The signal being transmitted by the local DSX-1 equipment is OK or the NCC 2020 card is configured for Mux mode (in Mux mode the EQPT LED is always green).
Solid Yellow The NCC 2020 is in a loop which faces the Equipment port (Repeater Loopback or Equipment Loopback).
A continuous error condition exists (Loss Of Signal, Loss Of Frame, Alarm Indication Signal, Remote Alarm Indication Signal) in the signal (or lack of a signal) being transmitted by the local DSX-1 equipment.
Flashing Red to Off
Bipolar Violations, CRC-6 Errors, or a low density condition have been detected in the local DSX-1 equipment transmit signal.
Flashing Red to Yellow
The NCC is looped toward the equipment (RLB, ELB) and errors are detected in the data stream being transmitted by the equipment.
The NCC has no power or, if other LEDS are lit, the NCC is defective.
NOTE: “Solid Red” events take priority over “Flashing Red” events, except when a loopback is enabled.
Front Panel LEDs
This section describes the function of the NCC 2020 LED indicators.
The EQPT (equipment) LED is a tri-color indicator with six states, as follows:
Table 5-3 Equipment LED States State
Verilink NCC 2020 User Manual