ZyXEL VES1724-56 User Guide - Page 348
Vdsl Line, Table 164, Label, Description
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Chapter 41 Loop Diagnostic Table 164 Single Ended Line Test (continued) LABEL SELT Start DESCRIPTION Click SELT Start to start a single-end loop test. Calibrate Note: Connect the Telco-50 connector to the VDSL Line port, but the selected DSL port must have an open loop. There cannot be a DSL device, phone, fax machine or other device connected to the subscriber's end of the VDSL line. The SELT takes at least fifteen seconds. To check the status of a SELT or look at the last SELT result of a port, select the port number from the Port drop-down list box and click Show Status. The results tell you what gauge of telephone wire is connected to the port and the approximate length of the line. Click Calibrate to reset the SELT parameters on the Switch to achieve high SELT accuracy. Loop Type Loop length Reflection Note: Make sure you disconnect the Telco-50 connector from the VDSL Line port before you do calibration. This field displays what gauge of telephone wire is connected to the port. This field displays the distance from the Switch to the subscriber's location. This field displays the index number of each reflection in a test. Only the first 4 reflection results are displayed. When you perform a SELT, the Switch sends a wideband signal and calculates the loop information from the signal echoes (reflections). Delay Error Atn@180kHz Atn@300kHz FitError Termination Note: Only the reflection from the end of a line indicates proper information for your reference. This field displays the estimated delays the Switch calculates from each reflection. This field displays the estimated errors the Switch calculates from each reflection. This field displays the estimated attenuation the Switch calculates for the band at 180kHz on the line. This field displays the estimated attenuation the Switch calculates for the band at 300kHz on the line. This field displays an indicator of the error in the attenuation fields. This field displays the phase jump at the line termination. A value of 0 indicates a shortcut termination. A value of 1 indicates an open termination. 348 VES1724-56 User's Guide
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