ACCULINK 316x DSU/CSU4-10 December 1996 3160-A2-GB22-10Starting a Data Terminal LoopbackThe Data Terminal loopback command (DTLB) loopsthe data received from the selected port, for all DS0channels allocated to the port, back out the port. Thisloopback occurs after the data passes through the portcircuitry but before it reaches the T1 framer.HANDLING PRECAUTIONSFORSTATIC-SENSITIVE DEVICESThis product is designed to protectsensitive components from damagedue to electrostatic discharge (ESD)during normal operation. Whenperforming installation procedures,however, take proper static controlprecautions to prevent damage toequipment. If you are not sure of theproper static control precautions,contact your nearest sales or servicerepresentative.To perform a Data Terminal loopback,1. Press F2 to select Test from the top-level menuscreen.F1DS U E SFStat Test CnfigF2 F32. From the Test screen, press F2 to select Lpbk.F1Test:Rlpbk Lpbk PtrnsF2 F33. From the Loopback screen, press four timesto display the DTLB selection on the screen.F1Loopback:Abort LLB PLBF2 F34. Press F3 to select DTLB.F1Loopback:RLB DCLB DTLBF2 F35. From the DTLB screen, press the function key forthe port for which you want to perform the dataterminal loopback. Use the scroll keys, ifnecessary.F1Loopback: DTLBPrt1 Prt2 Prt3F2 F3Test Started appears on Line 2. If a DataTerminal loopback is already in progress, theAlready Active message appears. If an invalidcombination of loopbacks is in progress, the errormessage Invalid Test Combo appears (seeTable 4-2 for valid loopback test combinations).
