Diagnostic Commands | Multi-Tech Systems MT2834MR6 manual

Chapter 3 - AT Commands

3.16 Diagnostic Commands

The MT2834MR6 has two diagnostic commands and four diagnostic modes. The power-on self-test is activated every time power is applied. The U command selects a loopback test, while the &T command enables a modem to respond to a loopback test from another modem. See Chapter 6, “Testing the MT2834MR6,” for a fuller discussion. Refer to the L8 command to see how to list the diagnostic online status.

&Tn	Respond to Remote Digital Loopback Signal
	n = 4 or 5
	Default: &T5
	The MT2834MR6 has several self-test features, discussed in Chapter 6. The &T command
	enables or disables the modem’s ability to recognize the remote digital loopback (RDL) test
	signal. (See Chapter 6 for remote digital loopback test procedures.)
	AT&T4 lets the modem respond to an RDL signal, and places it in digital loopback.
	AT&T5 causes the modem to ignore the RDL signal.
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 6, “Testing Your Modem,” 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.

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Multi-Tech Systems MT2834MR6 manual Diagnostic Commands

Contents

User Guide Trademarks Revision Date Description Contents Registers Warranty & Service Index 116 Introduction Manual Organization Introduction Description FCC Regulations for Telephone Line Interconnection FCC Fax Update Canadian Limitations Notice Technical Specifications Fax Carrier DiagnosticsBell 103/113 300 bps Power Supply Data Rate bps LED State Modem LED IndicatorsBusy Switch Speed Safety Warnings 10 MT2834MR6 Installation Notes Dialing and Answering Dial-Up Handshaking Details Dial-Up Automatic Answering Call Termination AT Commands Modes of Operation Working with AT Commands Command Editing Command Structure AT Commands Serial port baud rate Baud adjustFlow control disabled Modem baud rate Go back online Force answer modeAlternate out-of-band escape sequence Escape sequence selection = phone number Dialing CommandsDefault none Dial Pulse or Tone Dialing Dial Modifier CommandsDefault P Default R0 Or 4 through 255 seconds International models ATDT1028806127853500 $123456789 NdNe Number Linking = 0 or = 1 or Default none Phone Number Memory Commands P9,T14089876543 T14082345678 = 0, 8, or Configuration Storage and Recall CommandsDefault &W1 Default &F8 AT&F9&W0 AT&W1 defaultATZ AT&F8&W0 Modem Response Result Code Commands Default &A0 DefaultResult Codes and Call Progress Selection DCn AT Command Control = 0 or Default %DC0 Online Connection Commands#An Auto Speed Detection Default #A0 Default B0 DTn Dtmf Detection = 0 or Default DT0 CDn Cleardown at Disconnect = 0 or Default &CD0#Fn Fallback Modes = 0, 1, or Default #F2 G2 U.K. models only Default &G0 models outside U.KDefault *H0 Default &P0 Models outside U.K Issued #T0 disables TCM#T1 enables TCM Default Y0 V.34 Commands Default &R1 RS-232 Interface CommandsDefault &C1 Default &D2 S1 allows DSR to act normally, that is, to follow CD Default &S1Go high again S0 forces DSR high #Ln Error Correction Modes Default #L0 Error Correction and Data Compression CommandsDefault &E1 Default &E15 $An Autoreliable Buffering = 0 or Default $A0 $En Error Correction at 300 bps = 0 or Default $E0$Rn Retransmit Count = 0 or Default $R0 Speed Conversion Commands $SB2400 $SBn Serial Port Baud Rate = speed Default $SB57600$SB300 $SB1200 Immediate Action Commands Rate Renegotiation Flow Control Disable Flow Control CommandsBSn Maximum Reliable Block Size = 0 or Default &BS1 $EBn Asynchronous Word Length = 0 or Default $EB0 Default &E10 Default &E6Default &E8 Non-Error Correction Mode Flow Control = 12 or Default &E13#Xn Number of Xoff Characters Sent = 0 or Default #X0 Pacing Computer-Initiated Flow Control Escape Sequences Atcr Remote Configuration Escape Sequence Remote Configuration Commands Line Probe Commands Diagnostic Commands Registers Registers Return Character Default 13 MDefault 10 J Default 8 H Range 1-255 U.S.A Time for Carrier Abort TimerDefault 45 North America and International Unit 1 second Maximum S11 value is 255 ms 255 units Registers Registers Examples of Assigning Values Reading and Assigning S-Register 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 MNP Classes Data Compression 3 #L2 Command V.42 Mode Select Command #L1 #L0 Command 2 #L1 Command Modes of Operation Non-Error Correction Mode &E0Reliable Mode &E2 Autoreliable Mode &E1 Flow control and pacing Flow Control 1 XON/XOFF Flow Control &E5 Modem-Initiated Flow ControlHardware Flow Control &E4 Hewlett Packard ENQ/ACK Pacing &E9 Non-Error Correction Mode Flow Control &E10 and &E11Pacing &E13 1 XON/XOFF Pass-Through &E7 10.3 XON/XOFF Pass-Through 10.1 V.42 Error Correction ModesNon-Error Correction Mode Flow Control Modem-Initiated Flow Control Speed Conversion MNP Error CorrectionLAP-M Error Correction Result Codes Modem Baud Rate $MB Baud Adjust $BA Serial Port Baud Rate $SB Autoreliable Fallback Character $F Related CommandsAutoreliable Buffering $A Maximum Block Size &BS Summary 13.5 V.42 Error Correction at 300 bps $ERetransmit Count $R Testing & Troubleshooting Testing and Troubleshooting Local Analog Loopback Test V.54 Loop Test Procedure Remote digital loopback test Remote Digital Loopback Test V.54 Loop Local digital loopback test Local Digital Loopback Test V.54 Loop Warranty & Service Warranty Multi-Tech Systems, Inc. Warranty & Repairs Policies2 U.S. and Canadian Customers International Distributors International Customers outside U.S.A. and Canada Repair Procedures for International Customers Repair Procedures for U.S. and Canadian CustomersRepairs Internet Site Technical SupportCountry Telephone Appendices Appendix a Ascii Conversion Chart Dial Pulses Appendix B Figure B-2. Standard Dtmf frequencies Tone Dial Frequencies Result Code Summary Appendix C Standard AT Result Codes &Q1 Appendix D Register Unit Range Default DescriptionRegister Summary S34 Command Values Description AT Command SummaryAppendix E CDn 100 101 102 103 104 105 Signal Information Negative Positive RS-232C Interface SpecificationsAppendix F Transmitted Data TD Pin 2 To modem Functional Description of the RS-232C Signals Test Voltage +V Pin From modem External Transmit Clock XTC Pin To modem Appendix G Cable and Connector Diagrams Introduction to MultiTech Escape Methods Appendix H Escape Method 1 +++ATCR How to Select an Escape Method Aborting an Escape Sequence Registers and Escape Sequence Basic Procedure Introduction to Remote ConfigurationSetup Changing the Remote Escape Character Changing the Passwords Index Index 118 119 120 121 122 S000326A