Section 150-219-100-02
December 22, 1997
Page 16
HDU-217/219 and
HCC-239 List
1
TESTING THE UNIT
Using Alarms
The
HDU-217
and
HDU-219
front panel contains one tri-color
STATUS LED. The light color and whether it is steady or flashing
provides you with the information listed in Table 5.
Table 5. Front Panel Status Indicator
STATUS LED
Description
Flashing green
once per second
Synchronization is being attempted between the
HDU and the upstream (network) module.
Flashing green
more than once
per second
Synchronization is being attempted between the
HDU and the downstream (customer) module.
Solid green
HDSL frame synchronization has been achieved
between the HDU and both the upstream and
downstream modules.
Flashing red once
per second
HDSL Cyclic Redundancy Check (CRC) error
has occurred between the HDU and the upstream
module. See the "Fault Isolation" section of this
practice.
Flashing red
more than once
per second
An HDSL CRC error has occurred between the
HDU and the downstream module. See the
"Fault Isolation" section in this practice.
Flashing yellow
once per second
A Network Doubler Unit (NDU) loopback is in
effect in the HDU toward the network. This tests
the integrity of the upstream span.
Flashing yellow
more than once
per second
A CDU (HDU to Customer) loopback is in effect
in the HDU towards the customer. This tests the
integrity of the downstream span.
