Specifications

Excalibur Multirate DAP Installation and Operation
7-4
The Local-Error Test can also be used to check the customer's lines. (See Figure 7-3.)
When this test is activated, the DAP sends its transmitter output through the customer's
lines. The output is looped back via the looping cable.
Note: This test is effective provided the receive level loss is -20 dB or less. A receive
level loss of -21 dB or greater on the line will cause errors in the test pattern.
TX
RX
LOCAL DAP
EXTERNAL
LOOPBACK
CUSTOMER'S
LINES
TEST
PATTERN
GEN
TEST
PATTERN
COMP
Figure 7-3. Local-Error Test (Customer's Lines)
End-to-End Error Test
You can verify the operation of the DDS lines by running an End-to-End Error Test.
(See Figure 7-4.) You can run this test on the entire aggregate bandwidth (Aggregate
End-to-End Error Test), through an individual port (Port End-to-End Error Test), or
through a channel's lowest numbered port (Channel End-to-End Error Test). This test
should not be activated from the RCP. The test is not available in Clear Channel 64 Kbps
mode or when the Clear Secondary Channel feature is enabled.
Note: The Aggregate End-to-End Error Test is not available when the Diagnostic
Compatibility parameter in the RCP submenu is set to On. These tests are available at
the port or channel level.
During this test, the local and remote DAPs both send a test pattern across the DDS lines.
The test pattern comparators at both DAPs check the received pattern for errors. The
Excalibur Multirate DAP lets you program how long (1 - 999 seconds or continuous) you
wish this test to run. The recommended length is 60 seconds. Errors occurring during
this test generally indicate that the problem lies with the DDS lines.