Appendix C Loopback Tests, Introduction | Multitech MT5634ZBA-USB

Appendix B - Technical Specifications

Appendix C: Loopback Tests

Introduction

Each time you turn on your modem, it performs an automatic self-test to ensure proper operation. Your modem also has three diagnostic tests: local analog loopback, remote digital loopback, and local digital loopback. These ITU-T V.54 loopback tests isolate telephone circuit and transmission problems.

In a loopback test, data from your computer loops through the circuits of your modem and/or a remote modem before it appears on your monitor. When the loop has been completed, the data on your computer’s monitor should match the original data.

The local analog loopback test allows you to verify that the modem’s transmitter and receiver circuits are functioning properly.

The local digital loopback allows you to verify that the local computer or terminal, the two modems, and the transmission line between them are functioning properly.

The remote digital loopback test allows you to verify that the remote computer or terminal, the remote modem, the serial ports, the telephone line, and the local modem are functioning properly.

Note: All loopback tests operate at all speeds except 300 bps.

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Multitech MT5634ZBA-USB manual Appendix C Loopback Tests, Introduction

Contents

User Guide Trademarks Record of Revisions Contents Index Introduction and Description Product Description IntroductionUniversal Serial Bus USB MT5634ZBA-USB User Guide Introduction and Description What Is in Your Modem Package? MT5634ZBA-USB User Guide Quick Start What You Will Need Safety WarningsWe supply You supply Quick Start Assemble the Modem Install the Software Line Connection Connect the Modem to Your SystemPhone Connection USB Connection Test Your Modem Select the Modem Features Data FeaturesWhat Can You Do with Your Modem? Required Equipment FaxComputer Telephone Line Connecting to the Telephone Line Line Connecting to the Computer USBConnecting to a Telephone Set Phone Connections Front panel Front Panel MT5634ZBA-USB User Guide AT Commands, S-Registers and Result Codes AT Commands AT Command Summary Echo Command Mode Characters Command DS=n Dial Stored Telephone NumberMonitor Speaker Volume Echo Online Data Characters Return Online to Data Mode Monitor Speaker ModeResult Codes Enable/Disable Command Sr=n Set Register Value Command Xn Result Code Selection MT5634ZBA-USB User Guide Command Vn Result Code FormatCommand Yn Long Space Disconnect Modem Reset Command &Gn V.22bis Guard Tone Control Load Factory SettingsCommunications Mode Asynchronous Communications Mode Display Current Settings MT5634ZBA-USB User Guide Command &Tn V.54 Test CommandsCommand &Wn Store Current Configuration Select Stored Configuration for Hard Reset Modem Port Flow Control Error Correction Mode SelectionData Buffer Control Break Control Command %Cn Data Compression Control Inactivity TimerCommand %DCnAT Command Control Protocol Result Code Enter Setup Password Command %En Fallback and Fall Forward ControlCommand #S=x Store Setup Password Command%%%ATCRRemote Configuration Escape Sequence Registers Rates K56flex Rates S37S38 S43 S42S48 S89 Terse Verbose Description Result Codes MT5634ZBA-USB User Guide Remote Configuration Changing the Setup Password Basic ProcedureSetup Changing the Remote Escape Character Remote Configuration MT5634ZBA-USB User Guide Troubleshooting Modem Does Not Respond to Commands None of the Indicators Light Modem Dials But Cannot Connect Troubleshooting Modem Disconnects While Online Modem Cannot Connect When AnsweringModem Doesn’t Work with Caller ID Fax and Data Software Can’t Run at the Same Time Appendixes FCC Regulations for Telephone Line Interconnection Appendix a Regulatory Compliance Industry Canada Class B Statement FAX Branding Statement Canadian Limitations Notice New Zealand Telecom Warning Notice European DirectivesInternational Modem Restrictions Appendix B Technical Specifications Carrier Frequencies ConnectorsITU-T ITU-T V.32bis/V.32 Carrier Frequencies Indicators DiagnosticsDimensions Weight Introduction Appendix C Loopback Tests Local Analog Loopback Test V.54 Loop Figure C-1. Local analog loopback test Test Procedure Appendix C Loopback Tests Remote Digital Loopback Test V.54 Loop Local Digital Loopback Test V.54 Loop Figure C-3. Local digital loopback test Test Procedure Limited Warranty Appendix D Warranty, Service, and Technical SupportOnline Warranty Registration Service Multi-Tech BBS Technical SupportTo Log on to the Multi-Tech BBS To Download a File About the Internet About the Multi-Tech Fax-Back Service Index Index MT5634ZBA-USB User Guide