photoelectric sensors with special function - nowimex ax80.pdf · photoelectric sensors with...

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Photoelectric sensors with special function3.1 Area sensors 133

3.2 Surface sensors 153

3.3 Contrast scanners 159

3.4 Luminescence scanners 165 3

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Area sensorsGlossary of technical terms 134

AX80serie

High resolution area sensors - DC 140

AX100serie

Medium resolution area sensors - DC 144

AX500serie

Area sensors with parallel/analogic outputs - DC 148 3.1

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glossary of technical terms

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IntroductionOptoelectronic scanners are not covered bythe provisions of EN 60947-5-2, Sept. 95 andthe following details only refer to commonparameters.The technical terms of the paragraph headingsreflect those used in the wording of thislegislation, whilst those in italics aresynonyms.The specifications listed relate to the nominalperformance envisaged by said legislation andapp l y to p roduc t s whose t echn ica lspecifications do not include a specific figure.

Operating principleType-T Optoelectronic scanners are made up oftwo elements; an emitter and a receiver. Theemitter has an optical unit that consists of anarray of photoemitters which emit a series ofnarrow luminous pulses to the receiver in aconsecutive well-defined manner.Luminous radiation is generated by a solid-state source made up of high-performancelong-lasting semiconductor elements. Thisradiation can be from outside the visibleband.The receiver has an optical unit which is madeup of an array of photoreceivers whichcorrespond geometrically to those of theemitter.The luminous rad ia t ion reach ing thephotoreceivers is converted to an electricsignal, amplified and processed in order todrive receiver output elements. As there issynchronous reading of the luminous pulse, asynchronous signal must be transmittedbetween emitter/receiver. Detection occurswhen the path of the beam is interrupted bythe presence of an opaque object.

Parallel-ray scanningEvery pulse emitted by a single element of theemitter array must be synchronously read bythe corresponding element of the receiverarray so that the single pair can be consideredin light state. Every single emitter/receiverpair only controls its own axis of conjunction.Scanning determines an area crossed byparallel rays.Us ing pa ra l l e l ra y s enab l e s p rec i s einformation to be obtained regarding size andposition of target object.

Cross-ray scanningEvery pulse emitted by a single element of theemitter array must be synchronously read bythe corresponding element of the receiverarray, and by a variable number of otherreceivers positioned on either side of thecentral one, so that the single pair can beconsidered in light state (i.e. path of beamcompletely clear). Every single emitter/receiver pair controls a range of axes whichoriginate from the emitter and reach an arrayof receivers. Scanning determines an areacrossed by cross rays in a complex manner.The number of lateral receivers involved inreading the single emitter varies according tothe range of the particular model. Everyemitter must illuminate various receivers andcan only do so if the optical-beam angle issufficient for a certain distance. The numberof receivers enabled can also vary duringscanning. In extreme cases the two emitterson the edge of the array may only illuminatethe internal lateral receivers because theexternal ones do not exist. Another case inparticular is when single emitters must alwaysilluminate all the receivers. This operatingmode is simple to manage but requires largebeam angles.Operating with cross rays does not enableprecise information to be immediatelyobtained regarding size and position of targetobject, but merely reveals its presence.

Synchronising scanningIt is the function which allows a singleelement of the receiver array to be enabled toread only at the moment in which theluminous pulse is sent by the correspondingemitter element.The synchronisation serves to determine astrict relationship between correspondingemitter and receiver so as to reduce theeffects of interference from other signals.With type T parallel-ray scanning sensors usedfor determining size and position of objects,the synchronisation must be realised byconnecting a cable between emitter andreceiver.With sensors that are only used for detectingthe p re sence of an ob jec t , thesynchronisation can be sent optically. Usuallyan emitter is added to the receiver array sendssynchronisation message to an additionalreceiver in the emitter array. Alternatively,t im ing t echn iques can be u sed f o rautosynchronisation of the receiver, thuseliminating the need for cabling betweenemitter and receiver.Devices also exist whose arrays of opticalelements alternate between emitters andreceivers that pass the optical pulses on toeach other. This type of solution is anotherwhich does not require cable synchronisationand cannot be used for pinpointing positionand size of objects.

State of areaTo define the state of the area or the singleelements, reference must be made to thelight/dark condition of the receivers. Thedark condition is determined by the presenceof an opaque object that blocks the path ofthe rays. The light condition is on the otherhand determined by the fact that the pathbetween emitter and receiver is clear.

Output operating logicArea function outputAn output whose logic state is a function ofthe state of the area.OR function: The output represents the ORfunction indicating dark state of the single E/R pairs.If just one single pair is obscured, the darkstate will be assumed by the output.It is necessary that all the pairs are in lightstate before the output will assume lightstate.AND function: The output represents the ANDfunction indicating dark state of the single E/R pairs.It is necessary that all the pairs are in darkstate before the output will assume darkstate.If just one single pair is in light state, thelight state will be assumed by the output.• Array outputs (parallel)A group of outputs that indicate the light ordark state of the single elements of thereceiver array.

Independent actionSwitching of output status does not dependon the approach speed of the target and thereare no transition stages between ON and OFF.All barrier outputs which provide a logic levelare of this type unlike analogue outputswhich are not.

Standard targetWith type T scanning sensors, the standardtarget does not correspond to the targetwhich will in practice be detected but isinstead the emitter element.

Excess gain (Eg)Indicates the ratio between the signalobtained at a specific distance and that

necessary to trigger the device (see also“Excess-gain graph”). Although switching ofreceiver ON/OFF state always occurs at Eglevels close to 1, technical specificationsrelating to S parameter refer to Eg=1.5. Inthis case S is intended as the distancebetween the two elements at which a there isa guaranteed signal operating margin equal to1.5.

Operating distance (S)Generally used to indicate the operatingdistance between the two elements of thesystem, the emitter and receiver units in thecase of type T models, and between singleunit and reflector for type R. Unless otherwisestated, it is expressed for Eg=1.5.

Optical axis spacing (BS)Indicates the distance that exists betweenthe optical axes of the single elements of anarray and is necessary for defining resolutionand height of control area.

Diameter of optical lens (BD)Indicates the diameter of the optical lens of asingle array element and corresponds to thediameter of the optical beam in the proximityof the unit itself. It is necessary for definingresolution.

Number of optical elements (BN)Number of elements making up the array. It isused for defining height of control area.

Height of area (AH)Indicates the height of area selected for thepath of the optical rays that are transmittedto the receiver by the emitter; the formula is:

Blind zoneUsing cross-ray scanning makes it possible toobtain a reduction to 1/2 the vertical spacingbetween two contiguous rays. With thistechnique a reduction of the minimumdetectable diameter is obtained. This does nothowever occur in a uniform manner over thewhole control area. In the zones close to thesensor where the spacing of the rays remainsequal to that of the optical unit, the minimumdiameter of a detectable object remains thesame as it would have been if there were nocross rays. This is not as blind zone but onlyless fine resolution. The amplitude of thiszone is equal to 15% of the distance betweenE and R.

ResolutionIndicates the minimum dimensions (diameter)of the test target that it is possible tocontinually detect whilst moving the targetvertically in the control area (the test objectis a cylindrical bar of opaque material).In applications where it is necessary toguarantee with complete certainty that aparticular diameter will be detected withinthe whole area between emitter and receiver,the resolution must be set according to themechanical dimensions of the optical unit. Intype-T sensors the resolution corresponds tothe diameter that will always guarantee thatat least one optical beam is interrupted. Thisis equal to the optical element spacing plusthe diameter of the single optical lens.In detect-and-count appl icat ions theresolution can be defined with much lessrestrictions. Using the sensitivity control toreduce excess gain, it is possible to set theresolution at just the optical element spacing.Use of the cross-ray function can improve theresolution still further to 1/2 the spacing ofthe optical elements (this only applies to the

AH BS BN 1–⟨ ⟩×[ ] BD+=

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centre of the control area and not near to theoptical units; see blind zone).The cross ray function can detect fine objects,although they must be a certain width with aresolution which is effectively zero. Theminimum width for this resolution depends onthe inclination of the cross rays.

Rated operating distance (Sn)Nominal sensing distanceConventional value of operating distance S forphotoelectric switches without sensitivityadjustment. If there is a sensitivity adjuster,it is intended as being with adjustment atmaximum. This conventional value is a figure whichrefers to this series and does not considermanufactur ing to le rance (±10%) andvariations that can be produced by differentlyrated supply voltages and temperature outsidethe range 23±5ºC.

Sensing range (Sd)Range within which the operating distancerelative to the approach/withdrawal ofstandard target (emitter or reflector) can beregulated if the sensor is fitted with asensitivity adjuster. The maximum value of Sdhas the same definition as Sn (see above). Ifminimum value of Sd is not quoted it shouldbe taken as being equal to 0. If it is givenhowever, tolerance is not guaranteed that ofSn.

Effective operating distance (Sr)Is the operating distance S assumed by aspecific relative to the approach of standardtarget in nominal conditions of power supplyvoltage and ambient temperature (23±5ºC). Itis expressed as a percentage of Sn. This iseffectively the manufacturing tolerance.Type-T scanning barriers have guarantee of Srwithin range 90% -200% of Sn with Eg=1.5.

Usable operating distance (Su)Is the operating distance relative to theapproach of standard target calculated withpower supply voltage at between 85 and110% of nominal value and a specifiedambient temperature. The manufacturerguarantees that it is between 90 and 110% ofSr. Minimum Su is however guaranteed asbeing ≥81% of Sn.The user should consider this as the workingrange which is at all times guaranteed in thewhole range of environmental workingconditions specified.

Differential travel (H)This is given as a percentage of Sr andexpresses as an absolute value the maximumdifference between the switching pointsduring the target’s approach and departurefrom the operating face.The difference between the two switchingdis tances i s purpose ly int roduced toguarantee the constant state of the outputshould the object come to be found inside theswitching points. Unless otherwise indicated,0.02S≤H≤0.2Sr.H can be influenced by the thermal drift, butthe value specified remains inside thatdeclared in the ambient temperature range. Itshould be noted that in type-T sensors thetarget object crosses the optical beamsperpendicularly and therefore the hysteresisquoted as above bears no direct relation towhat actually happens in practice.

Rated operational voltage (Ue)Expresses the supply voltage range. Themanufacturer guarantees that the barrier willfunction correctly in a voltage range between0.85 Ue min. and 1.1 Ue max. (see Ub).

Voltage rating (UB)Operating voltageExpresses the power supply voltage rangebetween minimum and absolute maximumvalues.

RippleAmplitude of maximum acceptable ripple inthe DC power supply voltage expressed as apercentage of the average value of the latter.Correct operation is guaranteed with ripple <10% Ue. In actual fact many sensors operateperfectly well even when the ripple is muchhigher.

Voltage drop (Ud)Indicates maximum value of drop across theactive output, with rated load current (Ie),power supply voltage within UB range andtemperature 23±5ºC. Unless otherwise statedthe manufacturer guarantees the following fordc models:Ud ≤3.5V (3-wire models)

Rated insulation voltage (Ui)Unless otherwise stated, sensors up to 50 Vacand 75 Vdc are tested to 500V ac.

Impulse voltage withstandability (Uimp)Unless otherwise indicated, the supplyterminals and output leads of dc units aretested with a pulse amplitude of 1KV. Thespecifications are as follows: 1.2/50µs, 0.5J,generator impedance 500Ω.

No-load supply current (Io)The current drawn by the sensor from itssupply when not connected to a load.Specifications include Iomax which indicatesthe maximum current drawn within thevoltage range Ue.

Rated operational current (Ie)Load currentIs the current drawn by the load. The tablesquote the Iemin indicating that guaranteed inworst possible operating conditions.

Minimum operational current (Im)The current which is necessary to maintainON-state conduction of the switching elementwithin the supply voltage range Ue.

OFF-state current (Ir)Leakage currentThe current which flows through the loadcircuit in the OFF-state at the maximumsupply voltage (UBmax).The load value is specified in such a way thatat UBmax the load itself can be bridged by acurrent equal to Ie. The user must ensure thatthe Ir current is below that required to holdload in ON-state or this could result in theload remaining connected even if in OFF-state. With parallel connection of sensors theIrs need to be added together.

Utilisation categoriesUnless otherwise indicated, output utilisationcategories are as follows:Category DC-13; relay driver dedicatedoutputs.Category DC-12; logic-input-driver dedicatedoutputs

Switching element functionThe functions can be expressed as follows:a) by indicating the state of the receiver withreference to ON/OFF state; orb) indicating ON/OFF state with reference tothe presence of the target1a) Dark operate. Function that allowscurrent to flow when the path of the luminousbeams is interrupted and will prevent flowwhen the path of the luminous beams is not

interrupted.2a) Light operate. Function that allowscurrent to flow when the path of the luminousbeams is not interrupted and will prevent flowwhen the path of the luminous beams isinterrupted.1b) Make (NO normally open). A makefunction causes load current to flow when atarget is detected and not to flow when atarget is not detected.2b) Break (NC normally closed). A breakfunction causes load current to flow when atarget is detected and not to flow when atarget is not detected.Make-break or changeover functionA switching element combination whichcontains one make function and one breakfunction.Type of output and load connectionNPN: The switching element is connectedbetween output and negative terminal. Whenin ON-state the current is drawn from loadacross the output terminal. The other loadterminal is connected to the positive terminalof the power supply.PNP: The switching element is connectedbetween output and positive terminal. Whenin ON-state the current is drawn from positivepole and supplied to the load across theoutput terminal. The other load terminal isconnected to the negative terminal of thepower supply.Open collector: The output transistor is notinternally connected to a pull-up or pull-download. Therefore it is possible to connect anexternal load supplied by an external voltage.If the output is not the open-collector type, itis possible for the load to be supplied by anexternal voltage using a blocking diode inseries to the output.This solution increments the output voltagedrop..Analogue: Analogue outputs make availablea s igna l whose ampl i tude i s d i rec t l yproportional to the sensor area status, i.e.number of optical element in light or darkstate. The output will have a quantized signal.Two types of analogue output are available; acurrent-type with rating 4-20mA, and avoltage-type rated 0-10V.The analogue outputs can increase ordecrease their values according to size of areaand setting chosen which can be either NO(dark operate) or NC (light operate).The minimum amplitude of step variation willbe a function of the number of opticalelements present. The usual value of theoutput parameter will be:V output (Volt) = (10/Bn) x (No. of opticalelements occupied if NO or free if NC)I output (mA) = ((16/Bn) x (No. of opticalelements occupied if NO or free if NC))+4For example with 8 optical elements:V output = 1.25 x (No. of optical elementsoccupied if NO or free if NC) VI output = 4 + (2x (No. of optical elementsoccupied if NO or free if NC) mA.

The return of external analogue loadsconnected to analogue outputs must be tothe negative pole.An analogue voltage output has a currentrating of 10mA, therefore the minimumresistive value that can be applied as loadcorresponds to a 1KΩ resistor. The output hasoverload and short circuit protection with anintervention threshold of 25mA.Maximum voltage that can be delivered byanalogue current output is 11V. Maximumresistive value applicable is 500Ω.

Short circuit protectionAll outputs of category DC-13 are usuallysupplied with integrated short-circuitprotection, whilst category DC-12 devices do

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not have integrated protection. Output protection of dc sensors in the case ofshort circuit or overcurrent is effected byestablishing a maximum current threshold(limiting current). When this threshold isexceeded (usually between 1.5 and 3 timesIe), the sensor opens the output circuit.Normal operation is resumed by followingcertain procedures which vary according totype of protection:

a) autoreset:

reset occurs automaticallystraight after the cause of the short circuithas been removed

b) with hold:

to restore normal operation it isnecessary to effect a switching exercise orswitch off power supply and remove cause ofshort circuit.In both cases, during the short circuit a] oneor b] a burst of current pulses (whoseamplitude can reach 5A) will flow across theoutput.

Polarity-reversal protection

No damage will occur to sensor if the supplywires are reversed.

Overvoltage protection

When the UB voltage is exceed for a fewmoments, sensors wil l not generally be damagedprovided dissipated energy does not exceed0.5J (see also Uimp).

Inductive-load protection

Unless otherwise sated, dc sensors are fittedwith an inductive-load (surge) protectionwhich consists of a diode or Zener diode. Seesection “electrical connections” for maximumL value.

Time delay before availability (tv)

This is the time between the switching on ofthe supply voltage and the instant at whichthe sensor becomes ready to operate correctly. During this phase the output circuit remainsin OFF-state; false signals may be present fora maximum of 2ms. This time is necessary forpreventing that when switching on the sensoroutput find itself in an undefined state andthat there may be false operating cyclespresent capable of exciting the load. Unlessotherwise stated the delay is

≤

300ms.

Switching frequency (f)

This is the maximum output switchingfrequency performed by the output circuit andis stated as:

For ac sensors, the minimum output pulsewidth must not fall below half sine period.Alternatively, ton and toff may be suppliedinstead of f.

Turn on time (ton)

This information is not usually quoted. It isused along with toff to calculate f. The timeindicated represents that required to switchoutput to light state with respect to theinstant in which the receiver element haseffectively switched to this same state.

Turn off time (toff)

This information is not usually quoted. It isused along with ton to calculate f. The timeindicated represents that required to switchoutput to dark state with respect to theinstant in which the receiver element haseffectively switched to this same state.

Status indicators (LED)

The LED indicators can be classified accordingto colour:

CONTINUOUS GREEN:

Power on

CONTINUOUS YELLOW:

Output on

CONTINUOUS RED:

Fault.

Synchronisation output

Receiver output that must be connected tothe corresponding emitter. Digital informationregarding synchronisation of reading andstate of area can be transmitted.

Alarm output

It is an output supplied on some models thatremains in ON-state during normal conditionsand switches to OFF-state should an alarm betriggered.It is possible to add a self-checking pulse.

Alarms• Low signal alarm

This is defined by checking the signal levelreceived. A check is made on every element ofthe ratio between signal and two standardthresholds Sc and Sa.Sc is defined as the trigger threshold and isused to determine if state is light or dark.Sa is defined as the margin threshold and isused to determine that there is adequatesignal margin.If the sensor is in dark state, or if it is lightstate and all array receivers have a marginsuperior to Sa, the alarm output is in ONstate.If the sensor is in light state and not all arrayreceivers have a margin superior to Sa, shouldthis condition continue, the alarm output willswitch to OFF.

• Software alarm

Alarm condition caused by the Watchdogfunction of the receiver microcontroller. Inthe eventuality that a software fault occurs orthere is a stoppage of the quartz oscillator(no clock), the alarm switches to OFF-state.

• Hardware alarm

If the power supply is cut or a short circuitoccurs to one of the protected outputs, thealarm switches to OFF-state.

Autocheck

Self-monitoring

Master/Slave models have an autocheckcircuit which generates a continuous pulsetrain obtained as a complement of the actualoutput state. The pulses have a duration of200-400Ês. They are present in both ON andOFF output states and are generated at theend of the scanning cycle. These pulses onlydecrease the mean value of the outputcurrent by about 10%, therefore a standardload continues to operate correctly. Even anormal PLC input is not capable of detectingthese pulses.An external Watchdog circuit or a fast PLCinput can be used to detect the presence ofthe autocheck pulses: their presence meansthat the sensor works properly and theirabsence that a failure has occurred.These same pulses are used as synchronisingoutput in the Master/Slave function.

Check input

It is an input supplied on some models thatwhen disconnected results in the suspensionof luminous-pu l se emiss ion, wi thoutinterrupting the other functions. This functioncan be used to simulate the interruption of alloptical paths and allows a user-friendly testto be effected in order to verify that thesystem is operating correctly. If input isdisconnected with sensor in free state, outputshould switch from light to dark state. Ifswitching does not occur, it indicates a faultin the system.It can also be used to enable emission atcertain moments so as to eliminate problemsof interference with other optical devices.In the sensors selected as Slave it must be

connected to the alarm output of thepreceding sensor and performs the function ofsynchronising input.

NO/NC input

A dedicated input for programming theswitching function of the area or arrayoutputs. In some models it is only availableas a mechanical switch housed in the deviceitself.This input is only read when switching on toeffect time delay before availability. NO/NCcannot be modified during normal operation.

Power emission control input

An emitter dedicated-input for programmingpower emission. It can be used together withthe alarm function to verify the availablereserve of Eg. With input disconnected,emitted power is reduced by 20%. It isnormally in ON-state.

Slave/Master function

A function which can be activated by a switchsupplied on some receiver models that have aMaster configuration and can be chosen asSlave.This function is used to create a chain ofconnected optical scanner-systems in whichthe single emitter/receiver pairs effectscanning of the area in sequence thusavoiding the possibility of interferencebetween different units. The Master devicemust the first in the chain. Its alarm outputmust be connected to the enable input of thesuccessive Slave device. Any other Slavedevices must be cascade connected in thesame manner.The enable input of the Master devicetransfers the enable function to all the otherSlave devices that follow, leaving this controlfunction active along the entire chain. Thealarm condition spreads behind the pair thatactivated it thus making available the signalon the last alarm output of the chain.The receiver area-outputs that make up thechain can be parallel connected if it isnecessary to monitor the state of the entirearea. Selecting the NO function (dark pulse)for every sensor will produce the samefunction for the entire area.

Degree of protection

The minimum required degree of protectionfor photoelectric sensors is IP54 (partialprotection against dust and water jets). Ingeneral, the minimum degree of protectionoffered is IP65 (complete protection againstdust and water jets).

Pollution degree

The degree of environmental pollution forintended use is that relating to industrialenv i ronments (3 ) , wh ich a l l ows nonconductive dry pollution that could becomeconductive due to condensation. Thesedevices do not usually have exposed electricalcomponents. When connectors or terminalclips are fitted they will be enclosed in aprotected microenvironment.The operating distance of photoelectricsensors can be affected by a dirt beingdeposited on the optical components.

Ambient temperature range

Temperature range

Temperature swing for scanning sensors isguaranteed from -5 to 55°C. The figuresquoted are valid within the declared ambienttemperature range. Generally speaking thesensors can be used within a 10ºC greaterrange with only a slight loss of performance.Details regarding thermal drift of currentlyavailable sensors for wider temperatureranges are available on request.

f1

ton toff+---------------------=

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Temperature drift

Maximum change in the operating distancewithin the temperature range expressed as apercentage of the effective value Sr. Themanufacturer guarantees that photoelectricsensors have a thermal-drift range of ±10% ofSr.

Relative humidity (RH)

T

he relative-humidity range within whichnorma l pe r fo rmance i s gua ranteed.Photoelectric sensors can be affected by ahigh RH in the form of condensation whichcould be deposited on the optical surfaces.Some plastic materials can deteriorate if leftfor long periods in a dry environment(RH<10%), but even if used, these materialsdo not form part of the sensors functionalcomponents.

Ambient light interference

Interference to external light

Unless otherwise indicated, it is intended thatthe sensing range Sd remain unaffected whenthe receiver is illuminated by artificialambient light from lamps and light bulbs, etc.(3000°K) varying from 0 to 5000 Lux.. Thisimmunity level is not sufficient to exclude thepossibility that part of the sensor may beaffected by the presence of a strong natural orartificial illumination. It is advisable to keepthe receivers away from direct sunlight andpositions close to lamps and they should notbe placed facing lighting systems. Immunityto high-frequency fluorescent lights is lessthan that provided against incandescentlighting.

Excess gain graph

This expresses the signal margin with respectto the distance of the standard target. Thepoints at which Eg>1 indicate the distances atwhich the switch is in light state. Where Eg<1it is in dark state.

Parallel displacement graph

Fo r mode l T i nd ica te s the max imumdisplacement between the two parallel axes ofthe emitter in relation to distance for Eg=1.

Detection range graph

This is prepared when details regardingparticular types of targets are required (e.g.small diameters). Indicates the area in whichthe target is detected.

Angular displacement graph

Expresses maximum angle of displacement forEg=1 in relation to distance. It can besupplied for both elements. If only one curveis supplied, it is the more critical.

Mutual interference graph

It indicates minimum linear displacementrequired between the emitter and a receiver ofanother optical scanner pair in order to have ainterference signal lower than hysteresis inrelation to distance.

Choosing a sensor

• Choose a optical scanner suited to theworking environment: check chemicalcompatibility between the sensor buildmaterials and any substances present,temperature range, degree of protectionagainst dust and liquids, presence of dust orsteam, presence of condensation or ice,vibration, shock, presence of strong natural orartificial light, electromagnetic compatibility,suitability of power supply voltage and typeof l oad.

I f necessa ry cons ide r thepossibility of fitting specially-designedaccessories.

• Select an operating distance suited to thedimensions, colour and opaqueness of the

material to be detected.• Verify that minimum distances have beenrespected between sensor and other nearbysensors.• Ensure that the number of operationsrequired does not exceed the frequency ofoperating cycles. Should signal phase also beimportant, give careful consideration to

ton

and

toff.

Positioning of unit

All sensors must be positioned so as ensurethat dust and or liquids do not come intocontact with the optical surfaces and thusadversely effect the path of the luminousbeams. Mount in a position that protects bothoptics and body from coming into contactwith the target material and ensure thanpower cables are suitably placed where wear-and-tear and the possibility of breakage arereduced to a minimum. The receiver shouldnot be directly pointed towards sources ofartificial or natural light. Always keep sensoraway from sources of heat, in particularcolumns of hot air and radiation emanatingfrom incandescent material.

Installation

The instructions l isted below refer toparticular conditions of Eg which are asfollows:Eg=1; The signal received is very close to theON/OFF threshold and the sensor outputswitches at around this level. The output LEDor the load itself will indicate this state.Eg=2; The signal received is very nearlydouble the ON/OFF threshold and the sensoroutput is in light state. If present, it is thesignal margin LED that indicates this state. Insome models the safety margin is Eg=1.5 butthis fact does not alter the significance of thisdescription.

Refer to product specification sheets for afull explanation regarding LED indicators.

Type T with sensitivity adjustment.

It is first of all necessary to choose correctly thetype of emitter/receiver combination andoperating distance in accordance with type oftarget material (small or large objects, opaqueor semitransparent) and degree of dirt present inthe working environment (see Eg curves).a) With large and completely opaque objects orfor detecting holes, it is advisable to maximisesignal margin (EG>>2) by keeping the setsensitivity at maximum.If working environment is dusty it is necessaryto operate with ample margins of Eg (3-10) byusing distances below Sa.b) b) Fo r detect ing sma l l ob jec ts i t i srecommended to maintain Eg=2. In this case,the minimum diameter of the target objectcorresponds to the optical element spacing ifcross function is not activated. If smallerdiameters need to be detected, weigh up theneed for a model with cross-ray function andalso consider blind zones. When operating withsmall signal margins, the working environmentshould obviously have a degree of cleanlinessthat will not compromise the stability of thesetting.c) For detecting the presence of fine opaquesheets, the use of a c ross- ray model i sindispensable. The thickness of the sheet is oflittle importance is the width is sufficient toblock the inclined rays that cross the controlarea.d) If the target objects are close to shinysurfaces parallel to the optical axis, it isnecessary to consider the possibility that theobject may be not detected by the reflection onthe shiny surface of the peripheral beams. Inthis case use models with a narrow beam.

1)

Fix the sensor securely but not definitively, ifpossible using the brackets supplied. Positionthe two sensor elements so that the optical axescoincide as much as possible.

2)

Check that power supply voltage and load arewithin the prescribed limits and switch onsensor. If the check and power-increasefunctions are fitted, ensure that the former isdisconnected and the latter disconnected.

3)

Check that the power supply LEDs are on andthe alarm LEDs are off. If this is not the case,check power supply, load and cabling.

4)

6) Set the emitter trimmer to the maximumby turning clockwise. The emitter should beorientated by pointing an edge of the housingtowards the receiver.

5)

Next go to receiver and orientate towardsemitter with the maximum precision seeking toobtain minimum luminosity and the turning offof the Eg LED. If the Eg LED does go out, fixreceiver position in the middle of the zone.

6)

Go to emitter and repeat precision tuning oforientation as per 5) keeping a watch on thereceiver Eg LED.If the target objects are opaque and of largedimensions, verify that the trimmer is atmaximum and definitively fix photoswitch. If onthe other hand the objects are small and notcompletely opaque, continue as follows.

7)

Having obtained optimum orientation withEg>2, turn the trimmer anticlockwise untilobtaining Eg<2, and then turn clockwise untilobtaining Eg>2. Mark this point as position A.

The position found is that which offersoptimum working conditions for detectingpresence/absence of smal l objects orsemitransparent materials with equalprecision and discreet safety margins.8)

Place the target object along the optical axisand by moving check that the sensor switches(Eg<1). If this does not occur it means that thetarget object is too transparent or too small andit will be necessary to operate (environmentpermitting) with signal margins below 2. In thiscase, with the object still in position, turn thetrimmer anticlockwise until obtaining Eg<1.Memorise this point as position B and positiontrimmer at an intermediate point between A andB.Carefully check correct operation under actualworking conditions since this position is critical.In conclusion definitively fix photoswitch.

Type T without sensitivity adjustment

1), 2), 3) 4), 5), 6), 7)

as above.Models without sensitivity adjustment are notsuitable for detecting objects that require anEg close to 1 if this cannot be obtained bymerely by increasing the operating distance S.In extreme cases, low Eg can be obtained bymoving the single pairs out of line. However,this can cause non uniform Egs for the singleelements making it difficult to obtainconsistent performance over the whole controlarea. Carefully check correct operation under actualworking condit ions and in conclusiondefinitively fix sensors.

Electrical connections

• Sensor connection leads should not runclose to other power cables.• The synchronising connection betweenreceiver and emitter should be no longer than10m.• If lengthening power supply cables, use

≥

1mm cable. For lengths exceeding 100 m, fit afilter capacitor near to the sensor.• Ensure power supply voltage does notexceed the limits specified by Ub.If a non-stabilized supply voltage is used,check power supply peak-voltage value withminimum absorption. Also check minimumvalue and amplitude of ripple at maximumabsorption. If the same voltage is also usedto switch inductive loads, a suitably-sizedsuppressor should be installed. Suppressorsalso offer protection against incorrectconnection of the power supply that couldprove potentially disastrous for all sensors.

area sensors

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138

• Always expect the application of a fuse onthe feeder, even if regulated power suppliesare used.• Verify compatibility of load with type ofsensor output.The current drawn by the load must notexceed the value Ie but should not be lessthan Im. Load excitation voltage must not beless than the minimum supply voltage minusUd. Load deenergize current must be greaterthan Ir. When interfacing with logical inputscheck compatibility VIl /Ud. Driving afilament lamp could result in the interventionof the dc protection. If necessary arrange tolimit the lamp’s switch-on current.When driving dc inductive loads, check thatload inductance L (Henry) does not exceedthe value indicated in the following formulaand that the number of operations with this Lvalue is no more than 6/min (A13 category).

A dc capacitive load must not exceed therated value if the intervention of the current-limiting circuit is to be avoided. It should benoted that some logic or timer inputs mayhave an R-C coupling. If the peak currenttriggers the current-limiting circuit, theproblem can be resolved by fitting a 100-300

Ω

resistor in series at the input.When using very long connection leads,consider the cable capacitance (150pF/m).

Series/parallel connections

Parallel connection of two or more sensors isachieved by connecting their output terminalsto a common load. In this way it is possibleto realise OR logic with NO outputs (load isexcited even if just one of the sensors isactivated) and NAND logic with NC outputs(load is deenergized only if all sensors areactivated).With parallel connection it should be notedthat the OFF-state current through the load(the sum of the OFF-state currents of everys ing le sensor) must be less than thedeenergize current.With models that are not the open-collectortype, it is recommended that a diode beinserted in series at the output to maintainthe independence of the sensor’s internalLED.Series connection of photoelectric barriers isnot possible. Parallel series connections canhowever be created by using a complementaryoutput.If just two sensors are to be series connected,it is worth using two sensors having differenttypes of output (PNP/NPN) with loadconnected between them.

Electromagnetic compatibility

Fast transient burst immunity

Our dc and ac sensors all conform to standardEN61000-4-4, 1995. Unless otherwise stated,test level is 2KV with capacitive coupling.Criterion A is adopted for performanceanalysis during the test.The device should continue to operatecorrectly even in the presence of interferenceby maintaining a minimum performance level.Unless otherwise indicated, minimumperformance level is intended as meaning thatthe device must not be subject to false outputsignals or that in any event these false signalsshould have a duration of no more than 1 msin the case of dc devices and a half wave forac devices.All devices are tested in both ON and OFF-state with the signal received at least twotimes greater than the trigger threshold andat least half the trigger threshold.

Electrostatic discharge immunity

Our dc and ac sensors all conform to standardEN61000-4-2, 1995. Test levels are as follows: 4KV with contact discharge for devices withmetal housing, 8KV air gap discharge forplastic housing. Criterion B is adopted forperformance analysis during the testAfter the disturbance has finished, the deviceshould function normally without the need forresetting.

Radiated electromagnetic field immunity

A l l ou r dev ices con fo rm to s tanda rdENV50140, 1994. Unless otherwise stated,test levels are as follows:80MHz - 1GHz 3V/m 80% AM modulation1KHz sine wave. Criterion A is adopted forperformance analysis during the test.The device should continue to operatecorrectly even in the presence of interferenceby maintaining a minimum performance level.Unless otherwise indicated, minimumperformance level is intended as meaning thatthe device must not be subject to false outputsignals or that in any event these false signalsshould have a duration of no more than 1 msin the case of dc devices and a half wave forac devices. All devices are tested in both ONand OFF-state with the signal received at leasttwo times greater than the trigger thresholdand at least half the trigger threshold.

Radiated emission

All our devices conform to standard EN55022Class B, 1986.

Conducted emission

All our ac devices conform to standardEN55022 Class B, 1986.

Applications

Materials handling:

detection of object presence bydifferent and irregular shapes

Wood industry:

way in of a wood table with irregularprofile on painting machinery

Wood industry:

detection of a long board (even byvibrations) coming out from a rolling machine

Metal processing:

control of sheets coming out fromrulling machines (even by vibrations)

L 2U e2

10 3–×=

3.1


area sensors

139

Glass processing: detection of windscreen on conveyor belt

Moulding: control of pieces released by mouldingmachines

Materials handling: control of envelopes released fromconveyors

Food packaging: detection of object presence bydifferent and irregular shape

Extrusion machines: control of material presencecoming out

Handling automations: presence detection and objectpositioning on conveyors

Handling automations: presence detection and heightcontrol of objects on conveyors

3.1


DIMENSIONAL DRAWING

71

160

15

Ø50

EMITTER

AX-80AREA SENSOR

MADE IN ITALY

SENSITIVITY

RECEIVER

AX-80AREA SENSOR

MADE IN ITALY

NCNO

OUTPUT

28M18x1

74M12x1

36.5

1.5

18.2

20

1.5

3030

3714

16

15° 1

5°

3042

90°

15°1

5°

30

42

16

1440

3030

18.2

70.5

1.5

108

12

71

170

32

15

Ø60

M18x1

84

5

1

SW247

9 11

13SW24

AX80*/**-K***

20,6

M18x16

3

SW24

Pg 7

4

4

18

2

Key1 M12 plug-in exit (*) 8 Emitter with sensitivity adjustment AX80S/00-****

2 Cable exit with tang and metal housing 9 Slot for 1 turn trimmer

3 Cable exit for receiver with analogic outputs 10 Receiver with NO/NC selectable output

4 Protection screw.Remove the screw to reach at the adjustment 11 Dip-switch slot for NO/NC selection

5 Cable 4x0,34mm2, Ø5mm, PVC, 5m 12 ST 18-C right angle brackets, included

6 Cable 4x0,34mm2+ 2x0,22mm2 shielded, Ø7,5mm,PVC, 5m 13 ST 18-A axial brackets, included

7 Pipe connection for air inlet Ø4mm (external) (*) Connectors CD12L/0B-050A0 included

AX80 serie

140

SERIE AX80

High resolution area sensors12-24DC

Fine detection by 70mm area height Sensing range up to 2m Microcontrolled unit Analogic outputs (4-20mA, 0-10V) Exclusive housing (patented) Very quick fixing by M18x1 standard connection M12 standard connector exit Cable exit for models with analogic outputs Sensitivity adjustment available 3 indicator LEDs on both units Metal housing available for harsh

environment applications Timing function available IP65 protection degree Complete protection against electrical damage

ORDERING SYSTEM

A X 8 0 E / 0 0 - E A 0 0serie timing function receiverhigh resolution area sensor AX8 00 none

model 10 (1) 100ms delayemitter E Øobject / distance / response timereceiver for objects detection R A (2) Ø4-8mm / 2m / 10msemitter with sensitivity adjustment S B (2) Ø4-8mm / 1,5m / 10ms

C (2) Ø4-8mm / 1m / 3ms

output state D (2) Ø3-8mm / 0,6m / 2msNO/NC output, Analogic outputs, emitter 0 E (2) Ø2-8mm / 0,25m / 2ms

logic cable exitemitter 0 E M12 standard plug-in exitNPN output N K cable exit with tang and metal housingPNP output P A cable exit for analogic versionNPN output+analogic (with AX80S only) A

(1) models with different delays are available on request(2) Ø minimum detectable object for models with analogic output is 6-8mmNote: Models with holes detection function are available

3.1


area sensors

SPECIFICATIONSModel AX80*/**-*A*0 AX80*/**-*B*0 AX80*/**-*C*0 AX80*/**-*D*0 AX80*/**-*E*0

Nominal sensing distance Sn 2m 1,5m 1m 0,6m 0,25mControlled area height 70mmMinimum detectable object Ø4-8mm Ø3-8mm Ø2-8mmMinimum detectable object for analogic outputs Ø6-8mm, min. Ø holes 25mm (for Z models)Emission infrared (880nm) modulatedDifferential travel ≤10%Repeat Accuracy 5%Tollerance 0 / 20% of the nominal sensing distance SnOperating voltage 12-24Vdc (standard) - 15-24Vdc (with analogic outputs)Ripple ≤10%No-load supply current 50mA (receiver) - 100mA (receiver with analogic outputs) - 100mA (emitter)Load current 100mALeakage current ≤10µA (at 30Vdc)Voltage drop 1,2Vmax. (IL=100mA)Output type NPN or PNP,

NO / NC selectable - NPN + Analogic outputsAnalogic output (AX80R/0A-A**0 only) 0-10V(in voltage); 4-20mA (in current)Excess gain 2 (at the maximum distance)Angular displacement 3° (emitter) - 6° (receiver) at the maximum distanceResponse time 10ms 3ms 2msTiming function fixed (from 0 to 100ms)Time delay before availability 500msSupply electrical protections polarity reversal, transientOutput electrical protections short circuit (autoreset)Temperature range 0...+50°C (without freeze)Temperature drift 10% SrInterference to external light 1500 lux (incandescent lamp), 4500 lux (sunlight)Protection degree (DIN 40 050) IEC IP65Emitter’s LED indicators green (supply), red (alarm sync.), yellow (area state)Receiver’s LED indicators green (supply), red (alignment), yellow (output state)Housing material PMMATightening torque 5Nm (plastic nut) - 25Nm (metal nut)Weight (approx.) 380g (plastic housing); 650g (metal housing) - 800g, 900g (analogic outputs)

141

Metal housingavailable (cable exit K type) forapplication in harsh environments

Air pipes for keeping the lenses clean of dust in harsh environments.Cooling function.

Fine detection by 70mm area height and sensing range up to 2mAX80 serie generates a fine grid of 12 beams, which is able to intercept very small objects (down to a minimum diameter of 2mm)by every position within the controlled area.

First example of a new sensor’s generationFirst example of a new through-beam sensor’s generation for the area control. Precise detection of small objects with irregular shapes or unfaced is granted even by random position of the object for a reliable control.Patented cylindrical housing and M18 standard connectionfor an incomparable quick installation.

Exclusive M18standard connectioneasy mounting like a simplephotoelectric sensor

Operation and diagnostictest by microcontroller

3.1


AX80 serie

142

WIRING DIAGRAMSNPN output PNP output Analogic output

In case of combined load, resistive and capacitive, the max. admissible capacity is 0,2 µF, for max. output voltage and current.

BU/3

BN/1

BK/4

WH/2

12-24VDC

BU/3

BN/1

WH/2

BK/4SYNC +

SYNC -

NPNout

Emitter Receiver

BN/1

BU/3

WH/2

BK/4

12-24VDC

BN/1

BU/3

WH/2

BK/4SYNC -

SYNC +

PNPout

Emitter Receiver

BU

BN

BK

WH

15-24VDCBU

BN

WH

BKSYNC +

SYNC -NPNout

ORG

GRN

Emitter Receiver

out 4-20mA 500Ωmax

out 0-10V 100Ωmin

CONNECTORSM12

34

21

DIAGNOSTICS LED State Operation Check

GREEN receiverSUPPLY

stable on Supply is present and stable -unstable on Supply is present but not stable Supplyoff No supply or voltage lower than 8Vdc Supply

RED receiverALIGNMENT

full on No alignment Alignment *light on Partial alignment or short signal Alignment *off Correct alignment and sufficient signal -blinking on Receiver does not function correctly or output short circuit Wiring or failure

YELLOW receiverOUTPUT

on Output in ON state -off Output in OFF state -

GREEN emitterSUPPLY

stable on Supply is present and stable -unstable on Supply is present but not stable Supplyoff No supply or voltage lower than 8Vdc Supply

RED emitterSYNC. ALARM

off Synchronism property received -on Synchronism is not received or emitted Wiring or failure

YELLOW emitterAREA STATE

on Engaged area or uncorrect alignment Alignment *off Free area or correct alignment -

* by free area3.1


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