Multitech MT2834MR, MT2834MRK, MT2834MRI Owner's Manual

PN 88300150

MT2834MR, MT2834MRI, and

MT2834MRK

Owner’s Manual

4/3/01 1

PN 88300150

MT2834MR, MT2834MRI, MT2834MRK

Owner’s Manual

MOD PN 88300150 Version 1.00 - 4/3/01

(Replaces Manual PN 82035706 Rev. G)

Multi-Tech Systems, Inc. makes no representations or warranties with respect to the contents hereof and specifically disclaims any implied warranties of merchantability or fitness for any particular purpose. Furthermore, Multi-T ech Systems, Inc. reserves the right to revise this publication and to make changes from time to time in the content hereof without obligation of Multi-Tech Systems, Inc. to notify any person or organization of such revisions or changes.

Record of Revisions

Revision

F 08/19/96 Manual revised to include technical and editorial changes G 11/11/96 Manual revised to include the Firmware Version 1.11 Product H 4/3/0 1 Manual revised and reformatte d for distr ibution on diskette.

Trademarks of Multi-Tech Systems, Inc. are as follows: MultiModem, MultiModemII, MultiModemManager, MultiExpress, MultiExpressFax, Multi-Tech and the Multi-T ech logo. MNP and Microcom Network Protocol are trademarks of Microcom Inc. AS/400 and System/3x is a trademark of IBM. Macintosh is a trademark of Apple Computer Inc. Unix is a trademark of X/Open Co. Ltd. AT&T is a trademark of American Telephone and Telegraph Company.

This device covered by one or more of the following patents: 6,031,867; 6,012,113; 6,009,082; 5,905,794; 5,864,560; 5,815,567; 5,815,503; 5,812,534; 5,809,068; 5,790,532; 5,764,628; 5,764,627; 5,754,589; D394,250; 5,724,356; 5,673,268; 5,673,257; 5,644,594; 5,628,030; 5,619,508; 5,617,423; 5,600,649; 5,592,586; 5,577,041; 5,574,725; D374,222; 5,559,793; 5,546,448; 5,546,395; 5,535,204; 5,500,859; 5,471,470; 5,463,616; 5,453,986; 5,452,289; 5,450,425; D361,764; D355,658; D355,653; D353,598; D353,144; 5,355,365; 5,309,562; 5,301,274 Other Patents Pending

Date Description

throughout the manual. Update, PN 82053850.

TRADEMARKS

PATENTS

4/3/01 2

Multi-Tech Systems, Inc.

2205 Woodale Drive

Mounds View, Minnesota 55112 U.S.A.

(763) 785-3500 or (800) 328-9717

U.S. Fax (763) 785-9874

Technical Support (800) 972-2439

Internet Address:

http://www.multitech.com

PN 88300150

CHAPTER 1 - INTRODUCTION AND DESCRIPTION

1.1 Introduction.................................................................................6

1.2 How To Use This Manual ...........................................................6

1.3 Description..................................................................................7

1.4 FCC Regulations for Telephone Line Interconnection................8

1.5 Canadian Limitations Notice.....................................................10

1.6 Compliance with BABT Requirements (MT2834MRK only).....11

1.7 Technical Specifications...........................................................11

1.8 Power........................................................................................13

1.9 Modem LED Indicators .............................................................13

1.10 BUSY Switch.............................................................................14

1.11 Controls on PC Board...............................................................14

1.12 MT2834MRK Installation Notes................................................14

CHAPTER 2 - DIALING AND ANSWERING

2.1 Introduction...............................................................................15

2.2 Automatic Leased Line Restoral Operation..............................15

2.3 Manual Dial Backup Call Termination.......................................15

2.4 Dial Back-up Leased Line Restoral ..........................................16

2.5 Dial-up Automatic Answering ....................................................16

2.6 Dial-up Handshaking Details ....................................................16

2.7 Call Termination........................................................................16

CHAPTER 3 - COMMAND MODE OPERATION

3.1 Introduction...............................................................................18

3.2 Typographic Conventions Used in This Manual.......................18

3.3 Functional Modes .....................................................................19

3.4 AT Commands..........................................................................21

3.5 Result Codes ............................................................................24

3.6 Command Mode Fundamentals ...............................................26

3.7 Dialing Commands ...................................................................32

3.8 Immediate Action Commands ...................................................34

3.9 Configuration Commands.........................................................36

CHAPTER 4 - S-REGISTERS

4.1 Introduction...............................................................................38

4.2 Reading and Assigning S-Register Values...............................38

4.3 AT Commands that Affect S-Registers.....................................42

4.4 Summary...................................................................................43

CHAPTER 5 - ERROR CORRECTION, DATA COMPRESSION AND SPEED CONVERSION

5.1 Introduction...............................................................................45

5.2 How V.42 Detects and Corrects Errors.....................................46

5.3 Data Compression....................................................................47

5.4 MNP Classes............................................................................48

5.5 V.42 Mode Select Command (#L) ............................................48

5.6 Modes of Operation .................................................................. 49

5.7 Introduction to Flow Control......................................................49

5.8 Modem-Initiated Flow Control...................................................50

5.9 Terminal/Computer-Initiated Pacing (&E13).............................50

5.10 Xon/Xoff Pass-Through (&E7) ..................................................51

5.11 Normal Mode Modem Flow Control (&E10 and &E11).............52

5.12 Hewlett Packard ENQ /AC K Pacing ( &E9) ................................52

4/3/01 3

PN 88300150

5.13 Compression, Error Correction, Flow Control,..........................53

Pass Through and Pacing Commands.....................................54

5.14

5.14 Error Correction Result Codes..................................................54

5.15 Speed Conversion ....................................................................55

5.16 Related Command s..................................................................55

5.17 Summary...................................................................................56

CHAPTER 6 - TESTING YOUR MODEM

6.1 Introduction ..............................................................................57

6.2 Local Analog Loopback Test/V.54 Loop 3 ...............................57

6.3 Digital Loopback Test/V.54 Loop 2 (Local/Manual)..................57

6.4 Digital Loopback Test/V.54 Loop 2 (Remote/Automatic)..........58

6.5 Back-to-Back Test ....................................................................59

6.6 Synchronous Mode Testing......................................................60

6.7 Local Analog Loopback Test (Sync. Mode)..............................61

6.8 Digital Loopback Test (Local/Manual) (Sync. Mode)................62

6.9 Digital Loopback Test (Remote/Automatic) (Sync. Mode)........63

CHAPTER 7 - DIP-SWITCHES AND JUMPERS

7.1 Introduction...............................................................................64

7.2 16-Position DIP-Switches.........................................................65

7.3 16-Position DIP-Switch Settings...............................................68

7.4 Jumper Settings........................................................................70

CHAPTER 8 - SERVICE, WARRANTY & TECH SUPPORT

8.1 Introduction...............................................................................72

8.2 Limited Warranty.......................................................................72

8.3 Tech Support ............................................................................72

8.4 Service......................................................................................72

8.7 How to Find Multi-Tech on the Internet.....................................73

8.9 Upgrading the MT2834MR Firmware .......................................73

APPENDICES

Appendix A - ASCII Codes/Hex/Decimal Conversion Chart............74

Appendix B - Dial Pulse and Tone Frequencies..............................75

Appendix C - DIP-Switch Summary.................................................77

Appendix D - Result Code Summary...............................................78

Appendix E - S-Register Summary..................................................80

Appendix F - AT Command Summary.............................................81

Appendix G - V.25bis Operation ......................................................85

Appendix H - RS232C Interface Specifications ...............................93

Appendix I - Cable and Connector Diagrams.................................96

Appendix J - Escape Methods Used by Multi-Tech Systems .......100

Appendix K - Remote Configuration..............................................103

Appendix L - MT2834MRI PC Board ............................................104

4/3/01 4

PN 88300150

1.1 Introduction

Welcome to the world of data communications. You have acquired one of the finest rack-mount intelligent modems available, the MT2834MR, from Multi-Tech Systems. This owner’s manual will help you install, configure, test, and use your modem.

Your MT2834MR is designed to operate in two modes. First, it functions as a 33,600 bps leased line modem with dialback security. Communications over leased lines have been popular for many years primarily over 4-wire lines using V.29 modulation techniques. There have been dial back-up features in some leased line modems, but the dial back-up was at a slower speed. Your MT2834MR uses V.34 modulation that is designed for full 33,600 bps full duplex operation over 2-wires. That means when the MT2834MR uses its dial back-u p capa bi lit y, per for manc e do es not su ffer .

The second MT2834MR mode of operati on is as a standar d ITU-T V.34 2-wir e di al-up mo dem. As such, it has incorporated all the advanced features of other Multi-Tech intelligent modems.

This manual documents all of the MT2834MR’s features a nd ca pab il it ie s, su ch as auto di al, auto-answer, auto-fallback, number linking, option switches, phone number memory, call progress detection, and more. The next section will show you how to use this manual. The contents of each chapter are listed, so you will know where to turn for specific information.

1.2 How To Use This Manual

This manual is divided into eight chapters. There are also several appendices at the end of the manual, most of which repeat information contained in the chapters, but in a more condensed form. The information contained in each chapter and appendix is as follows:

Chapter 1 - Introduction & Description

This chapter begins with a short introduction, followed by a guide (which you are now reading) to the use of the manual. We then provide a more detailed description of the modem, as well as a chart containing the modem’s technical specifications. This is then followed by sections covering power, LED indicators and a brief summary of modem swit ch opt ion s. (C hapt er 7 cover s swit ch se tti ng s mor e thor ou ghl y.)

Chapter 2 - Dialing and Answering

This chapter covers Answer mode operation in detail, as well as the handshaking procedures between two modems and an auto-answer application. Various methods of call termination are also discussed.

Chapter 3 - Command Mode Operation

This may be the most important chapter of this manual. It begins with an introduction and discussion of the MT2834MR’s Command mode fundamentals. A flow chart is provided to illustrate Command mode and On-Line mode operation and the methods used to enter each mode. Next, there is a summary of the modem’s commands and responses. We then go into a detailed explanation of each command, providing examples where applicable.

Chapter 4 - S-Registers

This chapter covers the MT2834MR’s S-Reg is ters , whic h are used to store an d/or configure various modem options. All of the S-Registers are defined and explained, followed by instructions on accessing the S-Registers and reading or ch ang ing the ir val ue s.

Chapter 5 - Error Correction, Data Compression and Speed Conversion

This chapter provides information concerning some of the advanced features of the MT2834MR. Features such as V.42 Error Correction, MNP 5 Data Compression, Speed Conversion and others enable your MT2834MR to operate at a higher level of efficiency than possible with standard AT command set features.

4/3/01 5

PN 88300150

Chapter 6 - Testing Your Modem

This chapter provides information on loopback testing for your MT2834MR.

Chapter 7 - DIP Switches and Jumpers

The MT2834MR’s printed c ir cuit boar d optio ns ar e co ver ed in this chapt er . The DIP sw it ch se tti ng s and on-board jumper plugs are explained in detail, including all default settings.

Chapter 8 - Service, Warranty and Tech Support

This chapter provides instructions for getting modems serviced at the factory, a statement of limited twoyear warranty and information about Multi-Tech's Technical Support. Information on the modem upgrade feature is also provided.

Appendix A - ASCII/HEX/Decimal Conversion Chart Appendix B - Dial Pulses and Tone Dial Frequencies Appendix C - DIP-Switch Summary Appendix D - Result Code Summary Appendix E - S-Register Summary Appendix F - AT Command Summary Appendix G - V.25bis Operation Appendix H - RS232C Interface Specifications Appendix I - Cable and Connector Diagrams Appendix J - Escape Sequences Used by Multi-Tech Systems Appendix K - Remote Configuration Appendix L – MT2834MRI PC Board

1.3 Description

Each MT2834MR card has three integrated 33,600 bps MultiModems. Each of the three modems on the MT2834MR card can be configured in dep end ent ly from each other via the MultiCommManager (Model #MR4800). The rack can support and control up to 16 MultiModem cards, to a total of 48 modems per rack. Up to 254 racks can be networked, for a total of 12,192 modems on the network under control of a single PC. Refer to your MultiCommManager Owner’s Manual for more inf orm at ion on the rack and it s components.

Perhaps the most significant extras incorporated in the MT2834MR are its V.42 error correction and V.42bis data compression features. With error correction and data compression, transmission errors are eliminated while increasing the modem’s throughput by a ratio of up to 4:1, for an effective overall transmission rate approaching 115,200 bps.

The MT2834MR offers interactive automatic dialing capability, as well as Command Mode option configuration. Up to ten command line/telephone numbers, of up to 60 digits each, can be stored in the modem’s non-volatile memory. The modem uses pulse and/or tone dialing methods, and has the ability to recognize dial tones and busy signals for reliable call-progress detection.

The MT2834MR is FCC-Registered for direct connection to the public telephone networks. No Data Access Arrangements (DAA’s) are required.

The MT2834MR is fully compatible with the Standard AT command set, and is therefore compatible with all of the popular communications software packages.

4/3/01 6

PN 88300150

1.4 FCC Regulations for Telephone Line Interconnection

1. No repairs are to be made by you. Repairs are to be made only by Multi-Tech Systems or its licensees. Unauthorized repairs void registration and warranty. Contact Multi-Tech Systems, Inc. for details of how to have repairs made.

2. When trouble is experienced, you must disconnect your modem from the telephone company’s jack to determine the cause of the trouble, and reconnect your modem only when the trouble is corrected.

3. The modem cannot be connected to pay telephones or party lines.

4. If requested by the telephone company, you must notify them of the following before the MT2834MR is installed:

a. The particular phone line (phone number) to which the connection is to be made. b. The FCC Registration Number: AU7USA-20673-MM-E c. The Ringer Equivalence: 0.3B

d. Modems can only be connected to the phone lines through standard modular jacks. The Uniform Service Order Code (U.S.O.C.) for the standard modular jack which connect the modem to the phone lines are:

RJ11C or RJ11W (single line)

e. The manufacturer’s name and model number:

Multi-Tech Systems - Model MT2834MR

5. If the telephone company notifies you that your device is causing harm, unplug it. The telephone

company may disconnect your service if necessary and also may change its facilities, equipment,

operations or procedures which may affect operation of your equipment. Where practical, the

telephone company must promptly inform you in writing of the temporary disconnect or change in

service, give you the opportuni ty to mak e cha nge s al low ing un interrupted service, and inf or m you of

your rights to bring a complaint to the FCC.

1.4.1 FCC Fax Update

The Telephone Consumer Protection Act of 1991 makes it unlawful for any person to use a computer or other electronic device to send any message via a telephone fax machine unless such message clearly contains in a margin at the top or bottom of each page or the first page of the transmission, the date and time it is sent and an identification of the business or other entity, or other individual sending the message and the telephone number of the sending machine or such business, other entity, or individual.

See the cover page of your fax software man ua l for setup deta il s.

1.5 Canadian Limitations Notice

NOTICE: The Canadian Department of Communications label identifies certificated equipment. This certification means that the equipment meets certain telecommunications network protective, operational and safety requirements. The Department does not guarantee the equipment will operate to the user’s satisfaction.

Before installing this equipment, users should ensure that it is permissible to be connected to the facilities of the local telecommunicati on s com pan y. T he equ ipme nt mu st al so be in sta ll ed using an ac ce ptable method of connection. In some cases, the company’s inside wiring associated with a single line individual service may be extended by means of a certified connector assembly (telephone extension cord). The customer should be aware that compliance with the above conditions may not prevent degradation of service in some situat io ns.

4/3/01 7

PN 88300150

Repairs to certified equipment should be made by an authorized Canadian maintenance facility designated by the supplier. Any repairs or alterations made by the user to this equipment; or equipment malfunctions, may give the telecommunications company cause to request the user to disconnect the equipment.

Users should ensure for their own protection that the electrical ground connections of the power utility, telephone lines and internal metallic water pipe system, if present, are connected together. This precaution may be particularly important in rural areas.

The Load Number (LN) assigned to each terminal device denotes the percentage of the total load to be connected to a telephone loop which is used by the device, to prevent overloading. The termination on a loop may consist of any combination of devices subject only to the requirement that the total of the Load Numbers of all the devices does not exceed 100. The Load Number for this product is 5.

CAUTION: Users should not atte mpt t o mak e su ch con n e ct ion s themselves, but should contact the appropriate electric inspection authority, or electrician, as appropriate.”

This digital apparatus does not exceed the Class A limits for radio noise for digital apparatus set out in Department of Communications.

1.6 Compliance with BABT Requirements (MT2834MRK only)

European Low Voltage Directive

When correctly installed and maintained, the modem will present no hazard to the user. When co rrectly installed the modem will be connected to the PSTN or a PW and to a Data Terminal Equipment (DTE), whose modem connections comply with ITU-T recommendation V28. The DTE connections are therefore taken to be safe voltages (less than +30 volts).

Approved for connection to telecommunications system specified in the instructions for use subject to the conditions set out in them Approval no. NS/3422/23/N/603030 (Model #MT2834MRK).

Compliance with BS6305 Clause 6.2 BS6320 Clause 7.2 and BABT/SITS/82/005S/D

a. The modem is suitable for connection to the Public Switched Telephone Network (PSTN) provided by British Telecommunications pic or Kingston Communications (Hull) plc. Circuit supply by British Communications, Mercury Communication or Hull City Council. Only direct exchange lines may be used, not shared service. The modem may be connected to private speech band.

b. The modem is suitable for household, office and similar general indoor use. It is not suitable for use as an extension to a payphone.

c. BT lines supplied must support either loop disconnect or multifrequency tone signalling. d. REN (Ringer Equivalence Number). The REN value of a unit is calculated from 3/n where n is the total number of units which can be

connected in parallel which will still cause the standard bell (as defined in BS6305 Appendix D) to ring. REN values of less than 0.3 cannot be assigned. For apparatus which is not capable of forming part of a multiple installation, a REN value of 3 is assigned.

REN = 1

If a telephone or other device is connected in parallel with the modem, the combined REN must not exceed 4. A BT supplied telephone may be assumed to have REN of 1.0 unless otherwise noted.

The approval of this modem for connection to the British Telecom public switched telephone network is INVALIDATED if the apparatus is sub je ct to modif ic ation in any material way not authoriz ed by B ABT or if it is used with or connected to:

i. internal software that has not been formally accepted BABT.

4/3/01 8

PN 88300150

ii. external control software or external control apparatus which cause the operation of the modem associated call set-up equipment to contravene the requirements of the standard set out in BABT/SITS/82/005S/D.

All apparatus connected to this modem and thereby connected directly or indirectly to the British Telecom public switched telephone network must be approved apparatus as defined in Section 22 of the British Telecommunicat io ns A ct 1 984 .

Compliance with BS6789: Section 3.1 and Part 2

a. The modem is not capable of allowing Auto Call using ‘999’ or other PABX emergency numbers. b. Modes, other than modes 1,2 or 3 should not be used on the BT PSTN. This modem is a mode 1

device. c. Users are advised to check the numbers entered during the Auto Call set up phase prior to dialing. d. The user should not issue any sequence of commands to the modem which would cause the modem

to exceed the maximum allowable pause of 8 seconds from the time the modem goes off hook until dialing begins.

Compliance with BS6328 Part 1 and BABT/SITS/82/01/C (Use on Private Circuits)

a. The modem is not suitable for use on circuits with British Telecommunications signaling at a nominal frequency of 2280Hz.

b. The modem does not require signaling or otherwise employ the frequency range dc to 200Hz. c. The modem may be connected directly to a point-to-point two-wire or four-wire Private Circuit. d. The modem does not require dc from the Private Circuit for correct operation. The modem may be

damaged if connected, in privat e circ uit mo de, to a circu it su pply ing d c curr ent (the maxi mum per m iss ib le direct current is zero amps).

e. The approval of this modem for connection to British Telecom Private Speech band circuits is INVALIDATED if the apparatus is subject to any modification in any material way not authorized by

BABT or if it is used with, or connected to:

i) internal software that has not been formally accepted by BABT.

ii) external control software or external control apparatus which cause the operation of the modem or associated call set-up equipment to contravene the requirements of the standard set out in BABT/SITS/82/01/C.

All apparatus connected to this modem and thereby connected directly or indirectly to British Telecom Private Speechband circ uits mu st be appr o ved ap paratus as defined in Section 16 of the Briti sh Telecommunicat io n s A ct. 198 1 .

Compliance with DTI 83/009

a. The apparatus is only approved for compatible PBXs. Consult the supplier for an up to date list of compatible PBXs.

b. There is no guarantee of correct working in all circumstances. Any difficulties should be referred to Multi-Tech.

c. If sockets are req uire d for connection to the PBX, use the BT post card onl y if BT owns the wir i ng to the PBX.

4/3/01 9

PN 88300150

This apparatus has been approved for the use of the following facilities:

·Auto-calling

·Loop disconnect and MF dialing

·Phone number storage and retr ie va l by

a predetermined code

·Operation in the absence of proceed indi cat io n

·Detection of initial and se co ndar y pro ce ed in di cation

·Automatic storage of last number dia le d

·Tone detection-busy

·Auto clear from the originating end

·DTR dialing

·Modem

·PBX timed break register recall

Any other usage will invalidate the approval of the apparatus if as a result, it then ceases to comply with the standards against which appr o va l was granted.

1.7 Technical Specifications

Tradename MultiModemV34 Model Number MT2834MR, MT2834MRK, MT2834MRI Data Rates (bps) Three independent modems

(Modem A, B, C) each operating at 33,600, 31,200, 28,800, 26,400, 24,000, 21,600, 19,200, 16,800, 14,400, 12,000, 9600, 4800, 2400, 1200, or 0-300 bps

Data Format Serial, binary, asynchronous at 0-300, 1200, 2400, 4800, 9600, 14,000, 16,800,

19,200, 21,600, 24,000, 26,400, 28,800, 31,200, or 33,600 bps; synchronous at 1200, 2400, 4800, 9600, 14,400, 16,800, 19,200, 21,600, 24,000, 26,400, 28,800, 31,200, or 33,600 bps.

Configuration Each of the card’s 3 modem s ar e ind epe nde ntl y co nfi gurable Compatibility ITU-T V.42, V.42bis, V.34, AT&T V.32terbo, ITU-T V.32, V.32bis, V.25bis, V.21,

V.22bis, V.22, V.23, V.17, Bell 212A* and 103/113*

Error Correction MNP® Classes 3, 4, and LAPM Data Compression MNP 5, and V.42bis Speed Conversion Serial port data rates adjustable to 300, 1200, 2400, 4800,9600, 19,200, 38,400,

57,600, 115,200 bps

Flow Control Xon/Xoff, Hardware CTS/RTS, ENQ/ ACK Mode of Operation Full over both dial-up lines and 2- wire or 4-wire le as ed li ne s; auto mat ic Di alb ac k-up

on separate lines in leased line operation, in dial-up mode; automatic or manual dialing, automatic or manual answer.

Intelligent Features “Standard AT” command compatible, autodial, redial, repeat dial*, dial linki ng*,

pulse or tone dial, dial pauses, call status display, auto-parity and data rate selection, keyboar d-c ontr o lle d mod em opt ions, non-volatile memor y, Ca ller ID (optional feature), and on-screen displays for modem option parameters and up to ten telephone numbers/command lines of up to 60 digits each, help menus, remote configuration, and V.25bis dialing.

Commands 100% compatible with “St and ard AT " Compatibility Command Set

Command Buffer 60 characters

4/3/01 10

PN 88300150

Automatic Dialing Choice of “Standard AT” command asynchronous dialing, “AT” command-

controlled asynch-to-synch DTR dialing, or ITU-T V.25bis Synchronous or Asynchronous dia l ing.

Automatic Leased When in dial back-up mode, modem will Line Restoral attempt leased line restoral periodically according to software configuration.

Modulation Trellis Coded Modulation (TCM) at 33,60 0, 31,2 00, 28,8 00, 26, 400 , 24,00 0,

21,600, 19,200, 16,800, 14,400, 12,000, and 9600 bps; QAM at 9600 (non-trellis), 4800 and 2400 bps, PSK at 1200 bps, FSK at 300 bps

Carrier Frequencies Transmit Originate: 1200 Hz 2400 & 1200 bps Transmit Answer: 2400 Hz

(V.22 or Bell 212A Receive Originate: 2400 Hz Standard) Receive Answer: 1200 Hz

Carrier Frequencies,1270 Hz Mark, 1070 Hz Space for 300 bps* Transmit Originate (Bell Standard) 2225 Hz Mark, 2025 Hz Space for

Receive Originate 2225 Hz Mark, 2025 Hz Space for Transmit Answer 1270 Hz Mark, 1070 Hz Space for Receive Answer

Carrier Frequencies 980 Hz Mark, 1180 Hz Space for V.21 Transmit Originate

1650 Hz Mark, 1850 Hz Space for Transmit Answer 1650 Hz Mark, 1850 Hz Space for Receive Originate 980 Hz Mark, 1180 Hz Space for Receive Answer

V.23 390 Hz Mark, 450 Hz Space for

Transmit Originate 1300 Hz Mark, 2100 Hz Space for Transmit Answer 1300 Hz Mark, 2100 Hz Space for Receive Originate 390 Hz Mark, 450 Hz Space for Receive Answer

Carrier Frequencies 1800 Hz (V.32) V.32 and V.32bis

Fax Modulations V.21CH2 FSK at 300 bps

V.27ter DPSK at 4800 and 2400 bps V.29 QAM at 9600 and 7200 bps V.17 TCM at 14400, 12000, 9600, and 7200 bps

Fax Carrier V.21 CH2 (Half Duplex) Frequencies 1650 Hz Mark. 1850Hz Space for

Transmit Originate 1650 Hz Mark, 1850Hz Space for Transmit Answer V.27ter 1800 Hz Originate/Answer V.29 QAM 1700 Hz Originate/Answer V.17TCM 1800 Hz Originate/Answer

4/3/01 11

PN 88300150

Transmit Level -10 dBm (dial-up) 0 dBm (leased line, MT2834MR) -13 dBm (private wire

MT2834MRK) -11dBm (MT2834MRI)

Note: The Transmit Values apply to the domestic, U.K., and the standard International defaults only, country-spec ifi c mod e m s may vary.

Frequency Stability +0.01% Receiver Sensitivity -43 dBm under worst case conditions AGC Dynamic 43 dB

Range Interface EIA RS232C Diagnostics On-line Diagnostics

ITU-T V.54 Remote Loop, V.54 Digital Loop (with or without Pattern Generator) Offline Diagnostics ITU-T V.54 Analog Loop, Self-Tests Automatic Diagnostics Dial-up Tests

Firmware Upgrades via Flash PROM technology on Multi-Tech’s web site Indicators LEDs for Transmit Data, Receive Data, Carrier Detect, 28,800 bps, 24,000 bps,

19,200 bps, 14,400 bps, 9600 bps, 2400 bps, Off Hook, Data Terminal Ready, Test and Out-Of-Service, Fax and Error Correction.

Controls Toggle switches for Busy; DIP-Switches for

various modem options.

Operating 0

to 50o (32o to 120o F)

Temperature Power 5 Volts DC at 0.95 Amp

Requirements +/-16 Volts DC at 0.1 Amp Power ConsumptionApproximately 6 watts Dimensions, .9"x11"x15" (2.2x28x37 cm) HxWxD

card modem Weight 2.5 Lbs. (1.1Kg) Limited Warranty Two Years Fuses F1 (+5V), F2 (-16V), F3 (+16V)

1.8 Power

DC voltages are supplied to all of the modems in the CC4800 rack through one or two PS4800 power supplies, designed for conventional 115 or 230 VAC connection. The power supply is a universal input switching power supply.

4/3/01 12

PN 88300150

1.9 Modem LED Indicators

The MT2834MR has fifteen LED indicators. They are:

1. Transmit Data (XMT). This LED blinks when data is being transmitted, on for a space, off for a mark. The state of this LED matches that of the XMT circuit on Pin 2 of the RS232C interface.

2. Receive Data (RCV). This LED blinks when data is received, on for a space, off for a mark. The state of this LED matches that of the RCV circuit on Pin 3 of the RS232C interface.

3. Carrier On (CD). This LED lights when a valid carrier tone has been detected.

4. 28,800 bps (28.8K). This LED lights when the modem is set for 28,800 bps operation. This LED blinks slowly (1 blink per second) when the modem is set for 31,200 bps operation. This LED blinks quickly (5 blinks per secon d) when the mode m is se t for 33,6 00 bp s oper at ion.

5. 24,000 bps (24K). This LED lights when the modem is set for 24,000 bps operation.

6. 19,200 bps (19.2K). This LED lights when the modem is set for 19,200 bps operation.

7. 14,400 bps (14.4K). This LED lights when the modem is set for 14,400 bps operation.

8. 9600 bps (9600). This LED lights when the modem is set for 9600 bps operation.

9. 2400 bps (2400). This LED lights when the modem is set for 2400 bps operation. If the 2400 or 9600 indicators are not on, this indicates that the modem is set for 300 bps operation.

10. Off Hook (OH). This LED lights when the phone line is “off hook.” This will occur wh en the modem is dialing, on line, or answering a call. The indicator will also flash when the modem is pulse dialing in Command mode.

11. Data Terminal Ready (DTR). When the DTR LED is lit, the modem is permitted to answer an incoming call. When it goes off, a connected modem will disconnect. The state of this LED matches that of the DTR circuit on Pin 20 of the RS232C interface.

12. Error Correction (V.42). This LED lights when the modem is in error correction mode, and flashes on and off when data compression is enab led.

13. Fax (FAX). This LED lights when the modem is in Fax mode.

14. Test Mod e (TEST). This LED lights during test mode operation. With the optional MultiCommManager Software installed, a full suite of modem tests can be controlled from a central PC. Refer to the MultiCommManager Owner’s Manual for more test information. The Test LED lights during any of the software-control diagnostic tests.

15. Out-Of-Service (OOS). When the OOS LED is flashing, the le ase d line is down and the modem is in dialback mode or the self-test has failed. When OOS LED is continuously lit, the modem is in busy out/out of service (OOS) state.

Note: The PS4800 modem rack power supply has one LED that indicates the presence of all supply voltages.

1.10 BUSY Switch

The MT2834MR contains three two-position BUSY switches on the front panel. Each switch can be used to create a “busy out” (OOS) condition for one of the three on-board modems (i.e., Modem A, B, or C).

To place a modem in the Busy condition, move the appropriate BUSY switch to the right. The selected modem goes off-hook, its OOS and OH LEDs light, and incoming calls to this modem get a busy signal. If you suspect a problem with a particular modem, you can use the BUSY switch to have an optional device (such as a “hunt group”) that looks for a non-busy line to perform a “roll over” to the next available modem while you check the status of the Busy modem. Note: The MultiCommManager can perform the same function using software.

4/3/01 13

PN 88300150

1.11 Controls on PC Board

The MT2834MR modems contain three 16-position DIP-Switches and several jumper plugs. The DIPSwitches control various modem options or set default values for Command mode operation.

There are also “jumper” option settings on the circuit board, which control V.54/Test (OOS) functions. The toggle switch positions on the MT2834MR are be labeled “Busy” for each of the three on-board

modems (Modems A,B,C). Chapter 7 of this manual provides detailed instructions on configuring all of the MT2834MR’s DIP-

Switches and jumpers.

1.12 MT2834MRK Installation Notes

The installation instructions include information about the use of blanking plates to cover empty slots in the card frame. Be sure to follow the instructions on installation that are provided in your

MultiCommManager Owner’s Manual. Warning: Interconnection directly, or by way of other apparatus, of ports marked ‘SA FETY WARNING

see instructions for use’ with ports marked or not so marked may produce hazardous conditions on the network. Advice should be obtained from a competent engineer before such a connection is made.

This product is intended to be hard wired to the network. The final connection to the network is the responsibility of the public telecommunications network operator or a person authorized by that operator.

Any other apparatus, including cable and wiring, connected between the MT2834MRK modem and the point of connection to any speechband circuit shall comply with the following:

(1) the overall characteristics of this apparatus shall be such as to introduce no material effect upon

the electrical conditions presented to one another by the modem and the speechband circuit;

(2) the apparatus shall compr i se onl y;

(a) apparatus approved (see note) for the purpose of connection between the modem and a speechband circuit; and

(b) cable and wiring complying with a code of practice for the installation of equipment covered by this part of BS 6328 or such other requirements as may be applicable.

Note: Such apparatus may have been approved subject to limitations in its use.

4/3/01 14

PN 88300150

2.1 Introduction

This chapter describes the dialing and answering capabilities of the MT2834MR. Since the modem can be either a leased line with dialback modem or a standard ITU-T V.34 full duplex dial-up modem, both modes are described (in terms of dialing features) in this chapter.

2.2 Automatic Leased Line Restoral Operation

When the MT2834MR is in the dial back-up mode of operation, it will periodically check the leased line to see if it’s operational and try to restore the leased line if possible. This is the automatic leased line restoral feature.* The frequency of the restoral feature attempts are determined by the contents of SRegister S18. The default for S18 is 30 minute s and can be set in one minut e incr em en ts from 10 t o 255 minutes. Setting the restoral frequency under 10 minutes causes excessive breaks in the dial-up operation.

2.3 Manual Dial Backup Call Termination

If your MT2834MR is in the leased line mode (DIP Switch #10 in the Down (“Closed”) position) and with a dial back-up operation in process, there are two ways to manually terminate (other than automatic leased line restoral) the dialback call. In each of these cases, you will be attempting to establish the leased line connection because it is back in operating condition.

*Both local and remote modems should have S-Register S18 set identically.

The methods of dial-back call termination are:

1. DTR Control. If DTR (Data Terminal Ready) is turned off for 50 milliseconds or more, a disconnect will occur. This is probably the most common method used by computer systems at the automatic answer end of the line to cause the answering modem to disconnect after logging off procedures.

2. Command Mode Control. It is possible to enter Command Mode while remaining on-line by entering the Escape Sequence (+++AT<CR> in most cases). After you have entered Command mode, you may either return to the On-Line by typing ATO, or terminate the call with the H command. Typing ATH will hang up the line (bring it on-hook), bringing the modem out of the On-Line mode. So, the command to hang up a call is three plus signs, and then ATH.

3. Loss of Carrier. After a data connection has been establish ed, the mo dem wi ll disc on ne ct if a loss of carrier occurs for 700 milliseconds (.7 seconds) or more. The 700 mSec time can be configured for any time from 0 to 25.5 seconds, in 100 mSec increments, with S-Register S10. Note that one cause of carrier loss would be if one of the modems were to disconnect normally. S10 works for speeds of 2400 bps or below, otherwise carrier loss will take about 20 seconds in a V.34 connection.

2.4 Dial Back-up Leased Line Restoral

The dialing associated with the MT2834MR when it’s operating in leased line with dialback mode, involves the placing of a call from the originating modem due to a leased line failure. The call can be placed automaticall y by the mo dem whe n the belo w desc rib ed co nditions are met. The dialback co ndi ti on is indicated by the OOS LED blinking. After a preset period of time (determined by S-Register S18), the modem will try and restore the leased line automatically.

The parameters used to determine whether a leased line is down (so that automatic dialback can occur), is based on the MT2834MR doing a retrain on the leased line due to an error condition in the transmission. An error condi ti on is def ine d as a “hit” on the line (the Carrier gets interrupted).

The retrain is a “handshake” procedure between the modems to establish the Carrier again. If the retrain fails, both modems (originate and answer modems) start their Dialback timers. The time is determined by the setting of S-Register S19. The default for the time is one minute. During that minute, the originate modem will try to establish the leased line link. If during that time, the leased line is established, the timer is cleared and everything is back to normal. If the timer expires the modems will go to dialback mode.

4/3/01 15

PN 88300150

The purpose of the timer for the Answer modem is to determine when it will accept a dial-up call. When both timers have expired and the leased line has not been established the dialback procedure will start. The number dialed is the one stored in location N9 of the originate modem’s phone number memory. In preparation for proper dialba ck oper at io n, you must enter the prop er number in t he N9 locati on us in g the commands detailed in Chapter 3. Keep in mind that the number also can be a V.25bis command for synchronous operation.

2.5 Dial-up Automatic Answering

With your MT2834MR in the dial-up mode (12-Position DIP Switch #10 in the UP position), the MT2834MR can be used as an automatic answering modem.

The MT2834MR, when in its idle state, wil l be set up with origin a te mode frequencies. An incom in g rin g signal will automatically switch the modem into answer mode.

You can program the modem to answer a call after a certain number of rings by using the modem’s SRegister S0. (See Chapter 4). Refer to Section 2.6 for the handshaking procedures used by the MT2834MR in an automatic answering application.

2.6 Dial-up Handshaking Details

With your MT2834MR in the dial-up mode (12-Position DIP Switch #10 in the UP position), the following briefly explains what happens between two modems in a normal call. We are assuming that there are MT2834MR’s at both the originating and at the answering end of the telephone line. (If other brands of modems are used with our modems, they will still communicate, but each manufacturer tends to use slightly different delay timings and sequences, and many of the brands vary in their LED designations.)

Before V.34 negotiation takes place, remote and local modems transfer their functional capabilities using modulated calling and answering tones. First, the Calling Menu (CM), a data sequence using V.21 lowband modulation (a handshaking technique originally developed for 300 bps modems), is sent from the originating V.34 modem to the answering V.34 modem. This describes the range of functional capabilities the originating modem supports. The answering V.34 modem responds to the CM with a Joint Menu, or JM (using V.21 high- ba nd mod ula tio n) , ind ic ati ng the co mmo n cap abi li tie s of the mode m at each end.

Once this is done, a probing signal is passed between the modems to identify impairments in the telephone channel. After receiving the results of the probing signal, the modem receivers and transmitters will start with the lowest speed and move up until reaching the highest speed at which they can exchange data. All this occurs in about five seconds.

Note: In order for the called modem to be able to answer the call, it must have a high DTR (Data Terminal Ready) signal. This signal comes from the computer or terminal to which it is attached, on RS232C Pin 20, or it can be forced on by a switch in the modem.

Note: If you are using the Reliable or Auto-Reliable mode, some additional handshaking takes place. This is explained in Chapter 5, in the “Auto- R el iab le Mod e” section.

2.7 Call Termination

With your MT2834MR in the dial-up mode (12-Position DIP Switch #10 in the UP position), there are a number of methods by which you can terminate a call, or simply stated, hang up. They are:

1. Command Mode Control. It is possible to enter Command Mode while remaining on-line by entering the Escape Sequence (+++AT<CR> in mo st ca se s) . After you have entered Command Mode, you ma y return to the On-Line state by typing ATO, or you may terminate the call with the H command. Typing ATH will hang up the line (bring it on-hook), bringing the modem out of the On-Line state. So the command to hang up a call is three plus signs and then ATH.

4/3/01 16

PN 88300150

2. DTR Control. If DTR (Data Terminal Ready) is turned off for 50 milliseconds or more, a disconnect will occur. This is probably the most common method used by computer systems at the automatic answer end of the line to cause the answering modem to disconnect after log off procedures.

3. Loss of Carrier. After a data connection has been establish ed, the mo dem wi ll disc on ne ct if a loss of carrier occurs for 700 milliseconds (.7 seconds) or more. This time can be configured with S-Register S10 for any time from 0 to 25.5 seconds (in 100 mSec increments). Note that one cause of carrier loss would be if one of the modems were to disconnect normally. S10 works for speeds of 2400 bps or below. S10 has no effect at connections above 2400 bps.

4. Abort Timer. Answer Mode: When OH (Off Hook) comes on, the called modem will start a 45 second timer and wait for a carrier signal from the originating modem. If carrier is not detected within this period, the modem will disconnect (hang up) and be ready for another call. Originate Mode: The abort timer will function the same as in the answer mode, except that the timer will begin after the modem has completed dialing, instead of when it first goes off hook. It is possible to change this 45 second wait-period to any other value from 1 second up to 254 seco nd s by reco nfi gur i ng S-Reg i ster S7 (see C ha pter 4).

Inactivity Timer. Causes the modem to disconnect if no data is being transmitted or received for a

certain period of time. The timer is restored anytime a character is passed through the serial port in either a send or receive case. This function is controlled by S-Register S30. The inactivity timer can be disabled by setting S30 to 0, which is the factory default setting, or set to time out after the time (in minutes) selected by S-Re gi ster S3 0.

4/3/01 17

PN 88300150

3.1 Introduction

The MT2834MR incorporates a microprocessor-based Command Mode, which allows you to use your computer keyboard or communications software to interact with your modem. When your modem is in Command mode, you have access to a complete communications system which allows you to use a number of features including the basic AT command set described in this chapter. The basic AT command set allows you to type phone numbers for automatic dialing without a telephone set, configure various modem options and monitor phone activity. Beyond the basic AT commands and capabilities, your mode m can also perform advanced features such as error correction, data compres sion, speed conversion and more. Some of those features are covered in Chapter 5 of this manual.

This chapter explains Command mode, and shows you how to use each of the basic AT commands. The MT2834MR AT commands and responses are compatible with all systems and software that have

been programmed for automati c, sof tware- c ontr ol led aut odi al in g using the sta ndar d AT command set. The MT2834MR also provides V.42 error correction (using the MNP or LAP-M protocols), data

compression (using the MNP) Class 5 and V.42bis protocol), speed conversion, and remote configuration. These advanced features are described in either Chapter 5 of this manual.

3.2 Typographic Conventions Used in This Manual

It is important to point out the difference between the letter O and the number 0. Both of these characters will be used in the MT2834MR’s command s. As you can see, the lett er O is “fatter” than the number 0. We do not use the overstriken 0 to symbolize zero in this manual.

The Carriage Return and Control keys are used in many of the MT2834MR commands. Some keyboards label the Carriage Return key as ENTER, others use the word ENTER, and still others use an arrow pointing down and then left. The symbol <CR> is also commonly used. In this manual, we symbolize Carriage Return with the word ENTER, and will usually use the phrase “hit ENTER” to instru ct you to press the Carriage Return key.

We symbolize the Control key with CTRL. For example, Control X, which is accomplished by pressing the X key while holding down the Control key, is written as CTRL-X.

3.3 Functional Modes

The MT2834MR can be in one of two functional modes. These are “Command mode,” and “On-Line mode.” (There is also an in-between mod e, “Wait-For-Carrier,” where the modem is out of Command mode but not yet really On-Line.) When the modem is initially powered up, it is in Command Mode, and is ready to accept commands from your keyboard or software, and respond to any Command Mode commands (described later).

The MT2834MR enters On-Lin e mode after dia li ng and maki ng a con ne cti on with an other mod em, and then detecting a valid carrier si gna l tone. If no carrier signal is detected w ith in a certain time, the modem abandons the call and re-ent ers Command mode.

Once On-Line, the modem exits On-Line mode if the carrier signal is lost or intentionally dropped. When this happens, the modem hangs up and re-enters Command mode.

The MT2834MR can exit the On-Line mode without losing the carrier signal. This is accomplished by typing certain “escape” characters while on-line, which brings the modem back into Command mode without terminating the connection.

The MT2834MR can also enter On-Line mode without going through the dialing process, by typing either the O command or the A command. This is explained later in this chapter, as are all of the MT2834MR’s commands.

4/3/01 18

PN 88300150

3.4 AT Commands

A variety of autodial operations and modem options are controlled when the MT2834MR is in Command Mode. This chapter covers each co mma nd in deta il . There are also se veral option configurat io ns stor ed in “S-Registers”, which can also be accessed in Command Mode (refer to Chapter 6). Error Correction commands are covered in Chapter 5 of this manual.

The MT2834MR commands are list ed be low in alp hab etical order.

Modem Configuration - Command Letters

AT ATtention code that precedes most commands A Answer mode A/ Repeat Last Command A: Continuous redial unti l call answered* &A Answerback (proprietary feature) $An Auto-Reliable Buffering #An Auto Speed Select $AS IBM AS/400 Support Bn Bell or ITU-T answer tone select &Bn Transmit Buffer size &BSn Maximum TX Block Size $BAn Baud Adjust &Cn Carrier Detect control *C Caller ID Detection (optional) Ds Dial DsDn Store Telephone Number &Dn DTR Control $Dn DTR Dialing En Echo Commands $En Enable/Disable Error Correction %En Escape Method $EBn Asynchronous Word Length &En Mode [normal, auto-reliable, or reliable] &En Flow control [None, CTS, or Xon/Xoff] &En Pass through XON/XO F F &En Enq/Ack pacing &En Normal mode flow control &En Pacing &En Data compression disable/enable $F Enable/Disable Auto-Reliable Fallback Character #F Fallback modes when on-l ine &F Fetch Factory default values $Fn Enable/Disable Fallback character #Gn Guard tones* HHook on/off control, or Hang up $H Help screens *H Busy out after disconnect I Identify modem model/revision #L V.42 mode select (LAP-M/MNP) L List stored telephone number s L5 List current configuration parameters L6 List current S-Register Val ues L7 List additional configurat io n paramet er s L8 List On-Line Diagnostics &Ln Lease line commands $MI MI/MIC Control* Mn Sync/Async control

4/3/01 19

PN 88300150

$MBn Modem Baud Rate Nd Dial Stored Telephone Number NdNe Number Linking OOn-line from Command Mode P Pulse Dial &Pn Set Pulse dial ratio* #Pn Parit y Select Qn Result Codes &Qn Command set select Rn Reverse this mode &Rn CTS control *Rn Ring message on callback modem &RFn CTS follow RTS control $Rn Retransmit count S= S-Register, set value S? S-Register, read value $SBn Seri al por t Baud rate &Sn DSR control &SFn DSR follow CD control $SP UNIX UUCP Spoofing TTone dial #T Enable/Disable Trellis Coded Modulation &Tn Recognise RDL signal U U-loop test Vn Verbose or Terse result codes #V User control of V.32terbo in Answer Mode W Wait for new dial tone &Wn Store configuration in RAM X Extended or basic Result Codes and Call Progr e s s &Xn Clock selec t Yn Long space disconnect Z Zap (reset modem) +++ Escape to Command Mode when on-line , Pause in dialing ; Revert to Command Mode after dialing ! Flash On-Hook @ Quiet Answer +++AT<CR> Escape Sequence: Entering Command Mode While On-Line BREAK AT<CR> Alternate Escape Sequence: Entering Command Mode While On-Line

Refer to Appendix F of this manual for a summary of commands.

4/3/01 20

PN 88300150

3.5 Result Codes

You can choose result codes that closely match those of the “Standar d AT” command set (“Standard AT” Responses) or enhanced function result codes that have been used in Multi-Tech modems in the past (“Multi-Tech responses”). The &Q command selects which result codes will be used.

The Command mode provides you with several responses, or “Result Codes,” that can aid you in Command mode operation. These Result Codes are displayed on your monitor or printout.

You can choose to have these Result Codes displayed in a “verbose” format (complete words), or in a “terse” format (single digit numbers). The factory default setting is for the verbose format. To change this setting to the terse format, use the V command.

You can also choose basic result codes (connect with no speed indication), extended result codes (with speed indication), and whet her yo u want call progress indicatio ns (bu sy an d no dial ton e) added to the extended result code set. This is controlled with the X command.

MT2834MR RESULT CODES

CODE DESCRIPTION

OK Your command was executed, and the MT2834MR is ready for your next command. CONNECT A carrier signal was detected at 300 bps.* RING A ring signal was detected from an incoming call. NO CARRIER No carrier signal was detected, or the carrier signal was lost. ERROR An error is present in your command sequence, (e.g., invalid character or too many

characters).

CONNECT 1200 A carrier signal was detected at 1200 bps.* NO DIALTONE** No dial tone was detected, and your modem will not dial.** BUSY** A busy signal at the number you dialed was detected.** NO ANSWER The Remote system did not answer. CONNECT 2400** A carrier signal was detected at 2400 bps.* CONNECT 4800 A carrier signal was detected at 4800 bps.* CONNECT 9600 A carrier signal was detected at 9600 bps.* CONNECT 14400 A carrier signal was detected at 14,400 bps.* CONNECT 19200 A carrier signal was detected at 19,200 bps.* CONNECT 21600 A carrier signal was detected at 21,600 bps.* CONNECT 24000 A carrier signal was detected at 24,000 bps.* CONNECT 26400 A carrier signal was detected at 26,400 bps.* CONNECT 28800 A carrier signal was detected at 28,800 bps.* CONNECT 31200 A carrier signal was detected at 31,200 bps.* CONNECT 33600 A carrier signal was detected at 33,600 bps.* CONNECT 1275 The modem is connected in V.23 mode.

* These responses are used only in the Extended Result Code set, and the CONNECT response will indi cat e a bps connection.

When the Basic Result Code set is used, the CONNECT response can be any speed from 2400 through 33,600 bps. A connection using error correction will be indicated by the addition of the word LAP-M or RELIABLE (verbose) or the letter L or R (terse) to the CONNECT responses. A connection using MNP5 data compression will be indicated by the addition of the word COMPRESSED (verbose) or the letter C (terse) to the CONNECT responses.

** In the modem’s default setting of blind dialing, these responses will not be used.

4/3/01 21

PN 88300150

3.6 Command Mode Fundamentals

This section discusses Command Mode fundamentals, Dialing commands, Immediate Action commands (except dialing), and Configuration commands. The rest of the commands are covered in Chapter 5.

3.6.1 Entering and Executing Commands

When you type commands for the MT2834MR, each command must start with the Attention Characters AT. Attention characters can be typed in either upper case (capital) or lower case (small) letters.

The AT characters alert the modem that a command follows. The Attention command can also be used to clear the command buffer, by typing AT and then hitt ing ENTER.

Typing the AT characters automatically sets the modem’s speed to match the speed of your computer or terminal, and also sets the modem’s parit y.

The MT2834MR will not execute a command until you hit ENTER. Therefore, ENTER should be pressed when the entire command has been typed. There are some exceptions to this rule. The A/ (Repeat Last Command) command is executed without hitting ENTER. The A: command is also executed without hitting ENTER.

Typing A/ will cause the MT2834MR to repeat the last command that was executed. This last command remains stored in the modem’s command buffer until the Attention Command AT is typed. Therefore, AT must not be typed before A/ is typed. The A/ comm and w ill have no effect if there is no command stor ed in the command buffer. It is not necessary to hit ENTER to execute this command.

Many MT2834MR commands consist of a letter, followed by a number (0, 1, etc.). If a command like this is typed without the number, the modem will assume that its value is zero (0). For example, if you type ATH as a command without a 0 or 1 following the H, the command will be ATH0. (In this example, the effect is that the modem hangs up.) As you become more familiar with the MT2834MR’s command s, you will find yourself taking adva nta ge of t his shor t cut.

3.6.2 Command Editing

You can use the BACKSPACE key on your keyboard to edit characters in the command line. The command will not be executed until you hit ENTER. The BACKSPACE key erases the previous character for retyping.

The BACKSPACE key will not erase the AT characters once they are typed. If your keyboard has no BACKSPACE key, CTRL-H will accomplish the same thing. The character recognized by the modem as BACKSPACE may be changed t o any other AS CII char a ct er with S- Reg ister S5.

To cancel an entire command that has been typed but not yet executed, type CTRL-X. This also clears the command buffer. The effect is the same as backspacing to cancel the entire command, only quicker.

Characters typed in a command are stored in the MT2834MR’s Command Buffer (memory) unt il ex ec uted by hitting ENTER. The Command Buffer’s capacity is sixty characters. The Attention Characters AT do not count in the sixty allowed Command characters. Spaces, which may be used for increased display readability, may be used when typing a Command, but are not stored in the Command Buffer and are not counted in the sixty allowed characters. Hyphens, parentheses etc., are not allowed.

If the sixty character limit is exceeded or if invalid characters are typed, the Command Buffer is automatically erased, and an ERROR message appears. You then retype the command within the sixtycharacter maximum, using only the allowed characters.

Note: In some applications, such as auto-answer only, you may disable the Command mode altogether. When you do this, the MT2834MR ignores all commands, and functions as an auto-answer non-intelligent modem. This is done with DIP-Switch #8 on the modem card (explained in Chapter 7). The factory default setting is Command mode enabled.

4/3/01 22

PN 88300150

3.7 Dialing Commands

3.7.1 Dialing Action Commands

D Dial Command

The letter D in a command causes the MT2834MR to dial the telephone number immediately following it. For example, if you type ATD5551212 and hit ENTER, the MT283 4MR di als the number 555-1212.

The D command is also used in conjunction with a telephone set for manual dialing. You dial the number on your telephone set, and after hearing the answer tone on your handset, type ATD on your keyboard and hit ENTER. Then hang up the handset. Unless you have a specific need to dial in this manner, we recommend you use the first method, where you type the telephone number on your ke yb oar d.

The MT2834MR gives you sev eral choices regarding dia l ing met hod s. You can use tone or pulse dialing, by inserting a letter T or a letter P in the comma nd str in g. (See Section 3.7.2 on Dial Modifiers).

You can also configure the modem to either wait for and detect dial tones and busy signals (which we call “Wait-for-Dial-Tone” dialing or “Smart” dialing), or work with timed pauses without dial tone and busy signal detection (which we call “Blind” dialing). (See Section 3.9 X Command.)

Note: There is another method of dialing, called “DTR Dialing”, where by manipulating the DTR signal on pin 20 of the RS232C interface, a number stored in the modem’s memory is automati c ally dialed. See Section 3.9 on DTR Dialing ($D command) for details.

A: Continuous Redial (not used in MT2834MRK or MT2834MRI)

If you select the Wait-For-Dial-tone method of dialing (see X3 or X4 co m mand), it is possible for you to command the MT2834MR to continuously redial (maximum 10 redials for DOC units) a busy number until your call is answered. This is done with the A: command.

This command is used only if you have already reached a busy number after executing a normal dial command. Type A: (you need not type AT, nor do you need to hit ENTER), and the modem redials the number. If you again reach a busy signal, it redials again and again until it no longer detects a busy signal. To stop the redialing, press any key.

: Continuous Redial

Another way to redial a phone number continuously is to type a colon(:) at the end of the phone number. The result is the same as if you had typed A: after observing that the number was busy on the first dialing attempt. Using the colon in the dial command is a step saver.

H Hanging Up, and Bringing the Phone Line Off Hook

You can make the MT2834MR hang up (go On Hook), or go Off Hook, with the H command. Type ATH1 to bring the line Off Hook, just as if you had picked up the telephone handset.

To hang up, type ATH0 or ATH (remember that the default value is 0 when no number is typed).

It is not necessary to type H1 to bring the line Off Hook when using the D command to dial, since the modem will go off hook automatically when you hit ENTER at the end of the dial command.

4/3/01 23

PN 88300150

3.7.2 Dial Modifiers

There are several commands that can be included within a dialing command (following the letter D), called “dial Modifiers”. They have various functions, including the selection of Pulse or Tone dialing, pauses in the dial sequence, automatic redials if a number is busy, and reverting to Command mode or switching to Answer mode after dialing.

P, T Pulse or Tone Dialing

The MT2834MR can dial numbers using either pulse or tone dialing, or a combination of both methods. Pulse dialing is the method used by rotary-dial telephones, which involves the timed opening and closing of a line relay. Tone dialing is that used by pushbutton TouchTone™ telephones, and is sometimes referred to as DTMF, or Dual-Tone Multi-Frequency dialing.

The dialing method is controlled by typing a P for Pulse or a T for Tone in the dialing command, right before the digits you wish to have dialed in that manner.

For example, to pulse-dial the number 555-1212, type ATDP5551212 and hit ENTER. To tone-dial the same number, type ATDT5551212 and hit ENTER.

If neither Pulse nor Tone dialing is specified in the dial command, the MT2834MR uses whatever method was last used. If the modem has been reset or was just powered up, it uses Pulse dialing, even if you do not include the letter P in your dial command.

Nearly all telephone systems in the U.S. are compatible with tone dialing. Since that is the faster method, you will probably use tone dialing.

An example of combining pul se and tone dia lin g cou ld in vo lv e a PBX sys tem wher e 9 has to be pulse-dialed first, then the rest of the number tone-dialed after pausing for a second dial tone. To dial the number, type ATDP9, T5551212 and hit ENTER. (The comma causes a pause, which is explained soon.)

&P Set Pulse Dial Ratios

The &P command sets the time ratios between the open and closed positions of the dialing pulse frequencies. To set a dialing pulse ratio of 60mSec to 40 mSec, type AT&P0. To set a ratio of 67 mSec to 33 mSec, type AT&P1. The factory default setting is &P0.

The &P command is not available on the MT2834MRK.

, Automatic Pauses in Dialing

You can cause the MT2834MR to pause during the dialing sequence by typing a comma ( character where the pause is desired. This pause lasts two seconds (4.8 seconds on the MT2834MRK). If a longer pause is desired, more than one comma may be typed consecutively, with each one causing a two second pause. You can also change the length of the pause caused by the comma from 0 up to 255 seconds with S-Register S8 (refer to Chapter 4).

Each comma used in a dialing com ma nd do e s cou nt as one of the sixty allowed character s.

Y Long Space Disconnect

The Y command enables or disables the modem’s ability to respond to a long space disconnect condition. The command Y0 disables it (factory default setting) and Y1 enables it.

W Wait for New Dial-Tone

A W inserted in the dialing command causes the MT2834MR to wait for another dial tone, and the modem will not resume dialing unt il ano ther dial tone is dete cted .

, )

4/3/01 24

PN 88300150

It is not necessary to type a W at the beginning of the dialing command to wait for a modem dial tone, since the modem will pause automatically.

In order for this command to work, you must first select Wait-for-Dial-Tone dialing with the X2 or X4 command, so that your modem can detect the dial tone.

; Returning to Command Mode After Dial Command Execution

A semicolon (;), when typed as the last character of a dialing command, causes the MT2834MR to return to Command mode immediately after executing the command instead of waiting for a carrier signal and going on-line.

For example, type ATDT5551212; to simply tone-dial the number, and do nothing afterwards except go back into Command mode. This is useful in dialing applications where modem data transfer is not desired, such as voice communications, or in applications involving the use of Touch Tones as a data entry method, such as bank-by-phone.

R Reversing the Mode of Operation

In certain applications you may need to reverse the modem’s mode of operation from originate to answer, or answer to originate, so that it answers the phone and goes into originate mode, or dials a number and goes into answer mode. This command turns off the reversing function with the R0 command and turn it on with the R1 command.

! Flashing On Hook

Some switchboard systems react to a momentary On Hook. An exclamation mark inserted in the dialing command causes the mo dem to “flash” on hook for a half second, just as if you had held the switch hook on a telephone set dow n for a half se co nd. (Th e fla sh is 90 mS ec. on the MT2834MRK.)

For example, to flash On Hook after dialing the number 555-1234 in order to transfer to Extension -5678, type ATDT5551234,,!5678. The commas cause a 4 second pause (just to be safe).

@ Quiet Answer

The @ command causes the MT 28 34 MR to wait before pr o ce ssing the next s ymb ol in the dialing string. The wait is for one or more ringbacks, followed by 5 seconds of silence. If the time (specified by S-Register S7) passes before the rings and silence, a NO ANSWER (R) result code is processe d. The @ co mma nd is used for ac ce ss ing a syst em that does not provide a dial tone.

For example, ATDT5551212@7853500 causes the MT2834MR to dial the first number (555-

1212) and wait for the time specified in S-Register S7 for at least one ringback and 5 seconds of silence. If a busy signal is detected, the MT2834MR hangs up and generates a BUSY result code. If it does no t det e ct 5 seconds of silence , a NO AN SW ER res ult code is generated after hanging up. If 5 seconds of silence is then detected, 785-3500 is dialed.

3.7.3 Phone Number Memory Commands

D...N Storing Phone Numbers

A telephone number and command line of up to sixty charact ers ma y be stor ed in the MT2834MR number memory. As many as ten of these numbers may be stored. Each number is given a name, using the codes N0 to N9.

To store a phone number, type ATD, then the number as it would be dialed along with any P, T, R, ; or , characters, and then type N fol low ed by the pho ne num ber ’s “name,” (any number from 0 through 9) and then hit ENTER.

4/3/01 25

PN 88300150

For example to store the number 1-612-631- 3 550 as number N3, typ e ATDT16126313550N3 and hit ENTER. The number is not dialed with this store command.

After storing a phone number, check if it has been stored correctly by typing ATL and hitting ENTER.

When phone numbers are stored, the entire command line is also stored so that you can effectively create a macro for each number. For example, if you know a particular number needs extended result codes, detect busy/dial tone, error correction, Xon/Xoff flow control, pacing, and data compression, type: ATX4&E1&E5&E13&E15DT16126313550N3.

N Dialing a Stored Number

To automatically dial a telephone number that you a have stored in the MT2834MR number memory, type ATNn (where n = 0 through 9). For example, to dial a number stored at N3, type ATN3 and hit ENTER. Do not include the letter D in thi s com man d, or the st ored number is erased.

NN Number Linking

You may cause the MT2834MR to dial a second number automatically if the first number you dialed is busy. This is useful in a situation where a computer can be accessed through more than one phone number. This is called “linking”.

To link the number at N1 to the number at N2, type ATN1N2 and hit ENTER. Several numbers can be linked in the same command. For example, to link N1 to N2 to N3 to N4, or link N1 to N2 and back to N1 and then back to N2, type ATN1N2N3N4 in the first example, and ATN1N2N1N2 in the second example.

The only limit to the number of numbers that can be linked is the 60 characters allowed in a command line. Number linking can not be used with blind dialing, since busy signals would not be detected. You would have to select the Wait-for-Dial-Tone dialing method using the X command to use the Number Linking feature.

Note: The NN command is not used in the MT2834MRK.

L Listing Numbers Stored in Memory

Telephone numbers stored in the MT2834MR’s memory may be listed and displayed with the L command. It displays all ten stored numbers in a format like that shown below. All digits and command letters are show n. The numb er ’s “name” (0 thru 9) is shown first, followed by the complete dialing command and telephone number as originally typed.

Type ATL and hit ENTER to display these numbers on your video screen or printout. An example of an L command listing is shown be low.

0 T14082345678 1 T16125551212; 2 P9, T14089876543 3 T3738315,12101,16126313550 4 T6313551R 5 6 P9,4258513 7 8 ATX4&E1E5&E13&E15DT16126313550N3 9 T12138880123

4/3/01 26

PN 88300150

3.8 Immediate Action Commands

$H Help Screens

The $H command gives you short ex pla nat ion s on how to use ea ch MT28 34MR command. The $H command can be quite useful if your manual is not handy and you are in the middle of a communications session. Although the explanations are quite abbreviated compared to those in this manual, they should prove to be helpful reminders when needed.

At the time of this writing, we have three screens of Help information (Screen #1, #2 and #3), and more screens may be added in the future. The Help commands are structured so that you can call up one of three Help screens, as follows:

AT$H1 = Help Screen #1 AT$H2 = Help Screen #2 AT$H3 = Help Screen #3

+++AT<CR> Escape Sequences -- Entering Command Mode While Still On-Line

It is possible to cause the MT2834MR to enter the Command mode after the modem has gone on-line with a remote modem, without disconnecting the call. This is accomplished by typing an Escape Code. The default Escape Code used by the MT2834MR is three plus signs (+++) followed by the letters A and T, up to sixty command characters (most typically H, to hang up), and an ENTER. The number of command chara ct ers al lowe d after +++AT<CR>, is defined by S-Register S34. S-Register S34 defaults to ten command characters. When this is done, the modem will escape to Command mode, execute the command (if any), and then remain in Command mode. For example, to hang up the modem at the end of a call, the command would be +++ATH followed by ENT ER. Th ere is no nee d to incor p orate pa us es before and after the plus signs, as done in earlier modems.

BREAK AT<CR>

The MT2834MR provides an alt ernative Escape method, us in g a Break si gna l a s the Esca pe Code. The Break signal allows the start-stop DTE (data terminal equipment) to signal the modem without loss of character transparency. With this method, a BREAK signal is used instead of the three plus signs. The BREAK is followed by the letters A and T, up to 60 command characters, and ENTER. Wh en t his is do ne, the mod em w ill exe cute t hat command, but remain in the normal On- L in e mode un les s the co mm and wa s to hang up and/or reset the modem (an H or Z), in which case the modem would be in the Command mode after executing that command.

* Readers interested in further information on the use of BREAK signals as escape codes may wish to consult the ITU-T X.28

Recommendation. In the “Provisional Recommendation X.28 (Geneva 1977)”, information on the topic can be found in Section

4.9, entitled “Escape from the data transfer state”. More recent editions have been published in 1980, 1984 and 1988. ITU-T publications can be obtained from Omnicom, Inc., 112 Park Street SE, Vienna, VA 22180, Phone 703/281-1135, FAX 703/281-

1505.

%E Escape Sequence Options -- Entering Command Mode While On-Line

As mentioned, the default setting is for the modem to respond to the +++ escape method. Optional settings are for the modem to respond to the BREAK method, for the modem to respond to either the +++ or the BREAK Methods, and for the modem to ignore both methods and not escape. The %E command is used to select these options, as follows:

%E0 = Modem Won’t Escape %E1 = +++AT<CR> Method (factory def aul t settin g) %E2 = BREAK Method %E3 = Either +++ or BREAK Methods %E4 = Disable OK response to +++ %E5 = Enable OK resp on se to +++

4/3/01 27

PN 88300150

Note: The Escape Code for Remote Configuration (see Appendix K) has %%%AT<CR> for the factory default setting.

O Exiting Command Mode, Going Back On-Line

To bring the MT2834MR out of Command mode back into On-Line mode, type ATO (where O is the letter O, not the number 0). In this case, the O command reverses what was done by

typing the Escape Code. The O command places the modem in the same On-Line mode (Originate or Answer) that it was in prior to going into Command mode.

A Forcing Answer Mode

With the A command you can force the MT2834MR into the Answer mode. Type ATA Mode when in Command mode to immediately bring your modem off-hook, out of Command mode and into the On-Line Answer mode, and cause it to transmit its carrier signal over the phone line. If no responding carrier tone is received by your modem within 45 seconds (or some other time as determined by S-Register S7), your modem will cease transmitting its tone, hang up, and go back into Command mode.

I Inquiry for Product Code

Some systems or software packages automatically check the “Identification” of the modem with which they are communicating, by using the I command. This “read” command lets the software determine the type of modem with which it is communicating.

When ATI or ATI0 is typed, the MT2834MR responds with 247. When ATI1 is typed, the modem responds with a three-digit firmware version number.

L5, L7 Listing Current Operating Parameters

The L5 and L7 commands allow you to list the current operating parameters of your modem. This information can be very useful when reconfiguring your modem, such as when you are changing communications software or when you are changing your factory default settings.

To list the MT2834MR’s current operati ng par a meters, type ATL5 for the basic parameters. Type ATL7 to list additional parameters. The parameters for all of the configuration commands (covered in secti on 5.9) are lis ted.

L6 Listing S-Register Values

The L6 command lists the cur rent values stored in the modem ’s S-Registers. This information can be very useful if you wish to change S-Register values. (Refer to Chapter 4 for more information on S-Registers.)

L8 Listing On-Line Diagnostics

The L8 command displays the current on-line status (e.g., Link Type, Line Speed, Serial Speed, Type of Error Correction/Data Compression, Number of past Retrains, etc.) of the MT2834MR, the DSP code version number, and the processor speed. This display can be printed and used as a modem status report or as diagnostic information (such as when calling Tech Support). This report is given only when on-line. To activate this command type +++AT<CR> (on-line escape command while maintaining command mode), then type ATL8.

4/3/01 28

PN 88300150

3.9 Configuration Commands

3.9.1 Configuration Storage and Default Commands

&F Loading Factory Defaults

Because the modem has the capability of storing reconfigured parameters and S-Register values into its non-volatile Random Access Memory (RAM), you may wish to have a choice between these RAM stored parameters and values or the factory default parameters and values (as determined by the modem’s ROM and DIP-Switches). The &F command lets you set the modem to the factory defaults in ROM. The modem will then ignore the parameters and values that remain stored in R AM.

The command AT&F causes the MT2834MR to use the factory default setting ROM configuration parameters and S-Registers values. To replace the parameters and values stored in RAM with all factory default settings, combine the &F and &W commands by typing AT&F&W and hitting ENTER.

The &F8 and &F9 commands determine the function of the &F command. If you type the &F8 command (the factory default setting), and later type a subsequent &F

command, the modem reads the factory default settings, regardless of what is stored in nonvolatile RAM (defined by the &W command).

If you type the &F9 command, and then type a subsequent &F command, the modem reads the parameters and values stored in non-volatile RAM as the defaults. The result is that the setting of the &W command defines the source of the default parameters and values that your modem reads as its factory default settings.

&W Storing Configuration & S-Register Parameters in the Modem’s Non-Volatile Memory

The MT2834MR can store its configuration parameters and S-Register values in its nonvolatile read/write (RAM) memory.

Type the &W command to store parameter s and S-Register values in the modem’s RAM, and to prevent any reconfiguration from being lost on a power-down or Reset (ATZ) condition.

Type AT&W0 (or AT&W) to cause the modem to store its current parameters and values in its non-volatile RAM. This command also sets the modem so that when it is powered up, or when it is reset with the ATZ command, the modem will read all of its configuration and SRegister parameters from RAM, and not from the factory default setting in ROM.

Type AT&W1 to set the modem so that it does not store its parameters to RAM, and, when a subsequent power on condit io n or ATZ command is executed, parameters will be read from the factory default settings in ROM and from the DIP-Switch settings.

Z Modem Reset

Type the Z command to reset all MT2834MR configurations to their factory default settings, and to clear the Command mode buffer. When you type ATZ, the result is the same as if you had disconnected, and then reconnected power to the modem. When the ATZ com mand is executed, the state of the &W command determines where the default values originate. (&W0 defaults come from RAM and &W1 defaults come from ROM.)

4/3/01 29

PN 88300150

3.9.2 Command/Response

E Echoing Command Mode Characters

If the MT2834MR is connected to a full-duplex terminal or computer, you may have to configure the modem to echo back characters typed while in Command mode in order for them to be displayed. The E command is used to configure the Command mode echo, with

ATE0 disabling the echo and ATE1 enabling the echo.

Q Result Codes (Enable or Disable) and No Response Answer

The Q command enables or disables Result Codes and the No Response Answer mode of operation.

Regarding Result Code Enable/Disable, you may want to disable the Result Codes altogether in certain applications, such as computer-controlled autodialing. The command ATQ1 disables Result Code transmissions and ATQ0 (or ATQ) enables them. In typical operation, the originate mode and answer mode are “intelligent” operations, controlled by the position of the modem DIP-Switches and previously executed commands.

Regarding No Response Answer, you may want Answer mode handled without responses, and echo turned off but want Originate mode still intelligent. This is called the No Response Answer mode. ATQ2 selects the No Response Answer mode. If you do not select any mode, the factory default setting enables the Result Codes to be sent.

&Q Result Codes - "Multi-Tech" or "Standard"

The MT2834MR modems give you a choice between Multi-Tech responses (which include RELIABLE and COMPRESS ED respon ses), and a set that more closely match es the Standard AT command set res ult co des.

AT&Q0 selects Multi-Tech responses with Reliable/Compression modifiers, DIALTONE/BUS Y/NO AN SW ER . With this setting, the terse response for CONNECT 2400 is

9. This is the factory default setting. AT&Q1 selects Standard AT responses with no Reliable/Compression modifier. With this

setting, the terse response for CONNECT 2400 is 10. Refer to Appendix D for a summary of Result Codes.

V Result Codes - Word or Digit

The V command controls whether the MT2834MR’s result codes are displayed as words (“verbose”) or single digits (“terse”).

For example, if after dialing, no carri er sign al is dete cted , the re su lt can be di sp la yed either as NO CARRIER, or as the digit 3.

Type ATV0 (or ATV) to cause the MT2834MR to display the Result Codes as digits. Type ATV1 to display the Result Codes as words. If you do not select a method, the factory default setting will cause the modem to use verbose results.

X Result Codes (Basic or Extended) and Call Progress Method

The X command selects both the dialing method (“dumb” or “smart”), as well as various response combinations related to the dialing method selected.

Regarding result code selection, you can choose to have certain responses suppressed, and whether or not you want speed indications along with the CONNECT responses.

The MT2834MR provides “Basic” and “Extended” Result Code sets. The difference between the two is the Basic set provides one response (CONNECT) to indicate a connection, while

4/3/01 30

+ 76 hidden pages

Multitech MT2834MR, MT2834MRK, MT2834MRI Owner's Manual

Specifications and Main Features

Frequently Asked Questions

User Manual