TTC T-BERD 107A, Справочное руководство

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SECTION 3
3-8
INSTRUMENT
DESCRIPTION
T1 D1D — T1 D1D superframe mode config-
ures the T-BERD 107A to transmit and receive
D1D framed T1 data for testing D1D framed
circuits.
T1 TLB — T1 test loopback mode configures
the T-BERD 107A to echo the received data and
framing. This mode allows the T-BERD 107A
to emulate a CSU in loopback. The T-BERD
107A configures itself to the received framing
(or unframed) mode. If the received data pattern
matches the selected test pattern (i.e., QRSS),
pattern synchronization is declared; Pattern Sync
LED illuminates. BPVs are removed from the
received signal. However, BPVs, logic errors,
and B8ZS line code can be inserted into the
retransmitted data stream using the
ERR INS
switch and the B8ZS switch, respectively. To
obtain logic error test results, the T-BERD 107A
test pattern must be set to the received test
pattern.
In the T1 TLB mode, the LOOP CODES, LOOP
UP, and LOOP DOWN switches are disabled,
and the RCVD switch automatically defaults to
recovered timing (LED illuminated).
T1 LLB — T1 line loopback mode configures
the T-BERD 107A in a T1 Line Loopback
(LLB) mode in which all received data and
framing is echoed by the transmitter. This mode
allows the T-BERD 107A to emulate a repeater.
The T-BERD 107A configures itself to the
received framing (or unframed) mode. If the
received data pattern matches the selected test
pattern (i.e., QRSS), pattern synchronization is
declared; Pattern Sync LED illuminates. BPVs
are not removed from the received signal. The