User manual

Appendix F 105
AT& (Ampersand) Commands
&B
n
Autoretrain
Defines modem action when it receives a poor signal.
&B0: Hang up on a poor received signal.
* &B1: Retrain on a poor received signal. Hang up if condition persists longer than the threshold set
in register S7.
&B2: Do not hang up; do not retrain (tolerate any connection).
Result Codes:
OK Returned when
n
= 0, 1 or 2.
ERROR Returned for any other value of
n
.
&C
n
Data Carrier Detect Option (Async Only)
Controls how the state of the DCD or RLSD (Receive Line Signal Detect) relates to the carrier from the
remote system. Always use &C1 for Sync mode.
&C0: State of carrier from remote modem is ignored. RLSD circuit is always on.
* &C1: State of carrier from remote modem is tracked. RLSD circuit reflects the state of the carrier.
Result Codes:
OK Returned when
n
= 0 or 1.
ERROR Returned for any other value of
n
.
&D
n
Data Terminal Ready Option
Defines modem action when it receives a poor signal.
&D0: DTR ignored.
&D1: Go to command mode when DTR changes from on to off.
* &D2: Hang up and go to command mode when DTR changes from on to off. Auto answer is
disabled if DTR is low.
&D3: Reset when DTR changes from on to off.
Result Codes:
OK Returned when
n
= 0, 1, 2 or 3.
ERROR Returned for any other value of
n
.
&F Load Factory Settings
Loads the configuration programmed at the factory. This command replaces all command options and S
register settings in the active configuration with the factory values stored in the nonvolatile RAM.
&F: Recall factory setting as active configuration.