Verilink NCC 2020 (880-503284-001) Product Manual - Manual (Page 55)

Diagnostics
Verilink NCC 2020 User Manual 5-7
STAT LED The STAT (CSU status) LED is a tri-color indicator with six states, as
follows:
Table 5-4 Stat LED States
NET LED The NET (network) LED is a tri-color indicator with six states, as
follows:
Table 5-5 Net LED States
State Meaning
Solid Green The NCC has been loaded with the Test Set 2000 test program
using AM2000.
Solid
Yellow
A test is in progress and no errors are detected (a test signal is
currently being transmitted to the circuit by the CSU and the
received pattern matches the transmitted pattern).
Solid Red Some alarm condition has occurred within the last fifteen
minutes on either the Network or Equipment interface.
Flashing
Red to Off
Power-up self-test has failed. Verify that the rear CIM module is
of a correct type (CIM 2020 or CIM 2025).
Flashing
Red to
Yellow
Errors have been received during a test (a test signal is being
transmitted and the pattern received does not match the pattern
sent).
Not Lit No alarms have occurred within the last fifteen minutes. This is
the normal state for the Stat LED.
State Meaning
Solid Green A normal signal is being received from the network (all OK).
Solid
Yellow
The NCC is looped toward the network via a line loopback (LLB)
or payload loopback (PLB) and no errors are being received from
the network.
Solid Red Continuous errors are being received on the network interface
(e.g., LOS, LOF, RAI, AIS).
Flashing
Red to
Green
Bipolar violations or CRC-6 errors are being received on the
network interface.
Flashing
Red to
Yellow
The CSU is looped toward the network and errors are being
received (BPV or CRC-6).
Not Lit The NCC has no power or, if other LEDS are lit, the NCC is
defective.