Harris Constellation, Installation & Maintenance

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Harris Corporation Constellation™
Tributary BER Test 4-11
LO
OPBACK
TEST
ING
Tributary BER Test
From the Keypad
PERFORMANCE > TRIBUTARY BER
This command causes the far end to give a loopback to the near end. The near
end inserts an on-board pseudorandom generator on the transmitter side of the
DS1 circuit. A detector on the receiver side of the DS1 circuit gives you the BER
and also tells you how long the test has been running.
Figure 4-10 shows a BER testing of a 3xDS3 system with an add-drop
configuration.
Figure 4-10: BER testing of a 3xDS3/4xDS3 system with add-
drop configuration
Transmitter
Assembly
HLM-
3xDS3
Hi Cap
Modem
ACU
Receiver
Assembly
BER results from the
Keypad
Receiver
Assembly
HLM-
3xDS3
Hi Cap
Modem
ACU
Transmitter
Assembly
Local Terminal
Remote Terminal
M12
Unit n
M12
Unit n
Notes:
Terminating M12 Unit is not necessarily the next site in the system.
Only one DS1 per M12 can be tested at one time.
M12 Unit n, where n = 1... 7.