Rockwell RCV144ACx, Command Reference Manual

Page: 143 / 186

AT Command Reference Manual
1048 7-11
ATA - Answering in Voice/Audio
The answer action command works analogously to the way it works in Data and Fax Modes except for the following:
1. When configured for Voice/Audio Mode (#CLS=8), the modem enters Online Voice Command Mode immediately after
going off-hook. When the #CLS=8 command is issued, the modem can be programmed to look for 1100 and 1300 Hz
calling tones (see #VTD), thus eliminating the need to do so as part of A command processing. After the VCON
message is issued, the modem re-enters Online Voice Command Mode while sending any incoming DTMF or Calling
Tone indications to the DTE as described in Section 7.2.5.
2. After answering in Voice/Audio Mode (#CLS=8), the DTE, as part of its call discrimination processing, can decide to
change the #CLS setting to attempt receiving a fax in Class 1, or to make a data connection. In such a case, the DTE
commands the modem to proceed with the data or fax handshake via the A command even though the modem is
already off-hook.
Result Code:
VCON Issued in Voice Mode (#CLS=8) immediately after going off-hook.
ATD - Dial Command in Voice/Audio
The dial action command works analogously to the way it works in Data or Fax modes. When in Voice/Audio Mode
(#CLS=8):
1. The modem attempts to determine when the remote has picked up the telephone line and once this determination has
been made, the VCON message is sent to the DTE. This determination is initially made based upon ringback detection
and disappearance. (See #VRA and #VRN commands.)
2. Once connected in Voice/Audio Mode, the modem immediately enters the command state and switches to Online Voice
Command Mode which enables unsolicited reporting of DTMF and answer tones to the DTE.
Parameters: Same as Data and Fax modes.
Result Codes:
VCON Issued in Voice/Audio Mode (#CLS=8) when the modem determines that the remote modem or
handset has gone off-hook, or when returning to the Online Voice Command Mode. (See #VRA
and #VRN.)
NO ANSWER Issued in Voice/Audio Mode (#CLS=8) when the modem determines that the remote has not
picked up the line before the S7 timer expires. Though the modem reports "NO ANSWER", the
DTE has the responsibility of issuing an ATH (or ATZ) to disconnect the telephone line while
#CLS=8.
ATH - Hang Up in Voice/Audio
This command works the same as in Data and Fax modes by hanging up (disconnecting) the telephone line. There are,
however, some specific considerations when in Voice/Audio Mode:
1. The H command forces #CLS=0, but does not destroy any of the voice parameter settings such as #VBS, #VSP, etc.
Therefore, if the DTE wishes to issue an H command and then pursue another voice call, it must issue a subsequent
#CLS=8 command, but it need not re-establish the voice parameter settings again unless a change in the settings is
desired.
2. The #BDR setting is forced back to 0, re-enabling autobaud.
3. If the #VLS setting is set to select a device which is not, or does not include the telephone line (such as a local handset
or microphone), the H command deselects this device and reselects the normal default setting (#VLS =0). Normally, the
DTE should not issue the H command while connected to a local device such as a handset, because merely selecting
this device results in VCON. The normal sequence of terminating a session with such a device is to use the #VLS
command to select the telephone line, which by definition makes sure it is on-hook.
Parameters: Same as Data and Fax modes.
Result Codes: Same as Data and Fax modes.