Patton electronics NetLink 1094ARC User Manual

Contents

27 28Figure 13. Block Diagram Local Loop Mode 1Figure 14. Block Diagram Local Loop Mode 2Local Loop When the unit is placed into a Mode 1 Localwith 511/511E Loop and the 511/511E pattern generator is acti-vated, the local pattern generator begins send-ing out a 511/511E pattern to the Loop Controlblock. The Loop Control block will loop this databack to the 511/511E pattern detector block,which will evaluate the data for errors. Becausethe 511/511E pattern generator is containedwithin the Processor the data is unframed so theframer will begin seeing unframed packets. Theframer receives this unframed data and can notdistinguish this information from a line discon-nection (this would cause the units' Restart pro-cedure to start). What we have done to allowthis mode to work is to add time outs for the pat-tern generators. When the 511/511E is initiatedthe line restart procedure is changed to oneminute. The 511/511E pattern will timeout after45 seconds. So if the 511/511E is turned on dur-ing a local loop, the restart procedure is set toone minute, but the 511/511E pattern will time-out after 45 seconds, allowing the framer tobegin seeing framed packets (and not restart thebox). After the 511/511E pattern times out, theER led will begin flashing.Local Loop It will remain this way until the pattern generatorwith 511/511E switch is turned off. Note that the data at the(continued) local DTE and the remote DTE are not valid.Because the data is unframed there is no wayfor the framer to send this data out to the DTE.This is an important distinction because otherPatton units will send out the 511 pattern.When the unit is placed into a Mode 2 LocalLoop, the 511/511E pattern generator on thelocal unit is unavailable for transmission. As canbe seen from Figure 14, the 511/511E patterngenerator has no data path connections avail-able. The 511/511E pattern generator is stillavailable on the remote unit. For more informa-tion on the proper operation of this pattern gen-erator please refer to the "Remote Digital Loopwith 511/511E" section.Figure 15. Block Diagram Local Loop Mode 1 with 511/511EFigure 16. Block Diagram Local Loop Mode 2 with 511/511EPatternGen/DetLoopControlLoopContro lPatternGen/DetProcessorProcessorFramer FramerLinePatternGen/DetLoopControlLoopControlPatternGen/DetProcessorProcessorFramer FramerLinePatternGen/DetLoopControlLoopContro lPatternGen/DetProcessorProcessorFramer FramerLinePatternGen/DetLoopControlLoopContro lPatternGen/DetProcessorProcessorFramer FramerLine