ADTRAN 1200218L1, User Manual

Page: 45 / 122

Chapter 3. Configuration
61200663L1-1 OSU 300 User Manual 3-7
Transmit Clock
Selects the source of the clock used to transfer data from the DTE to
the OSU 300. Use the following chart to determine your selection:
O
FF
W
HEN
T
EST
The SR lead remains on except when the OSU 300 is
executing a test.
O
FF
W
HEN
OOS/OOF
OR
T
EST
The SR lead remains on except when the unit receives an
OOS/OOF condition from the network or when the unit is
executing a test.
CD Selects the control mode for the carrier detect (CD) lead.
F
ORCED
O
N
The CD lead remains active at all times.
O
FF
W
HEN
OOS/OOF
The CD control lead remains on unless the OSU 300 receives
an OOS/OOF condition from the network.
T
RANSMIT
C
LOCK
See the following section for a description of this item.
Table 3-2. Additional V.35 Interface Port Configuration Selections (Continued)
S
ELECTION
D
ESCRIPTION
S
ELECT
... I
F
...
N
ORMAL
you want the transmit clock to be derived from the
OSU 300.
I
NVERT
your DTE device cannot provide a transmit clock
signal and data errors are present between your DTE
and the OSU 300.
E
XTERNAL
you are transmitting at high rates. This selection
eliminates data errors caused by excessive delays in
the DTE transmit clock receiver, transmit data driver,
and cable length.
Selecting N
ORMAL
or I
NVERT
clocking options depends on your DTE,
cable length, and cable characteristics. To verify error free operation,
perform a DTE loopback test and a BERT test from the DTE. See the
chapter Diagnostics on page 6-1 for information on performing these
tests.