Online Connection Commands | Multi-Tech Systems MT2834MR6 instruction

Chapter 3 - AT Commands

3.7Online Connection Commands

The following commands control the conditions of the online connection.

#An	Auto Speed Detection
	n = 0–3
	Default: #A0
	An MT2834MR6 modem can operate as a 33,600 bps, 28,800 bps, 19,200 bps, 14,400 bps,
	9600 bps, 4800 bps, 2400 bps, or 300 bps modem. Use the #A command to select the
	speed that the modem uses for initial handshaking and subsequent speed selection. The
	#A command does not control the originating bps rate of the modem (that is done by the
	modem baud rate command $MB), but only the answer mode starting speed.
	#A0 causes the modem to start at maximum speed, with fallback to 31,200 to 28,800 to
	26,400 to 24,000 to 21,600 to 19,200 to 16,800 to 14,400 to 12,000 to 9600 to 4800 to 2400
	to 1200 to 300 bps.
	#A1 causes the modem to operate at maximum speed only.
	#A2 causes the modem to start at maximum speed, with decremental fallback to 4800 bps.
	#A3 causes the modem to start at 2400 bps in V.22bis mode, with fallback to 1200 to 300
	bps.
Bn	Answer Tone
	n = 0 or 1
	Default: B0
	The B command selects the frequency the modem uses for its answer tone. (The answer
	tone is the tone a modem receiving a call transmits to the modem that called it, thus
	initiating the handshake between the two modems.) At higher speeds (2400 to 33,600 bps)
	there is no conflict, because all protocols use the Bell frequency of 2225 Hz. However, the
	ITU-T specification for V.22 has an answer tone frequency of 2100 Hz. This command is
	available only in International models.
	B0 enables ITU-T frequencies including V.21 (300 bps) and V.23 (1200/75 bps).
	B1 enables Bell frequencies including Bell 103 (300 bps).
%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 autoanswer 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.

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Multi-Tech Systems MT2834MR6 manual Online Connection Commands, #An Auto Speed Detection Default #A0, Default B0

Contents

User Guide Revision Date Description Trademarks Contents Registers Warranty & Service Index 116 Introduction Introduction Manual Organization Description FCC Fax Update FCC Regulations for Telephone Line Interconnection Canadian Limitations Notice Technical Specifications Diagnostics Bell 103/113300 bps Fax Carrier Power Supply Modem LED Indicators Busy SwitchSpeed Data Rate bps LED State 10 MT2834MR6 Installation Notes Safety Warnings Dialing and Answering Dial-Up Automatic Answering Dial-Up Handshaking Details Call Termination AT Commands Working with AT Commands Modes of Operation Command Structure Command Editing AT Commands Baud adjust Flow control disabledModem baud rate Serial port baud rate Force answer mode Alternate out-of-band escape sequenceEscape sequence selection Go back online Dialing Commands Default noneDial = phone number Dial Modifier Commands Default PDefault R0 Pulse or Tone Dialing Or 4 through 255 seconds International models ATDT1028806127853500 $123456789 Phone Number Memory Commands NdNe Number Linking = 0 or = 1 or Default none T14082345678 P9,T14089876543 Configuration Storage and Recall Commands Default &W1Default &F8 = 0, 8, or AT&W1 default ATZAT&F8&W0 AT&F9&W0 Modem Response Result Code Commands Default Default &A0Result Codes and Call Progress Selection Online Connection Commands #An Auto Speed Detection Default #A0Default B0 DCn AT Command Control = 0 or Default %DC0 CDn Cleardown at Disconnect = 0 or Default &CD0 DTn Dtmf Detection = 0 or Default DT0#Fn Fallback Modes = 0, 1, or Default #F2 Default &G0 models outside U.K Default *H0Default &P0 Models outside U.K G2 U.K. models only #T0 disables TCM #T1 enables TCMDefault Y0 Issued V.34 Commands RS-232 Interface Commands Default &C1Default &D2 Default &R1 Default &S1 Go high againS0 forces DSR high S1 allows DSR to act normally, that is, to follow CD Error Correction and Data Compression Commands Default &E1Default &E15 #Ln Error Correction Modes Default #L0 $En Error Correction at 300 bps = 0 or Default $E0 $An Autoreliable Buffering = 0 or Default $A0$Rn Retransmit Count = 0 or Default $R0 Speed Conversion Commands $SBn Serial Port Baud Rate = speed Default $SB57600 $SB300$SB1200 $SB2400 Immediate Action Commands Rate Renegotiation Flow Control Commands BSn Maximum Reliable Block Size = 0 or Default &BS1$EBn Asynchronous Word Length = 0 or Default $EB0 Flow Control Disable Default &E6 Default &E8Non-Error Correction Mode Flow Control Default &E10 Default &E13 #Xn Number of Xoff Characters Sent = 0 or Default #X0Pacing Computer-Initiated Flow Control = 12 or Escape Sequences Remote Configuration Commands Atcr Remote Configuration Escape Sequence Line Probe Commands Diagnostic Commands Registers Registers Default 13 M Default 10 JDefault 8 H Return Character Time for Carrier Abort Timer Default 45 North America and InternationalUnit 1 second Range 1-255 U.S.A Maximum S11 value is 255 ms 255 units Registers Registers Reading and Assigning S-Register Values Examples of Assigning ValuesExamples of Reading Values AT Commands Affecting S-Registers Error Correction, Data Compression & Speed Conversion Error Correction, Data Compression, and Speed Conversion How V.42 Detects and Corrects Errors Data Compression MNP Classes V.42 Mode Select Command #L 1 #L0 Command2 #L1 Command 3 #L2 Command Non-Error Correction Mode &E0 Reliable Mode &E2Autoreliable Mode &E1 Modes of Operation Flow Control Flow control and pacing Modem-Initiated Flow Control 1 XON/XOFF Flow Control &E5Hardware Flow Control &E4 Non-Error Correction Mode Flow Control &E10 and &E11 Pacing &E131 XON/XOFF Pass-Through &E7 Hewlett Packard ENQ/ACK Pacing &E9 10.1 V.42 Error Correction Modes Non-Error Correction Mode Flow ControlModem-Initiated Flow Control 10.3 XON/XOFF Pass-Through MNP Error Correction LAP-M Error CorrectionResult Codes Speed Conversion Baud Adjust $BA Modem Baud Rate $MB Serial Port Baud Rate $SB Related Commands Autoreliable Buffering $AMaximum Block Size &BS Autoreliable Fallback Character $F 13.5 V.42 Error Correction at 300 bps $E SummaryRetransmit Count $R Testing & Troubleshooting Testing and Troubleshooting Test Procedure Local Analog Loopback Test V.54 Loop Remote Digital Loopback Test V.54 Loop Remote digital loopback test Local Digital Loopback Test V.54 Loop Local digital loopback test Warranty & Service Multi-Tech Systems, Inc. Warranty & Repairs Policies Warranty2 U.S. and Canadian Customers International Customers outside U.S.A. and Canada International Distributors Repair Procedures for U.S. and Canadian Customers Repair Procedures for International CustomersRepairs Technical Support Internet SiteCountry Telephone Appendices Ascii Conversion Chart Appendix a Appendix B Dial Pulses Tone Dial Frequencies Figure B-2. Standard Dtmf frequencies Appendix C Result Code Summary Standard AT Result Codes &Q1 Register Unit Range Default Description Appendix DRegister Summary S34 AT Command Summary Command Values DescriptionAppendix E CDn 100 101 102 103 104 105 RS-232C Interface Specifications Signal Information Negative PositiveAppendix F Functional Description of the RS-232C Signals Transmitted Data TD Pin 2 To modem Test Voltage +V Pin From modem External Transmit Clock XTC Pin To modem Cable and Connector Diagrams Appendix G Appendix H Introduction to MultiTech Escape Methods How to Select an Escape Method Escape Method 1 +++ATCR Registers and Escape Sequence Aborting an Escape Sequence Introduction to Remote Configuration Basic ProcedureSetup Changing the Passwords Changing the Remote Escape Character Index Index 118 119 120 121 122 S000326A