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<html><head><title>Rockwell Voice Commands</title></head><body><h1>Rockwell Voice Commands</h1><hr>This file is an HTML-ized version of<a href="ftp://ftp.whnet.com/rockwell/voice.commands">ftp://ftp.whnet.com/rockwell/voice.commands</a>.<br>Conversion made by<a href="http://www.geocities.com/SiliconValley/Pines/5004">Gianpaolo Macario</a><<a href="mailto:macario@mbox.vol.it">macario@mbox.vol.it</a>><br>Last modified on 13-FEB-1997 08:20 MET.<hr><pre>From: Les Reeves <lreeves@crl.com>Subject: Voice commands (long)To: wolfgang@whnet.com</pre><hr><h2>8. VOICE COMMANDS</h2>The modem may be configured in response to AT voice commands to provide enhanced Adaptive Differential Pulse Code Modulation (ADPCM) coding and decoding for the compression and decompression of digitized voice. ADPCM compression supports the efficient storage of voice messages, while optional coder silence deletion and decoder silence interpolation significantly increase compression rates.<p>The ADPCM Voice Mode supports three submodes once a voice connection is established (see #CLS command): Online Voice Command Mode, Voice Receive Mode, and Voice Transmit Mode.</p><h3>8.1. VOICE SUBMODES</h3><h4>8.1.1. Online Voice Command Mode</h4>Online Voice Command Mode is the default Voice submode entered when the <b>#CLS=8</b> command is issued, and may also be entered from Voice Receive Mode or Voice Transmit Mode. Entry into Online Voice Command Mode is indicated to the DTE via the VCON message, after which AT commands can be entered without aborting the telephone line connection.<p>If the modem is the answerer, it enters Online Voice Command Mode immediately after going off-hook, and can report instances of DTMF tones and calling tones to the DTE. If the modem is the originator,it enters Online Voice Command Mode based on detection of the ringback cadence going away, upon expiration of the ringback never came timer, or upon detection of answer tone, and the modem can report DTMF tones, answer tones, busy tone, and dial tone to the DTE. (Note that DTMF tone reporting is supported in this mode if DTMF reporting is enabled via the #VTD command.)</p><p>When this mode is entered as a result of going off-hook with the D or A command, VCON is always sent to the DTE, after which the modem accepts commands. If this mode is entered from Voice Transmit Mode, the DTE has issued the <DLE><ETX>, and the modem respondswith VCON. If this mode is entered from the Voice Receive Mode because of a key abort, the modem issues the <DLE><ETX> followed by VCON.</p><p>If the #VLS command has switched in a handset or other device in place of the telephone line, Online Voice Command Mode is immediately entered, whereas if the telephone line is selected, a physical connection with another station must occur before entering this mode.</p><h4>8.1.2. Voice Receive Mode</h4>Voice Receive Mode is entered when the DTE issues the #VRX command because it wants to receive voice data. This typically occurs when either recording a greeting message, or when recording voice messages from a remote station.<p>In Voice Receive Mode, voice samples from the modem analog-to-digital converter (ADC) are sent to the ADPCM codec for compression, and can then be read by the host. AT commands control the codec bits-per-sample rate and select (optional) silence deletion including adjustment of the silence detection period.</p><p>In this mode, the modem detects and reports DTMF, dial tone, busy tone cadence, and inactivity (periods of silence) as enabled by the #VTD and #VSS commands, respectively. The modem can exit the Voice Receive Mode only via a DTE Key Abort, or via Deadman Timer expiration (S30).</p><h4>8.1.3. Voice Transmit Mode</h4>Voice Transmit Mode is entered when the DTE issues the #VTX command because it wants to transmit voice data. In this mode, the modem continuesto detect and report DTMF and calling tones if enabled by the #VTD command. This mode is typically used when playing back greeting messages or previously received/recorded messages.<p>In this mode, voice decompression is provided by the codec, and decompressed data is reconstituted into analog voice by the DAC at the original voice compression quantization sample-per-bits rate. Optional silence interpolation is enabled if silence deletion was selected for voice compression.</p><h3>8.2. VOICE CAPABILITIES</h3><h4>8.2.1. Call Establishment - Originate</h4><h5>Directed Originate (Dial as a specific modem type)</h5>For most call originations, it is known ahead of time what type of call is being attempted, and it is acceptable to disconnect if the remote side of the connection does not cooperate. In this case, the modem can be configured ahead of time with the existing +FCLASS (and +FAA=0) or the #CLS command to be a data, fax, or voice modem. For Data and Fax Modes, the modem subsequently either succeeds with the desired type of connection, or eventually hangs up. For the Voice Mode, the DTE has the option of hanging up if there are indications that the remote station has not answered in voice, thus implementing a directed originate for voice. The following are the three connection type choices:<h5>Voice</h5>The modem dials and reports call progress to the DTE, which reduces to reporting "NO DIALTONE," or "BUSY."<p>The modem allows the DTE to program a time period, which if elapsed after any ringback is detected, forces the modem to assume the remote has gone off-hook. A secondary time period (safety valve) can de fine a maximum elapsed time after dialing for receivingno ringback before the modem assumes that the remote has gone off-hook.This safety valve is devised in case the remote picksup the telephone before any ringback is generated, and no other tones aredetected. In this mode, the modem is attempting tomake a voice connection only and therefore, while waiting for ringback todisappear, it is also feasible to disconnect upondetection something which is definitely not voice from the remote, such asany answer tone. The modem provides detection of"ringback went away or never came".</p><h5>Fax</h5>The modem dials and reports call progress to the DTE as in all modes. A fax Class 1 or Class 2 handshake is pursued accordingto the current configuration.<h5>Data</h5>The modem dials and reports call progress to the DTE as in all modes.A data handshake is pursued according to the currentconfiguration.<h5>Adaptive Originate (Dial with Voice/Data/Fax Discrimination)</h5>The DTE may wish to originate a call which adapts to the remote answerer.For instance, the user may wish to send a voice messageif a human picks up the telephone, but a facsimile if a fax machine answers. The modem can facilitate this type of adaptiveoriginate by extending what it does for the directed originate modes.After determining that the remote station has pickedup the line, the modem goes back to Online Voice Command Mode, thusterminating the "connecting state." Once in this mode,the modem reports what it receives from the answerer via specific resultcodes to the DTE. The DTE can then have the optionof pursuing a data, fax, or voice connection.<h4>8.2.2. Call Establishment - Answer</h4><h5>Directed Answer (Answer as a specific modem type)</h5>If the DTE wants to be only one kind of answerer (i.e., voice, fax,or data), it can configure the modem to answer exclusivelyin the chosen mode.<h5>Voice</h5>The modem is configured to answer in Voice Mode only and assumes the caller will cooperate. After going off-hook, the voiceVCON is issued, no answer tone is generated, and the modem is immediatelyplaced in Online Voice Command Mode. The DTE typicallyresponds by sending a greeting message of some type, and DTMF tonerecognition/reporting can be enabled. Eventually, an incomingvoice message can be recorded by the host. (Unpredictable results occur ifthe caller is not prepared for a voice call.)<h5>Fax</h5>The modem is configured to answer in Class 1 or Class 2 Fax Mode only, andit assumes the caller is going to cooperate. Thisconfiguration has the effect of disabling Voice Mode, forcing +FCLASS toeither 1 or 2, and forcing both +FAA and +FAE to 0.<h5>Data</h5>The modem is configured to answer in Data Mode only and assumes the calleris going to cooperate. This configuration has theeffect of disabling Voice Mode, forcing +FCLASS =3D 0, and forcing both+FAA and +FAE to 0.<h5>Adaptive Answer (Answer with Voice/Data/Fax Discrimination)</h5>In normal operation, it is desirable for a modem supporting fax and voiceto provide the ability to discriminate between thetwo when answering unsolicited or unattended calls. (It is most often thecase that a fax is received or a voice message recordedwhen nobody is present.)<h5>Data/Fax Discrimination</h5>If the DTE wishes to allow for a data or fax call, the +FCLASS and +FAA or+FAE commands can be configured for adaptive answerbetween data and Class 1 or Class 2 fax.<h5>Voice/Fax Discrimination</h5>This is the most important discrimination capability needed from the user's standpoint. The modem must be configured for Voice(#CLS=3D8), causing the modem to enter Online Voice Command Modeimmediately upon going off-hook. In Voice Mode, the DTE automaticallyreceives indications of DTMF tones and Calling Tones. The DTE can nowswitch to Voice Transmit Mode in order to play a greetingmessage, perhaps one which instructs the caller how to enter specific DTMFsequences to switch modes. The DTE can then reactto the response, or the lack thereof, to such a message. The modemsupports switching to a Class 1 or Class 2 answer mode byvirtue of the #CLS=3D1 or 2 commands, and if such a switch is made andfails, the modem reports the failure but does not hangup, allowing the DTE further experimentation time. If the user wishes toswitch to Class 1 or 2, but also wants the DTE toindeed hang up the line if the fax fails, the +FCLASS command should beused instead of the #CLS command. The only differencebetween these commands is that issuing +FCLASS cancels the modem's memoryof voice, whereas #CLS causes the modem to remainoff-hook, even if a fax or data handshake fails, until it receives an Hcommand.<h5>Voice/Data/Fax Discrimination</h5>The DTE can try data modem operation after an answer by changing the #CLSsetting to 0. A data handshake attempt can be addedbased upon DTMF responses or lack thereof.<h4>8.2.3. Voice Data Transfer</h4>A significant area of concern when handling the transfer of voice data isthe data transfer rate on the modem/DTE interface.Data transfer rates can be expressed as the number of interrupts which must be serviced per time period to keep up. This isa function of the sampling rate and compression method (if any) used by the modem, and the DTE interface speed required tohandle the data flow on the telephone line side.<p>Table 8-1 demonstrates the relationship between the sampling rate,interrupt rate, and DTE speed necessary for the modem tosupport various compression ratios. The 16C550 UART is strongly recommended to support Voice Mode operation, and is essentialfor MS Windows environments.</p><p><table border="1"><caption>Table 8-1. 7.2 KHZ Sample Rate DTE Speeds</caption><tbody><tr><th>Modem Samples per 8-bit Byte</th><th> Required Asynchronous DTE Speed (8N1 Format)</th><th> Implied DTE Speed Supported</th></tr><tr><td> 2 (4-bits)</td><td> 36,000 bps</td><td> 38.4 kbps</td></tr><tr><td> 2.66 (3-bits)</td><td> 27,000 bps</td><td> 38.4 kbps</td></tr><tr><td> 4 (2-bits)</td><td> 18,000 bps</td><td> 19.2 kbps</td></tr><tr><td colspan="3"> Note: The current exclusive sampling rate is 7.2 kHz.</td></tr></tbody></table></p><h4>8.2.4. Tone and Status Monitoring-Shielded <DLE> Statuses</h4>The modem can detect specific tones and other status information, andreport these to the DTE while in any of the three voicesubmodes. The modem simultaneously looks for 1300 and 1100 Hz calling tones when answering, and for CCITT and Bell answer toneswhen originating. The modem can also detect dial or busy tones in any ofthe three voice submodes. All detected tones, as wellas certain other statuses addressed in Table 8-2 such as silence and"telset off-hook" (i.e., handset off-hook) are reportedas shielded codes.<p>When in Online Voice Command Mode or Voice Transmit Mode, the codes inTable 8-2 are sent to the DTE immediately upon verificationby the modem of the associated tone, status, or cadence. In this mode, the2-character code is not buffered, nor does the DTEhave the ability to stop the code with flow control. If the DTE has started (but not completed) sending any AT command, theTone Monitoring function is disabled until the command has been receivedand processed.</p><p>The modem can discriminate between single and multiple DTMF tones received. If calling tone, dial tone, busy tone, or answertone is detected, this detection is reported repeatedly (at reasonableintervals) if the DTE takes no action, and the tonecontinues to be detected.</p><p><table border="1"><caption>Table 8-2. Shielded Codes Sent to the DTE</caption><tbody><tr><th>Code Sent to DTE</th><th>Meaning</th></tr><tr><td> <DLE>0 - <DLE>9, <DLE>*, <DLE>#,<DLE>A -<DLE>D</td><td><b>DTMF</b>.Digits 0 through 9, *, #, or A through D detected by the modem,i.e., user has pressed a key on a local or remote telephone.The modem sends only one <DLE> code per DTMF button pushed.</td></tr><tr><td> <DLE>a</td><td><b>Answer Tone (CCITT)</b>.Send to the DTE when the V.25/T.30 2100 Hz AnswerTone (Data or Fax) is detected. If the DTE fails toreact to the code, and the modem continues to detect Answer tone, the codeis repeated as often as once every half second.</td></tr><tr><td> <DLE>b</td><td><b>Busy</b>.Sent in Voice Receive Mode when the busy cadence is detected,after any remaining data in the voice receive buffer.The modem sends the busy <DLE>b code every 4 seconds if busy continuesto be detected and the DTE does not react. This allowsthe DTE the flexibility of ignoring what could be a false busy detection.</td></tr><tr><td> <DLE>c</td><td><b>Calling Tone</b>.Sent when the T.30 1100 Hz Calling Tone (Fax Modem)is detected in any of the voice operating modes. The modemassumes that the calling tone is valid and sends this code only after4 seconds of proper cadence has been detected.If the DTE does not react to the <DLE>c, and calling tone continues,⌨️ 快捷键说明
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