Abstract:
A system and methods for automating the testing of optical fiber are described. According to one aspect of the present invention, an automated conveyor system moves spools of optical fiber contained on pallets from testing station to testing station. According to another aspect of the present invention, a single spool is carried by a specially designed pallet. According to another aspect of present invention, an apparatus automatically strips, cleans, and cleaves the fiber ends once the spool reaches the apparatus. The fiber ends are then automatically manipulated into the appropriate location for a predetermined test to be performed. According to another aspect of the invention, an apparatus automatically acquires a sample length of the optical fiber and strips, cleans, and cleaves the fiber ends of the sample. The sample length of the optical fiber is then manipulated into the appropriate location for a second predetermined test to be performed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/166,015 filed on Nov. 17, 1999 and U.S. Provisional Patent Application Ser. No. 60/168,111 filed on Nov. 30, 1999, the content of which is relied upon and incorporated herein by reference in its entirety, and the benefit of priority under 35 U.S.C. § 120 is hereby claimed. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to improvements in the manufacture of optical fiber. More specifically, the present invention relates to methods and apparatus for automating the testing of optical fiber wound onto a spool.  
       BACKGROUND OF THE INVENTION  
       [0003]     In the current manufacturing process for optical fiber, optical fiber is typically wound onto a spool for measurement and testing, shipping to a customer, and subsequent processing at the customer&#39;s facility. The measurement and testing of optical fiber is currently performed manually by multiple technicians, with carts carrying a number of spools being manually moved from test station to test station. At a test station a technician removes a spool from the cart and places the spool on a measurement rack. The technician then strips and removes the plastic fiber coating from both ends of the optical fiber, cleaning off excess coating and any remaining debris. The fiber ends are manipulated by the technician into a cleaver and cut. Next, the technician loads the fiber ends into a computer controlled measurement system and initiates a measurement sequence to test at least one characteristic of the optical fiber, e.g., fiber cutoff wavelength, attenuation, fiber curl, cladding diameter, or coating diameter. The fiber is then removed from the testing system and the spool returned to the cart. All of the spools on the cart or only selected spools may be tested as desired. The cart is then manually moved to the next test station for another series of tests. The amount of manual labor involved results in high labor costs and higher manufacturing costs for optical fiber.  
         [0004]     Accordingly, it would be highly advantageous to further automate the manual steps of optical fiber measurement and testing, reducing the time required in the measurement and testing area and thus reducing the cost of manufacturing optical fiber and providing faster feedback on the manufacturing process. Additionally, it would be highly advantageous to provide methods and apparatus for the automated testing of optical fiber which reduces the opportunity for human error and provides a more repeatable process.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention provides advantageous methods and apparatus for the automation of the testing of optical fiber. The present invention includes an automated conveyor system which moves spools of optical fiber contained on pallets from testing station to testing station. According to one aspect of the present invention, a single spool is carried by a specially designed pallet which has a number of advantageous features described further below. According to another aspect of present invention, an apparatus automatically strips, cleans, and cleaves the fiber ends once the spool reaches the apparatus. The fiber ends are then automatically manipulated into the appropriate location for a predetermined test to be performed. According to another aspect of the invention, an apparatus automatically acquires a sample length of the optical fiber and strips, cleans, and cleaves the fiber ends of the sample. The sample length of the optical fiber is then manipulated into the appropriate location for a second predetermined test to be performed.  
         [0006]     These and other features, aspects and advantages of the invention will be apparent to those skilled in the art from the following detailed description taken together with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  shows a view of a spool which may suitably be used in conjunction with the present invention;  
         [0008]      FIG. 2  shows an isometric view of a pallet in accordance with the present invention;  
         [0009]      FIGS. 3A, 3B ,  3 C, and  3 D show, respectively, top, front, side, and isometric views of a pallet in accordance with the present invention;  
         [0010]      FIG. 4  shows an isometric view of the pallet of  FIG. 2  carrying the spool of  FIG. 1 ;  
         [0011]      FIG. 5  shows an isometric view of a pallet in accordance with another aspect of the present invention carrying the spool of  FIG. 1 ;  
         [0012]      FIGS. 6A, 6B ,  6 C, and  6 D show, respectively, top, front, side, and isometric views of the pallet of  FIG. 5 ;  
         [0013]      FIG. 7  shows an isometric view of the pallet of  FIG. 5  carrying the spool of  FIG. 1 .  
         [0014]      FIG. 8  is an overall view of an automated optical fiber testing system in accordance with the present invention;  
         [0015]      FIG. 9  shows a detailed view of a preparation station suitable for use in conjunction with the system of  FIG. 8 ;  
         [0016]      FIG. 10A  shows a detailed view of an optical time domain reflectrometry and optical dispersion test station suitable for use in conjunction with the system of  FIG. 8 ;  
         [0017]      FIG. 10B  is a flowchart of a method for automating the performance of the optical time domain reflectrometry and the optical dispersion tests of  FIG. 10A  in accordance with the present invention;  
         [0018]      FIG. 11A  shows a detailed view of a glass measurement and cutoff wavelength test station suitable for use in conjunction with the system of  FIG. 8 ;  
         [0019]      FIGS. 11B and 11C  are a flowchart of a method for automating the performance of the glass measurement and cutoff frequency tests of  FIG. 11A  in accordance with the present invention;  
         [0020]      FIG. 12A  shows a detailed view of a fiber deflection test station and coating geometry test station suitable for use in conjunction with the system of  FIG. 8 ;  
         [0021]      FIG. 12B  is a flowchart of a method for automating the performance of the optical fiber deflection and coating geometry tests of  FIG. 12A  in accordance with the present invention;  
         [0022]      FIG. 13A  shows a detailed view of a polarization modal dispersion test station suitable for use in conjunction with the system of  FIG. 8 ;  
         [0023]      FIGS. 13B and 13C  are a flowchart of a method for automating the performance of the polarization modal dispersion test of  FIG. 13A  in accordance with the present invention; and  
         [0024]      FIG. 14  shows a detailed view of an unload station suitable for use in conjunction with the system of  FIG. 8 . 
     
    
     DETAILED DESCRIPTION  
       [0025]     The present invention now will be described more fully with reference to the accompanying drawings, in which several currently preferred embodiments of the invention are shown. However, this invention may be embodied in various forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these representative embodiments are described in detail so that this disclosure will be thorough and complete, and will fully convey the scope, structure, operation, functionality, and potential of applicability of the invention to those skilled in the art.  
         [0026]     Referring to the drawings,  FIG. 1  shows a top view of a spool  10  which may be advantageously used in conjunction with the present invention. The spool  10  comprises a primary barrel  14  and a lead meter barrel  15  separated from each other by an outboard flange  16 . A length of optical fiber  12  has been wound onto the primary barrel  14  and the lead meter barrel  15  during the manufacturing process. In a presently preferred embodiment, spool  10  may be, for example, a “single” spool, having 25 km of optical fiber wound onto the primary barrel  14 , or a “double” spool containing 50 km of optical fiber wound onto the primary barrel  14 . A short length of the optical fiber  12  has been wound onto the lead meter barrel  15 . The outboard flange  16  has a slot  17  providing a path for the optical fiber  12  between the lead meter barrel  15  and the primary barrel  14 . As seen from the top view of  FIG. 1 , an outer end  12   a  of the optical fiber  12  extends from the underside of the primary barrel  14  and an inner end  12   b  extends from the underside of the lead meter barrel  15 . The optical fiber  12  also typically includes a plastic coating  13 . Further details of a presently preferred spool  10  for use in conjunction with the present invention are provided in U.S. Patent Application Ser. No. 60/115,540, filed on Jan. 12, 1999, entitled “System And Methods For Providing Under-Wrap Access To Optical Fiber Wound Onto Spools” which is incorporated by reference herein in its entirety.  
         [0027]      FIG. 2  shows an isometric view of a pallet  50  in accordance with a first embodiment of the present invention. The pallet  50  is adapted to carry the spool  10  of optical fiber  12  such that the fiber ends  12   a  and  12   b  are available to the testing equipment of automated fiber measurement system  100  described below. The pallet  50  includes a roller assembly  52  mounted on a base  54  adapted for carrying the spool  10 . The roller assembly  52  includes a pair of rollers  56  and a pair of base plates  58 . Also mounted on the base  54  are vertical brackets  60  and  62 , and an upright guide roller  64 .  
         [0028]     As shown in  FIGS. 3A and 3C , a guide bar  66  is mounted to the base  54 . A feed finger assembly  68 , a pickoff assembly  70 , and a clutch assembly  71  are rotationally mounted on the vertical bracket  60 . Mounted to the pickoff assembly  70  is a fiber guide  72  which includes an eyelet  74 . A feed finger assembly  76 , a guide roller  80 , and a fiberguide  81  including an eyelet  83  are mounted on the vertical bracket  62 . As best seen in  FIG. 4 , a center hole  84  extends through the rotational center of the feed finger assembly  68 , the pickoff assembly  70 , and the vertical bracket  60 .  
         [0029]     As shown in  FIG. 3D , a radio frequency (RF) identification tag  82  identifying the spool  10  is attached to the vertical bracket  60 . In addition to identifying the spool  10 , the RF tag  82  is capable of storing information which has been written to it, allowing the RF tag  82  to provide a travelling database for the spool  10  as it passes through the system  100 . The RF tag  82  provides processing instructions for individual test stations and stores the data of the test results. As each spool  10  is processed by the individual test stations of the system  100 , the results of each of the tests are written to the RF tag  82 . Thus, when the spool  10  has been processed by each of the appropriate test stations, the RF tag  82  contains the test results of all the tests performed. Additionally, the RF tag  82  also contains the routing instructions for the spool  10 , indicating which test stations need to process the spool  10 .  
         [0030]      FIG. 4  shows a view of the pallet  50  carrying the spool  10 . To load the spool  10  onto the pallet  50 , an operator manually places the spool  10  on the rollers  56  and feeds the inner end  12   b  of the optical fiber from lead meter barrel  15  through the eyelet  74 , center hole  84  and feed finger assembly  68  such that the end  12   b  extends outward from the feed finger assembly  68 . The outer end  12   a  of the optical fiber from primary barrel  14  is first fed around the guide roller  64 , over guide roller  80 , and then fed through the eyelet  83  and feed finger assembly  76  such that the outer end  12   a  extends outward from the feed finger assembly  76 . Thus, as shown in  FIG. 4 , the pallet  50  provides convenient access to the ends  12   a  and  12   b  of the optical fiber for both automated and manual test equipment.  
         [0031]     Furthermore, the spool  10  and pallet  50  advantageously allow the optical fiber  12  to be unwound from either the inner end  12   b  or the outer end  12   a  individually, or both the inner end  12   b  and outer end  12   a  simultaneously, without causing the opposite end to be disturbed. This allows both automated and manual test equipment to readily acquire samples of optical fiber from either or both of the fiber ends  12   a  and  12   b.  The fiber ends  12   a  and  12   b  may also be readily engaged and pulled or directed to test stations, allowing the optical fiber  12  to be tested while wound onto the spool  10 .  
         [0032]     The clutch mechanism  71  includes at least a single wheel  150  that is forced into contact with the spool  10 . The wheel  150  on clutch mechanism  71  rotates in a single direction which enables fiber to be pulled from fiber end  12   b,  in this case the direction indicated by arrow  151 . As optical fiber  12  is unwound from the outer end  12   a,  the spool  10  rotates in a counter-clockwise direction (as indicated by arrow  85  in  FIG. 4 ), dispensing the optical fiber  12 . Because the wheel  150  of clutch assembly  71  does not rotate in a direction which is counter to the direction indicated by arrow  151 , the force caused by the counterclockwise rotation of spool  10  causes the entire clutch assembly  71 , pickoff assembly  70 , and feed finger assembly  68  to rotate counter-clockwise around the axis of center hole  84  of feed finger assembly  68 . This rotation keeps the inner end  12   b  of optical fiber  12  from being removed from the spool  10 . As the outer end  12   a  of optical fiber  12  is unwound from the spool, the tension on the inner end  12   b  of the optical fiber  12  held by the fiber guide eyelet  74  exerts a counter-clockwise force on the fiber guide  74 , causing the clutch assembly  71 , the pickoff assembly  70 , and the feed finger assembly  68  to rotate in synchronization with the spool  10 . In other words, as the spool  10  is rotated counter-clockwise by optical fiber  12  being unwound from the outer end  12   a,  the optical fiber  12  extending from the spool  10  through the eyelet  74  of fiber guide  72  pulls the clutch assembly  71 , the pickoff assembly  70 , and the feed finger assembly  68  along with the rotating spool  10 .  
         [0033]     As optical fiber  12  is unwound from the inner end  12   b,  the clutch assembly  71 , the pickoff assembly  70  and the feed finger assembly  68  rotate counter-clockwise (as indicated by the arrow  85 ) , causing wheel  150  to rotate in the direction indicated by arrow  151 , to thereby remove optical fiber  12  from the lead meter barrel  15  while the spool  10  remains fixed, preventing optical fiber  12  from unwinding from the spool  10  on the outer end  12   a.  The weight of the spool  10  prevents the spool  10  from rotating as the fiber  12  is unwound from the inner end  12   b.  The tension caused by the optical fiber  12  being pulled through fiber guide eyelet  74  exerts a counter-clockwise force on fiber guide  72 , and thus clutch assembly  71 , the pickoff assembly  70 , and the feed finger assembly  68 , causing these elements to rotate in a counterclockwise direction as the optical fiber  12  is pulled through the feed finger assembly  68 .  
         [0034]     Alternatively, fiber can be removed from spool  10  simultaneously by simply pulling on both ends of fiber at the same time.  
         [0035]      FIG. 5  shows an isometric view of a pallet  90  in accordance with a second embodiment of the present invention. Since many components are arranged in the same manner as the first embodiment, like reference numerals are used to designate elements common to the two embodiments. The pallet  90  is adapted to carry the spool  10  of optical fiber  12  such that the fiber ends  12   a  and  12   b  are available to the testing equipment of system  20  described above. The pallet  90  includes a roller assembly  52  mounted on a base  54  adapted for carrying the spool  10 . The roller assembly  52  includes a pair of rollers  56  and a pair of base plates  58 . Mounted on the base  54  are vertical brackets  60  and  62 . As best seen in  FIGS. 6A and 6C , a vertical bracket  92  is also mounted on the base  54 . As shown in  FIG. 5 , a feed finger assembly  68 , a pickoff assembly  70 , and a clutch assembly  71  are rotationally mounted on the vertical bracket  60 . Mounted to the pickoff assembly  70  is a fiber guide  72  which includes an eyelet  74 . A feed finger assembly  76  and a fiber guide  81  including an eyelet  83  are mounted on the vertical bracket  62 . As best seen in  FIG. 6B , a fiber guide  94  including an eyelet  95  and a fiber guide  96  including an eyelet  97  are mounted on the vertical bracket  92 . A center hole  84  extends through the rotational center of the feed finger assembly  68 , the pickoff assembly  70 , and the vertical bracket  60 .  
         [0036]     As shown in  FIG. 6D , a radio frequency (RF) identification tag  82  identifying the spool  10  is attached to the vertical bracket  60 . In addition to identifying the spool  10 , the RF tag  82  is capable of storing information which has been written to it, allowing the RF tag  82  to provide a traveling database for the spool  10  as it passes through the system  20 . The RF tag  82  provides processing instructions for individual test stations and stores the data of the test results. As each spool  10  is processed by the individual test stations of the system  20 , the results of the tests are written to the RF tag  82 . The RF tag  82  also contains the routing instructions for the spool  10 , indicating which test stations need to process the spool  10 .  
         [0037]      FIG. 7  shows a view of the pallet  90  carrying the spool  10 . To load the spool  10  onto the pallet  90 , an operator manually places the spool  10  on the rollers  56  and feeds the inner end  12   b  of the optical fiber through the eyelet  74 , center hole  84  and feed finger assembly  68  such that the end  12   b  extends outward from the feed finger assembly  68 . The outer end  12   a  of the optical fiber is fed through the eyelets  97 ,  95  and  83 , in respective order, and then fed through the feed finger assembly  76  such that the end  12   a  extends outward from the feed finger assembly  76 . Thus, as shown in  FIGS. 5 and 7 , the pallet  90  provides convenient access to the fiber ends  12   a  and  12   b  of the optical fiber for both automated and manual test equipment.  
         [0038]     Furthermore, the spool  10  and pallet  90  advantageously allow the optical fiber  12  to be unwound from either the inner end  12   b  or the outer end  12   a,  or both the inner end  12   b  and the outer end  12   a  simultaneously, without causing the opposite end to be disturbed. As optical fiber is unwound from the outer end  12   a,  the spool rotates in a counter-clockwise direction (as indicated by arrow  85  in  FIG. 7 ), dispensing the optical fiber. While the spool is rotating counter-clockwise, the clutch assembly  71 , the pickoff assembly  70  and the feed finger assembly  68  also rotate counter-clockwise, preventing optical fiber  12  from pulling out of the feed finger assembly  68 . As the optical fiber  12  is unwound from the outer end  12   a,  the tension on the inner end  12   b  of the optical fiber  12  held by the fiber guide  74  exerts a counter-clockwise force on the fiber guide  74 , causing the clutch assembly  71 , the pickoff assembly  70 , and the feed finger assembly  68  to rotate in synchronization with the spool  10 . In other words, as the spool  10  is rotated counter-clockwise by optical fiber  12  being unwound from the outer end  12   a,  the optical fiber  12  extending from the spool  10  through the fiber guide  74  pulls the clutch assembly  71 , the pickoff assembly  70 , and the feed finger assembly  68  along with the rotating spool  10 .  
         [0039]     As optical fiber  12  is unwound from the inner end  12   b,  the clutch assembly  71 , the pickoff assembly  70  and the feed finger assembly  68  rotate counter-clockwise to remove optical fiber  12  from the lead meter barrel  15  while the spool  10  remains fixed, preventing optical fiber  12  from unwinding from the spool  10  on the outer end  12   a  The tension on the optical fiber  12  held by the fiber guide  74  exerts a counter-clockwise (as indicated by the arrow  85 ) force on the clutch assembly  71 , the pickoff assembly  70 , and the feed finger assembly  68 , causing these elements to rotate counter-clockwise as the optical fiber  12  is pulled through the feed finger assembly  68 . The weight of the spool  10  prevents the spool  10  from rotating as the fiber  12  is unwound from the inner end  12   b.    
         [0040]      FIG. 8  shows an overall view of an automated optical fiber measurement system  100  in accordance with the present invention. The system  100  may suitably include a load station  102  and an automated preparation station  104  for preparing the two ends of a length of optical fiber while is stored on a fiber storage spool. Such a spool could be, for example, a bulk storage spool or an actual fiber shipping spool. Shipping spool as used herein means a spool or reel containing a length of fiber and which is to be shipped to a customer. The system  100  may also include an optical time domain reflectrometer (OTDR) and optical dispersion test station  106 , a glass geometry measurement and fiber cutoff wavelength test station  108 , a fiber deflection and optical fiber coating geometry test station  110 , a polarization modal dispersion (PMD) test station  112 , a visual inspection station  114 , and an unload station  116 . While presently preferred optical fiber tests and test stations are disclosed herein, one skilled in the art will appreciate that the present invention may be utilized with fewer or additional tests and test stations, and should not be construed as limited to the tests and test stations shown and described herein. The automated measurement system  100  includes a conveyor system  118  for transporting the pallets  50  or  90  carrying spools  10  of optical fiber  12  from test station to test station. A local programmable logic controller (PLC)  121  controls the operation of the load station  102 , the preparation stations  104 , the visual inspection station  114 , and the unload station  116 . As described further below, additional local PLCs may be employed to control the operation of the other stations. A plurality of RF devices, discussed further below, adapted to read from and/or write to the RF tag  82  attached to the pallet  50  or  90 , are located in a plurality of locations adjacent to the conveyor system  118 . Instructions read from the RF tag  82  control the progress of the pallet  50  or  90  through the conveyor system  118  via the local PLCs.  
         [0041]     To begin processing, the spool  10  is loaded onto the pallet  50  or  90  with the fiber ends  12   a  and  12   b  positioned such they are readily accessible to the individual test stations of system  100 , as described above. As shown in  FIG. 8 , the spool is loaded onto the pallet  50  or  90  of the conveyor system  118  at the load station  102 . The conveyor system  118  then moves the pallet  50  or  90  to the preparation station  104 .  
         [0042]     As seen in  FIG. 9 , the preparation station  104  includes a stripping device  130  for stripping the protective coating off of the optical fiber, and a cleaning device  132  for cleaning the fiber after the fiber coating has been stripped from the optical fiber. Both the stripping device and the cleaning device are preferably operated by pneumatic control techniques, and preferably the operation of these devices is under control of the local PLC  121  (shown in  FIG. 8 ). Additionally, the PLC  121  controls the movement of the pallet  50  or  90  while the pallet  50  or  90  is being processed by preparation station  104 . After the PLC  121  has positioned the pallet  50  or  90  such that the end  12   a  is adjacent to the device  130 , the stripping device  130  operates by initially moving below the end  12   a  and then rising up and positioning itself around end  12   a.  An auxiliary fiber clip (not shown) engages and securely holds the end  12   a  between the striping device  130  and the pallet  50  or  90 . The stripping device  130  then closes around the end  12   a  and retracts in a direction away from the pallet to remove the coating  13  from the end  12   a  The stripping device also includes a fiber cutting device capable of performing a rough cut on the fiber to achieve a desired length of fiber extending from the feed finger assemblies. For example, in one embodiment, about 10 cm of fiber extends from the feed finger assemblies, about 5 cm of which is fiber whose protective coating has been removed. A vacuum nozzle then removes the coating debris into a central vacuum system.  
         [0043]     The fiber stripping devices employed herein to remove the protective polymeric can be conventional fiber stripping devices, for example such as are available from the Miller Ripley Company, Miller Division, Cromwell, Conn., USA. Preferably the stripping devices employed herein are connected to pneumatic valves which may be computer controlled to control operation of the stripping devices. Fiber cutting can be achieved using conventional shears which are capable of performing a rough cut on the fiber.  
         [0044]     The pallet  50  or  90  is then moved forward so that end  12   a  is adjacent to the cleaning device  132 . The cleaning device  132  operates to remove any debris from the fiber end  12   a.  The device  132  includes a cleaning head, which may be, which includes a gripper mechanism having two arms with felt or sponge pads or alternatively, a polyurethane based open cell foam material. First, a needle squirts alcohol on to the pads to moisten them. Then the gripper advances forward onto the fiber end  12   a  and the alcohol dampened pads close onto the fiber end  12   a  The gripper then pulls back away from the pallet  50  or  90 , thereby cleaning the fiber end  12   a  Preferably, the gripper is then rotated 90 degrees and the cleaning cycle is performed again.  
         [0045]     The PLC  121  then positions the pallet  50  or  90  such that the end  12   b  is adjacent to the stripping device  130 . The stripping, cutting, and cleaning process is then repeated for the end  12   b.  Alternatively, the coating  13  could be removed and the optical fiber cleaned by manual techniques. Preferably, the stripping and cutting device  130  and the cleaning device  132  are positioned so that, when one end of fiber is being stripped and cut to a desired length, the another end of fiber may be being cleaned. The automatic stripping, cutting and cleaning station is significant in that, for the first time, a fiber may be automatically prepared for testing, including removal of the protective polymeric coating and cutting of the end of the fiber, without any manual interaction from an operator.  
         [0046]     In the embodiment illustrated in  FIG. 8 , after an appropriate length of each fiber end  12 A and  12   b  has been stripped, cut, and cleaned, the pallet  50  or  90  is transported to test station  106 . Alternatively, however, the pallet could be transported to an alternative test station if desired. As shown in  FIG. 10A , the OTDR and optical dispersion test station  106  includes cutting devices  140 , a cleaving device  142 , fiber aligners  144 , and fiber discarding devices  146 . One fiber aligner  144  suitable for use with the present invention is the Model 1100 Single Fiber Aligner (PK Technology Inc., Beaverton, Oreg. 97008). The test station  106  includes an OTDR test machine  148  and an optical dispersion test machine  150 , both optically coupled to the fiber aligners  144  and controlled by one or more computers  154 . The test station  106  also includes a local PLC  152  communicatively connected to the computer  154 , an RF tag reading device  160 , and an RF tag writing device  162 . A pair of fiber clips  156  are mounted on a servo slide  158  and controlled by the local PLC  152 . Operation of the test station  106 , including the computer  154 , is controlled by the local PLC  152 .  FIG. 10B  illustrates aspects of a method  170  of automating the performance of the OTDR and optical dispersion tests utilizing the test station  106  shown in  FIG. 10A . In a first step  171 , the RF tag reading device  160  reads the RF identification tag  52 , determining routing instructions and processing instructions for the spool  10 . In a second step  172 , the PLC determines if the routing instructions indicate that the spool  10  should be processed by the test station  106 . If the local PLC  152  determines that the spool is not to be processed by the test station  106 , the pallet  50  or  90  is moved to the next test station in step  173 . If the local PLC  152  determines the spool is to be processed by the test station  106 , the pallet  50  or  90  is moved into position adjacent to the servo slide  158  in step  174 , as shown in  FIG. 10A . Clips  156  are provided to grip the ends of the fiber. Suitable clips for use as clips  156  can be so called Optical Fiber Clips which are available from EG&amp;G Fiber Optics, Wokingham, Berge, United Kingdom, or Optical Fiber Clips which are also available from PK Technologies Inc., Beaverton Oreg., USA. The fiber clips  156  preferably have a V-shaped groove therein parallel to the direction the fiber will be inserted into the clip, and into which the fiber is grasped by the clip. The opening and closing of the clips is preferably controlled using pneumatic control methods. The clips  156  are moved by the servo slide  158  to the ends  12   a  and  12   b  where the clips  156  engage and hold the optical fiber ends  12   a  and  12   b.  In step  175 , the servo slide  158  moves the clips  156  holding the fiber ends to the cleaving device  142  where the fiber ends  12   a,    12   b  may be cleaved, or precision cut, leaving a predetermined length of optical fiber  12  protruding from each clip  156 . The cleaving device preferably is capable of cleaving the fiber in a manner which results in a cleaved surface suitable for optical coupling, for example to one of the testing apparatus described herein. Such cleaving can be accomplished using optical fiber cleaving devices such as are available from Seimens in Germany. These fiber cutting devices are preferably also adapted to be controllable by pneumatic computer controlled devices. After an optical quality cleave has been made, in step  176  the servo slide  158  moves the clips  156  toward the fiber aligners  144 , inserting an appropriate length of the fiber ends  12   a,    12   b  into the fiber aligners  144 .  
         [0047]     Next, in step  178 , the computer  154  commands the OTDR test machine  148 , which is optically connected to the fiber aligners  144  as described above, to test the optical fiber  12 . The OTDR test machine  148  provides a measure of the fiber attenuation of the optical fiber  12  over a selected wavelength range. OTDR attenuation measurements are made at a plurality of wavelengths which are within a predetermined selected range. The measured attenuations are analyzed to produce a curve representing attenuation, i.e., spectral attenuation, for the wavelengths of the selected range.  
         [0048]     Next, in step  180 , the computer  154  commands the optical dispersion test machine  150 , which is also optically connected to the fiber aligners  144  as described above, to test the optical fiber  12 . The optical dispersion test provides a measure of the distortion of optical signals as they propagate down optical fiber  12 . Next, in step  182 , the fiber discarding devices  146  engage and grasp the ends  12   a  and  12   b  of the optical fiber, the cutting devices  156  cut the stripped ends  12   a  and  12   b  of the optical fiber  12 , and the fiber discarding devices  146  remove the pieces of optical fiber which were severed from the testing area. The fiber discarding devices  146  utilize a gripper mounted on a rod to grip the severed pieces of optical fiber and move them into a scrap trough. Alternatively, the scrap fiber can be removed via a vacuum which is mounted or movable to a position which is close enough to remove the scrap fiber. Next, in step  184 , the RF tag writing device  162  preferably writes the results of the OTDR and optical dispersion tests to the RF identification tag  52 . The conveyor  118  then transports the pallet  50  or  90  to the next test station.  
         [0049]     As shown in  FIG. 11A , the glass geometry measurement and cutoff wavelength test station  108  includes a fiber clip  200  attached to a deployment slide  202 , a cutting device  204 , and a fiber discarding device  206 . The test station  108  also includes mandrels  208   a,    208   b,    208   c,    208   d  rotatably mounted on a dial plate  210 . Mounted on each mandrel  208   a,    208   b,    208   c,    208   d  are fiber gripping clips  212 ,  213  located at the ends of extension arms  215 ( a ) and  215 ( b ) . A stripping device  214 , a cleaning device  216 , and cleaving device  218  are mounted on a slide  220 . A cutoff wavelength tester  222  and a glass measurement tester  224  are communicatively connected to a vision alignment system  226 . The test station  108  also includes an RF tag reading device  232  and an RF tag writing device  234 . Operation of the test station  108 , including one or more computers  230 , is controlled by a local PLC  228 .  
         [0050]      FIGS. 11B and 11C  show a method  250  for automating the performance of the glass measurement and cutoff wavelength tests utilizing the test station  108  shown in  FIG. 11A . In a first step  251 , the RF tag reading device  232  reads the RF identification tag  52 , determining routing instructions and processing instructions for the spool  10 . In a second step  252 , the local PLC  228  determines if the routing instructions indicate that the spool  10  should be processed by the test station  108 . If the local PLC  228  determines that the spool  10  is not to be processed by the test station  108 , the pallet  50  or  90  is moved to the next test station in step  253 . If the local PLC  228  determines that the spool  10  is to be processed by the test station  108 , the pallet  50  or  90  is moved into position adjacent to the slide  202  in step  254 , as shown in  FIG. 11A . The fiber clip  200  is moved by the deployment slide toward the spool  10 , where the fiber clip  200  engages and grabs the fiber end  12   a.  The deployment slide  202  then moves the clip  200  away from the pallet  50  or  90 , deploying a length of the optical fiber  12 . In step  255 , the fiber clip  200  passes the fiber end  12   a  to the fiber clip  212  mounted on the mandrel  208   a.  During this step, the fiber clip  200  moves laterally outward from slide  202  towards and into communication with clip  212  on mandrel extension arm  215 ( a ). Next, in step  256 , the mandrel  208   a  rotates counter-clockwise 1.5 rotations, wrapping approximately two meters of optical fiber  12  around the mandrel  208   a,  which is basically a cylinder having a diameter of about 11 inches, or 280 cm. During this step, a fiber guide ensures proper containment of the optical fiber  12  around mandrel  208 ( a ) while the fiber is being wound onto the mandrel. Next, in step  258 , the clip  213  attached to the mandrel  208   a  engages the optical fiber  12  and the cutting device  204  performs a cut on the optical fiber  12 , leaving about two inches of fiber end exposed for testing. Thus, test station  108  has acquired a sample length of the optical fiber  12  which is wrapped around the mandrel  208  and held by the clips  212  and  213 . Of course, this technique is not limited to use with an  11  inch diameter mandrel, and could be employed instead on mandrels having a different diameter, e.g.  3  inches.  
         [0051]     In step  260 , the dial plate  210  rotates 90° counter-clockwise, bringing the mandrel  208   a  adjacent to the slide  220 . In next step  262 , the fiber ends held by the clips  212 ,  213  are stripped of their plastic coating by stripping device  214 , cleaned of excess debris by cleaning device  216 , and cleaved by cleaving device  218 , much the same as was described above with respect the stripping, cleaving, and cleaning station illustrated in  FIG. 9 . The stripping device  214 , the cleaning device  216 , and the cleaving device are movably mounted along the slide  220 , and also are provided with transverse slides (not shown) which enable movement of these devices transverse to slide  220  to facilitate the stripping, cutting, and cleaning operations to the ends  12   a  and  12   b.  After these operations, in step  264 , the dial plate  210  rotates 90° counter-clockwise, bringing the mandrel to face the cutoff wavelength tester  222 , as illustrated by mandrel  208 ( c ). Each of the rotatable mandrels are mounted on a slide located under the mandrel, which enables movement of the mandrel in the directions indicated by arrow  217 . To interface the fiber ends  12   a  and  12   b  with cut-off tester  222 , the entire mandrel  208 ( c ) is moved towards cut-off tester to insert the fiber ends  12   a  and  12   b  into cut-off tester  222 .  
         [0052]     Next, in step  266 , the PLC  228  commands the computer  230  to run the cutoff wavelength tester  222  to test the sample of optical fiber. In this step  266 , the computer  230  directs the vision device  226  to align the lenses of the cutoff wavelength tester  222  with the fiber ends held by the clips  212  and  213 . The computer  230  then directs the cutoff wavelength tester  222  to test the sample of optical fiber. The cutoff wavelength test determines the cutoff wavelength at which the optical fiber begins to operate like a single mode optical fiber.  
         [0053]     Then, in step  268 , the mandrel retracts back, pulling the fiber ends  12   a  and  12   b  out of cut-off tester, and dial plate  210  rotates 90° counter-clockwise, bringing the mandrel  208   a  adjacent to the glass measurement tester  224 . In step  270 , the PLC  228  commands the computer  230  to test the sample of optical fiber. In this step  270 , the vision device  226  aligns the lenses of the glass measurement tester  224  with the fiber ends and the glass measurement tester  224  tests the optical fiber. The glass measurement tester  224  determines relative geometrical parameters of the core and clad portions of the optical fiber sample. Additionally, the glass measurement tester  224  may measure the core and clad concentricity.  
         [0054]     As shown in step  272 , the dial plate  210  rotates 90° counter-clockwise, bringing the mandrel  208   a  to face the pallet  50  or  90 . Next, in step  274 , the fiber discarding device  206  grips one of the fiber ends, the fiber clips  212 ,  213  release the fiber ends, and the fiber discarding device  206  removes and discards the optical fiber sample. Next, in step  276 , the RF tag writing device  234  writes the results of cutoff wavelength and glass measurement tests to the RF identification tag  52 . The conveyor  118  then transports the pallet  50  or  90  to the preparation station  104  before passing the pallet  50  or  90  to the next test station.  
         [0055]     The four mandrels  208   a,    208   b,    208   c,    208   d  advantageously allow four samples of optical fiber to be processed simultaneously, reducing equipment cost and improving throughput. While a first fiber sample is being acquired and wrapped around mandrel  208   a,  a second fiber sample wrapped around mandrel  208   b  may be being stripped, cleaned, and cleaved, a third fiber sample wrapped around mandrel  208   c  may be undergoing cutoff wavelength testing, and a fourth fiber sample wrapped around mandrel  208   d  may be undergoing glass measurement testing.  
         [0056]     As shown in  FIG. 12A , the fiber deflection and coating geometry test station  110  includes a fiber clip  300  attached to a deployment slide  302 , a cutting device  304 , a fiber discarding device  306 , and a coating geometry tester  308 . An optical fiber deflection tester  310  includes a spin drive  312 . The test station  110  also includes an RF tag identification read device  318  and an RF tag identification write device  320 . Operation of the test station  110 , including one or more computers  316 , is controlled by a local PLC  314 . According to a preferred embodiment of the present invention, two samples from each spool are processed simultaneously.  
         [0057]      FIG. 12B  shows a method  350  for automating the performance of the fiber curl and coating geometry tests utilizing the test station  110  shown in  FIG. 12A . In first step  351 , the RF tag reading device  318  reads the RF identification tag  52 , determining routing instructions and processing instructions for the spool  10 . In a second step  352 , the local PLC  314  determines if the routing instructions indicate that the spool  10  should be processed by the test station  110 . If the local PLC  314  determines that the spool  10  is not to be processed by the test station  110 , the pallet  50  or  90  is moved to the next test station in step  353 . If the local PLC  314  determines the spool  10  is to be processed by the test station  110 , the pallet  50  or  90  is moved into position adjacent to the slide  302  in step  354 , as shown in  FIG. 12A . The fiber clip  300  is moved by the deployment slide  302  toward the spool  10  where the clip  300  engages and holds the fiber end  12   a.  The deployment-slide  302  moves the clip  300  away from the pallet  50  or  90 , deploying a length (e.g., 8 inches) of the optical fiber. In step  355 , the cutting device  304  cuts the optical fiber, leaving a sample of the optical fiber held by the clip  300 . In step  356 , the fiber clip  300  moves along the slide  302  and passes the optical fiber sample to the spin drive  312  which holds the fiber sample by an end.  
         [0058]     Next, in step  358 , the PLC  314  commands the computer  316  to run the fiber curl tester  310 . The optical fiber sample is rotated about its axis by the spin drive  312  while measurements of deflection versus a reference are periodically taken. From this data, a measurement of fiber curl is determined. In step  360 , the clip  300  reacquires the sample from the spin drive  312  and slides the sample along the slide  302  to the coating geometry tester  308 . In step  362 , the fiber sample passes to a clamp or fiber gripping device which then rotates the sample of optical fiber into a vertical orientation and inserts it into the coating geometry tester  308 . The PLC  314  commands the computer  316  to run the coating geometry tester  308 . In this test, the fiber sample is placed vertically and rotated about its axis by the coating geometry tester  308  while data relative to coating and glass fiber geometry is measured. From this data, various parameters about the placement of the fiber within the coating are determined. Next, in step  364 , the fiber sample is removed from the coating geometry tester  308  by the clamp and passed to the clip  300 . The clip  300  moves the sample along the deployment slide  302  to the fiber discarding device  306  which acquires and discards the fiber sample. In step  366 , the RF tag writing device  320  writes the results of coating geometry and fiber deflection tests to the RF identification tag  52 . The conveyor  118  then transports the pallet  50  or  90  to the next test station.  
         [0059]     As shown in  FIG. 13A , the PMD test station  112  includes a fiber clip  400  and a gripper  401  attached to a deployment slide  402 , a cutting device  404 , and a PMD tester  408 . A V-groove tool  410  with clips  414  is located adjacent to the deployment slide  402 . The test station  112  also includes a transfer slide  412  with fiber clips  413 . Stripping devices  416 , cleaning devices  418 , cleaving devices  420  are located adjacent to the transfer slide  412 . The PMD tester  408  includes clips  421 . The test station  112  also includes an RF tag identification reading device  424  and an RF tag identification writing device  426 . Operation of the test station  1   12 , including one or more computers  428 , is controlled by a local PLC  430 .  
         [0060]     One exemplary type of PMD tester suitable for use with the present invention is described in U.S. Provisional Patent Application Ser. No. 60/127107, filed on Mar. 31, 1999, entitled “System and Method for Measuring Polarization Mode Dispersion Suitable for a Production Environment” which is incorporated by reference herein in its entirety.  
         [0061]      FIGS. 13B and 13C  show a method  450  for automating the performance of the fiber PMD test utilizing the test station  112  shown in  FIG. 13A . In a first step  451 , the RF tag read device  424  reads the RF identification tag  52 , determining routing instructions and processing instructions for the spool  10 . In a second step  452 , the local PLC  430  determines if the routing instructions indicate the spool  10  should be processed by the test station  112 . If the local PLC  430  determines that the spool  10  is not to be processed by the test station  112 , the pallet  50  or  90  is moved to the next station in a step  453 . If the local PLC  430  determines the spool  10  is to be processed by the test station  112 , the pallet  50  or  90  is moved into position adjacent to the slide  402  in step  454 , as shown in  FIG. 13A . The fiber clip  400  is moved by the slide  402  toward the spool  10  where the clip  400  engages and holds the fiber end  12   a  and the deployment slide  402  moves the clip  400  away from the pallet  50  or  90 , deploying a length (e.g.,  12  inches) of the optical fiber  12  above the V-groove of the V-groove tool  410 . In step  455 , the clips  414  of the V-groove tool  410  elevate and acquire the optical fiber as the clip  400  releases it. In step  456 , the cutting device  404  cuts the optical fiber, leaving a sample of the optical fiber held by the clips  414 . In step  457 , the clips  414  lower the optical fiber sample to the bottom of the V-groove and the clip  414  closest to the conveyor  118  is released. Also in the step  457 , air is forced through holes in the bottom of the V-groove, creating a bed of air which will allow the optical fiber sample to use its own torsional flex to unwind to an untwisted state. In step  458 , the felt-tipped gripper  401  attached to the slide  402  lowers and clamps the fiber sample at the end held by the clip  414 . The gripper  401  then moves along the length of the sample to straighten it. The clip  414  which had previously released the optical fiber sample in the step  457  reacquires the sample.  
         [0062]     Next, in step  459 , the clips  413  move along slide  412  to the V-groove and acquire the fiber sample from the clips  414 . After acquiring the sample, the clips move slightly towards each other, allowing a small amount of sag to develop in the optical fiber sample. In step  460 , the clips  413  move the sample along the slide  412  where the ends of the optical fiber sample are stripped by stripping devices  416 , cleaned by the cleaning devices  418 , and cleaved by the cleaving devices  420 . In step  461 , the clips  413  move along slide  412  and pass the sample to the clips  421  of the PMD tester  408  which tests the optical fiber sample. In step  464 , the sample of optical fiber is discarded by the discarding device  406 . In step  466 , the RF tag writing device  426  writes the results of PMD test to the RF identification tag  52 . The conveyor  118  then transports the pallet  50  or  90  to the next station.  
         [0063]     At the visual inspection station  114  shown in  FIG. 8 , an operator manually inspects the spool  10  at the visual inspection station  114 . The local PLC  121  routes the pallet  50  or  90  to the inspection station  114  after the spool  10  has passed all of the tests described above. In addition to inspecting the spool  10 , the operator tapes the optical fiber ends  12   a,    12   b  to the spool  10 . When the pallet  50  or  90  leaves the visual inspection station  114 , an RF tag reading device  115  reads the RF identification  52  and transmits the test results to the manufacturing line, allowing the manufacturing process to be adjusted with timely feedback from the system  100 . The conveyor  118  the transports the pallet  50  or  90  to the unload station  116 .  
         [0064]     As shown in  FIG. 14 , the unload station  116  includes an unload device  500 , a reject queue  502 , a rework queue  504 , and a passed queue  506 . The local PLC  121  routes the pallet  50  or  90  to the unload station  116  after the spool  10  has been manually inspected or has failed one of the tests described above. When the pallet  50  or  90  reaches the station  116 , the PLC  121  directs the unload device  500  to remove the spool  10  from the pallet  50  or  90  and place the spool in the appropriate queue. The empty pallet  50  or  90  then proceeds to the load station where another spool is loaded.  
         [0065]     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the present invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.