10.1 V.42 Error Correction Modes | Multi-Tech Systems MT2834MR6

Chapter 5 - Error Correction, Data Compression, and Speed Conversion

5.10Compression, Error Correction, Flow Control, and Pacing Commands

The MT2834MR6 has several commands that control error correction, data compression, and flow control:

5.10.1 V.42 Error Correction Modes

&E0 Non-auto correction mode (no error correction).

&E1 Autoreliable mode (factory default).

&E2 Reliable mode.

5.10.2 Modem-Initiated Flow Control

&E3 Disable flow control.

&E4 CTS/RTS hardware flow control (factory default).

&E5 XON/XOFF software flow control.

5.10.3 XON/XOFF Pass-Through

&E6 Respond to and discard XON/XOFF characters when &E5 is selected (factory default).

&E7 Respond to and pass through XON/XOFF characters when &E5 is selected.

5.10.4 Hewlett Packard ENQ/ACK Pacing

&E8 Ignore ENQ/ACK pacing characters (factory default).

&E9 Respond to ENQ/ACK pacing characters.

5.10.5 Non-Error Correction Mode Flow Control

&E10 Non-error correction mode flow control off (factory default). &E11 Non-error correction mode flow control on.

5.10.6 Pacing (Computer-Initiated Flow Control)

&E12 Pacing off.

&E13 Pacing on (factory default).

5.10.7 Data Compression

&E14 Data Compression disabled. &E15 Data Compression enabled.*

*The factory default setting for data compression is enabled, but the modem will not compress data unless &E1 (autoreliable mode) or &E2 (reliable mode) is also selected.

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Multi-Tech Systems MT2834MR6 10.1 V.42 Error Correction Modes, Modem-Initiated Flow Control, 10.3 XON/XOFF Pass-Through

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 300 bps DiagnosticsBell 103/113 Fax Carrier Power Supply Speed Modem LED IndicatorsBusy Switch 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 Modem baud rate Baud adjustFlow control disabled Serial port baud rate Escape sequence selection Force answer modeAlternate out-of-band escape sequence Go back online Dial Dialing CommandsDefault none = phone number Default R0 Dial Modifier CommandsDefault P 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 Default &F8 Configuration Storage and Recall CommandsDefault &W1 = 0, 8, or AT&F8&W0 AT&W1 defaultATZ AT&F9&W0 Modem Response Result Code Commands Result Codes and Call Progress Selection DefaultDefault &A0 Default B0 Online Connection Commands#An Auto Speed Detection Default #A0 DCn AT Command Control = 0 or Default %DC0 #Fn Fallback Modes = 0, 1, or Default #F2 CDn Cleardown at Disconnect = 0 or Default &CD0DTn Dtmf Detection = 0 or Default DT0 Default &P0 Models outside U.K Default &G0 models outside U.KDefault *H0 G2 U.K. models only Default Y0 #T0 disables TCM#T1 enables TCM Issued V.34 Commands Default &D2 RS-232 Interface CommandsDefault &C1 Default &R1 S0 forces DSR high Default &S1Go high again S1 allows DSR to act normally, that is, to follow CD Default &E15 Error Correction and Data Compression CommandsDefault &E1 #Ln Error Correction Modes Default #L0 $Rn Retransmit Count = 0 or Default $R0 $En Error Correction at 300 bps = 0 or Default $E0$An Autoreliable Buffering = 0 or Default $A0 Speed Conversion Commands $SB1200 $SBn Serial Port Baud Rate = speed Default $SB57600$SB300 $SB2400 Immediate Action Commands Rate Renegotiation $EBn Asynchronous Word Length = 0 or Default $EB0 Flow Control CommandsBSn Maximum Reliable Block Size = 0 or Default &BS1 Flow Control Disable Non-Error Correction Mode Flow Control Default &E6Default &E8 Default &E10 Pacing Computer-Initiated Flow Control Default &E13#Xn Number of Xoff Characters Sent = 0 or Default #X0 = 12 or Escape Sequences Remote Configuration Commands Atcr Remote Configuration Escape Sequence Line Probe Commands Diagnostic Commands Registers Registers Default 8 H Default 13 MDefault 10 J Return Character Unit 1 second Time for Carrier Abort TimerDefault 45 North America and International Range 1-255 U.S.A Maximum S11 value is 255 ms 255 units Registers Registers Examples of Reading Values Reading and Assigning S-Register ValuesExamples of Assigning 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 2 #L1 Command V.42 Mode Select Command #L1 #L0 Command 3 #L2 Command Autoreliable Mode &E1 Non-Error Correction Mode &E0Reliable Mode &E2 Modes of Operation Flow Control Flow control and pacing Hardware Flow Control &E4 Modem-Initiated Flow Control1 XON/XOFF Flow Control &E5 1 XON/XOFF Pass-Through &E7 Non-Error Correction Mode Flow Control &E10 and &E11Pacing &E13 Hewlett Packard ENQ/ACK Pacing &E9 Modem-Initiated Flow Control 10.1 V.42 Error Correction ModesNon-Error Correction Mode Flow Control 10.3 XON/XOFF Pass-Through Result Codes MNP Error CorrectionLAP-M Error Correction Speed Conversion Baud Adjust $BA Modem Baud Rate $MB Serial Port Baud Rate $SB Maximum Block Size &BS Related CommandsAutoreliable Buffering $A Autoreliable Fallback Character $F Retransmit Count $R 13.5 V.42 Error Correction at 300 bps $ESummary 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 2 U.S. and Canadian Customers Multi-Tech Systems, Inc. Warranty & Repairs PoliciesWarranty International Customers outside U.S.A. and Canada International Distributors Repairs Repair Procedures for U.S. and Canadian CustomersRepair Procedures for International Customers Country Telephone Technical SupportInternet Site 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 Summary Register Unit Range Default DescriptionAppendix D S34 Appendix E AT Command SummaryCommand Values Description CDn 100 101 102 103 104 105 Appendix F RS-232C Interface SpecificationsSignal Information Negative Positive 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 Setup Introduction to Remote ConfigurationBasic Procedure Changing the Passwords Changing the Remote Escape Character Index Index 118 119 120 121 122 S000326A