326XFAST-SDC Modem Application Examples

Configuring the Modem

Option Set 4—Synchronous Leased Line Applications with Dial Restoral (Models 3261/63/66/68)

Changing Default Configuration Settings

Depending on application requirements, you may change the following options:

•The default Restoral setting in Option Set 4 (leased line models) is Auto/FP. When first configuring the modem, set Restoral=Off. This prevents erroneous status errors from displaying while you configure leased line options. After configuration, if your application requires automatic initiation of dial restoral, set Restoral=Auto/FP.

•When installing the modem in a leased line application, the default Mode

setting (AT*CA, MODULATION OPTS category) is Answer. For proper operation, you must set Mode=Answer in one modem, and

Mode=Originate in the other modem.

•Depending on application requirements, you may change the following:

—Line (MODULATION OPTS). Default option is 2W Lease. Can also be set for 4W Lease application.

—No ACU Form (ACU OPTS). Default option is Sync. Can be set to Async.

—Answer (ACU OPTS). Default option is country-specific. Refer to Appendix C to verify that this option is appropriate for your application.

—Restoral (RESTORAL OPTS). Default option is Auto/FP (as described above). Can be set to Off to disable restoral.

—Clock (MODULATION OPTS). Default option is Internal. Can be set to external or loopback, depending on the network clocking source.

—DTE (TERMINAL OPTS). If No ACU Form=Async, customize your DTE port by selecting these options:

Set the modem’s DTE rate to match the asynchronous DTE’s rate using DTE Rate (AT*DE, TERMINAL OPTS category).

Set the modem’s parity to match the parity set in the asynchronous DTE using Parity (AT*RP, ACU OPTS category).

Set the modem’s character length to match the character length set in the asynchronous DTE, using Char Length ACU OPTS category)

(Refer to Appendix A for parameter and setting descriptions.)