Framer, Pattern Gen/Det, Loop Control | Patton electronic 1095

Framer	The framer is used to determine the status of
	the line. In normal operation the framer transmits
	and expects to receive framed packets from the
	far end. If the framer receives framed packets
	from the far end, CTS and CD will be active. If
	framed packets are not received, CTS and CD
	will be inactive. The restart procedure uses this
	information to determine if a valid connection is
	made (cable disconnect, poor cable quality, etc).
	In normal Data Mode, if the box receives 4 sec-
	onds 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 impor-
	tant when we discuss the Pattern Generator.
Pattern Gen/Det	This part of the Processor generates and
	detects the 511/511E patterns. When transmit-
	ting 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. 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.

Restart Procedure		The restart procedure is in place to allow the
and Time Outs		units 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 rea-
		son that there are different Restart Times will
		become apparent after reading 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 normal 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.

		Test Mode Timing
	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.)

Symbol Indicators

This symbol designates the origination or the termination of a data path. The direction of the arrow connected distinguish the two data paths.

This symbol designates an invalid data path. If there is data present it should be ignored.