Frame Relay - for Faster and More Efficient Data Communications ...

16Fig. 6Cable attenuation test at Ericsson's Fibroco factoryin SpainAfter the secondary coating has been applied,the fibre is subjected to quality inspection(secondary testing). This test iscarried out according to the same routinesas those applied in the primary OTDR test.The test data is usually stored directly inthe database.Terminals at the stranding lines registerthe fibre contents of each cable, and thecable is given a unique identification number— a cableid. The cable line operatorsalso handle the registration of cables. Tofacilitate work and minimise the risk of incorrectregistration, all terminals have abar code reader and a bar-code menu.Stranding is followed by intermediate testing,jacketing and delivery inspection.Intermediate testing comprises attenuationmeasurements of all fibres in thecable. The test data is stored in the database.The values obtained in these testsand in secondary attenuation tests arechecked against the primary attenuationvalues. The program issues a warning ifthe difference exceeds the tolerancesspecified.Delivery inspectionA cable which has passed the delivery inspectionis ready for delivery. A deliveryrecord for the customer is printed on a laserprinter.The delivery record documents the opticaland physical parameters of the cable, Fig.7. Since a cable may contain hundreds offibres, the delivery record will take up atleast two size-A4 pages. The first pagecontains statistical data, and the subsequentpages give test data of each individualfibre.The layout of the delivery record will vary,depending on the customer's requirementsand on the type of cable delivered.To rationalise handling, customers may receivecable parameters stored on diskette.StatisticsTwo main system requirements were definedwhen Dehlfi was put into service inApril, 1988: Automatic transfer of test datafrom test stations to the database, andprintout of complete delivery records. Duringthe subsequent development of theDehlfi system, a large number of quality inspectionparameters have been added,and the possibilities of using these parametersin quality work have also increased.Three program categories are available forthe processing of data extracted from thedatabase:- Search, processing and presentationComplete reports for recurrent follow-upare prepared- Search and processingData is prepared for presentation bymeans of a special graphicsprogram, e.g. Graph-in-the-Box- SearchRoutines which only locate predetermineddata for processing and presentationlater on by means of statistics software,e.g. Minitab.Minitab is a software package for advancedstatistical processing. EQFOS(Ericsson Quality, Design and StatisticalAnalysis of Experiments) is one of its users.Graph-in-the-Box is a very handygraphics program which also contains somestatistics functions.The software packages developed byEricsson Cable's own specialists includeone for collecting fibre data during a pre-ERICSSON REVIEW No. 1-2, 1992