Specifications

Excalibur Multirate DAP Installation and Operation
7-10
LOCAL DAP
MARKING
GEN
LINES
TX
RX
TX
RX
TRANSMITTER
RECEIVER
Figure 7-12. Non-Latching and Latching Loopback Tests
Latching Loopback Test
The Latching Loopback Test is an optional network loopback test initiated by the
reception of a complex sequence of code bytes as defined by AT&T Publication 62310.
It is operational in DDS-SC and Clear Channel 64 Kbps modes. This loopback test uses
the same signal routing as called for by the Non-Latching Loopback Test, except that the
mapping of some return bytes is different. (Refer to AT&T Publication 62310 for this
mapping.) The Latching Loopback Test may be enabled or disabled from the front panel.
(See Figure 7-12.)
Activating the Tests
To activate any of the Excalibur Multirate DAP tests, you must enter the Diagnostics
submenu. To do so, follow these steps, starting from the Top Level menu:
1. Press the 1 or 2 button depending on which DAP (local or remote) you wish to
test.
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