Un Loopback Test Modes | Multi-Tech Systems MT3334HD8 guide

3 AT Commands

Un Loopback Test Modes

n = 0–3 Default: None

Loopback tests send data through the modem in such a way that it loops back to the terminal where it was entered, testing all the circuits along the way. The U command selects from several loopback tests. See Chapter 5, “Testing the MT3334HD8,” for more information.

ATU0 places the modem in originate mode for the local analog loopback test.

ATU1 places the modem in answer mode for the local analog loopback test.

ATU2 performs the remote digital loopback test.

ATU3 performs the local digital loopback test.

CommPlete Communications Server

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Multi-Tech Systems MT3334HD8 manual Un Loopback Test Modes

Contents

MT3334HD8 Modem User Guide Multi-Tech Systems, Inc Woodale Drive Mounds View, Minnesota CommPlete Communications Server Canadian Limitations Notice FCC Fax Warning Table of Contents Warranty, Service, and Technical Support Testing the MT3334HD8Appendix D Appendix F Introduction Power Supplies LED IndicatorsIntroduction Manual Organization Installation Data Rates Modem Technical Specifications Introduction 2400 & 1200 bps MT3334HD8 User Guide Power Installation MT3334HD8 modem card Safety Warnings Installation Procedure Pre-Installation NotesPage AT Commands Command Structure Working with AT CommandsModes of Operation Command Editing AT Commands by Function $BA Dial Modifier Commands Dialing CommandsDs Dial Continuous Redial Wait for New Dial Tone Pulse or Tone Dialing Return to Command Mode After Dialing Rn Reverse Originate/Answer ModeDialing Pause Flash On-Hook @ Quiet Answer Phone Number Memory CommandsCall Card Tone Detect DsNd Store a Phone Number Wn Store Configuration Configuration Storage and Recall CommandsNdNe Number Linking List Stored Telephone Numbers Fn Load Default Configuration Modem Response Result Code CommandsReset Modem Echo Command Mode Characters Result Codes Verbose/Terse An Answerback Online Connection Commands#An Auto Speed Detection Bn Answer Tone CDn Cleardown at Disconnect DCn AT Command ControlDTn Dtmf Detection Gn Guard Tones #Fn Fallback ModesHn Busy-Out After Disconnect Pn Set Pulse-Dial Ratios $Tn Calling Tone RDn Square Wave Ring Detect#Tn Trellis-Coded Modulation Fn Echo Canceler Frequency Offset Compensation CommandsYn Long Space Disconnect RAn Asymmetric Bit Rate Cn Carrier Detect Control RS-232 Interface CommandsDn Data Terminal Ready Control Sn Data Set Ready Control Rn Clear to Send ControlRFn CTS/RTS Interaction Control SFn DSR/CD Interaction Control En Error Correction Modes Error Correction and Data Compression Commands#Ln V.42 Error Correction Modes En Data Compression $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 $MBn Modem Baud Rate Repeat Last Command Immediate Action CommandsInquire Product Code L5, L7 List Current Operating Parameters Flow Control Commands En Non-Error Correction Mode Flow Control E3 Flow Control DisableE4 Hardware Flow Control E5 XON/XOFF Flow Control #Xn Number of Xoff Characters Sent En Pacing Computer-Initiated Flow Control Escape Sequences Force Answer Mode+++ATCR In-Band Escape Sequence Breakatcr Out-of-Band Escape Sequence Atcr Remote Configuration Escape Sequence Remote Configuration Commands#Ixxxxxx Change Login Password Go Back Online #Syyyyyy Change Setup Password Line Probe CommandsDPn Read Line Probe Data DFn Format Line Probe Data Tn Respond to Remote Digital Loopback Signal Diagnostic CommandsRP Immediate Line Probe Ln Display Line Probe Data Un Loopback Test Modes MT3334HD8 User Guide Registers S0 Number of Rings Until Modem Answers RegistersS1 Ring Count S2 Escape Code Character S4 Line Feed Character S7 Time for Carrier Abort TimerS5 Backspace Character S6 Wait Time for Dial Tone S13 Remote Configuration Escape Character S10 Carrier Loss Disconnect Delay TimeS9 Carrier Detect Response Time S11 Tone Dialing Spacing and Duration S34 Command Buffer Length After Online Escape Sequence S30 Inactivity TimerS24 PBX/CBX Disconnect Drop Time for DSR/CTS/CD S25 DTR Dropout Time S37 DTR Busy-In Time S94 Out-of-Service TimeS43 Force V.34 Connect Speed S48 Maximum V.34 Connect Speed Reading and Assigning S-Register Values AT Commands that Affect S-RegistersExamples of Assigning Values Examples of Reading Values AT&E2$SP1#L3$R0$MB19200$SB115200$EB1S0=10&W0CR Testing the MT3334HD8 Local Analog Loopback Test V.54 Loop Test procedure Remote Digital Loopback Test V.54 Loop Testing the MT3334HD8 Dial 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 Warranty Recording Product Information Technical Support Logging onto the Multi-Tech BBS Multi-Tech BBSDownloading a File Reading a Message About CompuServeLeaving a Message Bulletins About the Internet About the Multi-Tech Fax-Back Service Upgrading the MT3334HD8 Firmware Using FlashPro to Upgrade Firmware MT3334HD8 User Guide Appendixes Ctrl Code HEX DEC Appendix a Ascii Conversion Chart Dial Pulses Appendix B Dial Pulses and TonesTone Dial Frequencies Figure B-2. Standard Dtmf frequencies Multi-Tech Result Codes &Q0 Appendix C Result Code Summary Standard AT Result Codes &Q1 Appendix D S-Register Summary Register Unit Range Default Description Sets fixed V.34 connect speed = 28800 bps Return Appendix E AT Command Summary CDn 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 Passwords Index 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