Digicom 3910, 3911 operation manual TX Clock Source Internal Nxt Internal External RXCLoop

DCP Configuration

Table 5-1

(8 of 10)

DTE Interface Configuration Options

TX Clock Source: Internal

Nxt Internal External RXC_Loop

This configuration option only appears if Async/Sync Mode is configured for Sync.

Transmit Clock Source. Determines the source of timing for synchronous data transmitted from the modem to the analog channel.

HInternal

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.

HExternal

The transmit data’s clock source is provided by the DTE on Pin 24 (XTXC) on the EIA-232-D interface.

HReceive 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.

The AT command for Internal is &X0.

The AT command for External is &X1.

The AT command for RXC Loop is &X2.

Bakup_TXClk_Src: Internal

Nxt Internal External RXC_Loop

This configuration option only appears in customized installations in which the Dual_Leased_Ln is configured for Enable and Async/Sync Mode is Sync.

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.

HInternal

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.

HExternal

The transmit data’s clock source is provided by the DTE on Pin 24 (XTXC) on the EIA-232-D interface.

HReceive 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.

XTXC Clamps TXC: Enable

Nxt Enable Disable

This configuration option only appears if TX Clock Source is configured for External.

External Transmit Clock Clamps Transmit Clock. Allows the modem’s TXC output (Pin 15 on the EIA-232-D interface) to be clamped OFF when TX Clock Source is configured for External.

HEnable

TXC is clamped off when TX Clock Source is configured for External.

HDisable

TXC continues to be provided when TX Clock Source is configured for External.

The AT command is S-Register S71=n, where n is 0 for Enable and 1 for Disable.

3910-A2-GN32-40 September 1998 5-17