Patton electronic 2720 user manual LED Descriptions, T1 Link, 10BT Link, Status, Alm

5.0 OPERATION

Once the NetLink-T1™ is installed and configured properly it is ready to place into operation. This section describes the function of the LED indicators, and the use of the loopback and pattern test modes.

5.1 LED DESCRIPTIONS

The NetLink-T1™ is equipped with six LED indicators that monitor the status of communication. Figure 12 (below) shows the location of the LEDs on the NetLink-T1™ Series front panel.

10BaseT T1/FT1 CSU/DSU

	Figure 7: 2720/I Front Panel
T1 Link	Solid green indicates that the end to end TI
	link is up. Signifying that the link is active.
	The TI link LED is off when the link is down
10BT Link	(Active Green) Solid green indicates that
	the 10BaseT Ethernet interface has detect
	ed a valid SQE heartbeat, signifying a valid
	10BaseT connection.
Status	Blinks yellow from one to eleven times to
	indicate system status. Each pulse pattern
	is separated by a 2 second “off” period.
	Greater pulse patterns have			higher
	priority (buffer saturation has greater priority
	than an empty MAC table). Valid system
	statuses are:
	1 pulse	=	system status is okay
	2 pulses =		no MAC entries in the
			MAC Address Table
	3 pulses =		Clear to Send (CTS) or
			Carrier Detect (DCD) from
			base unit are not asserted
	4 pulses	=	IM1/I buffer is saturated
	5 pulses	=	WAN receive frame(s) too large
	6 pulses	=	WAN receive frame(s) not octet
			aligned
	7 pulses	=	WAN receive frame(s) aborted
	8 pulses	=	Detected WAN receive frame(s) with
			CRC

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9 pulses = Detected LAN receive frame(s) too

	large
	10 pulses = Detected LAN receive frame(s) not
	octet aligned
	11 pulses = Detected LAN receive frame(s) with
	bad CRC
ALM	The alarm LED indicates the presence of a
	Blue or Yellow Alarm, or Out of Frame con-
	dition. The ALM LED will blink on every
	half-second. Alarms may occur due to:
	• Loss of Synchronization
	• Loss of Frame
	• AIS (Blue Alarm)
	• RAI (Yellow Alarm)
ER	The error LED indicates various error condi-
	tions, including framing bit errors, excessive
	zeros, controlled slips, severe errors, or bit
	errors (when sending V.52 test patterns).
	When sending a test pattern, the LED will
	remain lit if the unit does not receive the
	identical pattern. When it receives the cor-
	rect pattern, the LED will turn off. If error
	insertion is on, the LED will blink once a
	second if everything is operating properly.
TM	The test indicator LED blinks with a specific
	pattern depending on the type of test mode.
	When the unit is in local analog loop, the
	LED will blink on briefly. When the unit is in
	remote loop, the TM LED will blink off
	briefly. When the unit is sending a test pat-
	tern or is putting the remote unit into
	V.54/CSU loopback, the TM LED will stay
	on. These are the test modes:
	• V.54/CSU Loopback & V.52 Patterns
	• D4 Line Loop (CO initiated)
	• ESF Line Loop (CO Initiated)
	• ESF Payload Loop (CO Initiated)

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