Patton electronic 1094A user manual Framer, Pattern Gen/Det, Loop Control, Symbol Indicators

Framer	The framer is used to determine the status of
	the line. In normal operation the framer trans-
	mits 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 con-
	nection 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 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.

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