Front panel status indicator led – ADC and 3 Doubler User Manual
Page 11
LTPH-UM-1234-01
Product
Description
HDU-409 Lists 1, 2, and 3
April 30, 2003
5
Table 2.
Front Panel Status Indicator LED
LED
Description
Flashing Red about
once per second
Indicates an HDSL Cyclic Redundancy Check (CRC) error has
occurred between the HDU-409 and the upstream module.
Flashing Red rapidly
Indicates an HDSL CRC error has occurred between the
HDU-409 and the downstream module.
Flashing Yellow about
once per second
Indicates a Network Doubler Unit (NDU) loopback is in effect in
the HDU-409 towards the network. This tests the integrity of the
upstream span.
Flashing Yellow
rapidly
Indicates a Customer Doubler Unit (CDU) loopback is in effect in
the HDU-409 towards the customer. This tests the integrity of the
downstream span.
Flashing Green about
once per second
Indicates synchronization is being attempted between the
HDU-409 and the upstream (network) module.
Flashing Green rapidly
Indicates synchronization is being attempted between the
HDU-409 and the downstream (customer) module.
Steady Yellow
Indicates the HDSL margin is less than the margin threshold
provisioned for the circuit.
Steady Green
Indicates HDSL frame synchronization has been achieved
between the HDU-409 and both the upstream and downstream
modules.