8
November 1996
3980-A2-GZ40-20
Table 2
DTE Interface Configuration Options for SDC
Sync DTE Rate: 128000
Nxt 128000 115200 112000 96000 76800 72000 64000 57600 56000 48000 38400 28800 19200 14400
9600 4800 2400 1200
This configuration option does not appear when:
•
Async/Sync Mode configuration option is set to Async.
•
Sync Comp Mode configuration option is set to DirectMode.
•
Tx Clock Source configuration option is set to External.
•
The SDC feature is disabled.
Synchronous DTE Data Rate. Identifies the synchronous DTE’s operating rate to the modem. Data rates from
128,000 bps to 1200 bps are supported.
NOTE: A cable less than fifty feet in length is required for rates over 19,200 bps. Data synchronization at rates over
57,600 bps is sensitive to cable length and capacitance, and the DTE’s drivers and receivers. External transmit
clocking may be required.
The AT command for Sync DTE Rate is S30=
n. See Table 4, page 10.
Tx Clock Source: Internal
Nxt Internal External RXC_Loop
This configuration option only appears when Async/Sync Mode is configured for Sync.
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. This clock is available as an
output on Pin 15 (TXC) of the EIA-232-D interface.
External – The transmit data’s clock source is provided by the DTE on Pin 24 (XTXC) on 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.
NOTE: RXC_Loop does not appear if SDC is enabled.
NOTE: TMp tributaries are forced to RXC_Loop.
The AT command for Tx Clock Source is &X
n.
