Diagnostics
4-23
GDC 048R154-000
DTE Remote Digital Loopback with Self
Test
The data path for the DTE Remote Digital Loopback with Self Test is
illustrated in Figure 4-22. You can command the loopback by means
of the terminal interface screen or the front panel switches.
When you initiate a DTE Remote Digital Loopback with Self Test the
DSU transmits a PN127 code to the remote unit. The remote unit
responds by establishing a digital loopback toward the local DSU.
When the loop is established the DSU generates the selected test
pattern and transmits it to the remote DSU which loops it back to be
checked for errors at the local DSU. The DSUs are electronically
disconnected from their DTEs during the test.
To initiate the test from the terminal interface Diagnostics Selection
screen, select
[E] Start DTE Remote Digital Loopback
with Self Test
.
Figure 4-23 shows the switches and indicators that are involved when
you command a DTE Remote Digital Loopback with Self Test from
the front panel.
Figure 4-22
Data Path for DTE Remote Digital Loopback with Self
Test
Network
DeskTop T1 DSU
DTE
Network
Interface
TPG – Test Pattern Generator
TPC – Test Pattern Checker
TPG
TPC
DTE
Interface
Network
DeskTop T1 DSU
