Multitech MT5634ZBA-USB manual AT Commands

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MT5634ZBA-USB User Guide

AT Commands

AT commands are used to control the operation of your modem. They are so called because each command must be preceded by the characters AT to get the ATtention of the modem.

AT commands can be issued only when the modem is in command mode or online command mode. The modem is in command mode whenever it is not connected to another modem. The modem is in data mode whenever it is connected to another modem and ready to exchange data. Online command mode is a temporary state in which you can issue commands to the modem while connected to another modem. To put the modem into online command mode from data mode, you must issue an escape sequence (+++) followed immediately by the AT characters and the command, e.g.,

+++ATH to hang up the modem. To return to data mode from online command mode, you must issue the command ATO.

To send AT commands to the modem you must use a communications program. You can issue commands to the modem either directly, by typing them in the terminal window of the communications program, or indirectly, by configuring the operating system or communications program to send the commands automatically. Fortunately, communications programs make daily operation of modems effortless by hiding the commands from the user. Most users, therefore, need to use AT commands only when reconfiguring the modem, e.g., to turn autoanswer on or off.

The format for entering an AT command is ATXn, where X is the command and n is the specific value for the command, sometimes called the command parameter. The value is always a number. If the value is zero, you can omit it from the command; thus, AT&W is equivalent to AT&W0. Most commands have a default value, which is the value that is set at the factory. The default values are shown in the “AT Command Summary,” which begins on the next page.

You must press ENTER to send the command to the modem. Any time the modem receives a command, it sends a response known as a result code. The most common result codes are OK, ERROR, and the CONNECT messages that the modem sends to the computer when it is connecting to another modem. For a table of valid result codes, see “Result Codes” at the end of this chapter.

You can issue several commands in one line, in what is called a command string. The command string begins with AT and ends when you press ENTER. Spaces to separate the commands are optional; they are ignored by the command interpreter. The most familiar command string is the initialization string, which is used to configure the modem when it is turned on or reset, or when your communications software calls another modem.

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Contents User Guide Record of Revisions TrademarksContents Index Introduction and Description Universal Serial Bus USB IntroductionProduct Description MT5634ZBA-USB User GuideWhat Is in Your Modem Package? Introduction and DescriptionMT5634ZBA-USB User Guide Quick Start We supply Safety WarningsWhat You Will Need You supplyAssemble the Modem Quick StartInstall the Software Phone Connection Connect the Modem to Your SystemLine Connection USB ConnectionSelect the Modem Test Your ModemFeatures What Can You Do with Your Modem? FeaturesData Computer FaxRequired Equipment Telephone LineConnecting to a Telephone Set Phone Connecting to the Computer USBConnecting to the Telephone Line Line ConnectionsFront Panel Front panelMT5634ZBA-USB User Guide AT Commands, S-Registers and Result Codes AT Commands AT Command Summary Monitor Speaker Volume Command DS=n Dial Stored Telephone NumberEcho Command Mode Characters Echo Online Data CharactersResult Codes Enable/Disable Monitor Speaker ModeReturn Online to Data Mode Command Sr=n Set Register ValueCommand Yn Long Space Disconnect MT5634ZBA-USB User Guide Command Vn Result Code FormatCommand Xn Result Code Selection Modem ResetCommunications Mode Load Factory SettingsCommand &Gn V.22bis Guard Tone Control Asynchronous Communications ModeCommand &Wn Store Current Configuration MT5634ZBA-USB User Guide Command &Tn V.54 Test CommandsDisplay Current Settings Select Stored Configuration for Hard ResetData Buffer Control Error Correction Mode SelectionModem Port Flow Control Break ControlCommand %DCnAT Command Control Inactivity TimerCommand %Cn Data Compression Control Protocol Result CodeCommand #S=x Store Setup Password Command %En Fallback and Fall Forward ControlEnter Setup Password Command%%%ATCRRemote Configuration Escape SequenceRegisters S38 S37Rates K56flex Rates S48 S42S43 S89Result Codes Terse Verbose DescriptionMT5634ZBA-USB User Guide Remote Configuration Setup Basic ProcedureChanging the Setup Password Remote Configuration Changing the Remote Escape CharacterMT5634ZBA-USB User Guide Troubleshooting None of the Indicators Light Modem Does Not Respond to CommandsTroubleshooting Modem Dials But Cannot ConnectModem Doesn’t Work with Caller ID Modem Cannot Connect When AnsweringModem Disconnects While Online Fax and Data Software Can’t Run at the Same TimeAppendixes Appendix a Regulatory Compliance FCC Regulations for Telephone Line InterconnectionClass B Statement Industry CanadaCanadian Limitations Notice FAX Branding StatementInternational Modem Restrictions European DirectivesNew Zealand Telecom Warning Notice Appendix B Technical Specifications ITU-T ConnectorsCarrier Frequencies ITU-T V.32bis/V.32 Carrier FrequenciesDimensions DiagnosticsIndicators WeightAppendix C Loopback Tests IntroductionFigure C-1. Local analog loopback test Test Procedure Local Analog Loopback Test V.54 LoopRemote Digital Loopback Test V.54 Loop Appendix C Loopback TestsFigure C-3. Local digital loopback test Test Procedure Local Digital Loopback Test V.54 LoopOnline Warranty Registration Appendix D Warranty, Service, and Technical SupportLimited Warranty ServiceTo Log on to the Multi-Tech BBS Technical SupportMulti-Tech BBS To Download a FileAbout the Multi-Tech Fax-Back Service About the InternetIndex Index MT5634ZBA-USB User Guide
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