Data Port Loop Back (DPLB)
When DPLB is activated from the Loop Back Switch or from the far
end, Data Port Loop Back (DPLB) consists of a combination of Data
Port Loop Back and Data Terminal Loop Back (DTLB). It loops the
T1 bundle at the Data Port Interface without affecting the rest of the
payload (DPLB). At the same time the D-SERV DSU/CSU loops the
data equipment signal at the Data Port Interface (DTLB).
When to Use
DPLB is used to test the T1 side of the Data Ports and the data
equipment lines.
NOTE:
The DPLB switch position cannot be used if the
D-SERV unit is configured for data port timing (tail
circuit timing). In the event of a conflict the D-SERV
DSU/CSU will flash the front panel POWER, RED
ALARM, and DATA LEDs red.
Figure 26. Data Port Loop Back (DPLB)
Operator's Manual
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