Digicom 3911, 3910 operation manual Fallback2 Not available for TMp tributaries

COMSPHERE 3900 Series Modems

Table 5-1

(9 of 10)

DTE Interface Configuration Options

CT111_Rate Cntl: Disable

Nxt Disable Fallback1 Fallback2

CT111 Rate Control. Allows the DTE to control modem rate via Pin 23 of the EIA-232-D interface. This configuration option determines the effect of the DTE Rate control signal. CT111 is also known as CH on the EIA-232-D interface.

HDisable

Disregards CT111 Rate Control.

HFallback1

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.

HFallback2 (Not available for TMp tributaries)

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 V.32bis Autorate and V.32bis Automode configuration options.

The AT command is S-Register S61=n, where n is 0 for Disable, 1 for Fallback1, and 2 for Fallback2.

DTE_Rate=VF: Disable

End Disable Enable

This configuration option does not appear if Async/Sync is configured for Sync.

DTE Rate = VF. Forces the DTE’s data rate to be equal to the VF (telephone line) data rate.

HDisable

The data rate of the connection between the DTE and modem is the value of the Async DTE Rate configuration option.

HEnable

The data rate between the DTE and modem is the same as the modem’s VF data rate. As a result, when the modem is in Data mode, the speed of the data passed between the modem and DTE occurs at the VF data rate.

The AT command is S-Register S90=n, where n is 0 for Disable and 1 for Enable.

5-18 September 1998 3910-A2-GN32-40