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CSU/DSU MS/DBU
1=EXIT TEST—Terminates the test in progress and returns the CSU/DSU
MS/DBU to the main menu.
2=DISPLAY STATUS—Re-enters the test display for additional viewing.
Table 4-3. Submenu Test Commands.
Front Panel
AT Command
Description
1=EXIT TEST
&T0
Stops test/returns to data mode
2=DISPLAY STATUS
N/A
Displays present test status
2=LOOP ONLY (RT)
With the LOOP ONLY (RT) test, the network receive data is looped to the
network transmit Path inside the DTE interface section of the CSU/DSU
MS/DBU. The physical DTE interface is ignored for this test. A block
diagram illustrating the loopback point and the signal paths for this test is
shown in
Fig. A-2
in
Appendix A
.
This test allows the loop interface and a major portion of the DTE
interface for the local CSU/DSU MS/DBU to be tested from the remote site
over the actual communications circuit. Like the DTE and LOOP (LL) test,
the test from the remote site is usually done with a BERT tester.
While this test is being performed, the message, LOCAL LOOP (RT), is
shown on the CSU/DSU MS/DBU display. The other status messages shown
in the menu diagram are accessible by using the UP/DOWN SCROLL keys.
The loopback point within the CSU/DSU MS/DBU and its operation for
the LOOP ONLY (RT) test are the same as the Remote Digital Loopback
(RT) test initiated and controlled from a remote CSU/DSU MS/DBU.
Summary of Contents for CSU/DSU MS/DBU
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