Rockwell RCV144ACx, Command Reference Manual

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AT Command Reference Manual
1048 7-35
Table 7-8. Playback a Greeting Message
DTE to Modem Modem to
DTE
Description and Interpretation
#CLS=8 Configure the modem for Voice Mode.
OK The modem confirms command reception, and is now set up for voice.
#VBS=4 The DTE asks for 4-bit compression. The data from the DTE needs to travel at 38,400
bps since after start and stop bits are added, the speed increases to 36,000 bps.
OK The modem is configured for 4-bit compression (ADPCM).
#BDR=16 The DTE knows that compression requires a 38,400 bps speed, so it forces this as the
new speed. (For this example, lets say that the DTE was sending all commands,
including this one, at 4800 bps.)
OK This OK message is sent at 4800 bps, but the modem switches to 38,400 bps. All
subsequent commands are assumed to be sent at 38,400 bps. The DTE should switch
after the <CR><LF> following the OK. The S30 timer is now active.
#VLS=2 Select the speaker as the output device to be used by the modem.
VCON The modem confirms command reception, and enters Online Voice Command Mode.
Since this is an output only device, nothing more can happen yet.
#VTX This tells the modem that the DTE is ready to send voice per the current
compression/sampling settings.
CONNECT The modem tells the DTE that it can now send data. The modem enters Voice
Transmit Mode and ADPCM data flow begins.
<Data> The DTE sends data. The modem waits 1 second before starting to transmit to the
speaker to ensure uninterrupted data flow. If the voice transmit buffer runs empty, the
transmitter is disabled.
<DLE><ETX> The DTE has finished its transmission and now instructs the modem to enter Online
Voice Command Mode after emptying the voice transmit buffer.
VCON The modem tells the DTE it is done. If the DTE sends the <DLE><ETX> before the
modem has finished transmitting all the data in its buffer, the DTE must wait for this
response. (VCON indicates that the DTE can send more data at any time with #VTX.)