ADTRAN HDSL HTU-C/DDM+ warranty Hdsl Troubleshooting Guide, Indications And Probable Causes

HDSL TROUBLESHOOTING GUIDE

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INDICATIONS AND PROBABLE CAUSES

Front Panel or Circuit Parameters Indicate Abnormal Operation

Connect a terminal emulator via the RS-232 (DB-9) craft interface on faceplate. The terminal must be VT100 or compatible and set for 1.2 to 19.2 kbps, 8 data bits, no parity, 1 stop bit. Tap the space bar to establish communication with the unit. Select “M” from the ADTRAN Screen and “1” from the HDSL main menu. Verify the following conditions on the Current System Status Screen:

■Is signal quality fluctuating (graphical meter indicators bouncing up and down)?

■Is LOSS (pulse attenuation) > 30 dB?

■Are there any errors counting on the ES, SES, or UAS registers?

■If signal quality is NOT fluctuating, is it equal on both loops?

■Is the current signal quality indication (uppermost “x” on the meter) more than 1 dB below the MAX?

■Is the current LOSS reading more than 1 dB below the MAX?

If any of these conditions exist, a cable problem is probable and cable testing should be done to verify all HDSL deployment guidelines are met. These conditions may also reflect intermittent cable faults or excessive noise impairments. If intermittent faults or noise impairments are suspected, select “2” from the HDSL main menu and review the Performance History Screen.

If all of the above conditions are met, as well as the HDSL Deployment Guidelines (noted below), the circuit should provide quality service and can be released.

Front Panel Indications Under Normal Operation:

STATUS ● Green

Circuit Parameters Under Normal Operation:

LOSS < 35dB

Signal quality of 6 dB or higher, with no fluctuation and equal on both loops

All HDSL Deployment Guidelines are met

HDSL DEPLOYMENT GUIDELINES

■Cable pairs must be non-loaded

■Total bridged tap < 2.5 kft

■No single bridged tap > 2 kft

■196 kHz insertion loss < 35 dB

■Pulse attentuation (loss on HDSL current system status screen) 30 dB

■Maximum loop resistance is 800 Ω

■Impulse noises < 50 dBm as measured using a 50 kHz filter and quite termination

■Wideband noise ≤ 31 dBm as measured using a 50 kHz filter and quite termination