Digital Link DL600E, User Manual

Page: 111 / 147

Diagnosing the DL600E Unit
6-9
To run the Loop Up and Loop Down Remote tests from the front panel,
press the
REMOTE LPBK UP
and DOWN buttons, respectively.
.
Figure 6-5 Loop Up Remote Test
QRW Pattern Test
Use the Quasi-Random Word
(QRW)
test to measure Bit Error Rates
on the
E1
network. The DL600E unit sends a
QRW
pattern into the
network and monitors the received
E1
network signal for
QRW
bit
errors.
This test also looks for bit errors in both
E1
circuit directions when
the remote system is looped up. In this case, the system transmits the
QRW
to the
E1
network and the remote system loops it back to the
DL600E unit which monitors the signal for errors. You can also use
the
QRW
code to isolate an
E1
network problem to a speciÞc
transmission direction. In this case, both
E1
transmission directions
are monitored when the local and the remote system transmit
QRW
(the remote is not put into loopback).
Send 1:7 Pattern Test
This pattern stresses the timing recovery circuits of repeaters and
other intermediate equipment.
Send 3:24 Pattern Test
This pattern tests for ones density (consecutive zeros) tolerance.
Send 1:1 Test
This pattern sends alternate ones and zeros. It tests for bridge taps.
Send All Ones Test
This pattern measures signal power.
Send All Zeroes Test
This pattern is useful for veriÞcation of
HDB3
optioning of the
E1
facility.
DTE
DSU DSU
Network
Interface
DATA
Port
DATA
Port
Network
Interface
Remote Solo E1 Encore Local Solo E1 Encore