Chapter 6 – Voice Commands
SocketModem Global MT5634SMI Developer’s Guide 44
Chapter 6 - Voice Commands
Introduction
This chapter describes +V command support. The +V Command standard IS-101 Voice Control Interim Standard
for Asynchronous DCE (prepared by the TIA Technical Subcommittee TR29.2 on Facsimile Digital Interface)
defines the commands that a PC user may issue to configure and control a voice/fax/data modem, and the
responses (result codes) that the voice/fax/data modem may issue in response to those commands.
The +V commands and responses provide control of the following services:
· Recording and playback of digitized voice.
· Generation and detection of DTMF and other tones.
· Switching between voice, fax, and data modes.
· Control-related functions.
The Voice mode has three states, which correspond to the direction of voice data flow:
Voice command state (event reports only; no data transfers).
Voice transmit state (digitized, half-duplex voice data transfers from PC to modem).
Voice receive state, (digitized, half-duplex voice data transfers from modem to PC).
The modem supports three levels of voice service: Service Levels A, B, and C. Service Level A provides the
lowest level of services. Service level A performs operations and detects events as follows: Voice transmit,
Voice receive, and DTMF generation and Single tone generation. The following events (Result Codes) are
reported: 3, 4, 5, 6, 9, 10, 18, 19, 23, 25.
Service Level B provides an optionally greater amount of services, providing DTMF and facsimile calling tone
detection during voice transmits in addition to Service Level A. Service Level B provides event- reporting similar
to Service Level A, but with added event reporting states (e.g., fax calling in transmit state in addition to reporting
in command state).
Service Level C provides the highest service level with the addition of facsimile calling tone and Busy detection
during receives, Dial Tone detection, and double-tone detection. An example of event detection in a Service
Level C modem is shown below:
AT+VEM=?
"C"
0A000100
0E601800
1A803840
OK