ADC HDU-409 Lists 1 Manuel D’Utilisation

Page de 44
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.