Configure Branch
8-133980-A2-GB30-40 October 1998
Table 8-1
(7 of 7)
DTE Interface Configuration Options
TX Clock Source: Internal
Nxt Internal External RXC_Loop
Transmit Clock Source. Determines the source of timing for synchronous data transmitted from the DTE.
Internal – The transmit data’s clock source is derived from the modem’s internal clock and output on Pin 15 (TXC) of the
RS-232D interface.
External – The transmit data’s clock source is provided by the DTE on Pin 24 (EXT) on the RS-232D interface. This
configuration option automatically disables Autorate, Automode, and Asymmetric Rate mode when running V.34
modulation.
RXC Loop – The modem’s transmit clock is derived from its received signal and is output on Pin 15 (TXC) of the
RS-232D interface. RXC Loop does not appear if SDC is enabled.
NOTE: This configuration option only appears if Async/Sync Mode is configured for Sync.
The factory default is Internal.
AT command equivalent is &X
n
.
CT111_Rate Cntl: Disable
Nxt Disable Fallback1 Fallback2
CT111 Rate Control. Allows the DTE to control modem rate via Pin 23 of the RS-232D interface. This configuration
option determines the effect of the DTE Rate control signal. CT111 is also known as CH on the RS-232D interface.
Disable – Disregards CT111 Rate Control.
Fallback1 – Forces the modem to decrease its configured data rate to the next lower data rate when CT111 is Off. Valid
only for V.32bis, V.33, V.29 modulation. Modem will only fall back within the same modulation scheme. When CT111
turns ON, the modem returns to its previous data rate.
Fallback2 – Forces the modem to decrease two data rates while remaining in the same modulation scheme. When
CT111 turns ON, the modem returns to its previous data rate.
NOTE: This configuration option is only valid in Async Direct mode and Synchronous mode. For proper operation,
disable the Autorate and Automode configuration options. CT111 Rate Control is not supported with V.34.
The factory default is Disable.
AT command equivalent is S-register S61=
n
.
DTE Rate=VF: Disable
End Disable Enable
DTE Rate = VF Rate. Forces the data rate of the connection between the DTE (computer) and the modem to be the
same as the VF (telephone line) rate.
Disable – The DTE rate is the value of the Async DTE Rate configuration option.
Enable – The DTE rate is identical with the VF rate.
NOTE: Not all DTE rates are available in Async Dial Direct Mode. This configuration option has no effect if Async/Sync
Mode is set for Sync or if V.42/MNP/Buffer is set to DirectMode.
The factory default is Disable.
AT command equivalent is S-register S90=
n
.