Paradyne 7123, Руководство пользователя

Страница: 35 / 146

3. Configuration
7123-A2-GB20-00 September 2001
3-13
Configuring the User Data Port
Select Physical from the Data Ports menu to configure the physical characteristics
for the user data port (see
Table 3-3, Data Port Physical Interface Options ).
Main Menu
→
Configuration
→
Data Ports
→
Physical
Table 3-3. Data Port Physical Interface Options (1 of 3)
Port Base Rate
Possible Settings: Nx64, Nx56
Default Setting: Nx64
Determines the base rate of the data port. The actual data rate is a multiple (from 1 to
24 times) this base rate.
Nx64 – The port base rate is 64 Kbps.
Nx56 – The port base rate is 56 Kbps.
Invert Transmit Clock
Possible Settings: Auto, Enable, Disable
Default Setting: Auto
Determines whether the clock supplied by the DSU/CSU on interchange circuit DB
(ITU 114) – Transmit Signal Element Timing (DCE Source) TXC is phase inverted with
respect to the clock used to time the incoming Transmitted Data (TD).
Auto – The port will check the clock supplied by the DCE on TXC on this port. If
necessary, the port will automatically phase invert the clock with respect to the
transmitted data.
Enable – Phase inverts the TXC clock. Use this setting when long cable lengths between
the DSU/CSU and the DTE are causing data errors.
Disable – Does not phase invert the TXC clock.
Transmit Clock Source
Possible Settings: Internal, External
Default Setting: Internal
Determines whether the DTE’s transmitted data is clocked into the DSU/CSU by its
internal transmit clock or by the external clock provided by the DTE.
NOTE: Changing settings for this configuration option causes the DSU/CSU to abort
any physical port tests, including any DTE-initiated loopback tests.
Internal – The DSU/CSU uses the interchange circuit DB (ITU 114) – Transmit Signal
Element Timing (TXC) (DCE source) for timing the incoming data.
External – The DTE provides the clock for the transmitted data, and the DSU/CSU uses
the interchange circuit DA (ITU 113) – Transmit Signal Element Timing (XTXC)
(DTE source) for timing the incoming data.