Patton electronic 2720/I Series - Manual (Page 34)

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5 5..0 0 O OP PE ER RA AT TIIO ON N
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.
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
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Figure 7: 2720/I Front Panel
10BaseT T1/FT1 CSU/DSU
CRC
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)