User manual

Section 4
AT COMMAND SET
Copyright (C) Dataplex Pty Ltd
4-7
A/ Repeat Last Command
Parameters : None
Default : None
A/ is the only command that must not be preceded by an "AT" or terminated with a
carriage return (
K
). This command will repeat the preceding command string. This is
useful for redialling a previously engaged phone number.
ATA ANSWER
Parameters : None
Default : None
Causes the modem to answer an incoming call (go off-hook), try to train on the incoming
signal and then go on-line. There will be a 2.1 second delay to pass STD beeps, billing
meter pulses and the modem's answer tone. If the modem fails to detect carrier within the
time stored in register S7 (45 seconds), the modem will go on-hook and return to Local
Command State. The modem ignores all commands in a command line following the
Answer command.
ATB BELL/CCITT Select
Parameters : 0 or 1
Default : 0 (CCITT Modulation)
This command selects CCITT or BELL modulation format for signaling to line. In
conjunction with the ATFn command, the user can force the line speed and modulation to a
predetermined format instead of relying on the autoranging capabilities of the DPX-213.
The command is useful when placing international calls to Bell modems. Refer to the ATF
command description for full details on autoranging and other settings. The Bell 103 Mode
is only available when the Constant Speed Interface is disabled via the AT&I0 command.
Table 4.1 CCITT and Bell Selection
SPEED 300 1200/75 1200 2400
ATF1 ATF3 ATF4 ATF5
ATB0 V.21 V.23 V.22 V.22bis CCITT
ATB1 Bell 103 V.23 Bell 212 V.22bis Bell