ADTRAN TR OCU DP Installation And Maintenance Practice

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ADTRAN TR OCU DP Installation And Maintenance Practice Manual pdf 18 page image

Total Reach Office Channel Unit Data Port Installation and Maintenance Practice12 61292006L1-5CRemote End Initiated LBK TestsThe TR OCU DP supports loopbacks generated from the TR DDS-R, which allow testing to beperformed without coordination with the central office (CO) or test center. Loopbacks initiatedby the TR DDS-R front panel LBK pushbutton aid in system turnup testing or troubleshootingfrom the remote end. The TR OCU DP responds to a loopback command initiated at the TRDDS-R as follows:• Pressing the TR DDS-R LBK pushbutton once initiates a loopback at the TR OCU DP towardthe customer. Refer to Figure 6. This allows data to be sent from the remote end to test thelocal loop and the TR DDS-R. This loopback is indicated by a flashing CUST LED on the TRDDS-R and a solid CUST LED on the TR OCU DP.• Pressing the LBK pushbutton a second time initiates a loopback at the TR DDS-R towardthe 4-wire DDS (CPE) interface. Refer to Figure 7. A solid CUST LBK LED on the TR DDS-Rindicates a loopback at the TR DDS-R toward the customer equipment.• Pressing the TR DDS-R LBK pushbutton a third time disables all current latchingloopbacks.If errors exist, the loopbacks can help determine the source, either the local loop or the TRDDS-R. During a remote end initiated loopback, the Total Reach system transmits ASC (9Eh)toward the network, indicating an out-of-service condition generated by the remote end, asshown in Figure 6 and Figure 7.All Total Reach system latching loopbacks, whether initiated by a LBK pushbutton, CO, orfrom a remote Test Center, can be released by sending 35 DDS loop down TIP bytes (where X is a “don’t care” bit). All existing latching loopbacks can also bedisabled by pressing the LBK pushbutton on the CO or remote unit.Figure 6. TR DDS-R Remote End Initiated Loopback, Local LoopFigure 7. TR DDS-R Remote End Initiated Loopback, Customer Loop4-WireCPE InterfaceTR DDS-RPush once for TR OCU DPLoopbackLocal LoopASC 9Eh TR OCUDP LoopbackPushbuttonTestSet4-WireCPE InterfaceTRDDS-RPush twice for TR DDS-RLoopbackLocal LoopASC 9Eh TR OCUDP LoopbackPushbuttonTestSetASC 9Eh