Longshine LCS-8056C2 - Manual (Page 138)

Commands for Host-Processed Modems Reference Manual
5-6 Conexant 100498E
+VTR - Start Voice Transmission and Reception (Voice Duplex)
This command causes the modem to start the voice transmission and reception process (Voice
Duplex) without either acoustic echo cancellation or line echo cancellation. The modem
begins the Voice Duplex State by returning the CONNECT result code to the DTE. The
modem then sends <DLE> shielded voice data to the DTE, and the DTE can send <DLE>
shielded voice data to the modem. The modem will accept data from the DTE and send data
to the DTE in the format previously selected by the +VSM command, and use the flow
control method selected by the +IFC command.
The modem signals termination of the voice data stream by appending a <DLE><ETX>
command and padding out to an octet boundary if needed. The modem will issue the
<DLE><ETX> character pair (thereby ending the modem to DTE voice data flow) followed
by the OK result code, and return to the command mode after the modem has completely
transmitted the contents of its buffer.
There are two methods to leave the Voice Duplex State: the DTE sending a <DLE><^>
shielded code or the inactivity timer elapsing in the modem. The Voice Command State is
entered upon Voice Duplex State termination.
This command will function when the input and output are from/to the same I/O device, such
as local handset, line, or mic/speaker.
Syntax
+VTR
Result Codes
OK Upon command acceptance.
ERROR The modem is not connected to the line and a non-line device.