and receiver units, GS120 systems aremaintenance free. Use a soft, lint-free clothand an anti-static cleaner.
Do not use solvents of any kind.
4.2 SERVICING
The GS120 system is designed to be servicedat unit level. There are no user serviceableparts within the units.
When a safety-critical fault occurs in theGS120 system or in the machine interface, themachine will be disabled. It is first necessaryto establish whether the fault is in the GS120system or in the machine interface.
Use Table 1 / Table 2 to identify faults withinthe GS120 system.
If you require any assistance with theinstallation or maintenance of yourGS120 light curtain, please contact yourGuardscan authorised distributor.
36
5. TECHNICAL SPECIFICATION
5.1 GS120 LIGHT CURTAIN SYSTEM
maeB-itluM&niatruCthgiLsmetsyS
S tinUelgniS
M tinUretsaM
A tinUevalSyrailixuA
D tinUevalSdednE-elbuoD
maeB-itluM&niatruCthgiLegnaRgnitarepOsmetsyS
noitceteD egnaR
mm03 m51otm5.0
mm07 m51otm5.0
maeb2 m03otm5.0
maeb3 m03otm5.0
maeb4 m03otm5.0
smetsySniatruCthgiLthgieHdetcetorP
mm03 mm0081ot002
mm07 mm0081ot006
smetsySmaeB-itluMgnicapSmaeB
maeb2 mm005
maeb3 mm004
maeb4 mm003
sniatruCthgiLfoytilibapaCnoitceteD mm07romm03
smetsySmaeB-itluMnismaeBforebmuN 4ro3,2
elgnAerutrepAevitceffE º5±
emiTesnopseR
noitcetedmm03 .niatrucfomm002hcaerofsm4lanoitiddA.niatrucmm006otpusm02
noitcetedmm07 .niatrucfomm006hcaerofsm4lanoitiddA.niatrucmm0081otpusm02
maeB-itluM sm02
egatloVylppuS elppirlaudisermumixam%5,%02±.c.dV42
noitpmusnoCrewoP AV21<
gnitaRerusolcnE 56PI
htgnelevaWnoitaidaRhtgnelevaW mn088
ytisnetnI )1-52806CEI(tcudorpDEL1ssalC
epyTtuptuOytefaS
PNPnoisreV
epyT PNPetatsdiloS
yticapaC xamA1.0
egatloV V2sunimegatlovylppuS
RSSnoisreV
epyT yalereerf-tloVetatsdiloS
yticapaC xamA1.0
egatloV xam)cdroca(V84
ecnatsiser-no xammho02
deilppasdradnatS 3yrogetaC1-459NE&2epyT69416NE
erutarepmeTgnitarepO Cº05...º0
erutarepmeTegarotS Cº07...º02-
ytidimuH gnisnednoc-non%59ot%51
)tinuhcae(thgieW niatrucfomm001repgk2,0sulpgk3,0
noitcesssorc-snoisnemiD mm54x63
Table 3
37
GS120 / XXX / X / XXXX / XX / XXXX / XX
Outputs:PNP - 2 x PNP outputsSSR - 2 x Solid-State Relays
Curtain Type:S = Single UnitM = Master UnitA = Slave UnitD = Double-Ended Slave Unit
Curtain Length:200mm to 1800mm
Detection Capability:30mm or 70mm
Curtain Display:LED - Discrete LEDsDIAG - Dot Matrix Diagnostic Display
Bracket Options:AB = Adjustable BracketCB = Clamp BracketEB = End Cap Bracket
GS120 / XXX / X / X / XXXX / XX
Outputs:PNP - 2 x PNP outputsSSR - 2 x Solid-State Relays
Curtain Type:S = Stand Alone UnitM = Master UnitA = Slave UnitD = Double-Ended Slave Unit
Number of Beams:234
Curtain Display:LED - Discrete LEDsDIAG - Dot Matrix Diagnostic Display
Bracket Options:CB = Clamp BracketAB = Adjustable BracketEB = End cap Bracket
5.2 ORDER CODES AND MODEL NUMBERS
5.2.1 GS120 LIGHT CURTAIN ORDER CODE
5.2.2 GS120 MULTI-BEAM ORDER CODE
38
5.2.3 GS120 CONNECTOR CABLE OPTIONS
GS120 connector cable options are available as listed below:
5.2.3.1 PNP Systems
Emitter cable connector (5 way) 5mEmitter cable connector (5 way) 10mEmitter cable connector (5 way) 20m
Receiver cable connector (8 way) 5mReceiver cable connector (8 way) 10mReceiver cable connector (8 way) 20m
5.2.3.2 SSR Systems
Receiver & Emitter cable kit 1m
5.2.3.3 General
Slave connector cable 0.3m
