Patton electronic 1088/K Pattern Gen/Det, Loop Control, Restart Procedure and Time Outs

is made (cable disconnect, poor cable quality, etc). In normal Data Mode, if the box receives 4 seconds of unframed packets it will restart the box and begin trying to re-establish a connection with the far end. The distinction between framed packets and unframed packets becomes important when we discuss the Pat- tern Generator.

Pattern Gen/Det

This part of the Processor generates and detects the 511/511E patterns. When transmitting 511 patterns, the information is unframed (because it originates after the framer) and is intended to be evaluated only by another Processor. If the units are in Data Mode and the pattern generator is enabled on one end of the link, the far end will begin receiving unframed packets and assume that the line has gone down. During test modes, we force the pattern generator to time out before it can cause the link to be killed.

Loop Control

This part of the Processor is used to control loop-backs. In a Local Loop, the data is looped back towards the local DTE (G.703/ G.704). In a Remote Loop, the data is looped back to the line, but it is also allowed to pass through to the framer and to the remote DTE (G.703/G.704).

Restart Procedure and Time Outs

The restart procedure is in place to allow theunits to re-establish a connection after the framer begins seeing unframed packets. The Test Model Timing Chart below shows the amount of time the framer must see consecutive unframed packets before the unit will restart and try to establish a new line connection. The reason that there are different Restart Times will become apparent after read- ing the rest of the document. The 511/511E Time Out shown refers to the amount of time the 511/511E pattern will be valid. At the end of this time the pattern will automatically turn itself off and the nor- mal data path will be re-established.The ER led will flash indicating to the user that the test has timed out. The ER led will stop flashing once the 511/511E switch is placed into the normal position.

Item	Elapsed Time (seconds)
Start Up	50
Data Mode	4
511/511E Generator Enabled	60 (The generator will stop after 45 seconds.)
Remote End of an RDL	60
511/511E Time Out	45 (The pattern generator will automatically turn
	off after 45 seconds. The ER LED will flash until
	the user turns off the 511/511E switch.)

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