ADTRAN HDSL2 Installation And Maintenance Practice

Also see for 1223024L2: Installation and maintenance practice Manual

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ADTRAN HDSL2 Installation And Maintenance Practice Manual pdf 71 page image

HDSL2 for General Distribution Installation and Maintenance Practice HDSL2 Loopback and Control Codes61223HDSL2L2-5B A-3Table A-2. In-Band Addressable Loopback Codes(All codes listed below must be sent for a minimum of 5 seconds in order for them to be detected and acted upon.)Function Code Source Code and ResponseArm 11000 (2-in-5 pattern) (N) If the pattern is sent from the network, the unitsarm, and the H2TU-R loops back if Smartjack Loop-back is enabled.Disarm 11100 (3-in-5 pattern) (N/C) The H2TU-C is removed from the armed state. Anyunits in loopback when the 11100 pattern isreceived loop down. The LBK LEDs extinguish on allunits.H2TU-CNetworkLoopbackD3D3(1101 0011 1101 0011)(N) If the units have been armed and no units are inloopback, the H2TU-C loops back toward the net-work, 2 seconds of AIS (all ones) are sent, 5 secondsof data pass, and then 231 bit errors are injectedinto the DSX-1 signal. As long as the pattern contin-ues to be sent, 231 errors are injected every 20 sec-onds. When the pattern is removed, the unit remainsin loopback. If the pattern is reinstated, the injectionof 231 bit errors resumes at 20-second intervals.If Smartjack Loopback is enabled, then the H2TU-Rcan be in network loopback when the H2TU-C loop-up codes are sent.HRENetworkLoopbackC741(1100 0111 0100 0001)(N) If an HRE is present, the units have been armed, theHRE loops back towards the network, 2 seconds ofAIS (all 1s) are sent, 5 seconds of data pass, andthen 10 bit errors will be injected into the DSX-1 sig-nal. As long as the pattern continues to be sent, 10bit errors are injected every 20 seconds. When thepattern is removed, the unit remains in loopback. Ifthe pattern is reinstated, the injection of 10 biterrors resumes at 20-second intervals.H2TU-RLoopbackC742(1100 0111 0100 0010)(N) When set from the network, an HTU-R network loop-back is activated and a 20-bit error confirmation issent every 10 seconds.LoopDown9393(1001 0011 1001 0011)(N) When sent from the network, all units currently inloopback loop down. Armed units do not disarm. Inorder to behave like a smartjack, the H2TU-R doesloop down from a network loopback in response tothe 9393 pattern, if Smartjack Loopback is enabled.