Comtrol AT Command Set Rev A - Manual (Page 45)

AT Commands Reference Manual
100722B Conexant 3-19
101b is written to S22 bits 6, 5, and 4,
respectively.
3 Enables reporting of busy tones; send only OK,
CONNECT, RING, NO CARRIER, ERROR,
NO ANSWER, and CONNECT XXXX. Blind
dialing is enabled/disabled by country
parameters. If dial tone detection is enforced and
dial tone is not detected, NO CARRIER will be
reported. The value 110b is written to S22 bits 6,
5, and 4, respectively.
4 Enables reporting of busy tones; send all
messages. The value 111b is written to S22 bits
6, 5, and 4, respectively. (Default.)
Result Codes
OK = 0 to 4.
ERROR Otherwise.