Paradyne COMSPHERE 3920PLUS Technical Reference Manual page 88

Configure Branch
Table 5-1
(2 of 9)
DTE Interface Configuration Options — Multiport Mode l
Port4 Ext Alarm: Disable
Nxt Disable EnableLow EnableHigh
This configuration option only appears when MUX Mode is configured for TDM/MSD.
Port 4 External Alarm Monitor. Determines if Port 4 can be used to transmit user data. When enabled, this configuration
option prevents Port 4 of the modem from being used to transmit user data. Instead, inputs on Pins 18 (external
Alarm B) and 21 (External Alarm A) on Port 4 are used to monitor an external device for alarms (such as a power supply
that can generate alarm status signals that are compatible with RS-232 levels). Once this configuration option is
enabled and saved, all Port 4 configuration options become inaccessible. Also, all Port 4 rate configuration options are
automatically disabled, and the DTE RL (CT140) and DTE LL (CT141) configuration options are automatically set to
Disabled.
Disable – Port 4 of the TDM can be used for user data.
EnableLow – Port 4 of the TDM can only be used to monitor for external alarms. Low input signals are alarms, and high
input signals are normal.
EnableHigh – Port 4 of the TDM can only be used to monitor for external alarms. High input signals are alarms, and low
input signals are normal.
Bakup_TXClk_Src: Internal
Nxt Internal RXC_Loop Port1 Port2 Port3 Port4
This configuration option only appears when Dual_Leased_Ln is configured for Enable.
Backup Transmit Clock Source. Selects the clock reference source when operating in the Dual Leased Line Mode. This
is a special mode in which one leased line is used to back up another.
NOTE: If the DTE Bridge is enabled, Ports 2, 3, and 4 are not available.
Internal – The transmit data's clock source is derived from the modem's internal clock. This clock is available as an
output on Pin 15 (TXC) of the EIA-232-D interface.
Receive Clock Loop – The modem's transmit clock is derived from its received analog signal. The derived clock is
available as an output on Pin 15 (TXC) of the EIA-232-D interface.
Port1 – The transmit data's clock source is provided on Pin 24 (XTXC) of the EIA-232-D interface for Port 1.
Port2 – The transmit data's clock source is provided on Pin 24 (XTXC) of the EIA-232-D interface for Port 2.
Port3 – The transmit data's clock source is provided on Pin 24 (XTXC) of the EIA-232-D interface for Port 3.
Port4 – The transmit data's clock source is provided on Pin 24 (XTXC) of the EIA-232-D interface for Port 4.
CT111_Rate Cntl: Disable
End Disable Fallback1 Fallback2
This configuration option does not appear when V.34 is enabled for a leased or dial line.
CT111 Rate Control. Allows the DTEs to control modem rate via Pin 23 of the EIA-232-D interface. This configuration
option determines the effect of the DTE Rate control signals. CT111 is also known as CH on the EIA-232-D interface.
Disable – Disregards all CT111 Rate Control.
Fallback1 – Forces the modem to decrease its configured data rate to the next lower data rate when any of the CT111
signals are OFF. When all of the CT111 signals are 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 any
of the CT111 signals are OFF. When all of the CT111 signals are ON, the modem returns to its previous data rate. Note,
Fallback2 is not available for TMp tributaries.
NOTE: For proper CT111 operation, disable the Autorate configuration option and never enable CT111 Rate Control on
both modems of the tail circuit.
3920-A2-GH30-40 October 1998 5-11