Multi-Tech Systems MT3334HD8 manual DCn AT Command Control, CDn Cleardown at Disconnect

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3 AT Commands

%DCn AT Command Control

n = 0 or 1 Default: %DC0

The %DC command allows you to disable the modem’s ability to respond to AT commands. It can be used with auto answer applications in which no call origination is required, with some UNIX applications, and with other applications that require you to disable the modem’s command mode.

%DC0 enables command mode.

%DC1 disables command mode.

Note: If you save %DC1 as part of your default configuration, you can re-enable command mode by typing AT%DC0 and pressing ENTER in the first ten seconds after you power up the modem.

&CDn Cleardown at Disconnect

n = 0 or 1 Default: &CD0

In the V.32, V.32bis, and V.34 protocols, a cleardown is sent by one of the modems to signal the other modem that it is going to hang up. A cleardown is rate renegotiation in which the modem that is hanging up tells the other modem that it has no speeds that it can connect at. It is designed to help the remote modem detect a hang-up. However, it does take a second or two to send the cleardown. If you find this delay unacceptable, you can disable cleardown by using the &CD command.

&CD0 enables cleardown at disconnect.

&CD1 disables cleardown at disconnect.

>DTn DTMF Detection

n = 0 or 1 Default: >DT0

Normally, when it goes off-hook, a fax modem ignores tones from the other end of the connection unless they are fax or modem handshake tones, in which case it responds in kind. The >DT1 command causes the modem to report DTMF (touch-tone) tones and fax calling tones to software for further processing. A typical use would be for a program that routes calls to specific communications applications depending on the type of call or upon a DTMF tone added to a dialing string.

>DT0 disables DTMF detection.

>DT1 enables DTMF detection when the modem goes off-hook.

CommPlete Communications Server

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Contents MT3334HD8 Modem User Guide Multi-Tech Systems, Inc Woodale Drive Mounds View, Minnesota CommPlete Communications Server Canadian Limitations Notice FCC Fax WarningTable of Contents Appendix F Testing the MT3334HD8Warranty, Service, and Technical Support Appendix DIntroduction Manual Organization LED IndicatorsPower Supplies IntroductionInstallation Data Rates Modem Technical SpecificationsIntroduction 2400 & 1200 bps MT3334HD8 User Guide Power Installation MT3334HD8 modem card Safety WarningsInstallation Procedure Pre-Installation NotesPage AT Commands Command Structure Working with AT CommandsModes of Operation Command Editing AT Commands by Function $BA Continuous Redial Dialing CommandsDial Modifier Commands Ds DialWait for New Dial Tone Pulse or Tone DialingFlash On-Hook Rn Reverse Originate/Answer ModeReturn to Command Mode After Dialing Dialing PauseDsNd Store a Phone Number Phone Number Memory Commands@ Quiet Answer Call Card Tone DetectList Stored Telephone Numbers Configuration Storage and Recall CommandsWn Store Configuration NdNe Number LinkingFn Load Default Configuration Modem Response Result Code CommandsReset Modem Echo Command Mode Characters Result Codes Verbose/Terse Bn Answer Tone Online Connection CommandsAn Answerback #An Auto Speed DetectionCDn Cleardown at Disconnect DCn AT Command ControlDTn Dtmf Detection Pn Set Pulse-Dial Ratios #Fn Fallback ModesGn Guard Tones Hn Busy-Out After Disconnect$Tn Calling Tone RDn Square Wave Ring Detect#Tn Trellis-Coded Modulation RAn Asymmetric Bit Rate CommandsFn Echo Canceler Frequency Offset Compensation Yn Long Space DisconnectCn Carrier Detect Control RS-232 Interface CommandsDn Data Terminal Ready Control SFn DSR/CD Interaction Control Rn Clear to Send ControlSn Data Set Ready Control RFn CTS/RTS Interaction ControlEn Data Compression Error Correction and Data Compression CommandsEn Error Correction Modes #Ln V.42 Error Correction Modes$Fn Auto-Reliable Fallback Character Enable/Disable $En V.42 Error Correction at 300 bps$An Auto-Reliable Buffering $BAn Baud Adjust Speed Conversion Commands$Rn Retransmit Count $SBn Serial Port Baud Rate $MBn Modem Baud RateL5, L7 List Current Operating Parameters Immediate Action CommandsRepeat Last Command Inquire Product CodeFlow Control Commands E5 XON/XOFF Flow Control E3 Flow Control DisableEn Non-Error Correction Mode Flow Control E4 Hardware Flow Control#Xn Number of Xoff Characters Sent En Pacing Computer-Initiated Flow ControlBreakatcr Out-of-Band Escape Sequence Force Answer ModeEscape Sequences +++ATCR In-Band Escape SequenceGo Back Online Remote Configuration CommandsAtcr Remote Configuration Escape Sequence #Ixxxxxx Change Login PasswordDFn Format Line Probe Data Line Probe Commands#Syyyyyy Change Setup Password DPn Read Line Probe DataLn Display Line Probe Data Diagnostic CommandsTn Respond to Remote Digital Loopback Signal RP Immediate Line ProbeUn Loopback Test Modes MT3334HD8 User Guide Registers S2 Escape Code Character RegistersS0 Number of Rings Until Modem Answers S1 Ring CountS6 Wait Time for Dial Tone S7 Time for Carrier Abort TimerS4 Line Feed Character S5 Backspace CharacterS11 Tone Dialing Spacing and Duration S10 Carrier Loss Disconnect Delay TimeS13 Remote Configuration Escape Character S9 Carrier Detect Response TimeS25 DTR Dropout Time S30 Inactivity TimerS34 Command Buffer Length After Online Escape Sequence S24 PBX/CBX Disconnect Drop Time for DSR/CTS/CDS48 Maximum V.34 Connect Speed S94 Out-of-Service TimeS37 DTR Busy-In Time S43 Force V.34 Connect SpeedExamples of Reading Values AT Commands that Affect S-RegistersReading and Assigning S-Register Values Examples of Assigning ValuesAT&E2$SP1#L3$R0$MB19200$SB115200$EB1S0=10&W0CR Testing the MT3334HD8 Local Analog Loopback Test V.54 Loop Test procedureRemote Digital Loopback Test V.54 Loop Testing the MT3334HD8Dial the remote modem and establish your online connection Local digital loopback test Local Digital Loopback Test V.54 LoopPage Warranty, Service, and Technical Support Service Limited WarrantyRecording Product Information Technical SupportLogging onto the Multi-Tech BBS Multi-Tech BBSDownloading a File Bulletins About CompuServeReading a Message Leaving a MessageAbout the Internet About the Multi-Tech Fax-Back ServiceUpgrading the MT3334HD8 Firmware Using FlashPro to Upgrade FirmwareMT3334HD8 User Guide Appendixes Ctrl Code HEX DEC Appendix a Ascii Conversion ChartDial Pulses Appendix B Dial Pulses and TonesTone Dial Frequencies Figure B-2. Standard Dtmf frequencies Multi-Tech Result Codes &Q0 Appendix C Result Code SummaryStandard AT Result Codes &Q1 Appendix D S-Register Summary Register Unit Range Default DescriptionSets fixed V.34 connect speed = 28800 bps Return Appendix E AT Command SummaryCDn AT Command Summary $Fn Command Values Description Command Values Description $MBn RAn Command Values Description SFn Command Values Description #Vn Breakatcr Basic Procedure Appendix F Remote ConfigurationSetup Changing the Remote Escape Character Changing the PasswordsIndex MT3334HD8 User Guide Index Long space break Pacing, 36, 37, 38 enable/disable, 38 ENQ/ACK Commands Loopback tests, 42, 43, 54, 56 tone detection