MM-196A
Installation, Operation and Maintenance Instructions
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E-Z Tec® DSP Metal Detectors
ERIEZ MAGNETICS
HEADQUARTERS: 2200 ASBURY ROAD, P.O. BOX 10608, ERIE, PA PA 16514–0608 U.S.A.
WORLD AUTHORITY IN ADVANCED TECHNOLOGY FOR MAGNETIC, VIBRATORY and METAL DETECTION APPLICATIONS APPLICATIONS
Introduction This manual details the proper steps for installation, operation and maintenance of the Eriez E-Z Tec ® DSP Metal Detectors. Careful attention to these requirements will assure the most efficient and dependable performance of this equipment. If there are any questions or comments about this manual or the E-Z Tec ® DSP Metal Detector, please contact the factory for assistance at (814) 835-6000 or www www.eriez.com. .eriez.com.
CAUTION - ELECTROMAGNETIC FIELDS
• Metal Detectors emit electromagnetic electromagnetic fields. Contact the American Conference of Governmental Industrial Hygenists, Cincinnati, Ohio, U.S.A., (www.acgih.org) for additional information. • If you use a medical implant impl ant or similar devic device, e, you must never approach the equipment because your device may malfunction in the electromagnetic field, with consequences up to and including death. Contact Eriez if you have a question regarding these precau tions.
CAUTION
Safety labels must be affixed to this product. product. Should the safety label(s) be damaged, dislodged or removed, contact Eriez for replacement.
© 2003 ERIEZ MAGNETICS
ALL RIGHTS RESERVED
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Handling Instructions PLEASE LEAVE THESE INSTRUCTIONS ATTACHED TO THE EQUIPMENT UNTIL INSTALLATION IS COMPLETE 1.
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DO NOT NOT LIF LIFT T THE THE MET METAL DE DETE TECT CTOR OR BY BY INSERTING ANYTHING INTO OR THROUGH THE APERTURE. The inner surface of the aperture is delicate and protects the precisely tuned electronic circuit and internal parts. The integrity of this liner and seal must be maintained. Any damage to this surface or any aperture distortion caused by handling will invalidate Eriez’ warranty. This aperture liner also protects the internal parts against water damage. The seal must be maintained. HANDLE HAND LE THE THE SHIP SHIPPI PING NG PALL PALLET ET,, NOT NOT THE THE DETECTOR. Keep the metal detector on its shipping pallet as long as possible.
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When When rremo emovin ving g the the det detect ector or from from the the shippi shipping ng pallet, LIFT ONLY ON THE DETECTOR HOUSING SURFACES, SUPPORTING “FEET” OR TAPPED LUGS.
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IF POSSI POSSIBLE BLE,, LIF LIFT T BY BY HAN HAND, D, or by using using a crane and soft nylon slings running under the entire detector housing – NOT THROUGH THE APERTURE. Block the slings to prevent rubbing on the remainder of the detector housing.
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The The me meta tall detec detecto torr is heav heavy y. Use Use care care when when handling to avoid injury to personnel or damage to property prop erty..
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Never Never weld weld a any ny attach attachmen mentt to to tthe he det detect ector or housing. Do not attempt to drill and/or tap the metal detector housing for lifting or mounting attachments.
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Never Never lift lift with with a crane crane or forkli forklift ft under under the the co conntrol housing that protrudes from the body of the metal detector. Make certain that lifting straps and other handling equipment do not contact the control housing.
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If h hand andlin ling g with with e eye yebol bolts ts use use onl only y th the e prepretapped holes. Make sure that eyebolts are strong enough for the loads that will be applied. Never apply loads perpendicular to the shank of the eyebolts; they will break.
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Table of Contents Contents ERIEZ E-Z TEC DSP METAL DETECTORS
PRINCIPLE OF OPERATION OPERATION ......................... ...................................... .......................... .......................... .......................... ............... .. 6 SPECIFICATIONS SPECIFICATIONS ......................... ...................................... .......................... .......................... .......................... .......................... ................... ...... 8 INSTALLA INSTALLATION TION CAUTION!! ......................... ...................................... .......................... .......................... ......................... .................. ...... 9 MECHANICAL INSTALLAT INSTALLATION ION ......................... ...................................... .......................... .......................... .......................... .............9 9 Introduction ......................... ...................................... .......................... .......................... ......................... ......................... ......................... ............9 9 Handling .......................... ....................................... .......................... .......................... .......................... .......................... .......................... .............10 10 Location of Sensing Head ......................... ...................................... .......................... .......................... .......................... .............10 10 Metal Free Area .......................... ...................................... ......................... .......................... .......................... .......................... ................ ... 10 Electrical Current Loops ......................... ...................................... .......................... ......................... ......................... ................. .... 11 Insulating the Conveyor Shafts .......................... ....................................... .......................... .......................... ................. .... 12 Permanent Current Loops ......................... ...................................... .......................... .......................... .......................... .............13 13 Supporting Structure .......................... ....................................... .......................... .......................... .......................... .................... ....... 14 Belt and Belt Splices ......................... ..................................... ......................... .......................... .......................... ...................... ......... 15 Conveyor Slider Bed ........................ ..................................... .......................... .......................... .......................... ...................... ......... 16 Product Position ......................... ...................................... .......................... .......................... .......................... .......................... ............... .. 16 Reject Proximity Switch ......................... ...................................... .......................... .......................... ......................... ................. ..... 16 ELECTRICAL INSTALLAT INSTALLATION ION ......................... ...................................... .......................... .......................... ......................... ............17 17 Introduction ......................... ...................................... .......................... .......................... ......................... ......................... ....................... ..........17 17 Choice of Input Power Source .......................... ....................................... .......................... .......................... .................. ..... 17 Relays .......................... ....................................... .......................... .......................... .......................... .......................... .......................... ................ ... 17 Tachometer Input .......................... ....................................... .......................... .......................... .......................... ......................... ............18 18 Proximity Switch ......................... ...................................... .......................... .......................... .......................... .......................... ............... .. 18 Reject Confirmation (Rej Con) .......................... ....................................... .......................... .......................... .................. ..... 18 Reject Reset (Rej Reset) Reset) ......................... ...................................... .......................... .......................... .......................... ............... 19 Remote Computer Port ......................... ...................................... ......................... ......................... .......................... .................. ..... 19 Conduit .......................... ....................................... .......................... .......................... .......................... .......................... .......................... ............... .. 19 Power Switch ......................... ...................................... .......................... .......................... .......................... .......................... ................... ...... 19
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Table of Contents (cont.) OPERATION ....................................................................................................... 23 Initial Start-up ................................................................................................ 23 Operator Interface .........................................................................................25 Menu Structure .............................................................................................. 25 Password Menu ............................................................................................ 25 Quick Menu ...................................................................................................26 Report Menu ................................................................................................. 27 Fault Menu ....................................................................................................27 Clock Setup ...................................................................................................27 Calibration Setup ........................................................................................... 27 Password Setup ............................................................................................ 27 Diagnostic Menu ........................................................................................... 28 Machine Menu ............................................................................................... 28 Product Setup ............................................................................................... 28 Operating Procedure ..................................................................................... 33 Boot-up Menu ................................................................................................ 33 Monitor Menu ................................................................................................ 33 Set Time and Date ........................................................................................35 Set Date ........................................................................................................35 Initial System Configuration .......................................................................... 35 Verify Detection ............................................................................................. 38 Additional Functions ...................................................................................... 39 MAINTENANCE .................................................................................................. 40 TROUBLESHOOTING ........................................................................................41 SPARE PARTS....................................................................................................43 APPENDIX .......................................................................................................... 44
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Principle of Operation The E-Z Tec DSP Metal Detector uses a balancedcoil system to detect various types of metallic contamination such as mild steel, non-ferrous metals and stainless steel. The E-Z Tec DSP Metal Detector uses a three-coil detection system (Figure 1). The signal voltage in the primary coil is driven by an oscillator. Two secondary coils, on a common axis with the primary, are coupled into the field of the primary coil in such a manner that the system is in balance and the induced voltages in the two secondary coils cancel.
Material to be screened for metal creates a distortion in the electromagnetic field as it passes through the detector aperture. This distortion results in a difference in the induced voltages in the two secondary coils. The voltage difference is amplified, digitized, and filtered to extract detection information that is used to decide whether the signal represents metal or the user’s product. If the signal represents the user’s product, it is ignored. If it represents metal that exceeds a pre-set sensitivity level, the detector generates a detection signal that initiates reject and/ or alarm actions. Figure 2 shows a typical installation of an E-Z Tec Metal Detector.
Figure 1. Principle of Operation
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Figure 2. Typical E-Z Tec DSP Metal Detector Installation
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Specifications SUPPLY VOLTAGE Automatically adapts to line voltage from 100 to 250 VAC at 50 to 60 Hz. The maximum allowable surge voltage is 150 Vrms at 110 V nominal or 300 Vrms at 220 V nominal for 2 seconds. A dedicated line to the main power bus, containing a reliable ground for connection to the “GND” in the detector or system junction box, is required for optimum performance.
OUTPUTS Two reject relays: (1) two form “C” contacts; (2) one form “C” contact. Rated 5 amps up to 250 VAC or 30 VDC. One fault relay with one form “C” contact rated 5 amperes up to 250 VA or 30 VDC. Two 5 ampere fused outputs at the detector’s supply voltage.
MAXIMUM DEMAND 60 VA, not including any connected loads. The maximum connected external load is 5 amperes.
One 0.5 ampere 12/24 VDC output jumper selectable.
OPERATING AMBIENT TEMPERATURE -10 C (14 F) to 45 C (113 F) °
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TIMER Programmable travel time and reject time 0 to 60 seconds.
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STORAGE TEMPERATURE -10 C (14 F) to 80 C (175 F) °
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TACHOMETER INPUT Voltage Logic 0 - 0.0 to 0.9 VDC Logic 1 - 3.15 to 50 VDC (NPN Opened Collector can also be used)
RELATIVE HUMIDITY 0 to 95% ENCLOSURE The standard enclosure is rated NEMA 4X / IP66 and will withstand normal wash-down procedures. Unless specified upon order placement, the unit is not warranted against damage caused by highpressure spray directed at the control panel. Consult the factory for an optional protective cover if caustic wash-down solutions or high pressure wash-down are used.
Current Source N/A Sink 1.0 mA minimum Frequency - 50 Hz maximum Minimum Pulse Width - Logic 0 and Logic 1 is 5 msec
PRODUCT VELOCITY 2 ft/min (0.6 m/min) to 7800 ft/min (2400 m/min), dependent on aperture size.
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Installation Caution!! E-Z Tec ® DSP Metal Detectors are manufactured to very stringent quality standards to ensure that they will provide years of trouble-free service. To achieve this trouble-free service, the installer must follow the installation procedures outlined in this manual. The details of the procedures are important, and must be followed precisely for proper metal detector operation .
correctly. Metal detectors are sensitive to vibration and may false trip (generate a false reject signal) when the conveyor starts and stops. These problems can be prevented by proper installation techniques. Please read all instructions prior to using the metal detector. Problems caused by improper installation techniques are not covered by warranty. Time invested on the up-front installation process will be worthwhile and provide a trouble-free startup and continued reliable service.
Metal detectors are extremely sensitive to very small changes in the electrical and physical environment. Unstable operation is possible unless installed
Mechanical Installation INTRODUCTION The metal detector contains several components which must be physically mounted to a conveyor or suitable stand: 1) the sensing head, 2) the control (if remote), and 3) other devices such as the tachometer, alarm horns, etc. Most E-Z Tec Metal Detectors have an integral sensing head and control, thus simplifying installation and wiring (see Figure 3). The sensing head contains the coils and main electronics. The head must be installed so the products being examined can pass through the aperture in a consistent and controllable manner. It is vital that the sensing head be protected from excessive vibration, physical abuse, electromagnetic interference, static electricity, and corrosive materials. The conveyor belt, chute or other product conveyance device must not contact the metal detector aperture. In remote mounting situations, the control enclosure must be mounted to a convenient surface, with minimal vibration, that is easily accessible for adjustment. The control enclosure is fitted with plastic mounting feet that must be used for remote mounting situations.
Figure 3. E-Z Tec DSP Metal Detector with Integral Sensing Head and Control
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Mechanical Installation (cont.) fringing of the field exists at the inlet and outlet of the opening. The fringing field causes the metal detector to be affected by metal in the vicinity of the aperture. Metal that is not part of the product stream must not be located in this area. The required metal-free area depends on the size of the smaller dimension of the aperture. Normally, 1.5 times the smaller aperture dimension is sufficient clearance for non-moving metal. If space allows, a 1.75 multiplier on the smaller aperture dimension should be used. If there is relative movement between the sensing head and adjacent metal or the metal is a rotating cylinder, use a 2.0 multiplier. (For example, stationary metal should not be located closer than 6 to 7 inches (150 to 175 mm) from either the inlet or outlet of a metal detector with a 4x8-inch aperture. Moving metal should not be closer than 8 inches (200mm) from the entrance or exit of such a detector. Refer to Figure 4 for details. Large metallic devices rotating or moving across the belt should be tested to determine the necessary metal free distance.
HANDLING The metal detector must be handled with care during installation. Follow the specific handling guidelines attached to the detector and included at the front of this manual.
LOCATION OF SENSING HEAD The location of the metal detector sensing head is extremely important. When selecting a location, consider the surrounding processing equipment, product velocity, and rejection of contaminants. Operator convenience should also be evaluated. Be certain to read and understand all installation guidelines before the final location is selected. If there are any questions please contact Eriez for assistance.
METAL FREE AREA The metal detector monitors an electromagnetic field to detect metal. This field is predominantly contained within the aperture of the detector. However, some
Figure 4. Metal Free Area
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Mechanical Installation (cont.) The schematic diagram shown in Figure 5 provides a simplified view of a typical metal detector and conveyor. The arrows represent electrical currents. As the bearings supporting the pulleys and idlers turn, they make and break contact with their respective races. Likewise the cross-members of the conveyor framework represent possible break points. Over time, these connections can work loose or corrode and may make and break the electrical connections due to vibration. The interruption or change, of the current is a source of electromagnetic interference detectable by the metal detector.
ELECTRICAL CURRENT LOOPS The most frequent problem encountered in metal detector installations is false tripping caused by unsteady electrical current loops. The fringing field (described in the previous section) dissipates in strength with distance to a point that metal outside the “metal-free” area will not cause false detections. Since the field is time varying, it will generate small electrical currents in conductive paths (i.e., metalwork) quite some distance from the aperture, even beyond the nominal metal free area. These currents, and ground currents from other nearby equipment, will not cause false detection as long as they are constant. If the current is disrupted, however, the resulting electromagnetic disturbance may cause the metal detector to false trip.
Figure 5. Conveyor (Overhead View) Showing Ground Current Paths
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Mechanical Installation (cont.) shoulder washer. The shoulder washer wall thickness should be at least 1/32" (1 mm). The bearing block should also be insulated from the conveyor frame with UHMW insulators extending across the base of the block.
INSULATING THE CONVEYOR SHAFTS A continuous electrical path through pulleys and idlers cannot be assured. As a result, current changes can not be prevented in these components. They must be electrically isolated from the remainder of the system by introducing an insulating medium into the conductive path. Figure 6 shows two common methods of accomplishing this task.
Both of the insulating methods are reliable. However, it takes only a small metal shaving or burr to cut through and short-circuit the insulators. For this reason, check the integrity of the insulation with an ohmmeter. Insulating either end of the shaft will prevent current loops. However, leaving one end uninsulated will prevent testing with an ohmmeter. For this reason insulating both ends is recommended.
The method shown in Figure 6-A requires machining the end of the shaft to a smaller diameter to allow space for a nylon plastic sleeve. The outside diameter of the sleeve is the same as the inside diameter of the bearing. This sleeve breaks the electrical connection between the bearing and the shaft, thus permanently preventing current flow. WARNING: Do not cut through the sleeve when tightening the bearing set screw.
Build-up of a static electric charge on the conveyor belt can also cause false tripping. A static charge can build up on pulleys or idlers that are insulated on both ends. To prevent false tripping, the insulation must be modified to ensure a ground. After the integrity of the insulators is checked with an ohmmeter, on e end of each shaft should be electrically reconnected to the conveyor frame. If the sleeve insulating method has been used, the setscrew of one of the bearings should be extended
Figure 6-B shows a method of insulating the complete bearing block from the conveyor frame. This requires drilling the bolt holes through the bearing block to a diameter large enough to accept an insulating
Figure 6. Insulating Pulleys and Bearings
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Mechanical Installation (cont.) to make contact with the shaft. This may require drilling a small hole through the sleeve and inserting a sharp, pointed setscrew. If the bearing block insulating technique has been used, simply remove one of the shoulder washers on one end of the shaft. Using either method, the integrity of the insulators can be easily rechecked.
PERMANENT CURRENT LOOPS Permanent conduction paths (such as cross members) in the conveyor frame should be welded securely to provide a reliable path for any currents that may be created. Bolted construction may eventually degrade, and is not recommended unless designed and executed by experts in metal detector conveyor construction. Any conduction path that is to remain removable or that cannot be welded or permanently bolted must be insulated from the conveyor frame.
NOTES: If a drive pulley is powered by a metal chain, it is not necessary to remove the insulators on either end of the shaft as described above. The metal drive chain will bleed off any static charge that may accumulate on the pulley.
Figure 7 shows a conveyor frame properly modified for a metal detector installation. Note that possible breaks in the current paths no longer exist, and the only currents in the conveyor frame are running through a welded, permanent connection. These currents will be constant and therefore will not cause false detections.
If a non-metallic conveyor belt is used, insulate the conveyor pulley on the side opposite the drive motor.
Figure 7. Conveyor Support Frame Showing Typical Current Paths
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Mechanical Installation (cont.) by tightening the mounting bolts. This will put uneven stresses on the sensing head shell which may cause instabilities in operation. If the mounting feet do not rest flat on the supporting structure, shim with appropriate washers. All four mounting feet must be supported equally.
SUPPORTING STRUCTURE The structure that supports the metal detector sensing head must be strong, rigid, and as free as possible from vibration. Electronically, the metal detector can be configured to be relatively insensitive to vibration. Better sensitivity can be obtained by preventing mechanical vibration from reaching the detector head.
NOTE: Only the insulating mounting feet and electrical connections should contact the sensing head. Conduit attached to the metal detector sensing head should utilize plastic fittings (refer to Electrical Installation).
Four insulating mounting feet are supplied with the metal detector. These mounting feet must be used to ensure proper operation (refer to Figure 8) . All four mounting feet must sit flat on the supporting structure. Do not draw the feet down to the structure
Figure 8. Use of Detector Mounting Feet
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Mechanical Installation (cont.) Cold bonding is a popular and acceptable on-site practice. In this case, the splice is usually a beveled or step-lap type. In either case, the splices should be diagonal rather than straight across the belt. Although the cold-bond, diagonal splice is adequate for many applications, the vulcanized finger splice is preferred.
BELTS AND BELT SPLICES The metal detector-sensing head cannot be disassembled to be fitted around the conveyor belt. For this reason the conveyor must be designed to return the belt through the aperture, or the belt must be cut and spliced back together. Splicing the belt with lacing or clamps is not recommended since foreign materials tend to collect at the joint and may eventually cause false detections.
NOTE: During all splicing it is absolutely necessary to ensure that no foreign material (especially metal) is trapped within the splice. If metal is trapped in the splice, the detector will trip each time the splice passes through the aperture. Since the metal is trapped inside the splice, it cannot normally be located and removed without ruining the belt.
A proven, trouble-free choice for metal detector conveyor belts is modular plastic conveyor belts. Conductive plastic components, belts, and metallic hinge pins or rods must be avoided. Vulcanized belt splices are most reliable and are recommended for continuous belt applications (Refer to Figure 9). If the belt is single-ply, the finger splice configuration should be used. If the belt is multi-ply, a combination of the step and finger splice configuration is recommended.
Figure 9. Conveyor Belt Splices
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Mechanical Installation (cont.) multiple products with differing sizes, design the system to center the largest product in the aperture. In such a case be aware that the sensitivity of the detector to metal of a particular size and type may vary with the product position, and may require different detector settings for the different product sizes and positions in the aperture.
CONVEYOR SLIDER BED The conveyor belt must be supported as it travels through the metal detector. This is accomplished by providing a stationary slider bed, which must be capable of holding the belt off the aperture liner even when fully loaded. The slider bed must not touch the aperture liner.
REJECT PROXIMITY SWITCH
The slider bed should be made of static-resistant non-metallic material. Wood and phenolic are good choices. Most solid plastics cannot be used because these materials tend to generate static electricity as the conveyor belt slides across. ‘Static-resistant’ plastics that incorporate metallic particles cannot be used.
A proximity switch indicates when a package is aligned with a reject device. For example, a product in a box may need to align with a reject device, such as a pusher arm. To be rejected reliably, the proximity switch indicates when the alignment is achieved. The normal position for the proximity switch is just after the reject device so that it trips as the product aligns with the reject device. If it is difficult to install a switch in that location, install upstream from the reject device. In this case the metal detector incorporates a timer capable of delaying the output until the product aligns with the reject device. Be certain not to infringe on required detector “metal-free” area when choosing the location of the proximity switch.
PRODUCT POSITION The product should always be guided through the center of the aperture, both vertically and horizontally. The product must be centered regardless of the method of conveyance through the metal detector (i.e., conveyor, chute, or vertical pipe application). If the same metal detector will be used to inspect
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Electrical Installation should be grounded at only one point - through the power supply ground wire. No other ground connections are permitted. This includes mounting hardware and conduit.
INTRODUCTION All electrical connections are made within the NEMA4X (IP-66) enclosure. This enclosure is attached to the metal detector housing, except for remote applications. Figures 10 and 10A show the enclosure and the electrical connections to the circuit board. For convenience, connections are pull-apart terminal blocks. The pull-apart feature allows the connections to be made outside the enclosure and then snapped back in place. See drawing Figure 10B for typical wiring diagrams for reject devices.
A circuit breaker/on-off switch protects the metal detector electronics. Fuses (5A/250 V) are located between the circuit breaker and input terminals to protect power output terminals 7, 9, 16, and 18.
WARNING: L1 Fused and L2 Fused are not disconnected by the internal circuit breaker. Disconnect incoming power before servicing. Failure to follow this precaution may result in serious injury or death.
CHOICE OF INPUT POWER SOURCE The metal detector is equipped with filtering devices to reduce incoming electrical noise. Inductive loads sharing the same power circuit usually create noise. Even with filters, there is a limit to what the metal detector can withstand without false tripping.
RELAYS The E-Z Tec DSP Metal Detector provides three relays as follows:
The best insurance against electrical noise is to run a separate circuit to the metal detector from the main power bus. This circuit should be free of all loads except the metal detector. The power line should be run in its own metal conduit. If this is impractical, reliable operation can often be obtained by powering the metal detector from a “clean” lighting or instrument circuit. This circuit must be free of inductive loads such as motors, solenoids, motor starters, etc. If the metal detector must be powered by a less favorable source, a harmonic neutralized constant voltage transformer can be used to reduce false tripping from line noise. This transformer should be mounted within 3-5 feet of the detector. The power source is connected to terminals L1 and L2. Note that L1 and L2 are connected through fuses and circuit board traces to other terminals on the circuit board as labeled. These terminals are intended to be conveniently available to the user to power various auxiliary equipment. The fuses have limited capacity as indicated in the specifications. If a piece of auxiliary equipment requires a power in excess of the fuse capacity, the auxiliary equipment must be powered from a separate source.
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Relay K1 - has two sets of form “C” contacts (1A and 1B). Either or both sets may be connected as normally open or normally closed. Relay K1’s current is limited to a 5A at 250 VAC or 30 VDC. The relay timing is controlled by the reject settings in the metal detector. (Product / Reject Menu).
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Relay K3 - has a single set of form “C” contacts. The output terminals may be connected as normally open or normally closed. Relay K3’s output current is limited to a 5A at 250 VAC or 30 VDC. The action of Relay K3 is instantaneous upon metal detection.
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Fault Relay K2 - has a single set of form “C” contacts. The terminals may be connected as normally open or normally closed. The fault relay output current is limited to a 5A at 250 VAC or 30 VDC. This relay is activated by self-detection of a fault within the metal detector, and may be used to notify the operator or control the production line in such a case.
All of the relays are normally energized to provide fail-safe operation. If a fault in the system occurs, the relay changes to the de-energized state. After the fault is cleared, the relay must be reset.
The metal detector power source must contain a reliable ground. It must be connected to the “GND” terminal of the metal detector. The metal detector
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Electrical Installation (cont.) RELAY NOTES If switched power is needed for an external device in excess of the 5 amperes maximum current, it must be supplied to the appropriate device from an external source using an auxiliary relay or solenoid. The voltage and ampere ratings for all detection alarms, reject devices etc. switched by the relays should not exceed the relay ratings.
Current Source N/A. Sink 1 mA min. Frequency 50 Hz max. Minimum Pulse Width Logic 0 - 5 mSec. Logic 1 - 5 mSec.
TACHOMETER INPUT (TACH) Applications having variable speed product flow and requiring automatic reject timing use this input. A tachometer is used to allow the metal detector control to monitor product speed and reject according to the distance the product has traveled rather than according to elapsed time since detection.
NOTE: The right terminal (number 25 “COM”) of this input is ground. Since the metal detector is grounded only by the input power supply ground, this terminal must not be grounded by the proximity device.
The electrical specifications are as follows:
The reject confirmation input is used to monitor the function of the reject device. It is usually a limit switch attached to the reject device that indicates it is functioning. For example, the reject device may be a pusher bar. The reject confirmation switch, wired to the reject confirmation input, is positioned in such a way that it closes as the pusher bar reaches its maximum extension. The electrical specifications are as follows:
REJECT CONFIRMATION (REJ CON)
Voltage Logic 0 – 0 to 0.9 VDC Logic 1 - 3.15 to 50 VDC (NPN Open Collector can also be used) Current Source N/A. Sink 1 mA min. Frequency 50 Hz max
Voltage Logic 0 - 0 to 0.9 VDC Logic 1 - 3.15 to 50 VDC (NPN Open Collector can also be used)
Minimum Pulse Width Logic 0 - 5 mSec. Logic 1 - 5 mSec.
Current Source N/A. Sink 1 mA min.
PROXIMITY SWITCH The metal detector can also be used to scan and automatically reject packages. In this application, a proximity switch is used to sense the location of the package so it can be reliably rejected. The device can be a mechanical switch, photo-eye, or any other device that is capable of precisely locating the package. The electrical specifications are as follows:
Frequency 50 Hz maximum Minimum Pulse Width Logic 0 - 5 mSec Logic 1 - 5 mSec NOTE: The right terminal of this input (number 27 “COM”) is ground. Since the metal detector is grounded only by the input power supply ground, this terminal must not be grounded by the limit switch.
Voltage Logic 0 - 0 to 0.9 VDC Logic 1 - 3.15 to 50 VDC. (NPN Open Collector can also be used)
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Electrical Installation (cont.) wiring (i.e. tachometer and reset switch). Keep all metal detector wiring separate from electrical supplies carrying heavy or switched loads. This is especially true for variable speed motor control wiring. Interference from electrical noise will be greatly decreased by following these guidelines.
REJECT RESET (REJ RESET) The metal detector has two reject outputs, Direct and Timed. The “Direct Relay” always resets automatically following a reject. The “Reject Reset” input can be used to reset the timed reject. Typically, a momentary normally-opened (NO), push-button switch is used for this purpose. The timed output can be adjusted to reset automatically or manually. The electrical specifications are as follows:
The use of metal conduit will provide necessary shielding for the supply wires. The metal conduit, however, also represents a potential ground path. Metallic conduit fittings must not be used to attach conduit to the metal detector housing. Always use a plastic fitting for this purpose
Voltage: 5 VDC Current: 20 mA Note: The right terminal of this input (number 23 “COM”) is ground. Since the metal detector is grounded only by the input power supply ground, this terminal must not be grounded by the switch.
POWER SWITCH The on-off circuit breaker/switch located inside the control enclosure is intended to be a service convenience only. It is recommended that the metal detector remain ON at all times to provide the optimum metal detector performance. This will also enhance the longevity of electronic components and minimize the chance of operating the product line without metal detector surveillance.
REMOTE COMPUTER PORT The E-Z Tec DSP Metal Detector is capable of communicating with a remote computer through an RS-485 link. The optional E-Z Link™ software package is required to use this feature.
CONDUIT Wiring to and from the metal detector should be routed through metal conduit. High voltage wiring for the power supply and reject devices should not be located in the same conduit as low power sensor
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Electrical Installation (cont.)
Figure 10. Connection Terminals
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Electrical Installation (cont.)
Figure 10A. Connection Terminals
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Electrical Installation (cont.)
Figure 10B. Connection Terminals
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Operation This section of the manual describes the set-up procedure and operation of the Eriez DSP Metal Detector. To understand the following discussion, it is important first to understand that ‘product’ is the material that is being inspected. Product may be conductive or non-conductive, but generally cannot be metallic. ‘Metal’ is the unwanted metallic material that may contaminate the product.
products, such as paper and textiles, produce a product signal that occurs at a zero degree angle. Conductive products (those that contain water and salt or minerals, etc.) are distinguished by an offzero signature. Depending on the nature of the conductive product, this signal can occur at any angle between zero and 360 degrees. A typical polar coordinate system illustrating both types of product signals is shown in Figure 11.
The Eriez DSP Metal Detector uses a balanced coil arrangement for metal detection. When an object– either product or metal– enters the aperture, the balanced electromagnetic field is disrupted which, in turn, generates a corresponding signal. A change in the phase and amplitude of the signal is detected.
Using the polar coordinate system shown in Figure 11, detection is defined as a signal that breaks the boundary defined by the football. The auto setup feature of the E-Z Tec DSP Metal Detector automatically determines the length and width of the “football” for a particular product. Signals from metal contamination usually exceed the boundary of the “football” and the metal detector processes these as detect signals.
The output (detection) signal from the metal detector is represented by using a polar coordinate system. The signal has an amplitude, which is proportional to the distance from the origin of the coordinate system to the point representing the signal at that instant. The instantaneous signal also has a phase angle relative to the undisturbed signal (from 0 to 360 degrees), which is represented by the angular position of the point of the signal at that instant. A periodic signal that eventually returns to its initial conditions would be represented by a closed loop in the polar coordinate system. Such a signal might be caused by the product or metal moving through the detector aperture. The orientation of the long axis of the signal’s phase-amplitude representation loop may itself be referred to as the ‘phase angle’ of the signal.
INITIAL START-UP If the Metal Detector was stored at or below 0 C for longer than six hours and then moved to a warmer location, the temperature of the unit should be allowed to stabilize long enough to allow drying of moisture, which may have accumulated on the electronic components (overnight stabilization is recommended). DO NOT APPLY POWER UNTIL ELECTRONIC CIRCUITRY IS COMPLETELY DRY. °
The detector can be activated after it has been properly connected to the power source (see Electrical Installation section). Use caution when first applying power, as the reject devices may actuate when power is first applied. To avoid injury to personnel or equipment damage, the area around all reject devices should be clear of personnel and obstructions before the application of power.
The phase and amplitude of the signal, returned by product passing through the detector, are represented by a ‘football’ shape that occurs on the polar gridcoordinate system. The specific phase angle is representative of the type of product, i.e., conductive or non-conductive. Non-conductive
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Operation (cont.)
Figure 11. Showing the Relationship of Phase, Sensitivity Length and Width
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Operation (cont.) OPERATOR INTERFACE
MENU STRUCTURE
Operation and set-up of the E-Z Tec DSP Metal Detector are implemented using a 1/4 VGA touch screen interface LCD display on the control panel. The LCD screen displays various menus with buttons to select the desired functions. The operator controls the detector by touching appropriate areas of the display. Pressing a button on the screen will select the associated function. Data entry to the various menus is achieved via five types of data entry operator interface screens. They include the following:
The primary (Level I) menu that appears after the start-up sequence is the Monitor Menu. All other submenus are accessible from the Monitor Menu. The four Level II menus are the Password, Quick, Main and Product menus (see Figure 16 and Appendix A). Each of the Level II menus have various submenus that are described in the following sections. Note that a menu item can only be accessed if the alpha description menu name is enclosed by a button on the screen. Accessibility varies depending on the current user password.
Alpha Entry – allows for input of alpha-numeric characters.
PASSWORD MENU (LEVEL II) The E-Z Tec DSP menu structure allows the customer to review and/or change most metal detector settings and reports. Changes cannot be made without the appropriate password. Each password consists of a four-digit number. The default passwords stored in memory at the time of manufacture are shown below. There are five separate passwords with the following hierarchy:
Number Entry – allows for keypad selection and input of numeric values. Time Entry – allows for input of day/date. Toggle Selection – Used to switch between various choices (i.e., on/off, yes/no). Immediate – No input option. This feature provides an instant return to previous menus or reset to predefined values. For example, pressing the “Darken” option under the Monitor/Quick Menu will instantly darken the LCD touch screen.
View: Password 0000 is the default user level when the system is powered up. Nothing can be changed at this level. Operator: Password 1111 allows the operator to change only the running product.
Figure 12. Operator Interface Primary Menu Structure
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Operation (cont.) Supervisor: Password 2222 enables the customer to change the Product Number, Sensitivity, Phase, Product Description and the Detect Mode. Reject reports can also be erased at the supervisor level.
QUICK MENU (LEVEL II) The quick menu contains eleven Level III menus that provide information and adjust user interface items. The Level III menus are as follows (see Figure 13):
Engineer: Password 3333 allows access to all parameters plus the reject settings.
Information – Provides basic information about manufacture of the DSP Metal Detector.
Factory: Access to the factory level is not permitted. This level of access is used only for initial set-up during manufacture of the metal detector.
Alarm – Used to toggle on/off the audible alarm used to indicate a detection. Beep – Used to toggle on/off the audible confirmation of a touch screen input.
To change the password, press “PW” (password). A numeric keypad will appear. Enter the four-digit password number and press “Enter”. The system will automatically return to the previous menu. The default password values can be changed using the Password Set-Up Menu. Entering the password menu screen and returning with no action will default the system to the view access level.
Darken – Used to darken the contrast on the touch screen. Lighten – Used to lighten the contrast on the touch screen.
Figure 13. Quick Menu Structure
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Operation (cont.) Reset LCD – Used to reset the touch screen to a pre-assigned contrast brightness value. The preassigned value is accessed through the Machine SetUp Menu.
Time – Used to adjust clock settings or to toggle clock on/off. CALIBRATION SET-UP The calibration feature provides an automatic prompt to conduct a calibration test using the test sticks provided with the metal detector. The calibration setup menu contains five sub-menus which control the following features:
Zero – Used to induce a hardware zero. This is a troubleshooting feature and should only be used after contacting Eriez. Pass Calibration – Used to acknowledge that the detector passed the automatic calibration procedure. This option is described in greater detail in the section describing the auto-calibration feature. The feature is located in the calibration menu.
Test – Toggle used to turn the test feature on/off. Start – Time entry screen to specify the start time for the automatic calibration test. Delta – Time entry screen to specify the time between tests.
Reset Reject – Used to reset the reject output if the running product is set for manual reset. The manual reset parameter can be selected in the reject set-up menu.
Next – Label that specifies the time of the next test. Pass Calibration – Provides the same function as the Pass Calibration item described in the quick menu. This action is used to acknowledge that the detector passed the automatic calibration procedure.
Bar Graph – Toggle selection used to turn on/off the bar graph at the top of the display. English – Used to select between available languages.
PASSWORD SET-UP Password set-up is used to change the various password numeric codes set by the factory. Passwords should be changed periodically for proper operational security, keeping in mind that the metal detector may be a critical quality control device. The Operator password is the lowest access level and allows the least number of changes. The Engineer password is the highest level of access available to the customer. The password can only be changed for the current security level and lower. For example, if the system is at the supervisor level, only the supervisor and operator passwords can be changed. Each password can be changed using the numeric keypad prompt in the Password Set-Up Menu. The four sub-menus are as follows:
MAIN MENU (LEVEL II) The main menu contains eight Level III sub-menus that control various machine functions. Each Level III menu contains one or more Level IV sub-menus. A detailed description of the function of each menu item follows. Report Menu – The report menu is used to manage the report data stored in the metal detector. The E-Z Tec DSP can store up to 100 reports. The following commands are used to manipulate the report data base. Page – Allows the user to page through ten screens of previous reports. Each screen contains up to ten individual entries. Clear Report – Clears entries that accumulated since the last clear report action.
Operator – Allows entry of a new operator password.
Fault Menu – Displays current system faults.
Supervisor – Allows entry of a new supervisor password.
Clear Fault – Clears the current list of faults.
Engineer – Allows entry of a new engineer password.
Clock Set-Up Date – Used to adjust date or to toggle date on/off.
Factory – Factory use only. No access allowed.
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Operation (cont.) DIAGNOSTICS MENU The diagnostic menu provides access to the internal operation of the metal detector and should only be used under supervision by Eriez.
Password – The password menu item is used to enter the default time in seconds between password selection and default to the viewer access level. For example, if a value of 300 is entered, the metal detector touch screen will default to the “View” access level after five minutes have elapsed without an operator action on the touch screen. The touch screen back light will also dim after the elapsed time.
Frequency – Displays the current operating frequency. Drive – Toggle used to turn on/off the oscillator drive pulses.
TR485 – Toggle to determine if a 485 termination resistor is in the circuit. If only one metal detector is connected to a 485 network, this feature should be turned “ON”. If multiple metal detectors are connected on a 485 network all of the units should be off except for the farthest unit from the PC.
Sample – Toggle used to turn on/off the sample pulses. Diags. – Mask used to turn on extra diagnostic features. Climate – Diagnostic tool used to measure background noise in the environment.
LCD – The LCD menu item allows the default brightness contrast to be changed on the touch screen pad. The screen will immediately adjust to this value when the “Reset LCD” button is pressed under the Quick/Reset LCD menu.
Talk – Toggle used to turn on/off communication between internal hardware. MACHINE SET-UP MD Add. – Network address used in conjunction with the E-Z Link PC software package. Each metal detector must have a unique address.
FACTORY SET-UP The factory set-up menu is used during manufacture to properly configure the metal detector for each customer application. This menu can not be accessed by the user.
Name – Name of metal detector. Used in conjunction with E-Z Link PC software package.
PRODUCT MENU (LEVEL II) This Level II menu contains fifteen Level III submenus to adjust product sensitivity and to configure the product and reject system settings. Each Level III menu contains one or more Level IV sub-menus. The organizational structure of the Product Menu is shown in Figure 14. A detailed description of the function of each menu item follows.
Bar Graph – Used to switch the bar graph on/off. Zero – Used to adjust the scaling of the bar graph. This feature should only be changed with direction from Eriez. Span – Used to adjust the scaling of the bar graph. This feature should only be changed with direction from Eriez.
The E-Z Tec DSP stores 50 sets of product settings in a table. The Product Menu allows the user to view, edit, or run any of the 50 products in the table. Before proceeding it is important to distinguish between the running product and the product being edited. The running product is always displayed in the top blue portion of the LCD screen. The operation of the metal detector is determined by the running product. The product being edited is the product displayed in the product menu. If the product being edited is the same as the running product, then changes to the parameters take effect immediately. If the product
RejCon – Reject confirmation time out specified in seconds. This command determines the amount of time to wait for a reject confirmation before a fault occurs. The reject confirmation is selected in the reject set-up menu. Tach – Tachometer time out specified in seconds. This setting determines the amount of time allowed between tach pulses before a fault occurs. This feature provides a check to ensure that the tachometer is functioning properly.
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Operation (cont.)
Figure 14. Organizational Structure of Product Menu
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Operation (cont.) being edited is different from the running product, then changes to the parameters are stored in the table but do not affect the operation of the metal detector. The edited product can be made the running product by simply pushing the “Run this Product” button.
length of time and reset. The noise signals in ‘’B’’ of Figure 15 would be ignored because they are unipolar. In general Mode 2 may be somewhat less sensitive than Mode 1 detection. Mode 2 detection may allow metal to pass undetected in certain instances. Figure 15C shows an analog signal representing a small piece of metal followed by a large piece of metal in the production stream. The beginning of the signal is similar to the beginning of the signal shown in Figure 15A, but as it moves toward the negative detection threshold, the signal of the small piece of metal is absorbed by the signal of the larger piece of metal following it. The larger piece of metal is detected at “G”. Note that the small piece of metal is not detected (although it may be rejected along with the closely following large piece). Extremely large pieces of metal will cause larger fractions of the product stream to be ignored because the electronics will require more time to recover. Therefore the probability of missed small metal increases with the size of the largest expected tramp metal. Normally this area is small because the tramp metal is small. The probability is low that metal will be missed, but the possibility exists and must be considered before one decides to use Mode 2 detection.
Product Used to select the product to edit from the table. Name Used to enter the alphanumeric description of the product. MODES Mode 1 - The metal detector processes an analog signal from the receiver coils of the metal detector. Conceptual examples of metal signals are shown in Figure 15. If the magnitude of the metal signal rises above a predetermined detection threshold, the metal detector will output a ‘detect signal’. Note that the analog signal has a positive and a negative portion. In detect Mode 1, the metal detector will detect on both portions of the signal. The detect signal typically begins with the first portion of the signal crossing the detection threshold (at point “A” Figure 15) and ends after the second portion of the signal returns through the opposite detection threshold (at point “B” Figure 15). Mode 1 is usually the more sensitive of the two modes and is therefore used in most applications.
If the metal detector works reliably using Mode 1 detection, Eriez recommends using this mode. Some applications are electrically noisy and the number of false trips is high enough that the metal cannot be used in Mode 1. In this case one must decide whether to use Mode 2 detection with an increased probability of missing a small percentage of metal. Eriez recommends its use only when necessary.
Mode 2 - Occasionally a metal detector is used in an environment where significant interference is experienced. Typical sources of interference are lightning, static electricity, and nearby equipment with inductive loads. These types of interference usually cause analog signals that have only one polarity. Figure 15B shows typical uni-polar noise signals at “D”, “E” and “F”. Each of these signals will cause a metal detector to false detect when operating in Mode 1 because they exceed the detection threshold level. The metal detector can be adjusted to ignore many of these signal types by using Mode 2 detection. Refer again to the analog signal of Figure 15A. Notice that the metal signal has both a positive and negative polarity. Mode 2 detection does not detect a uni-polar signal. It holds off detection until the second polarity of the signal occurs. For the signal in Figure 15A the detection would occur at point “C”. It would last a predetermined
Every E-Z Tec DSP Metal Detector leaves the factory with an Individual Unit Specification Sheet. This sheet will indicate whether the unit is set for Mode 1 or Mode 2 detection. Most units will be set for Mode 1 detection. The mode is shown on the Monitor Menu at power up.
Speed The speed in units of feet/minute at which the product is passed through the aperture.
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Operation (cont.)
Figure 15. Example of an Analog Detection Signal
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Operation (cont.) Gain This is a factory setting set by Eriez.
Paste Copies all of the product settings from temporary memory, when the “Copy This” button was pressed, to the product being edited. This button works in conjunction with the “Copy This” button.
Phase Adjusts the phase of the elliptical ‘football’ signal boundary used to determine detection. This adjustment is used to prevent the metal detector from detecting the product under inspection. More information can be found in the Operation section of this manual.
Active This button works in conjunction with the “<->” and “<+>” buttons. The “<->” and “<+>” buttons allow the user to scroll through all of the “Active” products in the table. If Active=YES for a product entry in the table then it is added to the list of entries that will be scrolled through when the “<->” and “<+>” buttons are pressed.
Sensitivity Scales the length and the width of the elliptical ‘football’ signal boundary used to determine detection. Controls the ability of the metal detector to detect metal. The range is 00 to 250, with the metal detector most sensitive at a setting of 250. After an automatic setup, the sensitivity will be set to 100. If the detector is not responding to metal particles of the desired size, increase the sensitivity slightly. If the detector experiences excessive false detects, decrease the sensitivity slightly. After any reduction in sensitivity, verify that the target metal particles are still detected reliably. More information can be found in the Operation section of this manual.
Run this Product Makes the product being edited the running product. Auto Set-Up The E-Z Tec DSP is equipped with an Auto Product Set-Up function that provides for automatic set-up of the detection parameters (Phase, Length, Width and Sensitivity). A product sample and metal test sphere are required to complete the auto-product set-up procedure. Ancillary equipment such as conveyor belts should be operating prior to initiating the auto product set-up procedure. All other machinery located near the metal detector should be operating normally. This is imperative to ensure that the metal detector is set-up under normal background conditions. The automatic set-up procedure is initiated by pressing the “Auto Set-Up” button. A menu to learn environmental noise will appear for several seconds after depressing the auto set-up button. The system will then provide an option to “Start” or “Cancel” the calibration procedure.
Length Adjusts the length (primary axis) of the elliptical ‘football’ signal boundary used to determine detection. This value should only be changed by a person with an understanding of metal detector signals. Note that the length should always be greater than the width. More information can be found in the Operation Section of this manual. Width Adjusts the width of the elliptical ‘football’ signal boundary used to determine detection. This value should only be changed by a person with an understanding of metal detector signals. Note that the width should always be less than the length. More information can be found in the Operation section of this manual.
Start - Used to initiate the Auto-Product Set-Up procedure. After initiating the auto-product set-up procedure, the user will have the option to stop the procedure after passing the product through the metal detector or canceling the procedure. If the process is canceled, the user will be returned to the Product Menu. After stopping the auto-product set-up procedure, the user can accept the result or cancel the procedure. Accepting the result will return the user to the Product Set-Up Menu.
Copy This Copies all of the settings from the product being edited into temporary memory. This button works in conjunction with the “Paste” button.
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Operation (cont.) Cancel - Used to terminate the Auto-Product SetUp procedure.
be used to monitor the conveyor speed and supply this information to the detector. If the “Tach” input is set to “Yes”, the function of the travel time input changes from a number value representing time to a number value representing the number of tachometer pulses needed to move a detect signal through the shift register and output a reject signal. Select “No” if a tachometer is not used.
Reject Set-Up Travel - Enter the time (0 to 60 seconds) delay from detection to actuation of the reject device. Successive detections are stored in memory and are not lost. They are sequentially moved through a shift register and emerge as reject outputs with the delay.
RejCon - The reject confirmation input is used to monitor the function of the reject device. It is usually a limit switch attached to the reject device that indicates that the latter is functioning. For example, the reject confirmation device may be a switch attached to a pusher bar used to reject a box from a conveyor. The switch is positioned in such a way that it closes as the pusher bar reaches its maximum extension. If reject confirmation is needed select “Yes”, if not select “No”.
Duration - Enter the time that the reject signal is to be held on, after the travel time (0 to 60 seconds). Reset - The reject signal can be set to reset automatically or remain on until reset is initiated via an appropriate switch. Select “Auto” for automatic reset. Select “Manual” to use a switch for reset. Index - An index device is a mechanical switch, proximity switch, photo-eye etc., used to indicate when a product is in position for the reject device to divert contaminated product from the product stream. Select “Yes” or “No” depending on whether an indexing device is used or not used.
OPERATING PROCEDURE The following procedures provide a step-by-step procedure for programming the essential menu items, calibrating and operating the E-Z Tec DSP Metal Detector.
Space - This setting is selected to indicate whether there is always space between adjacent products. Set this to “No” if it is not certain that there will always be space between adjacent products.
BOOT UP MENU Upon power up the “Boot Up” screen will appear on the display for about ten seconds, (See Figure 16). This display is a system self check showing coded messages. If this screen stays on longer than ten seconds, a message appears “cycle power to continue” (i.e. turn the power off and on). If such a message appears, turn the power off and then on again.
Window - In the case of packaged product, the exact position of metal inside the product package is not known when it is detected. Depending on product separation, it may be impossible to know which package contains the metal. The “window” is used to set up a range of time or tachometer pulses (perhaps a few packages long) where it is certain the metal is located.
MONITOR MENU After the self-check, the metal detector will default to the Monitor Menu (See Figure 17) and the message “Please Wait” will appear at the top of the screen. Once the message disappears, the touch screen will become active and the detector will be operational. This menu displays the normal operating conditions and allows access to the four Level I menus described above: Password, Quick, Main and Product. The date and time appear in the upper right hand corner. The word “View” appears in the lower left hand corner indicating the password level. The display automatically returns to this menu if no inputs are made in other menus for a user-specified time.
Delay - Used only with an index device. Enter the time between the index device sensing the product and the reject device activating, (0 to 60 seconds). If an index device is not used set the time to zero. Tach - Applications with inconsistent or changing product speed cannot use time as the criterion to issue the reject signal, because the time required for the contaminated product to travel from the metal detector to the reject device varies. An example of this is a variable speed conveyor. A tachometer must
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Operation (cont.)
Figure 16. Boot-Up Menu
Figure 17. Monitor Menu
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Operation (cont.) SET TIME AND DATE The real time clock is set at the factory to the local factory time and date. To change the time and or date for your location proceed as follows:
arrow keys to the desired character position and then incrementing either a letter or a number with the plus “+” and minus “-” keys. A letter is selected by pressing the “Alpha” key. A number is selected by pressing the “Number” key. Press “Enter” and the display will return to the Product Menu.
Set the password level to supervisor (2222) or higher and select the “Main Menu” followed by “Clock Setup” and then “Time” . The E-Z Tec DSP clock operates on a 24-hour time standard. The time entry screen appears and the current time setting is shown. The time is incremented up or down using the “+” plus or “-” minus keys. The left-hand keys increment the hours and the right-hand keys increment the minutes (See Figure 18). Press “Enter” to set the new time. The “Enter” command resets the seconds to zero.
Select the “Mode” function and choose the Mode of Operation (Mode 1 or Mode 2). E-Z Tec DSP Metal Detectors can operate in either of two detect modes. The most appropriate mode for a given application depends largely upon environmental conditions and upon the mix of tramp metal in the product stream. A detailed discussion of the mode function was presented in a previous section of this manual. Select the “Speed” option under the “Product” menu (Figure 21). The number entry keypad will appear. Enter the product speed in feet per minute. Press “Enter” and the display will return to the product menu.
SET DATE To change the date, return to the “Clock Setup” menu and select “Date” . The date entry screen will appear showing the current date. The date is incremented up or down using the plus “+” or minus “-” keys. The right-hand keys increment the years, the middle keys increment the day, and the left-hand keys increment the month. (See Figure 19).
If applicable, turn the metal detector conveyor on. Check to determine if all devices, machines, etc. located near the metal detector are operating normally. This is necessary during the auto-product set-up step since the metal detector will learn about its operating environment. Press “Auto Setup”. A noise menu will pop up for approximately five seconds followed by a start menu. Press “Start” and pass the product through the aperture. The detector should not beep before the product is passed through the aperture. If it does, press “Back” and repeat this step. Press “Stop” after the product passes through the aperture. At this point the screen will update showing the “Old Settings”, “New Settings, and the “Measured Values”. Press “Accept” .
INITIAL SYSTEM CONFIGURATION The initial set-up procedure for the E-Z Tec DSP Metal Detector consists of entering the following parameters: • Password (s) • Product Name (s) • Operating Mode • Speed
Repeat the auto-product set-up procedure and compare the old and new settings. Repeat this process to get a feel about how the product is reacting. If the new and old values for length and width are within 10%, the auto setup process is complete. Note that pressing “ Back” at any time will move the process back one step. Press “Cancel” to return to the “Product Menu”. This completes the automatic product set-up procedure.
• Auto Setup • Reject Setup Select the “Password Menu” and enter the Engineer Password (3333). Press “Enter” and the system will return to the Monitor Menu. Select “Product Menu” and then “Name” to enter the product name. An alpha entry screen will appear (See Figure 20) and the product name can be entered by scrolling the
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Operation (cont.)
Figure 18. Clock Set-Up Menu
Figure 19. Date Set-Up Menu
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Operation (cont.)
Figure 20. Alpha Entry Screen for Product Name
Figure 21. Product Menu
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Operation (cont.) The final step of the set-up procedure requires input of the various values associated with the reject mechanism. These options are summarized in the table “Reject Set-up Input Parameters”.
metal. The detector should only respond with detect indications while the test metal is passing through the aperture. CAUTION: Reject devices may activate. Make sure personnel and equipment are clear.
In some cases, a tachometer must be used to monitor the conveyor speed. If the “Tach” input is set to “Yes”, the travel time entry changes from a number value representing time to a number value representing the tachometer pulses needed to move a detect signal through the shift register and output a reject signal. See previous sections of this manual for a more detailed explanation of each item in the table.
The sensitivity adjustment range of Eriez DSP Metal Detectors is 00 to 250. Refer to Figure 11 for an understanding of sensitivity. As shipped, the E-Z Tec DSP is adjusted to detect the rated metal size with the “Sensitivity” set at 100. A security level of supervisor or higher is required to change the sensitivity. The sensitivity is adjusted by entering the “Product Menu” and selecting “Sensitivity” . The “Number Entry” screen will appear and a rectangular box in the upper left hand portion of the screen below the “Sensitivity” button will indicate the current setting. The sensitivity can be adjusted by typing the new value on the keypad and pressing “Enter” or the value can be incremented in steps of ten with the plus “+” or minus “-” keys and pressing “Enter”.
The metal detector and/or its system is now operational. Check that the product runs properly.
VERIFY DETECTION Normally every Eriez Metal Detector is calibrated before shipment to detect a specific sphere size of a specific material. Appropriate test spheres are shipped with each unit. Using the test sphere(s) provided and/or samples of the metal you desire to detect, pass the metal through the aperture. It is important that the metal pass through the aperture at a speed and in the direction that it is expected to pass during normal operation. Do not bring your hands close to the aperture while performing this test, the detector may respond to the hand as if it were
The “Phase” setting is used to prevent the metal detector from detecting the product under inspection. The phase is determined during the automatic product set-up procedure. Changes to this value should only be attempted by personnel with metal detector experience or with supervision from Eriez.
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Operation (cont.) ADDITIONAL FUNCTIONS The Product Menu has a “Copy This” and a “Paste” button. These can be used to copy the settings from one product number to another. To copy the settings of a current product to a different product, press “Copy This” followed by “Product”. Enter the new product number using the “Number Entry” keypad and press “Enter”. Press “Paste” when the “Product Menu” appears. A verify screen will appear with “Yes” and “No” buttons to confirm the operation.
contact Eriez for assistance. To change the password, go to the “Main Menu” and press “Password Setup” . Press “Operator”, “Supervisor” or “Engineer” to select the password level to change. The number keypad will appear. Type a four or less digit number disregarding the leading zero and press “Enter”. The monitor will return to the previous screen where another level can be selected. If no more entries are made after the user specified time, the screen will return to the monitor “View” menu.
It is critical to remember changes to your password(s). The metal detector cannot be adjusted without the correct passwords. If the passwords are forgotten,
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Maintenance E-Z Tec Metal Detectors are water tight and will not be damaged by normal water contact, including ju dicious use of high pressure sprays. Go od maintenance practice, however, dictates that highpressure spray should not be directed at precision components in areas that do not contact the product, such as the control panel. This preventative action will prolong the life of the metal detector. The standard metal detector control panel may incur damage during high-pressure wash down. Such damage is not covered by warranty. Some cleaning agents may cause damage or discoloration of the control panel and/or the aperture liner. An optional clear protective cover for the display is available for high pressure washdown applications.
Required periodic maintenance for conveyors and/ or reject devices supplied by Eriez will be specified on the system outline drawings and/or on placards attached to the components themselves. For the typical system, check the following at least once per 40-hour work week: • Conveyor and drive belts for tension, alignment and condition • Bearings for lubrication, metal contamination and wear • Air supply for pressure and moisture trap condition • Support frame for loose connections, rust and wear from belt contact
The metal detector should be inspected regularly for physical damage, especially in the region of the aperture liner. The unit should be kept clean and dry, if possible. Generally, this is all that is necessary to keep the unit working at peak performance. In the event of any abnormality, please contact the factory. No periodic maintenance or adjustment of the metal detector is required. A quick test at the beginning of every shift is recommended.
• Conveyor belt slider bed for condition including wear and embedded metal • All operating mechanisms (reject pusher arms, gates, chutes, etc.) for condition and timing of operation.
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Troubleshooting Current or Ground Loops are a common cause of trouble in Metal Detection Systems. Many false detections by a Metal Detector are caused by the presence of current or ground loops. Current loops are best described as any combination of piping, conduit or structural steel forming an electrical loop near the detector aperture. A loop acts as a secondary turn on a transformer, absorbing energy from the detector. If a change occurs in a loop, that is, if the loop is opened or closed, it will absorb more or less energy from the detector. The detector will, in turn, sense this change and a false detection will occur.
The effect of ground loops is not restricted to the conveyor frame. Pipes or conduits in the vicinity of the aperture (not necessarily tied to the conveyor frame) may form loops which, if interrupted, may cause a false detection. Insulating or bonding any loose contact areas will eliminate the effect of these loops on the detector. To locate current loops or determine whether they are causing false detection, shut down the conveyor while leaving the metal detector energized. Manually shake or probe conveyor idlers, conduits, etc., to determine where contact is being interrupted. Conveyor idlers adjacent to the aperture and return belt idlers in close proximity should receive particular attention. Experience indicates that a majority of false detection problems have been attributed to conveyor belt idlers. The need for thorough inspection of idlers cannot be over-emphasized. The best method of determining whether a conveyor idler is causing a problem is to stop the conveyor and manually attempt to move the idler within its bearing (with the conveyor stopped and the detector energized). If a particular idler is a source of trouble, the metal detector can be made to false detect. If it is determined that a particular idler is causing a false detection, it must be either removed or the bearings insulated from the conveyor frame. The troubleshooting guide presented below can be used as a guideline to evaluate potential ground loop and power supply problems.
This phenomenon can be simulated by placing a loop of wire approximately 2-3 feet (600-900mm) in diameter in close proximity to, and in the same plane, as the aperture. Opening and closing the loop circuit can make the detector false trip. As the loop is moved farther from the aperture, a point will be reached where the loop ceases to have an effect on the detector. This is determined by the size of the loop, its orientation with respect to the detector aperture, sensitivity setting of the detector and detector aperture size. Observing a conveyor (see Figure 5), it can be seen how the ground loops can be formed by the structural members of the conveyor. For example, the idler rolls on either side of the aperture, in conjunction with the conveyor frame, form a loop around the detector aperture. If the idler bearing momentarily loses electrical contact with the shaft, a false detection may occur.
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Troubleshooting (cont.)
Spare Parts
Appendix A
Figure A1. Monitor Menu
Figure A2. Password Menu
Appendix A (cont.)
Figure A3. Quick Menu
Figure A4. Main Menu
Appendix A (cont.)
Figure A5. Product Menu
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