User's Manual

\A – MNP Block Size
This command specifies the maximum number of data bytes in an MNP data
frame. A smaller size may improve throughput on high-impairment (noisy)
telephone lines.
AT\A0 Maximum block size is 64 bytes
AT\A1 Maximum block size is 128 bytes
AT\A2 Maximum block size is 192 bytes
AT\A3 Maximum block size is 256 bytes (factory setting)
\B – Sending a Break Signal
The \B command is used to send a Break signal to the remote modem (see \K
command). In order to enter the \B command, you must first return from the
existing data connection to the Command mode, using the Esc sequence. The
Break signal is fixed at 300 ms.
\C – Set Auto-Reliable Buffer
In auto-reliable mode (\N3), this command determines the fallback method and
enables data buffering. The settings for this command are used by the modem
during the V.42 detection phase.
AT\C0 Does not buffer data (factory settings)
AT\C1 Buffers data for four seconds or until 200 characters have been
buffered or the SYN character is detected, then switches to reliable
mode. If the buffer fills, data is passed to the serial port.
AT\C2 Does not buffer data. Switches to buffer (normal) mode upon receipt
of autoreliable fallback character and passes it to serial port. This
feature allows non-V.42. modems to connect immediately to a V.42
modem without data loss.
\G – Set Modem Port Flow Check
In buffer (normal) mode (either) \N0 or after fallback), this command enables
modem-to-modem flow control using XOFF (13h) to stop and XON (11h) to
start transmission between modems.
AT\G0 Disables port flow control (factory setting)
AT\G1 Set port flow control to XON/XOFF
2-16 AT COMMANDS: DATA MODEM