4. Configuration Options
9128-A2-GB20-80 September 2002 4-39
Max Port Rate (Kbps)
Possible Settings: 1536, 2048
Default Setting: 1536
Specifies the maximum clock rate for a user data port. The data rate for this port is limit ed
to the rate specified by this option so that the maximum rate supported by an attach ed
DTE is not exceeded.
Display Conditions
– This option only appears when the Port Use is set to Frame Rel ay
and, if the unit has multiple data ports, the selected port is Port-2.
1536 – The maximum port rate for the port is 1536 Kbps.
2048 – The maximum port rate for the port is 2048 Kbps.
Port Base Rate (Kbps)
Possible Settings: Nx64, Nx56
Default Setting: Nx64
Specifies the base rate for the data port, which is a multiple (from 1 to 24) of the base rate
specified by this option. N is a number from 1 to 24.
Display Conditions
– This option only appears when Port Use is set to Synchronous
Data. This option does not appear for a FrameSaver SLV 9128-II.
Nx64 – The base rate for the port is 64 Kbps.
Nx56 – The base rate for the port is 56 Kbps.
Invert Transmit Clock
Possible Settings: Auto, Enable, Disable
Default Setting: Auto
Determines whether the clock supplied by the FrameSaver unit on interchange circuit DB
(ITU 114) – Transmit Signal Element Timi ng (DCE Sour ce) TXC is phase inverted with
respect to the clock used to time the incoming Transmitted Data (TD).
Auto – The port checks the clock supplied by the DCE on TXC on this port. If necessary,
the port automatically phase inverts the clock with respect to the transmitted dat a.
Enable – Phase inverts the TXC clock. Use this setting when long cable lengths between
the FrameSaver unit 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 cloc ked into the FrameSaver unit by it s
internal transmit clock or by the external clock provided by the DTE.
NOTE: Changing settings for this configuration option causes the FrameSaver unit to
abort any physical port tests, including any DTE-initiated loopback tests.
Internal – The FrameSaver unit uses th e int erchange circuit DB (ITU 114) – Trans mit
Signal Element Timing (TXC) (DCE source) for timing the incoming data.
External – The DTE provides the clock for the transmitt ed data, and the FrameSaver unit
uses the interchange circuit DA (ITU 113) – Transmit Signal Element Timing (XTXC) (DTE
source) for timing the incoming data.
Table 4-7. Data Port Physical Interface Options (2 of 5)