2755-829, Enhanced Medium-Speed Scan Head User`s Manual
Contents
1. 5 Intended Audience No special knowledge is needed to read this manual and follow its directions If the system will be used to communicate with a higher level controller we assume you are familiar with communication terminology Warnings and Cautions Both warnings and cautions are found in this manual and on the equipment The following symbols are used CAUTION This laser caution symbol appears where laser radiation is present WARNING A warning symbol means people might be injured if the procedures are not followed CAUTION A caution symbol is used when machinery could be damaged if the procedures are not followed Chapter 1 Using This Manual a Danger and Caution The scan head is labeled in accordance with federal Labels regulations If any label is removed lost or becomes illegible order a replacement from your Allen Bradley representative Figure 1 1 shows location of the labels on the scan head WARNING No user maintenance of the scan head is required Do not open the enclosure WARNING Improperly controlling adjusting or operating the scan head can result in hazardous radiation exposure Figure 1 1 Location of Warning and Caution Labels on the Scan Head DANGER LASER RADIATION WHEN OPEN CAUTION LASER RADIATION OO NOT STARE INTO BEAM AVOID DIRECT EXPOSURE TO BEAM CLASS H LASER PRODUCT fe L2. 4 4 Using the Flat Mounting Plate 4 5 Installing the Package Detect Assembly 4 6 Table of Contents 2 Chapter Title Page 5 Maintenance and Troubleshooting Chapter Objectives 5 1 Maintaining the Equipment 5 1 Scan Window Removal 5 1 Cleaning the Glass Window 5 2 Cleaning the Plastic Window 5 3 Troubleshooting the System 5 4 6 Specifications Scan Head Chapter Chapter Objectives Overview of This Manual 1 Using This Manual Read this chapter to familiarize yourself with the rest of the manual You will learn about Contents of the manual Intended audience Warnings and cautions This manual is for Catalog No 2755 L4FAA L4FBA L4FCA L4FDA L4RAA L4RBA L4RCA L4RDA L5RAA L5RBA L5RCA and L5RDA Enhanced Medium Speed Scan Heads Using This Manual Provides an overview of the manual pan Features and capabilities 3 How the System Operates Bar code operation is explained Rules and recommen Installing the Scan Head dations are detailed 5 Maintenance and Troubleshooting Troubleshooting guidelines are provided Electrical mechanical environmental and oper ational information is Specifications Chapter 1 Using This Manual 1 E
3. tt ALLEN BRADLEY A ROCKWELL INTERNATIONAL COMPANY User s Manual 40062 133 01 A Publication 2755 829 October 1989 Important User Information Solid state equipment has operational characteristics differing from those of electromechanical equipment Application Considerations for Solid State Controls Publication SGI 1 1 describes some important differences between solid state equipment and hard wired electromechanical devices Because of this difference and also because of the wide variety of uses for solid state equipment all persons responsible for applying this equipment must satisfy themselves that each intended application of this equipment is acceptable In no event will Allen Bradley Company be responsible or liable for indirect or consequential damages resulting from the use or application of this equipment The examples and diagrams in this manual are included solely for illustrative purposes Because of the many variables and requirements associated with any particular installation Allen Bradley Company cannot assume responsibility or liability for actual use based on the examples and diagrams No patent liability is assumed by Allen Bradley Company with respect to use of information circuits equipment or software described in this manual Reproduction of the contents of this manual in whole or in part without written permission of the Allen Bradley Company is prohibited 9 1989 Allen Bra
4. Air Optics rated clean air Solution Optics rated cleaning solution designed for use on plastic coated lenses Wipe Optics quality lens cleaning paper designed for use on plastic lenses Use the following procedure to clean the plastic window CAUTION Do not use organic solvents on the plastic window CAUTION Do not use abrasive materials such as disposable paper wipes to clean the scan window Most disposable wipes or paper towels use glass fibers which will scratch and cloud the window Step 1 Turn the decoder OFF The switch is located on the rear of the decoder Step2 Check that the PWR ON indicators on both the decoder and scan head are OFF Step3 Remove the scan window Figure 5 1 illustrates the removal Step4 Use the optics rated clean air to blow any any dust or foreign material off of the window Step5 For stubborn film and finger prints apply any optics rated cleaning solution designed for plastic lenses To avoid smearing film and fingerprints you should blot not rub the surface of the window Each time you blot the surface use a new dry section of the optics quality lens cleaning paper Step6 Replace the scan window Step 7 Turn the decoder ON The PWR ON indicators on both the decoder and scan head should not be ON Note When the window is clean you will barely be able to see the reflection of the laser beam in the window Chapter 5 Maintenance and Troubleshooting 5 4 Trou
5. Figure 3 5 shows a correctly placed symbol as well as misaligned symbols WARNING If at any time during operation an intense dot of light is reflected onto a label instead of a line of light rotate the shutter control knob on the scan head to close the scan window Then turn the decoder OFF 3 4 Chapter 3 How the System Operates Positioning the Symbols Correctly _ Figure 3 5 continued Examples of Correctly Positioned and Misaligned Symbols Skewed package and symbol Pitched package and symbol Tilted symbol Correctly positioned symbol and package When setting up a raster scaning model the pattern created by the raster can overlap the entire symbol to aid in the scanning of misaligned symbols or be restricted to cover only a portion of the label which is helpful when scanning symbols of poor quality Refer to figure 3 6 Figure 3 6 Raster pattern LU a Chapter 4 Installing the Scan Head Chapter Objectives Carefully read this chapter before installing the system We will present rules and recommendations for installing and connecting the scan head Warnings and Cautions WARNING Do not make adjustments to the equipment Only use procedures specified in this manual WARNING If at any time during operation an intense dot of light is generated instead of a thin line of light immediately close the shutter control on the scan head and remove power
6. Grounding Grounding is an important safety measure in electrical Recommendations _ installations With solid state systems grounding also helps limit the effects of noise due to electromagnetic interference EMI An authoritative source on grounding requirements is the National Electrical Code published by the National Fire Protection Association of Boston Massachusetts Article 250 of the Code discusses the types and sizes of wire conductors and safe methods of grounding electrical equipment and components POO al Connecting Connect your equipment using the appropriate cables Your Equipment Follow the step by step procedure described below Step 1 Connect the scan head to the port labeled SCAN HEAD on the back of the decoder Step2 Connect the terminal that will be used for programming to the proper port on the decoder refer to the User Manual supplied with your decoder Step3 The initial programming should be done at this time ifit was not done earlier refer to the User s Manual supplied with your decoder er Chapter Installing the Scan Head 4 3 Connecting Step4 Ifa host computer will be used connect it to the Your Equipment port labeled COMM on the back of your Catalog continued No 2755 DM1 decoder or the port marked HOST on your Catalog No 2755 DM6 decoder refer to the User s Manual supplied with your decoder Step5 Ifoutput devices will be used connect them to the
7. This application guide was based on no more than 30 pitch and 20 skew For applications outside of the designated areas and for applications using a 2755 DM1 to decode UPC or Code 128 labels consult the factory Symbol lengths greater than one half the usable beam width will restrict the near range Table 2 A 2755 L4 Catalog Number identification Scan Range inches O Minimum Bar Width Raster Scanning 9 3 Chapter 2 Description 4 OOO 0 Reading Distance Figure 2 2 shows the size and shape of the scanning window The black area is a no read area The Usable Beam Length bottom of chart is compared to the the Reading Distance top of chart The Usable Beam Length is slightly less than the total beam length The reading distance is measured from the scan window to the center of the label Figure 2 2 Reading Distance vs Usable Beam Length Catalog No 2755 L4F L4R Reading Distance 0 5 10 15 20 25 30 35 40 45 50 Usable Beam Length 47 6 10 14 18 22 27 31 35 39 43 Usable Beam Length Catalog No 2755 L5R Reading Distance 96 0 5 10 15 20 25 30 35 40 45 50 Usable Beam Length 40 5 8 11 14 18 21 24 27 31 34 Usable
8. if the scan head is mounted so the laser beam 15 Symbols Correctly in the vertical direction then the symbol must also be continued mounted vertically commonly known as the ladder orientation Figure 3 2 shows a vertically oriented system Figure 3 2 Scan Head and Symbol in a Ladder Orientation Scan head is mounted on its narrower side If the scan head is mounted so the beam is in the horizontal direction the symbol must also be in the horizontal direction This is termed picket fence orientation Refer to figure 3 3 for an example of the scan head and symbol in a picket fence orientation Figure 3 3 Scan Head and Symbol in a Picket Fence Orientation Scan head is mounted on its wider side Chapter 3 How the System Operates ae Positioning the When setting up a front or side scanning model you should Symbols Correctly attempt to have the laser line of light perpendicular to the continued bars and spaces of the symbol For optimal performance mount the scan head at a 10 to 20 angle off normal from the label as shown in figure 3 4 Figure 3 4 Proper Mounting of Scan Head The scan head can successfully decode symbols that are up to 50 out of alignment provided that the projected or apparent bar element widths are within the minimum widths shown in table 2 A Symbols that are pitched or tilted up to 455 are still readable Skewed symbols can also be read as long as the misalignment is less than 50
9. Street SALES HEADQUARTERS Milwaukee W153204 USA Allen Bradley Europa B V Tel 414 382 2000 Amsterdamseweg 15 sl A 11016 1422 AC Uithoorn FAX 41 4 3824444 The Netherlands Tel 31 2975 6061 1 Telex 844 18042 FAX 31 2975 60222 Publication 2755 829 October 1989 2901 Great Eagle Center 23 Harbour Road G P O Box 9797 Wanchai Hong Kong Tel 852 5 739391 Telex 780 64347 FAX 852 5 834 5162 135 Dundas Street 1201 South Second Street Cambridge Ontario N1R 5X1 Milwaukee WI 53204 USA Canada Tel 414 382 2000 Tel 519 623 1810 Telex 43 11 016 Telex 069 59317 FAX 414 382 2400 FAX 519 623 8930 40062 133 01 A
10. to the bar width G Glossary pO bar width The thickness of a bar measured from the edge closest to the symbol s start character to the trailing edge of the same bar bi directional symbol A bar code symbol that can be read in complementary two directions binary code A power of two code each bit position has a weighted value bit An acronym for Binary Digit The smallest unit of information in the binary numbering system Represented by the digits 0 and 1 CCD Acronym for Charge Couple Device a linear image sensor that scans at high speeds approximately 4 000 times per second and detects the presence or absence of marks passing under the device character A single group of bars and spaces representing an individual number letter or punctuation mark A graphic shape representing a letter number or symbol character alignment The vertical or horizontal position of characters with respect to a given reference line character density The dimension in linear inches required to encode one character character reading Reading of alpha or numeric characters and or symbols by optical means character set Those characters available for encoding purposes character skew See skew character spacing The horizontal distance between two adjacent characters check digit A digit included within a symbol whose value is based mathematically on other characters included in the symbol Itis used to mat
11. ASER LIGHT IS EMITTED FROM THIS APERATURE AVOID EXPOSURE WARNING HIGH VOLTAGE POWER SUPPLY DISCONNECT POWER AND DISCHARGE ANODE BEFORE SERVICING Retin ov orm WARNING 3 SS DANGER LASER RADIATION WHEN OPEN AVOID DIRECT EXPOSURE TO BEAM 89 285 3 Chapter 2 Description Chapter Objectives The capabilities of the scan head are described when connected to a Catalog No 2755 DM1 or DM6 Decoder Overview The Enhanced Medium Speed Scan Head is a moving beam bar code scan head capable of scanning symbols up to 50 inches away when connected to a Catalog 2755 DM1 or DM6 Decoder Scanning is bi directional at approximately 200 scans per second Scan heads are available in 3 different configurations e Front scanning Catalog No 2755 L4FxA Side scanning Catalog 2755 L4RxA Raster scanning Catalog No 2755 L5RxA The x stands for one of 4 different range selections The range selections A through D are illustrated in Figure 2 1 The front scanning model allows the beam to exit through the front of the scan head The side scanning model uses an additional mirror to reflect the beam out the side of the scan head The raster scanning model uses a mirror oscillating at 20Hz to project what appears to be a number of parallel beams This type of scan head is useful when attempting to scan poor quality or misaligned labels Chapter 3 explains how to correctly posi
12. Beam Length Measured from the scan window to the center of bar code symbol Distances will be reduced by 10 on all side scanning models 2755 L4R 5 Chapter Features Cabling 2 Description 2 5 Shutter control Rotate this knob to prevent projection of the laser beam LED indicators There are two LEDs on the back of the scan head They are defined in Table 2 B Table 2 B The LEDs on the Scanner label Meaning PWRON The scan head must be connected to the decoder and the decoder must be ON before this LED lights VALID READ Flashes momentarily after any valid label is scanned Package Detect Port Connect the optional Package Detect Assembly Catalog No 2755 NP1 to this port to allow the scan head to be turned on only when there isa package present Figure 2 3 Scan Head Features Shutter Package Detect Port Control 89 285 15 89 285 16 To provide maximum installation and application possibilities the scan head is housed in a separate enclosure from the decoder The small size of the scan head allows it to be installed in tight areas Refer to table 2 C for information necessary to order a cable Chapter 2 Description RN I I LT TT ED Accessories Several accessories are available to provide installation and operational flexibility including Package detector assembly This assembly consists of a photoelectric switch and a reflector You use the swi
13. CANINE 25 2 ee eras NE EAREN 2 5 caution 1 1 1 3 4 1 5 3 ete 2 2 2 4 hing a eh 4 4 2 2 2 3 4 2 configurations 2 2 2 4 ced ae eee wos 5 4 rene ae 2 6 4 7 considerations 4 1 5 prorat ecu as cease cee aie Se era se esate 5 1 D oTa e Acecyse en pees eek ee 1 3 decode cri annann 2 2 2 3 3 3 4 7 decoder 2 5 3 3 4 2 4 3 4 7 5 2 diffuse return 3 1 DM1 Decoder expectations 2 1 2 4 DM6 Decoder expectations 2 1 2 4 E effectiveness reduction 5 2 oe a ee 4 2 enclosure warning 1 3 F eade aaa ees ween ad 4 4 frontscanning 2 1 2 4 4 3 Index G gasketed cover 5 1 grit removal from window 5 2 GlOUN GING 5554 55553 A er ee eae 4 2 l illegible labels ee E EE ES 1 3 installation eee ae 2 5 2 6 4 2 4 4 4 6 intended audience 1 2 interconnect cs Lely eels Veo eee 5 4 isopr
14. CAUTION Do not look directly into the laser beam since you could damage your eyes CAUTION No user maintenance of the hardware is required Do not open the unit s housing gt gt WARNING Do not open the unit s housing No user maintenance of the scan head is required Before You Start The angle and distance between the scan head and the labels is an important consideration These considerations orientation and alignment are described in Chapter 3 3 Chapter 4 Installing the Scan Head 4 S Tools You Will Need Normally the only tool you will need for installation is an adjustable open ended wrench Ifthe optional Swivel Mounting Base and Plate are used Catalog No 2755 NM1 and 2755 NM2 you will also need a screwdriver and a 3 16 inch allen wrench eh How to Handle When the system is operating in a noise polluted industrial Excessive Noise environment special consideration should be given to possible electrical interference The effect of electrical interference has been minimized by the basic design of the hardware Properly grounding the equipment correctly routing wires and the use of shielded cables will also help minimize interference 2
15. Connects Catalog No 2755 DM1 Decoder to scan head 2755 CK25 25 ft Cable Connects Catalog No 2755 DM6 Decoder to scan head Replacement part number Chapter 3 How the System Operates Chapter Objectives Bar code operation is briefly described The importance of proper symbol positioning and movement is also discussed How the Scan Inside the scan head is the laser the lens and mirror system Head Operates and the electronics The laser generates a small concentrated light beam that is focused and projected through a window This light is reflected by a label and returned to the scan head for processing The signal is then sent to the decoder for further processing Refer to figure 3 1 Light collector A Figure 3 1 How the Scan Head Operates Video signal Video generator board Video detector Scanner driver Laser enable High voltage He Ne Lenses power supply Laser Mirror amp SNA NN d E E Label scanning motor Diffusely reflected lightfrom label Diffuse Return Positioning the As the symbols move past the scan head they must be Symbols Correctly correctly oriented The laser s line of light must cut through all the bars and spaces in one sweep Laser s line of light cuts through the entire symbol 55 Chapter 3 How the System Operates eee Positioning the For example
16. The length of the symbol measured from the beginning of the quiet area adjacent to the start character to the end of the quiet area adjacent to a stop character U unattended system A Scanner decoder combination that is triggered or activated by an external source such as a computer PLC or mechanical switch UPC Universal Product Code The standard bar code symbol for retail food packaging in the United States V vertical bar code ladder orientation A code pattern in which the overall coded area from start to stop is perpendicular to the horizon The individual bars appear as rungs of a ladder void s The absence of ink within printed bars The absence of ink within the confines of a character W wand A hand held scanning device used as a contact bar code or OCR reader Index a a a a ES SIRE S accessories AE 2 6 AUGOMGING 64 4534 orate tad eakine acest ae 3 1 3 3 anti reflective replacement windows 2 6 attaching WAG PIQUE Ae ests dos ete 2 Bere ee 4 5 scan head hee Seabee hoes eho Gnd be tach hate oe 4 4 swivel ball 4 4 T mounting plate 4 5 B bar code cde bee es Pe 2 2 2 4 3 1 3 4 WIG sede thee tech let ck we ars eas 2 2 2 4 3 3 beamwidth Doha e eed wish dene bees 2 4 brackets A 2 6 4 4 4 5
17. UTION Do not use abrasive materials such as disposable paper wipes to clean the glass scan window Most disposable wipes or paper towels use glass fibers which will scratch and cloud the window Step 1 Turn the decoder OFF The switch is located on the rear of the decoder Step2 Check that the PWR ON indicators on both the decoder and scan head are OFF Step3 Remove the scan window Figure 5 1 illustrates the removal Step 4 Use the lens cleaning paper to wipe any dust or foreign material from the window Be careful not to scratch the window with any grit that might be on the window Step5 For stubborn film and finger prints use isopropyl alcohol 100 solution and cotton tipped swabs To avoid smearing film and fingerprints rotate the cotton tipped swab while it s on the glass nearly one revolution then discard it Step6 Replace the scan window Step 7 Turn the decoder ON The PWR ON indicators on both the decoder and scan head should be ON Note When the window is clean you will barely be able to see the reflection of the laser beam on the clear glass Chapter Maintenance and Troubleshooting Cleaning the Do not use abrasive materials such as disposable paper Plastic Window wipes to clean the plastic scan window Most disposable wipes or paper towels use glass fibers which will cloud and blur the window thus reducing the effectiveness of the scan head Instead you may use the following materials
18. X axis 2 The normal distance between the centerline or adjacent characters pre printed symbol A symbol which is printed in advance of application either on a label or on the article to be identified Print Contrast Signal PCS A measurement of contrast brightness difference between the bars and spaces of asymbol A minimum PCS value is needed for a symbol to be scannable PCS R Rp R_ where is the reflectance factor of the light background and Rp is the reflectance factor of the dark bars PCS values can be calculated and displayed automatically on suitable instruments print quality The complete analysis of a printed symbol with regard to reflectance properties as well as bar and space resolution with regard to symbol specification The inter relationship of printed material and imprinted material that affects the optimum performance of the scanner proximity sensor A method of object detection in which the source and detector are located on the same side the detector senses energy from the source which ts bounce back by the object being detected Q quiet area quiet zone See clear area G 8 G_ Glossary R raster scanner Also available as an optional raster assembly Raster scanners are similar to standard scanners The beam still travels from left to right but it now does so ina sinusoidal or top to bottom pattern This allows the scanner to see different scan paths so if a bar is deformed or soile
19. ad is not securely mounted Improve mounting Rotate shutter control knob in order to close window and then turn decoder OFF Improperly positioned labels Warning Laser beam is an intense dot of light Laser scanning mechanism is not operating correctly Chapter 6 Specifications Chapter Objectives Scan Head Electrical Catalog No 2755 L Receives power from decoder Scan sweep angle Scan Range Mechanical Enclosure Cast aluminum NEMA 12 13 LED Indicators Power On Valid Read Weight 4 lbs 1 8 kg Dimensions 10 25 x 4 25 x 2 50 26 0 x 10 8 x 2 50 cm Environment Ambient temperature range 32 to 122 F 0 to 50 C CDRH Standards Meets Class II standards Optical Light Source Focused helium neon He Ne laser 632 8nm Power 1 5 mW max Fixed Scan Rate 200 scans second 5 Raster at 20 cycles per second Front scanning unit 47 Side scanning unit 47 Raster scanning unit 40 5 to 50 from scan window Depth of Field 5 to 50 from scan window 0O Label Skew 5 to 50 from normal Label Pitch 5 to 45 from normal Package Detect Min OFF State Voltage 11 VDC Max ON State Voltage 2 VDC Depending on the model selected Distances will be reduced by 10 on all side scanning models 5 Depending on label quality G Glossary A AIM Acronym for Automatic identification Manufacturers alignment The relative position of a scanner
20. ation This does not mean that a system which has a first read rate of less than 90 is unacceptable G guard bars The bars at the ends and center of a UPC and EAN symbol They ensure a complete scan of the bar code hand held scanner Refers to any scanning device that must be held over the bar code symbol height of scan The maximum vertical scanning dimension of a moving beam scanner at a specific distance from the face of the scanner helium neon laser The type of laser most commonly used in bar code scanners Because the laser beam ts bright red bars must not be printed with red ink since they would be indistinguishable from the background horizontal bar code Picket Fence A bar code or symbol presented in such a manner that its overall length dimension is parallel to the horizon The bars look like a picket fence I incandescent light source Intense white light used to illuminate an object as it passes under a CCD camera G Glossary be intercharacter gap The space between two adjacent bar code characters For example the white space between two characters in AIM USS 39 interleaved bar code A bar code in which characters are paired together using bars to represent the first character and spaces to represent the second asin USS I 2 5 K key mark or trigger A code bit s that provides the scanner with the instruction that the code isin a position to be read used in some fixed beam readers L ladde
21. bleshooting the System Probable Cause Possible Solution Decoder is not turned ON Turn decoder ON Improper connection to power Reconnect power cord to source PWR ON indicators SUPPly on both scan head and decoder do not light Line fuse on decoder is blown Faulty power cord or switch Replace fuse on decoder Check that voltage is present at service outlet a Interconnect cable between decoder Reconnect cable and check PWR ON indicator on and scan head is loose connections scan head does not light but PWR ON on decoder Interconnect cable is damaged Replace cable is lit i Scan head is damaged Replace scan head Shutter on scan head is closed Rotate shutter control knob No laser beam emitted from window of scan head Verify sending of scan trigger by either package detect or host command No scan trigger signal Check that reading distance is correct and orientation of labels to scan head is correct Check that labels are good quality Poor quality labels and within specifications Unable to read a label Shutter control knob is not fully Rotate shutter control knob on open Scan head Decoder is improperly programmed Refer to the appropriate User s Manual Loose cables or connections Check cables and connections Shutter on scan head is not fully Rotate shutter control knob Laser beam expands open and contracts Scan he
22. cts energy back to the source from which it came Itis also known as a corner reflector reverse image A symbol in which the normal dark areas are represented in the light areas G Glossary 5 scan The search for a symbol or marks which are to be optically recognized scan area The area intended to contain a symbol scan head scanner A device that optically scans bar code symbols and converts the optical information into digital or analog form and sends it to a decoder scanning curtain The effective reading area width x height of a moving beam scanner which is equal to its depth of field and height of scan at a specific operating range scanning range The combined distance of optical throw and depth of field scanning wand See wand segment See element self checking A bar code or symbol using a checking algorithm which can be applied to each character to guard against undetected errors Non self checked codes may employ a check digit or other redundancy in addition to the data message serial code A bar code symbol typically used with a fixed beam scanner where the scanning action is caused by the motion of the symbol past the scanning head The bits of the symbol are evaluated one at a time serially skew Rotation about the Y axis Rotational deviation from correct horizontal and vertical orientation may apply to a single character line or the entire encoded item space The lighter el
23. d in one place it may still be read due to the sinusoidal sweep of the beam read A successful scan of a bar code symbol reflectance The amount of light returned from an illuminated surface reflectance absolute The ratio of the total reflectance by a document to the total light incident on the document reflectance diffuse Reflected light whose angle of reflection varies from the angle of incidence of the illuminating light such as reflection from a non glossy surface reflectance specular Reflected light whose angle of reflection is equal or nearly equal to the angle of incidence of the illuminating light as in reflection from a mirror reflex A method of object detection in which the source and detector are located on the same side aretroreflector on the far side returns the energy from the source to the detector reject See no read non read non scan resolution 1 The measure of the ability of a lens a photographic material or a photographic system to distinguish detail under certain specific conditions 2 The dimension of the smallest element which can be printed employing a particular technique 3 The narrowest element dimension which can be distinguished by a particular reading device retro See retroreflective retroreflective Characteristic of material causing it to reflect light back to its source regardless of angle of incidence retroreflector A reflector specially constructed which refle
24. decoder refer to the User s Manual supplied with your decoder Step6 Ifa package detector will be used connect it to the small port on the scan head Determining the The decoder and scan head are separate units that can be Space Requirements mounted on separate surfaces A 10 or 25 foot cable is used to connect the two units Figure 4 1 illustrates the dimensions of the scan head Figure 4 1 Mounting Dimensions of the Scan Head Side Scanning Model i I t i I All Models l lt 350 iE 100 gt a 88 i I l I l 25 gt Location beam in Front Scanning Model Scanning Window All Models Chapter 4 4 Installing the Scan Head How to Install the Swivel Mounting Base Catalog No 2755 NM1 and 2755 NM2 4 Installing the Scan Head Before installing the scan head review the following information Determine the optimum position of the scan head relative to the labels that are to be read Refer to Chapter 3 for positioning information e Ifyou are using the optional swivel base or brackets add their dimensions into your positioning calculations e Allow a minimum clearance of inches at the rear of the scan head so you can attach the cables to the various ports Securely mount the scan head to a rigid surface to ensure proper operation of the scanning mechanism Because the thickness of the mounting surface table to
25. dley Company 25 00 Table of Contents Chapter Title Page 1 Using this Manual Chapter Objectives 1 1 Overview of This Manual 1 1 Intended 1 2 Warnings and Cautions eau 1 2 Danger and Caution Labels 1 3 2 Description 2 1 OVEINIOW 24560652 beeen esata oie 2 1 Lens Combinations 2 3 Reading Distance 2 4 2 5 CODING 55 fc 2 5 Accessories 2 6 3 How the System Operates 3 1 How the Scan Head 3 1 Positioning Symbols Correctly 3 1 4 Installing the Scan Head Chapter Objectives bed camauiaxneweses 4 1 Warnings and Cautions 4 1 Before You Start ees eee eee 4 Tools You Will Need LW 4 2 How to Handle Excessive Noise 4 2 Grounding Recommendations 4 2 Connecting Your Equipment 4 2 Determining Space Requirements 4 3 Installing the Scan Head 4 4 How to Install the Swivel Mounting Base
26. e a a eee fhe 2 2 2 3 6 1 skewed labels 3 3 3 4 SMearInNg sei Shoe ed 5 2 5 3 SOVENT cers as a San e A 5 2 5 3 specifications 4 6 5 4 61 step by step procedure 4 2 swab cotton 5 2 swivel ball 2 6 4 4 4 5 swivel mounting base 2 6 4 2 4 4 4 5 symbol 1 2 2 1 2 4 3 1 3 4 l 4 index T terminology 4 24 cies ae ede ue outaetwnnetagene 3 1 2 tolerance eed ei annann aa nanoa onone Cee 4 6 WHIOQClEG E E ESE E A EE EE EEEE 4 7 troubleshooting LIREO PE TE ETTE 5 1 5 4 U UDe hese E ae 2 2 2 3 eee ea T 2 3 2 4 user supplied 2 6 W Warning 1 1 1 3 3 3 4 1 5 1 5 4 acto avd doth edged bas bee onto ace we 4 4 td rats Beans 2 2 2 3 3 3 window SCAN 2 6 4 3 5 2 es ee ee aes oh ee a eae 5 2 tt ALLEN BRADLEY A ROCKWELL INTERNATIONAL COMPANY With offices in major cities worldwide WORLD HEADQUARTERS EUROPE MIDDLE EAST AFRICA ASIA PACIFIC HEADQUARTERS CANADA HEADQUARTERS LATIN AMERICA Allen Bradley Hong Kong Limited Allen Bradley Canada Limited HEADQUARTERS 1201 South Second
27. ement of a bar code formed by the background between bars Space encoding See interleaved bar code special symbol character In a character set a character that is neither a numeral letter ora blank for example spectral response The variation in sensitivity of a device to light of different wavelengths specular reflection Reflection of light from a surface at an angle equal but opposite to the angle of incidence See reflectance specular G Glossary spots Ink or dirt spots within the spaces or clear area of a bar code which may reduce first read rate start stop character A bar code character that provides the scanner with start and stop reading instructions as well as code orientation stepladder code See vertical bar code substitution error This error can be seen in a mis encodation mis read or human operator error Characters are substituted with erroneous information Example correct information is 1 2 3 4 substitution is 1 2 5 4 Substitution errors are usually the result of bar code labels with printing defects Substitution errors are extremely difficult to determine and are usually not found until the data has been processed and an obvious data error is noticed symbol A combination of characters including start stop characters and check characters as required which form a complete scannable entity symbol density The number of characters per linear inch symbol length
28. hematically check the accuracy of the read clear area A clear space containing no dark marks that precedes the start character of a symbol and follows the stop character That region a document reserved for OCR characters and the required clear space around these characters G Glossary 2 2 code A set of rules governing how the bars and spaces of the symbol will represent characters and groups of characters bar code code medium The material used to construct a machine readable code Such materials may be retroreflective or opaque code reader or scanner A device that examines a spatial pattern one part after another and generates analog or digital signals corresponding to the pattern contact scanner A code reader that requires physical contact with the code medium continuous code A bar code or symbol that does not use an intercharacter gap between characters in the code Code 128 is an example of intercharacter gap D decoder An unattended device used to decode or make usable a digital or analog signal transmitted from a scanning device decoder logic The electronic package which receives the signals from the scanner interprets the signals into meaningful data and provides the interface to other devices depth of field The distance between the maximum and minimum plane where a symbol can be read diffuse reflection Reflection of light in all directions Diffuse reflection occurs from non glossy
29. ion The package detect LED on the Decoder will light when the package detect input is active Note If the laser is programmed to be ON only upon a package detect the laser will be OFF until the package detector is triggered Chapter Maintenance and Troubleshooting Chapter Objectives Maintenance procedures are stated and troubleshooting charts are provided in this chapter Maintaining the Equipment WARNING No user maintenance of the scan head is required Do not open the enclosure Scan Window The scan window fits into a cut out in the front or Removal side ofthe scan head A gasketed cover is then tightly secured over the window to ensure a Nema 12 13 rating To remove the scan window 1 Remove the six Phillips head screws from the cover 2 Lift the cover away from the scan head Handle the scan window by the edges to avoid finger prints Make sure the scan window does not fall out Refer to figure 5 1 Figure 5 1 Scan Window Chapter Cleaning the Glass Window 5 Maintenance and Troubleshooting Do not use abrasive materials such as disposable paper wipes to clean the glass scan window Most disposable wipes or paper towels use glass fibers which will scratch and cloud the window Instead you may use the following materials Solvent Isopropyl alcohol 100 solution Wipe Optics quality lens cleaning paper and cotton tipped swabs Use the following procedure to clean the glass CA
30. opyl alcohol 5 2 L LAFANA ces anise Mies da tests Susie teres ann 8 ate ave aid ote Ge tenes ee 2 2 bg on tenia amp eet cient aie ea et 1 1 2 2 UA 1 1 2 2 1 1 2 2 LAR tet teas Se bee cs ee ek a eer 2 4 PAR be week ob 1 1 2 2 aa 1 1 2 2 a ha eileen ele ates ee estes te 1 1 2 2 LARDA uence eRe alae Sate oe 1 1 2 2 WO ees See doe wate a ee ae Ce ee eee 2 2 2 3 r is 1 1 2 2 GRBA 1 1 2 2 LORCA 1 1 2 2 LORDA ie tee ee cae Eee ee cea 1 1 2 2 laser 1 2 2 5 3 1 3 2 4 1 4 6 4 7 5 2 ee eRe ee et we 2 5 M maintenance 5 1 5 4 minimum bar width 2 2 2 3 irk pan eRyesies ten thee tease 3 3 3 4 MOUNUNG senna 2 6 4 3 4 5 ee ne ns Bn eee 1 1 6 1 noise polluted at 4 2 E ates 5 2 5 3 optimum position 4 4 orientation ex oad 654584 ebb cae eee 3 1 3 2 4 1 5 4 OSCINAUING urarea k ap ogadu oie oc
31. or light source to the target or the receiving element alphanumeric or alphameric The character set which contains letters digits and other characters such as punctuation marks aspect ratio The ratio of height to width of a bar code symbol A code twice as high as wide would have an aspect ratio of 2 a code twice as wide as high would have an aspect ratio of or 0 5 attended system A Scanner decoder combination that must be activated or attended by an operator average background reflectance Expressed as a percent this is the simple arithmetic average of the background reflection reading from at least five different points on a sheet average edge An imaginary line bisecting the irregularities of the character edge B background The area surrounding a printed symbol bar The dark element of a printed symbol bar code The vertical bars and spaces found in a bar code symbol bar code density The number of characters which can be represented in a lineal inch bar code label A label that carries a bar code and is suitable to be affixed to an article bar code reader A device used to identify and read a bar code symbol Also know as a decoder bar code symbol A group of vertical bars that represents a character or group of characters whose spacing is determined by a specific set of rules In most cases human readable characters are also printed below the bars bar length The bar dimension perpendicular
32. p shelf or bracket determines the length of the screws or bolts required fasteners are not supplied with the scan head You will need two 10 32 hexagon head cap screws with flat and split washers Select a length that equals the thickness of the mounting surface thickness of the washers plus 3 g inch depth of screw holes For greater installation flexibility you can attach the scan head to an optional Swivel Mounting Base The installation dimensions of the Swivel Base and its associated T Mounting Plate are shown in Figure 4 2 Chapter Installing the Scan Head p Figure 4 2 Mounting Dimensions of Swivel and T Mounting Plate 180 O14 4 PLACES Tia 20 UNF 24 Wie 20 01 28 5 8 OFEP 00 Z213 002 OIA 2 HOLES Swivel Mounting Base T Mounting Plate Using the Flat A Flat Mounting Plate is also available By attaching this Mounting Plate plate to the bottom of your scan head you can position the Catalog No 2755 NM2 swivel mounting ball close to the base of the scan head You may also use the Flat Mounting Plate when you want to mount the scan head with brackets of your own design The dimensions are shown in Figure 4 3 Figure 4 3 Mounting Dimensions of the Flat Plate 6 32 UNC 2 8 4 PLACES 204 83 Dia CSK 100 390 2 O14 2 PLACES P Chapter 4 Installing the Scan Head 4 Installing the Package The Package Detect Assembly consists of Detect Assembly Ca
33. printing from the back side or the next sheet 2 The ratio of the paper reflectance with a black backing to the paper reflectance with a white backing scanning range The sum of the scan head s optical throw and depth of field optical throw The distance from the face of the scanning device to the center of the depth of field orientation The alignment of bars and spaces to the scanner Often referred to as vertical picket fence or horizontal ladder G Glossary overhead The fixed number of characters required for start stop and checking ina given symbol For example a symbol requiring a start stop and two check characters contains four characters of overhead To encode three characters of data seven characters are required P parallel beam A beam of light that is optically controlled so the light travels ina parallel path Generally used when the object is larger than the lens diameter parallel code A code configuration that is optically scanned in its entirety at one time Since all codes marks are read simultaneously the code can move pass the reader in either direction parity bar parity bit parity module A parity bit is added to a binary array to make the sum of all the bits always odd or always even a fundamental check permanent code A code which is indefinitely reused in a bar code application picket fence code See horizontal bar code pitch 1 Rotation of a code pattern about the
34. r orientation See vertical bar code laser scanner An optical bar code reading device using alow energy laser light beam as the source of illumination Light Emitting Diode LED A semiconductor diode generally made from gallium arsenide that can serve as a near infrared light source when voltage is applied continuously or in pulses LED s have extremely long lifetimes when properly operated being solid state they are very resistant to shock and vibration light operated Condition in which the control operates when the light beam in uninterrupted mis encodation When the characters which were to be represented in symbol form are not correctly encoded Example desired number is 1 2 3 4 the encoded number is 1 2 5 4 misread A condition which occurs when the data output of a reader does not agree with the encoded data presented See substitution error module A group of elements The term module is used by the Uniform Product Code Council in it descriptions of the UPC code A module is the narrowest unit of measure in the code A module may be black or white Contiguous modules are used to form bars or spaces that are wider than one unit modulo check digit or character A calculated character within a data field used for error detection The calculated character is determined by applying a code algorithm to the data field contents modulus 43 check character Used in Code 39 for data security in addi
35. surfaces Also see specular reflection dirt In paper refers to the presence of relatively non reflective foreign particles imbedded in the sheet The size and lack of reflectance of the particles may cause the optical scanner to mistake the dirt for inked areas discrete code A bar code or symbol where the space between characters intercharacter gap are not part of the code as with Code 39 Also see continuous code diverging beam A beam of light that is optically controlled so the light extends in different directions from the source G 4 G _ Glossary E EAN Acronym for European Article Numbering System the international standard bar code for retail food packages edge error Irregularities with respect to the average edge of an element element 1 Asingle binary position in a character 2 Dimensionally the narrowest width in a character bar or space encoded area The total linear dimension consisting of all the characters of a code pattern including start stop characters and data extraneous ink Ink in a scan area not intended to be there first read rate The first read rate is the percentage of bar code symbols that are read with the first pass of the bar code wand under ideal conditions Bar code symbols should have a first read at least 90 of the time A first read rate of less than 90 usually means that either the bar code symbols or scanning device need some type of adjustment or modific
36. swe wae 2 1 Index package detector 2 6 4 7 picket fente eo Ore 3 2 casi oo eRe 3 4 5 4 5 TaSTI NECE 3 1 4 4 programmed 4 2 4 7 5 4 ees ind a ara ene 2 5 5 2 5 4 R ONGO 22 eee aon cee 2 1 2 3 4 6 6 1 raster _rasterscanner 2 1 2 4 3 4 6 1 read 1 1 1 2 2 4 2 5 3 3 41 4 4 4 6 5 4 6 1 reading distance 2 4 recommendations 4 1 4 2 reflection daii arean aN N ei 5 2 5 3 replaceable windows 2 6 5 1 5 3 restrict near range 2 3 5 scan head 1 1 1 3 2 1 2 5 3 3 4 1 4 5 5 1 5 4 scan Tange aisha Sli Se etal Shae sans ti nae ks 2 3 scan WINdOW 000 000 cee ee eee eee 5 1 5 3 abrasive materials 5 2 canst dun eden ah cteadased 9 2 5 3 removal aie cheese 5 1 5 3 e ae aae 3 4 2 5 scanning 2 1 2 3 2 4 3 1 3 4 4 3 4 4 5 4 self contained 4 6 base EE eee 4 2 Shutter 0 0000 0 2 5 3 3 4 1 5 4 side scanning 2 1 2 3 3 2 SKOW Sheer ideea at
37. talog No 2755 NP1 1 A self contained photoelectric switch 2 A3 inch diameter reflector The switch has the following specifications Maximum operating range 18 feet Operating temperature 13 to 158 F 25 to 70 C Tolerance to ambient sunlight 10 000 foot candles When installing the switch we recommend you observe the following guidelines Install the switch at an angle to the labels to minimize the affect of light reflecting off the labels Install the reflector so it does not exceed its operating range The package detector beam must be broken before the label is in position to be read Figure 4 4 shows a typical package detector installation Figure 4 4 Recommended Placement of the Package Detect Switch and Reflector Reflector Photoelectric Switch Scan Head The laser beam should not strike the reflector or you may get inaccurate reads Chapter Installing the Scan Head Installing the e Figure 4 5 specifies which pins on the Package Detector Port Detect Assembly Connector Catalog No 2755 NC7 are used Catalog No 2755 NP1 continued Figure 4 5 Pins Used on Package Detector Connector Common Package Detect Input Package Detect Port on Scan Head If triggering on package detect with Pin 3 open no bar code information is decoded and the Package Detect LED is OFF The package detect input must be pulled low in order to decode informat
38. tch to indicate to the Decoder when a package is present e Mounting hardware A swivel ball mounting base and flat mounting plate are available for the scan head to provide installation flexibility Replaceable Windows Replaceable glass and plastic windows are available Table 2 C lists system accessories Table 2 C Accessories Available for the Scan Head Catalog Fiat Mounting Plate An infrared photoelectric switch and reflector For 2755 NP1 Package Detector Assembly package present detection i nyn Use to mount Swivel Mounting Base Catalog No 2755 2755 NM2 T Mounting Plate NM1 to scan head No 2755 NM1 when you want the swivel ball close to 2755 C2 25 ft Cable Connects Catalog No 2755 DM1 Decoder to scan head W77119 023 019 Replacement Window Anti reflective optical glass replacement window 2755 NC7 Package Detector Port Use to connect user supplied package detector to scan Connector head Attach this plate to scan head in order to use your own 2755 NM3 the base of the scan head 2755 CK10 10 ft Cable Connects Catalog No 2755 DM6 Decoder to scan head W77119 159 019 Replacement Window anti reflective plastic replacement Universal swivel ball mount for greater installation flexibility 2755 NM 1 Swivel Mounting Base hn tage Note Must be used with T Mounting Plate Catalog No 2755 NM2 brackets or to use the Swivel Mounting Base Catalog 2755 1 10 ft Cable
39. tion labels and illustrates a raster pattern figure 3 6 created by a raster scan head Figure 2 1 illustrates the average reading ranges relative to the symbol s minimum bar width that you should expect when using a Catalog No 2755 DM1 or DM6 Decoder Not all symbols or applications are perfect so slight variations in the the reading distances will occur Chapter 2 Description 2 Overview continued Figure 2 1 l l Average Scan Range vs Minimum Bar Width 50 45 40 35 Minimum Bar Width 30 mils 25 20 15 10 5 10 15 20 25 30 35 40 45 50 Scan Range inches from scan window Distances will be reduced by 10 on all side scanning models 2755 L4R L5R Scan Range will vary with symbol quality This application was based on no more than 30 pitch and 20 skew For applications outside of the designated areas and for applications using a 2755 DM1 to decode UPC or Code 128 labels consult the factory Chapter 2 Description i5 Lens Combinations Table 2 A compares the minimum bar width to the scan range of each catalog number Front Scanning Side Scanning 2755 L4FAA 2755 L4RAA 2755 L5RAA 10 16 8 19 2755 L4FBA 2755 L4RBA 2755 L5RBA 6 21 15 32 15 50 2755 L4FCA 2755 L4RCA 2755 L5RCA 15 50 10 24 8 27 2755 L4FDA 2755 L4RDA 2755 LSRDA 6 33 Distances will be reduced by 10 on all side scanning models 2755 L4R L5R Scan Range will vary with symbol quality
40. tion to the built in self checking characters The check character is the modulus 43 sum of all of the character values in a given message and is the last character in the code G 6 G Glossary moving beam scanner A device which dynamically searches for a bar code pattern by sweeping a moving optical beam through a field of view N nanometer Unit of measure used to define the wavelength of light 10 9 meters no read non read non scan The absence of data at the scanner output after an attempted scan due to no code defective code scanner failure or operator error nominal size The standard size for a bar code symbol Most codes can be used over a range of magnifications from 0 80 to 1 20 nominal numeric A machine vocabulary that includes only the numbers as contrasted to alphanumeric which includes both letters and numerals O OCR Acronym for Optical Character Reader An information processing device that scans and decodes human readable OCR symbols OCR A An abbreviation commonly applied to the character set contained in ANSI Standard x3 17 1974 OCR B An abbreviation commonly applied to the character set contained in ANSI Standard x3 49 1975 off line Refers to devices that operate independently of a central processing unit on line An operation in which peripheral devices are connected directly to the computer central processor unit Opacity 1 The property of paper that minimizes the show through of
Download Pdf Manuals
Related Search