Voice Modem Command Examples; Notes For Speakerphone Examples - US Robotics 56K USB Modem User Manual

Voice Modem Command Examples

The application issues AT commands to request actions by the modem, and the modem responds with
standard TIA-602 result codes to tell the application that the requested action has been completed.

Notes for Speakerphone Examples

1. If the user decides to pick up his local (parallel) phone while in the middle of a speakerphone call, the
DCE senses the transition and sends the application a <DLE>-H sequence. The application, which
should always be screening for DLE-shielded codes in the background when the modem is in the voice
mode, can then respond to the <DLE>-H (for example, by resetting speakerphone buttons or doing
whatever else needs to be done with the speakerphone interface).
2. DLE-shielded codes that the modem sends to the application while in speakerphone mode are listed in
Table 226.
Table 226. DLE-Shielded Codes
Command
DLE - c FAX calling tone detect.
DLE - e Data calling tone detect.
DLE - h Local phone went on-hook (hung up).
DLE - H Local phone went off-hook (picked up).
3. When the user is in the middle of a speakerphone call, call waiting (hold operation) can be initiated
when the user hears the call waiting signal through the speaker. Call waiting entails the following com-
munication between the application and the modem.
Command/Response
ATD!
OK
To terminate the second call and return to the first, the application should again send the modem the ATD!
command.
Command/Response
ATD!
OK
Description
Put the current call on hold, and answer the new incoming call.
DCE responds. Original call is on hold, and the speakerphone user is con-
nected
to the second call.
Terminate the second call and return to the original call.
DCE responds. Second call is terminated and the user is again connected to
the original call.
Description
Description
Command Reference - 109
56K USB Modem
User Guide