*********************************** * * * COURIER V.34 Manual * * * *********************************** Copyright 1994 by U.S. Robotics, Inc. U.S. Robotics, the U.S. Robotics logo, and HST are registered trademarks of U.S. Robotics, Inc. Courier HST Dual Standard Fax, Courier V.32 terbo Fax, Total Control, and Adaptive Speed Leveling (ASL) are trademarks of U.S. Robotics, Inc. V.Fast Class and V.FC are trademarks of Rockwell International. Any trademarks, tradenames, service marks or service names owned or registered by any other company and used in this manual are the property of their respective companies. ***************************************************************************** TABLE OF CONTENTS ***************************************************************************** How to Use this Manual Table of Contents Limited Warranty FCC Registration Numbers IC (Industry Canada) Connecting to the Telephone Company Radio and Television Interference For Canadian Modem Users PART I. INSTALLATION AND OPERATION Chapter 1--Features and Compatibility Introduction Features Compatibility Fax Standards Other Compatibility Features Chapter 2--External Modem Set Up Switches on the Modem Front Panel Indicators on the Modem Package Components What You Need An RS-232 Cable Communications Software. . . Telephone Adapter. . . You Should. . . Refer to Appendix F. . . Refer to Appendix G. . . Installing the Modem Testing the Installation Chapter 3--Internal Modem Set Up Package Components What You Need Communications Software. . . A Telephone Adapter You Should. . . Refer to Appendix F. . . Refer to Appendix G. . . Before Installing the Modem Select a Serial Port Select an Interrupt Request (IRQ) Reset the Jumpers Set DIP Switches Installing the Modem Testing the Installation Chapter 4--Data Mode Command Summary Command Set Usage Basic Commands Dialing/Answering Dialing Dial Options Cancel Dialing Store Phone Numbers Redialing Answer Mode Hanging Up Setting/Using Defaults Customizing NVRAM Resetting the Modem Configuration Echo/Speaker Result Codes Additional Result Code Sets Modulation Error Control/Data Compression Data Rates RS-232 Signal Operations Flow Control S-Registers Inquiry and Help Testing International Calls Miscellaneous Commands Chapter 5--Fax Operations and Call Detection Fax Operations Notes to Programmers Call Detection Chapter 6--Queries and Help Screens User Inquiries S-Register Query Phone Number Query Last-Dialed Number Inquiry Stored Command String Query Help Screens Stop/Restart Display Cancel Display Basic Command Set Extended Command Set Dialing S-Register Functions Percent Commands PART II. REFERENCE Appendix A--Link Negotiation (Handshaking) and Error Control V.34 Handshaking V.Fast Class (V.FC) Handshaking U.S. Robotics V.32 terbo to U.S. Robotics V.32 terbo Other V. Protocol Operations Dual Standard Handshaking Error Control and Throughput V.42 Handshaking MNP Handshaking Data Compression Flow Control Throughput Guidelines Typical Throughput Appendix B--Summaries and Tables The RS-232 Interface Front Panel Indicators DIP Switch Summary Default Settings Factory Templates &F1 Hardware Flow Control (Default) &F2 Software Flow Control &F3 HST Cellular &F0 No Flow Control NVRAM Options S-Register Summary ASCII Chart Appendix C--Alphabetical Command Summary Command Set Usage Basic Command Set Ampersand (&) Command Set Percent (%) Command Sets Appendix D--Dial Security/Remote Access Dial Security Remote Access Appendix E--Troubleshooting Appendix F--Synchronous and Leased Line Operations Synchronous V.25 bis Online synchronous Dedicated Line and Leased Line Operations Appendix G--Additional Operations Cellular Operations Voice/Data (External Modems Only) Hewlett Packard 3000 Installations MI/MIC Operations (External Modems Only) Appendix H--Modem Testing Testing with &T Ending a Test--&T0, S18 Analog Loopback--&T1, &T8 &T2 Digital Loopback--&T3 &T4, &T5 Remote Digital Loopback--&T6, &T7 Testing with Register S16 Analog Loopback--S16=1D Dial Test--S16=2 Test Pattern--S16=4 Remote Digital Loopback--S16=8 Appendix I--Software Upgrades Appendix J--Glossary Appendix K--Technical Specifications Index ********************** HOW TO USE THIS MANUAL This manual contains operating instructions for Courier Dual Standard V.34 and Courier V.34 modems. These modems have many similar features except for the signaling they use to connect with remote modems at high speeds: V.32/V.32 terbo, HST, V.FC, or V.34. Courier HST Dual Standard modems use any type of signaling, depending on the type of remote modem. V.34 modems can connect at rates up to 28.8K bps. Below is a brief description of the manual's contents. * Chapter 1--Operating and Compatibility Features * Chapter 2--Installation * Chapter 3--Internal Modem Installation * Chapter 4--Data Mode Commands * Chapter 5--Fax Mode and Call Selection * Chapter 6--Queries and Help commands to display current settings, operational summaries, and other data * Background information on protocols, error control, and throughput * Summaries and tables * Alphabetical Command Summary * Dial Security operations * Troubleshooting * Online synchronous and V.25 bis synchronous operations * Additional features such as HST Cellular and voice/data switch * Procedures for modem testing * Procedures for upgrading your modem via software downloads * Glossary * Warranty/Service/Certification information ********************************* A Note on Communications Software If you're using a computer rather than a terminal, you need communications software. Many brands are available, all of which are based on the modem's AT command set. Some users prefer their communications software to take control of the modem, and are more comfortable with a program that makes the modem almost transparent. Others prefer a program that allows them to use the modem's AT command set sometimes, and their software at other times, depending on the task at hand. Review at least Chapter 4 so that you have a basic understanding of the modem's requirements and operation. **************** LIMITED WARRANTY U.S. Robotics, Inc., warrants to the original consumer or other end user purchaser that this product is free from defects in materials or workmanship for a period of two years from the date of purchase. During the warranty period, and upon proof of purchase, the product will be repaired or replaced (with the same or similar model) at our option, without charge for either parts or labor. This warranty shall not apply if the product is modified, tampered with, misused, or subjected to abnormal working conditions. REPAIR OR REPLACEMENT AS PROVIDED UNDER THIS WARRANTY IS THE EXCLUSIVE REMEDY OF THE PURCHASER. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE OR PURPOSE, AND U.S. ROBOTICS SHALL IN NO EVENT BE LIABLE TO PURCHASER FOR INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND OR CHARACTER. Some states do not allow the exclusion or limitation of incidental or consequential damages or allow limitations on how long an implied warranty lasts, so the above limitations or exclusion may not apply to you. This warranty gives you specific legal rights. You may also have other rights which vary from state to state. Should you encounter problems in operating this device, follow the instructions in Appendix E in Part II of this manual. The appendix contains solutions to operating problems as well as procedures to follow if there is an apparent modem malfunction. **************** FCC REGISTRATION FCC68: CJEUSA-73130-FA-E RINGER EQUIVALENCE: 0.4B FCC15: CJE-0263 (External modem) CJE-0269 (Internal modem) CJE-158-243 (Motherboard) CJE-0151-243 (Daughterboard) ******************** IC (Industry Canada) This digital apparatus does not exceed the Class B limits for radio noise emissions from digital apparatus set out in the radio interference regulations of Industry Canada (formerly Canadian Department of Communications). Le present appareil numerique n'emet pas de bruits radio-electriques depassant les limites applicables aux appareils numeriques de la classe B prescrites dans le Reglement sur le brouillage radioelectrique edicte par le ministere des Communications du Canada. *********************************** Connecting to the Telephone Company It is not necessary to notify the telephone company before installing the modem. However, the telephone company may request the telephone number(s) to which the Courier is connected and the FCC information printed above. If the modem is malfunctioning, it may affect the telephone lines. In this case, disconnect the modem until the source of the difficulty is traced. Do not use the modem on party or coin telephone lines. ********************************* Radio and Television Interference This equipment generates and uses radio frequency energy, and, if not installed and used properly in strict accordance with the manufacturer's instructions, may cause interference to radio and television reception. Courier high speed modems have been tested and found to comply with the limits for a Class B computing device in accordance with the specifications in Part 15 of FCC rules, which are designed to provide reasonable protection against such interference in a residential installation. However, there is no guarantee that interference will not occur in a particular installation. If this device does cause interference to radio or television reception, which you can determine by monitoring reception when the modem is on and off, try to correct the problem with one or more of the following measures. * Reorient the receiving antenna. * Relocate the computer with respect to the receiver. * Relocate the computer and/or the receiver so that they are on separate branch circuits. If necessary, consult your dealer or an experienced radio/ television technician for additional suggestions. You may find the following booklet, prepared by the Federal Communications Commission, helpful: How to Identify and Resolve Radio-TV Interference Problems Stock No. 004-000-0345-4 U.S. Government Printing Office Washington, DC 20402 In accordance with Part 15 of the FCC rules, any modification to or tampering with this device that causes harmful interference to others may be reason for prohibiting future operation. ************************ For Canadian Modem Users The Industry Canada (formerly DOC) label identifies certified 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 a user's satisfaction. Before installing this equipment, make sure you are permitted to connect it to the facilities of the local telecommunications company. You must also install the equipment using an acceptable method of connection. In some cases, you may also extend the company's inside wiring for single line individual service by means of a certified connector assembly (telephone extension cord). You should be aware, however, that compliance with the above conditions may not prevent degradation of service in some situations. Repairs to certified equipment should be made by an authorized Canadian maintenance facility designated by the supplier. Any repairs or alterations made by a user to this equipment, or equipment malfunctions, may give the telecommunications company cause to request the user to disconnect the equipment. For your own protection, make sure 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. WARNING: Do not attempt to make such connections yourself; contact the appropriate electric inspection authority or electrician. Courier High Speed Modems Load Number: 5 The Load Number (LN) assigned to each terminal device denotes the percentage of the total load to be connected to the telephone loop used by the device, without 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 not exceed 100. Chapter One--Features and Compatibility ************ INTRODUCTION Congratulations! The Courier modem you've purchased represents powerful, advanced electronic design that offers exceptional reliability, compatibility and flexibility at all standard rates up to 28,800 or 28.8K bits per second (bps). The transmission rate between the computer and modem, depending on your equipment and software support, can be as high as 115.2K bps. ******** Features The following features and capabilities assure you of superior reliability and performance. Connections up to 28.8K bps With the V.34 standard and the V.Fast Class modulation scheme, two modems can connect at rates up to 28.8K bps, twice as fast as the rates of standard ITU-T (formerly CCITT) V.32 bis modems, which are limited to calls of 14.4K bps or less. Software Upgrades Courier high speed modems are now software upgradable, allowing you quick, easy access to the latest advances in data communication technology. See Appendix I. Quick Connect In V.32 terbo mode, Courier high speed modems can handshake and start transmitting much faster than typical training times that range between 9 and 18 seconds for other modems. Universal Connect Courier high speed modems automatically detect and connect at the fastest available speed. Adaptive Speed Leveling (ASL) Like most high speed modems, Courier modems fall back to the next lower speed—for example, 19.2K, then 16.8K in V.terbo mode--if poor line conditions warrant. In addition, Courier V.32 bis, and V.32 terbo modems detect improved line conditions and shift upward again to the next higher speed. Both transmit and receive channels adapt independently, each detecting and adjusting to line conditions. ASL keeps the modems online, always operating at the highest possible speed, and constantly ensuring data integrity. Fax Capability You can use your modem with Class 1 or Class 2.0 facsimile software to exchange faxes with millions of Group III fax machines worldwide. See Chapter 5. Error Control--V.42/MNP Data integrity is ensured when the modems connect with remote modems that use the V.42 (LAPM), HST, or MNP error control protocols. Error control is available on calls at 1200 bps and above. Data Compression--V.42 bis/MNP5 Data compression enables potential throughput of up to 115.2K bps on 28.8K bps connections. Couriers connecting under V.42 or HST error control use V.42 bis compression. Couriers connecting under MNP error control use MNP Level 5 compression. Typical throughput of text and other types of files using V.42 bis is provided in Appendix A. Flow Control/Variable Serial Port Rates Flow control, required under error control, also allows the local serial port (DTE) rate to be set higher than the link (connection) rate, enabling greater efficiency and throughput. If your equipment and software support high rates, data can be sent from the computer to the modem at 115.2K, 57.6K, 38.4K or 19.2K bps, regardless of the link rate. Voice/Data Switch A switch on the modem's front panel allows you to change from voice to data and back again, without issuing a command. See Appendix G. Stored Command String If you don't ordinarily use voice and data in the same call, you can assign the voice/data switch a different function that normally requires a command, such as resetting the modem or executing a stored command string. See Voice/Data in Appendix G for instructions on use of the voice/data switch. Asynchronous/Synchronous Capability Courier high speed modems operate synchronously as well as asynchronously. A personal computer equipped with a synchronous interface adapter can call computers that use standard synchronous protocols. See Appendix F for more information. Synchronous Operations with V.25 bis Used with computers that have a synchronous card and port, Courier high speed modems combine the power of older modems and automatic calling units in the mainframe environment. They make synchronous connections by utilizing V.25 bis, character-oriented (similar to BISYNC) and HDLC protocols. See Appendix F for more information. Dial Security With Dial Security, you will be able to prevent unauthorized access to a system with the use of Autopass, Prompting, and Dialback. See Appendix D for more information. Programmable Nonvolatile Memory You can tailor your own default settings and store them in nonvolatile random access memory (NVRAM). Each time the Courier is powered on or reset, it operates at the settings you've specified. See Chapter 4, Appendix B, and Appendix C. Link Rate Negotiation The Courier automatically lowers its link rate to match a lower rate of a remote modem, in both Originate and Answer Modes, allowing connections with a wide range of installed modems. Link Diagnostics After each call, you can display a Link Diagnostics screen containing information about the last call, including the number of data characters transferred, line statistics, the call's rate and the reason the call was disconnected. See Chapter 6. Modem Diagnostics ITU-T V.54 loopback testing with the &T command options, and earlier Courier Register S16 test options are available. The modem performs three loopback tests: analog, digital, and remote digital. See Appendix H for information. Inactivity Timer You can set the modem to automatically hang up after a specified number of minutes if there is no activity on the phone line. See Register S19 in Appendix B. Call Duration Reporting The modem records the duration of your calls in hours, minutes, and seconds. This feature enables you to display and print an audit of your calling activities. You can optionally use the modem clock as a real-time clock. See the I3 and I6 screens in Chapter 6 and the K command in Chapter 4 and Appendix C. Call Progress Detection An optional set of result codes (screen messages) lets you know when a line is busy, a person rather than a modem has answered the phone, there is no dial tone, or the distant phone is ringing. Modem Settings Displays On command, the modem displays its current settings, a handy way to check your transmission rate, S-Registers and other operational controls. The modem also displays the defaults stored in nonvolatile memory as well as its default configuration templates. See Chapter 6. HELP Screens The modem displays screens that summarize the command sets, Dial command options, and S-Register functions. See Chapter 6. Bottom Panel Reference Command summaries and other information are printed on the bottom of the modem case. A Dual In-Line Package (DIP) switch guide makes it easy to tailor the switch settings to your terminal or software requirements. Dialing the Last-Dialed Number The modem has a buffer that stores each dialed number until it is cleared by another Dial command. A few keystrokes cause the modem to redial the number in the buffer without your having to enter the number again. See the DL command in Appendix C. Automated Redialing You can put the modem into Repeat Mode to continuously redial if a previous dial attempt fails to connect. This is especially useful in dialing services whose lines are often busy. See Chapter 4. Quote Mode Set the modem to Quote Mode if you want it to dial an alphabetic acronym instead of a numeric number. See Chapter 4. ************* COMPATIBILITY The Courier adheres to the following modulation schemes and standards, ensuring compatibility with a wide base of installed modems. Unless otherwise indicated, Dual Standard V.34 modems conform to the listed standards. NOTE: The International Telecommunication Union (ITU-T) was formerly the International Telegraph and Telephone Consultative Committee (CCITT). ITU-T V.34 28.8K/26.4K/24K/21.6K/19.2K/16.8K/14.4K/12K/ 9600/7200/4800/2400 bps V.FC 28.8K/26.4K/24K/21.6K/19.2K/16.8K/14.4K bps V.32 terbo 21.6K/19.2K/16.8K/14.4K/12K/9600/ 7200/4800 bps HST 16.8K/14.4K/12K/9600/7200/4800 bps (Dual Standard modems in HST mode with ASL up to 21.6K bps) HST Cellular Cellular connections at 12K/9600/7200/ 4800/2400/1200/300 bps (Dual Standard modems in HST mode) ITU-T V.32 bis 14.4K/12K/9600/7200/4800 bps ITU-T V.32 9600/4800 bps ITU-T V.22 bis 2400 bps Bell 212A 1200 bps (also V.22) ITU-T V.23 1200 bps with 75 bps back channel (some U.K. and European phone systems) ITU-T V.25 Answer sequence for calls originating outside the U.S. and Canada ITU-T V.25 bis For synchronous communications using HDLC and character- oriented protocols Bell 103 300 bps (ITU-T V.21 optional) ITU-T V.42 LAPM error control, 1200 bps and higher ITU-T V.42 bis Data compression, 1200 bps and higher MNP Levels 2, 3 and 4 error control, level 5 data compression, 1200 bps and higher ITU-T V.54 Analog, digital and remote digital loopback testing ************* Fax Standards The Courier modem provides Group III-compatibility when combined with Class 1 or Class 2.0 fax software. In addition, the modem adheres to the following standards. TIA/EIA-578 Service Class 1 Asynchronous Facsimile DCE Control Standard TIA/EIA-592 Service Class 2.0 Asynchronous Facsimile DCE Control Standard ITU-T V.17 14.4K/12K bps ITU-T V.29 9600/7200 bps ITU-T V.27 ter 4800/2400 bps ITU-T V.21 300 bps **************************** Other Compatibility Features Other compatibility features include the following standards and certification: * Can be used with any computer or terminal that is compatible with the RS-232 standard interface. * Can be used with any computer or terminal that uses ASCII, the standard character code supported by most equipment manufacturers. * Is fully FCC- and IC-certified for the uses described in this manual. Chapter 2--Modem Set Up ******** Reminder To prevent overheating, do not cover the vents on the top of the modem case. ********************* Switches on the Modem Voice/Data This push-button switch is used primarily to switch between voice and data communications during a call. Detailed instructions are in the Voice/Data Calls section in Appendix G. Volume Control This is a slide switch underneath the right side panel of the modem, near the front corner. Sliding it toward the front of the modem increases the modem speaker's volume; sliding it toward the rear of the modem decreases the volume. Front Panel Indicators on the Modem The modem has twelve status lights, or LEDs. See Appendix B for descriptions of their operations. PACKAGE components Your Courier modem package contains the following items: * The modem you purchased: Courier V.34 * An RJ11C phone cord * A power adapter * Fax software and manual * A Quick-Reference card ************* What You Need The Courier modem has minimal operational requirements. Be sure to read the information in the front of this manual about radio and television interference and connecting to the phone company. In addition, you should be aware of the following requirements. An RS-232 Cable You need an RS-232 cable to connect the modem to your computer or terminal. Use a shielded cable to ensure minimal interference with radio and television reception. NOTES: * Refer to Appendix B for a listing of RS-232 pin assignments required to operate the modem. Be sure to check the appendix if you're not sure what type of cable you need, or if you're building your own. * If your machine has other than a 25- or 9-pin port, check your computer documentation or consult your dealer to find out what type of RS-232 connector is required. WARNING: If you're planning to use the high speed computer-to-modem rates of 115.K, 57.6K or 38.4K bps, follow the instructions concerning the RS-232 cable in Appendix B. The guidelines there will help you to avoid signal degradation at very high speeds. Communications Software. . . . . .if the modem is attached to a computer instead of a terminal. The software uses the modem's AT command set to control many communications functions, including configuring the modem, dialing, and answering calls, and also enables the transfer of files and other operations. Some users prefer their communications software to take control of the modem, and are more comfortable with a program that makes the modem almost transparent. Others prefer a program that allows them to use the modem's AT command set sometimes, and their software at other times, depending on the task at hand. Review Chapter 4 so that you have a basic understanding of the modem's requirements and operation. Telephone Adapter. . . . . .if you have an older telephone installation that does not have the appropriate modular wall jack and plug. Adapters and RJ11C connectors are available from your telephone company or computer dealer. *************** You Should. . . Refer to Appendix F. . . . . .if your phone line is user-installed or if it is leased from the telephone company. Refer to Appendix G. . . . . . if your modem is installed in a Hewlett Packard system that uses the Ack/Enq communications protocol. ******************** Installing the Modem 1. Turn off the computer or terminal and its peripheral devices. 2. Examine the label on the bottom of the modem. In addition to the summaries and other information, the label contains icons to aid in modem installation. 3. Make sure that the modem's power switch is OFF; press it towards the zero in the 0/1 icon on the bottom label. 4. Plug the power supply adapter's small connector into the power jack at the back of the modem. Plug the adapter into a standard 115-volt AC wall socket. 5. Disconnect your present phone cable from the wall jack. Plug one end of the supplied phone cable into the modem's phone jack (refer to the bottom label). Plug the other end into the wall jack. If you want to keep your telephone connected for conventional calls, plug its cord into the modem's telephone jack (refer to the bottom label). 6. Check the positions of the bank of Dual In-Line Package (DIP) Switches located in the well at the bottom of the modem. These switches are set at the factory to the positions most users require. Check your software documentation for its requirements, particularly for DIP switches 1, 4, 5 and 6. You'll also find descriptions of switch functions and options in Appendix B. NOTE: If you have built your own RS-232 cable and it does not support the Data Terminal Ready (DTR) signal, set DIP switch 1 ON, for DTR override. The override causes the modem to operate as if the DTR signal were always ON, and enables the modem to accept commands. Most purchased communications software, however, requires normal DTR. 7. The final step is to connect the modem to the computer's or terminal's serial port with the RS-232 cable. Attach the appropriate connectors to the modem and to the serial port. ************************ Testing the Installation Use the following procedures to verify that your modem is working properly. 1. Turn on your computer or terminal. Then turn the Courier's power switch ON. The following front panel indicators, or LEDs, will light up on the modem. CD Carrier Detect, if you have set DIP switch 6 ON, enabling the CD override TR Data Terminal Ready, if you have set DIP switch 1 ON, enabling the DTR override MR Modem Ready/Power ON CS Clear to Send 2. If you're using a personal computer, load your software to start the program. Set your terminal or software to 19.2K bps or 9600 bps. In addition, set a word length of either 7 bits plus 1 parity bit, or 8 bits with no parity—it doesn't matter which at this time—and 1 Stop bit. Set the software to use the correct serial port (port through which the modem connects to the computer). 3. Perform the function that lets you send AT commands to the modem, that is, puts the computer in Terminal mode. Some communications programs do this automatically upon loading. Others require you to display a communications or terminal screen, type a Function key, or perform some other operation. Review your communications software documentation for instructions. 4. Send the following attention command. Type either upper or lower case letters, not a combination, and then press the Enter (Carriage Return) key, shown in the example below between angle brackets. (Don't type the angle brackets.) AT If everything is correct, the modem responds as follows: OK Go on to step 5. Troubleshooting If your entered command is not displayed, your local echo is OFF. To turn the local echo ON, send the modem the following command: ATE1 If double characters appear on the screen, both your modem and software are set to local echo ON. Either set your software to local echo OFF, or turn the modem's echo OFF with the following command: ATE0 If no OK appears on your screen after you completed Step 4, review the following checkpoints: a. Make sure you type all upper or lower case letters and press . b. Check to see that you set your communications software to the correct serial port. The correct serial port is the port through which the modem is connected to the computer. c. Make sure your software has put the computer in Terminal mode, so that you can send the modem commands. Then review Step 4, on the previous page. d. Be sure that DIP switches 1 and 6 are set ON or OFF according to your terminal or software requirements. The table in Appendix B explains each function, and you may also need to review your terminal or communications software documentation. e. If you set DIP switch 8 OFF, for Dumb mode, reset the modem to Smart mode: set DIP switch 8 to ON. f. The modem is shipped with DIP switch 3 ON, enabling the result codes. If DIP switch 3 is OFF, set it to the ON position. Then initiate the new switch setting with the following reset command: ATZ 5. As a final check, make sure the modem gets a dial tone. Type the following Dial command: ATD On receipt of the command, the modem goes off hook and waits for a dial tone. The OH indicator lights up, and you'll hear the dial tone from the modem's speaker. To cancel the operation, press any key. Troubleshooting If you don't hear the dial tone, first increase the volume by sliding the volume control switch towards the front of the modem. If that doesn't work, check to see that the phone cable from the wall jack is connected to the correct jack on the modem (See Figure 2.3). If necessary, reconnect the phone cable correctly. Then try the Dial command again, ATD . Chapter Three--Internal Modem Set Up ****************** Package Components Your Courier modem package contains the following items: * The modem you purchased: Courier V.34 * An RJ11C phone cord * A power adapter * Fax software and manual * A Quick-Reference card ************ What You Need The Courier modem has minimal operational requirements. Be sure to read the information in the front of this manual about radio and television interference and connecting to the phone company. In addition, you should be aware of the following requirements. Communications Software. . . . . .if the modem is attached to a computer instead of a terminal. The software uses the modem's AT command set to control many communications functions, including configuring the modem, dialing, and answering calls, and also enables the transfer of files and other operations. Some users prefer their communications software to take control of the modem, and are more comfortable with a program that makes the modem almost transparent. Others prefer a program that allows them to use the modem's AT command set sometimes, and their software at other times, depending on the task at hand. Review Chapter 4 so that you have a basic understanding of the modem's requirements and operation. A Telephone Adapter. . . . . .if you have an older telephone installation that does not have the appropriate modular wall jack and plug. Adapters and RJ11C connectors are available from your telephone company or computer dealer. *************** You Should. . . Refer to Appendix F. . . . . .if your phone line is user-installed or if it is leased from the telephone company. Refer to Appendix G. . . . . . if your modem is installed in a Hewlett Packard system that uses the Ack/Enq communications protocol. *************************** BEFORE INSTALLING THE MODEM A typical new modem user has a PC with a printer connected to the PC's parallel printer port, and a mouse cable attached to the PC's first serial port. For this user, the modem is the only device that requires a second serial port. If this is your situation, you can skip this entire section except for DIP Switches, just before Installing the Modem. Just remember that after you load your communications software, you'll have to set the software to use the COM2 serial port. IBM PC-compatible serial ports are referred to as COM ports. Two COM ports are standard: COM1 and COM2. DOS recognizes up to four COM ports, although more can be programmed. The Courier is set at the factory to use COM2. This is because many computers are shipped with COM1 equipped with an external serial connector for attaching a device such as a serial printer or serial mouse. If you have one or more of these devices, you're probably already familiar with COM ports on a PC. If you're only using COM1 for a device, you can skip this section except for DIP Switches, just before Installing the Modem. If you've already installed devices at both COM1 and COM2, you will have to select either COM3 or COM4. Carefully review the following section for complete instructions. ******************** Select a Serial Port WARNING: If you are going to use COM1, COM3, or COM4, you must change some switches on the modem board, called jumpers. First, you need to select the correct Interrupt Request (IRQ) to use at that serial port. Peripheral devices use IRQs to instruct the computer to stop the processor's current operation; this allows the devices to perform their operations. Using COM1, 2, 3 or 4 depends on your equipment's configuration, as described below. Remember which serial port you assign to the modem, because you must specify it to your communications software later. The table in the next section includes hexadecimal addresses, required by some software. COM1: You may use this port if the computer does not have an installed serial connector at COM1. (This situation is unlikely.) You will have to modify some switches on the modem, so be sure to read this entire section of the chapter. However, you may prefer to leave the modem set to COM2 and proceed to DIP Switches, just before the installation instructions. COM2: If your computer is equipped with one serial connector at COM1, and if you are not already using COM2 for another device, use this port. (This is the most common configuration.) Since the modem is already set to operate at COM2, skip the rest of this section and proceed to DIP Switches, just before the installation instructions. COM3, COM4: If you have two serial devices that already use COM1 and COM2, you can set the modem for either COM3 or COM4. Review your communications software documentation to be sure your program supports these additional serial ports. (Most programs do.) If your software doesn't, you will have to remove one of the other devices. ********************************* Select an Interrupt Request (IRQ) IBM-compatible computers reserve IRQ4 for COM1 and IRQ3 for COM2, as shown below. Some communication programs support reserved IRQs for two serial ports. Serial Port IRQ Serial Port Address (Hex) COM1 IRQ4 3F8-3FF COM2 IRQ3 2F8-2FF COM3 IRQ4* 3E8-3EF COM4 IRQ3* 2E8-2EF *Select IRQ4 (COM3) or IRQ3 (COM4) only after reading the following guidelines: If you need to use COM3 or COM4, keep the following in mind: * The Courier supports three additional IRQs: IRQ2, IRQ5 and IRQ7. Your software must support the one you use for COM3 or COM4. However, if your computer is XT-compatible, IRQ5 is reserved for the hard disk, and it is not available for a serial port. IRQ5 is available on 286-PCs and higher. * Two devices should not use the same IRQ at the same time, because there will be a conflict and you will probably lose data. For example, if you use IRQ4 for a mouse installed at COM1 and for your modem installed at COM3 (as shown in the previous table) you cannot use the mouse and the modem at the same time. Additionally, if an installed device doesn't use IRQs, you can use the IRQ normally associated with that COM port. For example, if you have a serial printer at COM1 and you know it does not use an IRQ, you can use IRQ4 at COM3. Similarly, you could use IRQ3 at COM4 if the device at COM2 doesn't use IRQ3. If you cannot find the information you need in your software documentation, call your software's Technical Support Department for help in selecting an IRQ. You may find it necessary to re-install your serial devices to correctly allocate the available serial ports and IRQs. ***************** Reset the Jumpers If you hold the modem so that the rear panel is at the bottom and the edge connector is at the left of the circuit board you can locate the COM and IRQ jumpers near the center left side of the board. Each jumper has two upright contacts connected by a black plastic piece, called a shunt, placed over the contacts for the COM2 and IRQ3 settings. This shunt selects the jumper by closing the circuit. To change a jumper setting, gently lift off the black shunt and replace it over the contacts you want. As we've said, your choice of an IRQ for COM3 or COM4 depends on your hardware/software configuration. If the device at COM1 or COM2 isn't using IRQ4 or IRQ3, you may use one of them. Otherwise, check your PC and software documentation to see if you may use IRQ2, IRQ5 or IRQ7. WARNING: Do not select an IRQ position until you've read the previous guidelines and reviewed your software documentation. **************** Set DIP Switches A ten-position bank of Dual In-Line Package (DIP) switches is located at the rear of the modem. A summary of the DIP switch functions and options is in Appendix B in this manual and on the Quick Reference Card. WARNING: Check your software documentation for its requirements, particularly for DIP switches 1, 4, 5 and 6. NOTE: Once the modem is installed, the DIP switches are accessible through the computer's rear panel. ******************** Installing the Modem 1. Turn off the computer and peripheral devices. 2. Remove the computer's cover. Refer to the computer manual, if necessary, to see which rear panel screws to remove before sliding the cover off. NOTE: Our illustration shows expansion slots lined up vertically on the floor of the computer. Some computers are configured so that the expansion slots are stacked horizontally, one on top of another. The following instructions apply for both configurations. 3. Unscrew the solid bracket at the back of any available expansion slot. (The modem board requires at least a standard half-card slot.) The bracket will pop out of the back, leaving an opening in the rear panel for access to the modem's phone jacks and DIP switches. 4. Expansion slots have either a 3-inch-long groove, or a 3-inch and a 2-inch groove. These grooves are lined on both sides with metal guides. Insert the modem board into the slot you've chosen, as in Figure 3.3, with the leads on the modem board's edge connector firmly in the 3-inch groove. 5. Screw the vertical bracket at the back of the modem firmly to the computer's rear panel, as shown in Figure 3.3. This helps block radio frequency emissions from the computer and keeps the modem board firmly in place. 6. Replace the cover of the computer and replace the screws. 7. If you currently have a phone plugged into the wall jack, disconnect it. Plug one end of the phone cable that came with the modem into the TELCO jack at the rear of the modem. This allows the modem to switch into the telephone network, get a dial tone, and so on. Plug the other end of the cable into the wall jack. NOTE: The phone cable is equipped with two standard, modular RJ11C phone connectors. If you have an older type of wall jack, you can purchase an adapter and RJ11C connector from your phone company or computer dealer. 8. If you wish, plug your phone's cord into the second jack on the modem, labeled PHONE. This enables you to use your phone for conventional voice calls, and also allows you to switch between voice and data transmission in the same call. See Voice/Data Communications in Appendix G for more information. ************************ Testing the Installation Use the following procedures to verify that your modem is working properly. 1. Turn on your computer. Then turn the Courier's power switch ON. The following front panel indicators, or LEDs, will light up on the modem. CD Carrier Detect, if you have set DIP switch 6 ON, enabling the CD override TR Data Terminal Ready, if you have set DIP switch 1 ON, enabling the DTR override MR Modem Ready/Power ON CS Clear to Send 2. If you're using a personal computer, load your software to start the program. Set your terminal or software to 19.2K bps or 9600 bps. In addition, set a word length of either 7 bits plus 1 parity bit, or 8 bits with no parity—it doesn't matter which at this time—and 1 Stop bit. Set the software to use the correct serial port (port through which the modem connects to the computer). 3. Perform the function that lets you send AT commands to the modem, that is, puts the computer in Terminal mode. Some communications programs do this automatically upon loading. Others require you to display a communications or terminal screen, type a Function key, or perform some other operation. Review your communications software documentation for instructions. 4. Send the following attention command. Type either upper or lower case letters, not a combination, and then press the Enter (Carriage Return) key, shown in the example below between angle brackets. (Don't type the angle brackets.) AT If everything is correct, the modem responds as follows: OK Go on to step 5. Troubleshooting If your entered command is not displayed, your local echo is OFF. To turn the local echo ON, send the modem the following command: ATE1 If double characters appear on the screen, both your modem and software are set to local echo ON. Either set your software to local echo OFF, or turn the modem's echo OFF with the following command: ATE0 If no OK appears on your screen after you completed Step 4, review the following checkpoints: a. Make sure you type all upper or lower case letters and press . b. Check to see that you set your communications software to the correct serial port. The correct serial port is the port to which the modem is connected to the computer. c. Make sure your software has put the computer in Terminal mode, so that you can send the modem commands. Then review Step 4, on the previous page. d. Be sure that DIP switches 1 and 6 are set ON or OFF according to your terminal or software requirements. The table in Appendix B explains each function, and you may also need to review your terminal or communications software documentation. e. If you set DIP switch 8 OFF, for Dumb mode, reset the modem to Smart mode: set DIP switch 8 to ON. f. The modem is shipped with DIP switch 3 ON, enabling the result codes. If DIP switch 3 is OFF, set it to the ON position. Then initiate the new switch setting with the following reset command: ATZ 5. As a final check, make sure the modem gets a dial tone. Type the following Dial command: ATD On receipt of the command, the modem goes off hook and waits for a dial tone. The OH indicator lights up, and you'll hear the dial tone from the modem's speaker. To cancel the operation, press any key. Troubleshooting If you don't hear the dial tone, first increase the volume by using the L command. If that doesn't work, check to see that the phone cable from the wall jack is connected to the correct jack on the modem. If necessary, reconnect the phone cable correctly. Then try the Dial command again, ATD . Chapter Four--Data Mode Operations The information in this chapter applies to asynchronous calls only. For synchronous operations, refer to Appendix F. Detailed command descriptions are in this chapter. Additional command summaries are in Appendix C, on the bottom panel of the modem, and in the Quick-Reference Card. ***************** COMMAND SET USAGE The Courier command set enables you to send the modem two kinds of instructions: * operations, such as dialing or hanging up * configurations, such as enabling error control or data compression Follow these guidelines: 1. Your software must be loaded and, if you are using a computer, it must be in Terminal mode. Some communications programs put the computer in terminal mode automatically when they are loaded. Others require you to display a communications terminal screen, press a Function key, or perform some other operation. Refer to your communications software documentation for instructions. In Terminal mode the computer acts as if it were a standard terminal such as a teletypewriter, rather than a data processor. Keyboard entries go directly to the modem, whether the entry is a modem command or data to be transmitted over the phone lines. Received data is output directly to the screen. 2. Type commands in either upper or lower case, not a combination (AT or at--not At). 3. All commands except A/, A> and +++ are preceded by the AT (attention) prefix and are executed with the Enter/Carriage Return key (). 4. Command length = 60 characters maximum. The modem doesn't count the AT prefix, Carriage Return character, or spaces. It counts (but doesn't act on) punctuation such as hyphens and parentheses. 5. A missing numeric parameter is assumed to be zero, as in the command to hang up: ATH is the equivalent of ATH0 . Example (spaces are not required, but are added here for readability): AT &K3 X2 DT 071 312 1234 AT Attention; a command follows. &K3 Disable MNP5 data compression; use only V.42 bis compression. X2 Use the X2 result code subset. DT Dial the following number using tone dialing. Execute the commands. This chapter groups related commands into the following categories. * Basic Commands * Dialing/Answering Dialing Dial Options Cancel Dialing Store Phone Numbers Redialing Answer Mode Auto Answer Hanging Up * Setting/Using Defaults Customizing NVRAM Resetting the Modem * Configuration: Echo/Speaker Result Codes Modulation Error Control/Data Compression Data Rates RS-232 Signal Operations Flow Control * S-Registers * Inquiry and Help * Testing * International Calls * Miscellaneous Commands For an alphabetical listing of commands, check the first page of the index. NOTE: The defaults listed are based on the modem's shipping configuration: load from nonvolatile random access memory (NVRAM), DIP switch 10 OFF, which is the same as the &F1 configuration template). For a complete listing of default configuration templates, see Appendix B. ************** BASIC COMMANDS AT Attention command prefix. Use AT alone to test for the OK result code. AT must prefix all commands except A/, A> and +++. Any Terminate the current dialing operation resulting from an key issued Dial command; terminate Repeat mode (> or A>). ***************** DIALING/ANSWERING Dialing Dn Dial the specified phone number; also execute Dial options. The maximum number of characters allowed is 60, including the AT prefix, punctuation and spaces. The Carriage Return (Enter key) isn't counted as a character. NOTE: With the exception of the following Dial options, the modem ignores any commands issued after D in the same command string. Dial Options D Dial the number that follows and enter Originate mode. Optional parameters: P Pulse dial. Default. T Tone dial. , (Comma) Pause for 2 seconds before continuing to dial. ; Return to Command mode after dialing. If your phone is plugged into the modem, you can use this option to have the modem Auto Dial a telephone rather than a modem. The Courier dials, remains off hook and returns the OK message, indicating it is in Command mode. For example, to have the modem place a voice call, enter the Dial command with a semicolon: ATDT5551234; When the modem returns the OK result, pick up your phone receiver so you can talk to the other party, and send the command that hangs up the modem: ATH " Dial the letters that follow (in an alphabetical phone number). NOTE: If you are including another command after the dial string, use closing quotation marks before the additional command. ! Transfer a call (flash the switch-hook). This command applies to modems in installations where other modems share the phone line. The modem flashes the switch-hook (goes off hook 0.5 seconds, on hook for 0.5 seconds and off hook again) to dial the specified extension. W This command is useful in situations where you must wait for a second dial tone before continuing dialing. For example, if you need to dial for an outside line, the Courier continues dialing as soon as it detects the next dial tone. AT DT 9 W 5551234 NOTE: This command executes only if result code option X3 or greater has been issued. If the modem is set to X2 or lower, the modem interprets the W as a comma (two-second pause). @ Wait for an answer (with X3 or higher). Some online services answer the phone and return a tape-recorded request for information before processing transactions. In such instances, the @ command can be used in the Dial string to tell the modem to detect at least one ring, wait for five seconds of silence at the other end of the call, and then continue to execute the Dial string. To use the @ command, set the modem to X3, X4 or X7. If the modem is set to X2 or lower, the modem returns an ERROR message when encountering the @ character in a command string. If set to X5 or X6, the modem hangs up when it detects a voice answer and sends the VOICE result code. / A slash (/) causes a pause of only 125 milliseconds. R Reverse frequencies. This command allows calls to an originate-only modem. It reverses the modem's originate/answer frequencies, forcing the Courier to dial out at the answer frequency. The command follows the Dial command, before or after the phone number: AT D1234567R X2-X7 Adaptive dialing. When any of the X2 through X7 options is in effect and you do not issue a dialing type in the Dial string, the Courier uses tone dialing, which is faster than the default pulse type. However, if the phone company's central office does not have tone detection equipment, the modem cannot break dial and continues to detect the dial tone. If this occurs, the modem automatically reverts to pulse dialing. DL Dial the last-dialed number. The modem stores each Dial command until it receives the next Dial command. Use DL instead of A/, described on the next page, if you wish to send the modem non-Dial commands before dialing again. DSn Dial the number stored in nonvolatile random access memory at position n, where n = 0 through 9. Cancel Dialing To cancel Dial-command execution, press any key. If you inadvertently hit a key on the keyboard while the modem is dialing, the call is canceled. If this occurs, type the A/ command explained under Automated Redialing below. When the modem receives a command, it stores the instruction in its command buffer until it receives the next AT command. Note that if you've sent the modem an additional command since the Dial command, A/ re-executes that command instead of redialing. Store Phone Numbers &Zn=s This command stores up to ten numbers, where n is the position 0 through 9 in nonvolatile memory, and s is the phone number string. The number-string may be up to 40 characters long, including any Dial command options. AT &Z2=555-6789 Do not include modem settings in the &Zn string. If the call requires a special setting, insert it in the command string before the DSn command. In the following example, &M0 (no error control) is inserted before the Dial command: AT&M0 DS2 NOTE: The &Zn=s command functions differently when Dial Security is enabled. See Appendix D for more information. &Zn? Display the phone number stored in NVRAM at position n (n = 0 through 9). Redialing A/ Re-execute the last issued command. A/ doesn't take the AT prefix or a Carriage Return, and can be used to redial. A/ Automated Redialing (>, A>) While > and A> can be used to continuously repeat any command, they are designed for automated redialing. Enter Repeat Mode > If you know the modem you are calling is frequently busy, include the Repeat command in the Dial string, as follows: AT > DT 1234567 or AT DT 1234567 > The modem enters Repeat mode, dials the number, waits 60 seconds for a carrier (default), and hangs up. Then after a two-second pause, it redials. The cycle continues until the modems connect or the modem reaches a maximum of 10 attempts. The 10-try limit is mandated by Industry Canada (IC) to prevent tying up local telephone company exchanges with unconnected calls. A> This command combines the features of both the A/ and > commands. The modem enters Repeat mode as described above, and redials the Dial string in the command buffer. Like the A/ command, A> does not take the AT prefix or a Carriage Return. Exit Repeat Mode Should you use > or A> with a command other than a Dial string, abort the cycle by pressing any key. To abort automated redialing, be sure to press any key when the result code appears, during the pause before the modem begins dialing again. If you press any key while the modem is dialing, that dial attempt is canceled but the cycle continues. Answer Mode Force Answer Mode A Force Answer mode when the modem hasn't received an incoming call. Auto Answer The Courier is shipped with DIP switch 5 ON, Auto Answer suppressed. To set the modem to automatically answer incoming calls, do one of the following: 1. Before powering on the modem, set DIP switch 5 OFF. When you turn the computer on, the modem answers incoming calls on the first ring. 2. When the modem is on, set your communications software to enable auto answer. The following command instructs the modem to answer on the first ring. (You can substitute a higher value. See the S-Register summary in Appendix B.) AT S0 = 1 When the modem senses a call coming in, it sends the result code RING to your screen, goes off hook, and sends the remote modem a high-pitched answer tone. If there is no Carrier Detect within 60 seconds, the modem hangs up. If the connection is made, the modem sends a CONNECT result code. When the call is disconnected by you or the remote user, the modem hangs up and returns the NO CARRIER code. NOTE: If DIP switch 5 is OFF and S0=0, the Auto Answer will be disabled. Be sure that S0=1 through 256. Suppressing Auto Answer To disable Auto Answer, reverse Steps 1 or 2 above. Set DIP switch 5 ON before powering on the modem, or set the modem to answer on zero rings with the following command. AT S0 = 0 Points to Remember 1. If the modem is attached to a computer, you can set the modem to receive calls when you're not at your computer. Load your communications software as you normally do, and set the modem to Auto Answer. Also set your software's host mode function to save incoming messages and/or files. 2. If you've attached your phone so it can be used for conventional calls, disable Auto Answer when you are not expecting incoming data calls. Otherwise, your modem may answer the phone before you do, greeting a voice caller with a high-pitched answer tone. Hanging Up Hn On/off hook control. H0 Hang up (go on hook). H1 Go off hook. +++ Escape code operations. Once the modem is online to another system, the only command it recognizes is an escape code of three typed pluses, which forces the modem back to Command mode. Do the following when issuing the command: * Wait one second after sending the last item of data * Type: +++ * Wait one second before typing any data Do not type the AT prefix or a Carriage Return. The guard time of one second before and after the code prevents the modem from misinterpreting the occurrence of +++ in the transmitted data stream. If necessary, the character used in the escape code or the duration of the guard time can be changed by resetting Register S2 or S12. See the S-Register Summary in Appendix B. In response to +++, the modem returns to Command mode. However, it keeps the line open or hangs up, depending on the setting of DIP switch 9: DIP Switch 9 Response to +++ OFF Modem goes on hook (hangs up), sends NO CARRIER result code (factory setting) ON Modem maintains connection (Online-Command mode), sends OK result code The factory setting (OFF) forces an automatic disconnect when you issue +++. One advantage of this is that you are not likely to inadvertently run up an all-night phone bill. Set DIP switch 9 ON if you want the modem to respond to +++ by entering Online-Command mode, enabling it to execute commands and return online. (See the O command, next.) WARNING: For unattended modem operations: in rare instances, the modem may fail to recognize the +++ escape code sequence. If you are running the modem under software control for unattended operations, we suggest you use the sure fire method of dropping the DTR signal from the computer or terminal for at least 50 milliseconds, to avoid costly phone charges. Methods of turning the DTR signal off--for example, closing the communications port-- differ from one computer to another. Returning Online On If DIP switch 9 is ON (on detection of the escape code the modem maintains the connection), you can issue commands and then toggle the modem back online with the On command, as in this example: AT Q1 O There are two ways to return online. ATO0 Return online (normal). (Used in the example above.) ATO1 Return online and retrain. Use to have the modem re-synchronize if there were errors in a non-ARQ data transfer. Hanging Up If DIP switch 9 is ON, the escape code forces the modem back to Command mode but leaves the line open. If you want the modem to hang up, issue the following command once the modem sends the OK result code: ATH If DIP switch 9 is OFF, the modem automatically hangs up on receipt of the escape code. ********************** SETTING/USING DEFAULTS The modem's read-only memory (ROM) permanently stores the modem's four factory template settings. Nonvolatile random access memory (NVRAM) allows you to save one of these four templates, or add your own modifications, and write all the settings to NVRAM as your power-on defaults. &Fn The modem is shipped with four configurations (templates), &F0 through &F3, stored in permanent nonprogrammable memory (ROM). Appendix B includes configuration listings for each template. Any one of the templates may be loaded into current memory (AT &Fn) or written to nonvolatile memory to serve as the reset default (AT &Fn &W). Note, however, that &F0 is always loaded into memory if DIP switch 10 is ON. When you power on the Courier, it loads the settings stored in NVRAM if DIP switch 10 is OFF. Until you write your own settings to NVRAM, the defaults stored there are the same as the permanent ROM factory settings stored in position 1, &F1. To view the &F1 settings, select option 5 of the I (inquiry) command: AT I5 Customizing NVRAM &W To substitute a template other than &F1, write the desired template to NVRAM, using the &W command. AT &F2 &W To modify the &Fn configuration in NVRAM, type your changes and then save them to NVRAM, as in the following example. The original factory template remains intact. AT M2 S10=40 &A2 &W \ NOTE: When writing a different default configuration to NVRAM, insert any additions after the &Fn command but before &W. Otherwise they will be overwritten by &Fn. After sending a configuration to NVRAM, you can change any setting just for the current session, as in the following example. The NVRAM configuration remains intact. ATX6 But if you want the new setting to be a default, write it to NVRAM at the same time, as in the following example. X7 is substituted for the Xn value stored earlier. Any other setting that was changed and can be saved to NVRAM will also be saved. AT X7 &W Resetting the Modem Z Software reset to NVRAM settings when DIP switch 10 is OFF (factory setting). If DIP switch 10 is OFF, the modem resets to the &F0 configuration template, with no flow control. NOTE: Use the ATZ command also if you've changed the position of DIP switches 1 through 7 or 9 while the modem is on, so that the modem can read the new setting. The only other way to initiate a new setting for switches 1 through 7 and 9 is to turn the modem off and on again. ************* CONFIGURATION Echo/Speaker En Command mode local echo. Enables/disables the display of your typed commands. If double characters appear on the screen, both the modem's local echo and your software's local echo are on. The Courier is shipped with DIP switch 4 OFF, enabling local echo. The En command controls the local echo for a current session, independently of the switch setting. At power-on and reset, the modem operates according to the DIP switch setting. The En command is not stored in nonvolatile memory as a power-on/reset default. E0 Command mode echo OFF. The modem does not display keyboard commands. E1 Command mode echo ON. Fn Online local echo. This command causes the modem to display a copy of the data it is transmitting to another system. Many systems, however, return a copy of received data, which is called a remote echo. If the modem's online echo is ON and there is also remote echoing, double characters appear on the screen. In some microcomputer documentation, the term duplex is applied to local online echoing, although the term is not technically accurate. F0 Online echo ON. Sometimes called half duplex. As the modem transmits data to a remote system, it also sends a copy of the data to the screen. F1 Online echo OFF. Sometimes called full duplex. Default. Mn Speaker (audio monitor). M0 The speaker is always OFF. M1 The speaker is ON until carrier is established. Default. M2 The speaker is always ON, including during data transfer. M3 The speaker is ON after the last digit is dialed and remains ON until carrier is established. Result Codes Qn Enable/suppress the display of result codes. The Courier is shipped with DIP switch 3 ON, to display result codes. Use the Qn command to control the display for a current session, independently of the switch setting. At power-on and reset, the modem operates according to the DIP switch setting. The Qn command is not stored in nonvolatile random access memory. Q0 Result codes displayed. Q1 Result codes suppressed (quiet). Q2 Result codes suppressed in Answer mode. Vn Return result codes in words or numbers (Verbal/Numeric mode). At power-on and reset, the modem operates according to the DIP switch setting. The Vn command is not stored in nonvolatile memory as a power-on/reset default. V0 Numeric mode. V1 Verbal mode. Xn Result code set options. Use the following table (Default = X7, all codes except 12/VOICE). For result codes for synchronous operations, see Appendix F. Setting Result Codes X0 X1 X2 X3 X4 X5 X6 X7 0/OK * * * * * * * * 1/CONNECT * * * * * * * * 2/RING * * * * * * * * 3/NO CARRIER * * * * * * * * 4/ERROR * * * * * * * * 5/CONNECT 1200 * * * * * * * 6/NO DIAL TONE * * * * 7/BUSY * * * * * 8/NO ANSWER * * * * * 9/RESERVED 10/CONNECT 2400 * * * * * * * 11/RINGING * * * 12/VOICE * * 13/CONNECT 9600 * * * * * * * 18/CONNECT 4800 * * * * * * * 20/CONNECT 7200 * * * * * * * 21/CONNECT 12000 * * * * * * * 25/CONNECT 14400 * * * * * * * 43/CONNECT 16800 * * * * * * * 85/CONNECT 19200 * * * * * * * 91/CONNECT 21600 * * * * * * * 99/CONNECT 24000 * * * * * * * 103/CONNECT 26400 * * * * * * * 107/CONNECT 28800 * * * * * * * Functions Adaptive Dialing * * * * * * Wait for 2nd Dial Tone (W) * * * * * Wait for Answer (@) * * * * * Fast Dial * * * * NOTE: Additional messages indicate an error control connection and the modulation for a call. See the next section, Additional Result Code Subsets. Result Code Meaning 0/OK Command has been executed. 1/CONNECT Connection with another modem; if set to X0, connection may be between 300 and 28.8 bps; if X1 or higher, connection is at 300 bps. 2/RING Incoming ring detected. 3/NO CARRIER Carrier detect has failed or carrier has been dropped due to disconnect. 4/ERROR Command is invalid. 5/CONNECT 1200 Connection with another modem at 1200 bps. 6/NO DIAL TONE Dial tone not detected during the normal 2 seconds, set in Register S6. 7/BUSY Busy signal detect; modem hangs up. 8/NO ANSWER After waiting 5 seconds for an answer, modem hangs up; returned instead of NO CARRIER when the @ option is used. 10/CONNECT 2400 Connection with another modem at 2400 bps. 11/RINGING The modem has dialed; remote phone line is ringing. 12/VOICE Voice answer at remote site; modem hangs up. 13/CONNECT 9600 Connection at reported rate. Same meaning for results of 4800 (18), 7200 (20), 12K (21), 14.4K (25), 16.8K (43), 19.2K (85), 21.6K (91), 24K (99), 26.4K (103), or 28.8K (107) Adaptive The modem attempts to use tone dialing and, if that Dialing doesn't work, reverts to rotary dialing. Wait for The modem continues dialing as soon as it detects Another Dial another dial tone. See the dial options earlier in this Tone (W) chapter. Wait for an The modem continues dialing when it detects 5 seconds of Answer (@) silence on the line. See the dial options earlier in this chapter. Fast Dial The modem dials immediately on dial-tone detect, instead of waiting the normal 2 seconds set in Register S6. Additional Result Code Subsets NOTE: ARQ (Automatic Repeat Request) is used in this manual to denote calls under error control. &An Enable/disable additional result code subsets. See the Xn command earlier in this chapter. &A0 ARQ result codes are disabled. This setting does not affect an error control connection; the modem returns the standard CONNECT messages if result codes are enabled. &A1 ARQ result codes are enabled, indicating that a connection is under error control. Message 14 is displayed if the modem is set to X0 and the connection is at any rate from 1200 to 28.8K bps. The remaining results indicate the connection rate and require a setting of X1 or higher. 14/CONNECT/ARQ 47/CONNECT 16800/ARQ 15/CONNECT 1200/ARQ 88/CONNECT 19200/ARQ 16/CONNECT 2400/ARQ 94/CONNECT 21600/ARQ 17/CONNECT 9600/ARQ 100/CONNECT 24000/ARQ 19/CONNECT 4800/ARQ 104/CONNECT 26400/ARQ 22/CONNECT 12000/ARQ 108/CONNECT 28800/ARQ 24/CONNECT 7200/ARQ 26/CONNECT 14400/ARQ &A2 Additional VFC, V34, HST, or V32 modulation indicator. Included for users of HST Dual Standard modems. If your software cannot handle the added modulation information, select &A1 or &A0. 23/CONNECT 9600/HST 27/CONNECT 9600/ARQ/HST 28/CONNECT 4800/HST 29/CONNECT 4800/ARQ/HST 30/CONNECT 7200/HST 34/CONNECT 7200/ARQ/HST 31/CONNECT 12000/HST 32/CONNECT 12000/ARQ/HST 35/CONNECT 14400/HST 36/CONNECT 14400/ARQ/HST 53/CONNECT 16800/HST 57/CONNECT 16800/ARQ/HST 33/CONNECT 9600/V32 37/CONNECT 9600/ARQ/V32 38/CONNECT 4800/V32 39/CONNECT 4800/ARQ/V32 40/CONNECT 7200/V32 44/CONNECT 7200/ARQ/V32 41/CONNECT 12000/V32 42/CONNECT 12000/ARQ/V32 45/CONNECT 14400/V32 46/CONNECT 14400/ARQ/V32 83/CONNECT 16800/V32 84/CONNECT 16800/ARQ/V32 87/CONNECT 19200/V32 90/CONNECT 19200/ARQ/V32 93/CONNECT 21600/V32 96/CONNECT 21600/ARQ/V32 97/CONNECT 21600/VFC 98/CONNECT 21600/ARQ/VFC 101/CONNECT 24000/VFC 102/CONNECT 24000/ARQ/VFC 105/CONNECT 26400/VFC 106/CONNECT 26400/ARQ/VFC 109/CONNECT 28800/VFC 110/CONNECT 28800/ARQ/VFC 139/CONNECT 14400/VFC 141/CONNECT 14400/ARQ/VFC 143/CONNECT 16800/VFC 145/CONNECT 16800/ARQ/VFC 147/CONNECT 19200/VFC 149/CONNECT 19200/ARQ/VFC 111/CONNECT 21600/V34 112/CONNECT 21600/ARQ/V34 113/CONNECT 24000/V34 114/CONNECT 24000/ARQ/V34 115/CONNECT 26400/V34 116/CONNECT 26400/ARQ/V34 117/CONNECT 28800/V34 118/CONNECT 28800/ARQ/V34 120/CONNECT 2400/V34 122/CONNECT 2400/ARQ/V34 124/CONNECT 4800/V34 126/CONNECT 4800/ARQ/V34 128/CONNECT 7200/V34 130/CONNECT 7200/ARQ/V34 132/CONNECT 9600/V34 134/CONNECT 9600/ARQ/V34 136/CONNECT 12000/V34 138/CONNECT 12000/ARQ/V34 140/CONNECT 14400/V34 142/CONNECT 14400/ARQ/V34 144/CONNECT 16800/V34 146/CONNECT 16800/ARQ/V34 148/CONNECT 19200/V34 150/CONNECT 19200/ARQ/V34 &A3 Additional error control indicator (LAPM, HST, MNP, SYNC, or ONE) and data compression type (V42BIS or MNP5). Default. When the call is not under one of those protocols (and ARQ is not included in the result code), the modem reports either SYNC, indicating a synchronous connection, or NONE, for no protocol. If the modems are using data compression, the type of compression, V42BIS or MNP5, is added to the result code. In the first of the following examples, the modems negotiated error control for the call (ARQ), used VFC modulation, are using the LAPM error control protocol, and are using V.42 bis compression. CONNECT 28800/ARQ/VFC/LAPM/V42BIS [or MNP/MNP5] CONNECT 19200/ARQ/V32/LAPM/V42BIS [or MNP/MNP5] CONNECT 16800/ARQ/HST/HST/V42BIS [or MNP/MNP5] CONNECT 14400/ARQ/V32/LAPM/V42BIS [or MNP/MNP5] CONNECT 9600/ARQ/HST/CELLULAR/HST/V42BIS [or MNP5] CONNECT 9600/SYNC CONNECT 2400/NONE NOTE: Although these codes will return numeric identifiers, they are the same numeric identifiers used for &A2 result codes. If the modem is in Numeric mode (V0) and set to &A3, you will not be able to differentiate between &A2 and &A3 result codes. &A3 result codes may not be compatible with some software. Modulation Bn Handshake options. There are three commands that apply to international calls above 1200 bps--Bn, &Gn, &Pn. See International Calls later in this chapter for information on the other two settings. B0 ITU-T (formerly CCITT) answer sequence. Default. This is required to answer all V.32-type calls, as well as calls from overseas. B1 Bell answer tone. This setting selects HST modulation in Dual Standard modems, but should only be used if the modem is not required to answer V.32-type calls. NOTE: This setting is required for HST cellular calls. Error Control/Data Compression &Mn Enable ARQ (error control) or synchronous protocols. Both your modem and the remote modem must use the same protocol. &M0 Normal mode, no error control. Due to the nature of phone line channels, this is never recommended for calls above 2400 bps. &M1 This setting is exclusive of the modems' error control and is used only for online synchronous mode without V.25 bis. See Appendix F for more information. &M2 Reserved. &M3 Reserved. &M4 Normal/ARQ mode. Default. If an ARQ connection isn't made, the modem operates in Normal mode, as though it were set to &M0. NOTE: When V.32-type modems revert to Normal mode, they transfer data at high speeds without the reliability of error control. To avoid this, both local and remote modems should always be set for error control. Modems in HST mode, if unable to establish an error control connection, drop to 2400 bps. &M5 The modem enters ARQ asynchronous mode. The modem hangs up if an ARQ connection cannot be made. &M6 The modem enters V.25 bis synchronous mode, using a character-oriented link protocol similar to BISYNC. See Appendix F for more information. &M7 The modem enters V.25 bis synchronous mode, using the HDLC link protocol. &Kn Enable/disable data compression. &K0 Data compression disabled. &K1 Auto enable/disable. Default. The modem enables compression if the serial port rate is fixed, &B1. It disables compression if the serial port rate follows the connection rate, &B0, because compression offers no throughput advantage when the serial port and connection rates are equal. Compression may even degrade throughput. &K2 Data compression enabled. Use this setting to keep the modem from disabling compression. &K3 Selective data compression. The modem negotiates only for V.42 bis compression, and disables MNP Level 5 (MNP5) compression. Use this setting to transfer 8-bit binary files, .ZIP files, and other files that are already compressed. See the note below. NOTE: MNP5 compression is not useful when transferring files that are already compressed, such as the .ZIP files downloaded from many Bulletin Boards and 8-bit binary files, which appear to the modem to be compressed. MNP5 tends to add data to the transmission so that throughput over the link degrades. V.42 bis compression dynamically detects when data is already compressed and turns off until it detects that compression will work to advantage. The special &K3 setting enables the best throughput for already- compressed files. See Throughput Guidelines and Data Compression in Appendix A for more information, including throughput to expect for different kinds of files. Data Rates The modem can be set to a fixed or variable serial port rate. A fixed rate sets the modem for the highest possible throughput and provides the best performance. A variable rate allows the modem to switch to match the more limited rate on the phone connection. Your software must support fixed or variable serial port rates, and must be set to either of the two settings. NOTE: Your software may refer to these options with terms like locked serial port (fixed rate) or autobaud (variable rate). &Bn Serial port rate variable or fixed. &B0 Variable rates. When the modem switches its connection rate to connect with a modem operating at a different rate, it also switches its serial port rate. The software or terminal also switches serial port rates to match the connection rate. &B1 Fixed rate. Default. The modem always communicates with the terminal or computer at the rate at which you have set the terminal or software, regardless of the connection rate. For the greatest throughput, set the serial port to 115.2K, 57.6K, 38.4K bps for high speed calls and to at least 9600 bps for 2400-bps calls. This setting is not affected by the &N setting. However, the serial port rate must be equal to or higher than the &Nn rate. &B2 Fixed for ARQ calls/Variable for non-ARQ calls. Answer mode only. When the modem goes off hook and connects in ARQ mode, it shifts its serial port rate up to a user-specified rate, for example, 38.4K bps. If the connection is not under error control, the modem behaves as if it were set to &B0 and switches its serial port rate to match the connection rate of each call. To implement this feature, first set your software to the desired rate. Then send the modem the AT &B2 [other settings] &W command. The modem stores the rate of the command in NVRAM along with the settings. Each time it makes an ARQ connection, the modem checks NVRAM for the specified serial port rate. When sending subsequent configurations to NVRAM, be sure your software is set to your selected serial port rate, so that the correct rate is maintained. &Nn Connection rate variable or fixed. &N0 Variable rates. Default. The Courier negotiates with the remote modem for the highest possible connection rate, depending on the capabilities of the remote modem. &N1- Fixed rate. The modem only connects if the remote &N14 modem is operating at the same rate. If not, the modem hangs up. If you wish, you can filter out calls at other than a specific rate, for security or other reasons, by fixing the connection rate. The connection rate must always be lower than, or equal to, the serial port rate, never higher. The options are as follows. &N1 300 bps &N8 14.4K bps &N2 1200 bps &N9 16.8K bps &N3 2400 bps &N10 19.2K bps &N4 4800 bps &N11 21.6K bps &N5 7200 bps &N12 24K bps &N6 9600 bps &N13 26.4K bps &N7 12K bps &N14 28.8K bps ************************ RS-232 Signal Operations &Cn Carrier Detect operations. At power-on and reset, the modem operates according to the setting of DIP switch 6. This command is not stored in nonvolatile memory as a power-on/reset default. &C0 CD override, CD always ON. &C1 Normal CD operations. The Courier sends a CD signal when it connects with another modem and drops the CD when it disconnects. &Dn Data Terminal Ready (DTR) operations. At power-on and reset, the modem operates according to the setting of DIP switch 1. This command is not stored in nonvolatile memory as a power-on/reset default. &D0 DTR override. The modem operates as though the DTR is always ON. &D1 Advance usage: If issued before connecting with another modem, the modem can enter online command mode during a call by toggling DTR. (Most communications software packages have a method for toggling DTR.) &D1 functions similarly to the escape code (+++), except that this setting is independent of DIP switch 9. If DIP Switch 1 is ON (DTR override) when you issue the &D1 command, the DTR override is automatically turned off. However, if you change the setting of DIP switch 1 after issuing &D1, the DIP switch setting takes precedence. Return online with the On command, or hang up with the Hn command. &D2 Normal DTR operations. The terminal or computer must send a DTR signal for the modem to accept commands. Dropping DTR terminates a call. &Sn The modem sends the computer or terminal a Data Set Ready (DSR) signal via the RS-232 interface. (Data Set is industry jargon for modem.) Few, if any, commercial communications programs require the modem to control DSR, &S1. Leave the modem set for DSR overridden, &S0, unless you know that your installation requires a different setting. &S0 DSR is always ON (override). Default. &S1 In Originate mode, the modem sends the DSR after it dials, when it detects the remote modem's answer tone. In Answer mode, the modem sends the DSR after it sends an answer tone. &S2 This option is for specialized equipment such as automatic callback units. On loss of carrier, the modem sends a pulsed DSR signal with Clear to Send (CTS) following Carrier Detect (CD). &S3 This is the same as &S2, but without the CTS following CD. &S4 The modem sends the computer a DSR signal at the same time that it sends the Carrier Detect (CD) signal. &S5 CTS follows Carrier Detect with SSR normal ************ Flow Control Flow control allows the modem to monitor the amount of data coming from the computer or the remote modem, and notify either end if its buffers are too full, so that they stop sending data for a moment. The modem uses either hardware or software flow control. Your software and machine must support whichever type you select. Hardware Control The modem drops the Clear to Send (CTS) signal it's been sending to the computer or terminal when the modem's buffer nears 90% capacity. It starts sending CTS again when the buffer is about half full. Software Control The modem sends the computer or terminal the standard ASCII Transmit OFF (XOFF) character, -S, when its buffer nears 90% capacity. The modem sends the ASCII Transmit ON character, -Q, when the buffer is about half full. ASCII definitions are as follows: XON -Q (ASCII 17 Decimal, 11 Hex) XOFF -S (ASCII 19 Decimal, 13 Hex) NOTE: You should set your software as well to either hardware or software flow control. Some programs also require that you turn off the type you are not using. The ASCII characters may be user-defined. See Registers S22 and S23 in Appendix B. That appendix also includes an ASCII chart. WARNING: If possible, always use hardware flow control, the factory default. You may lose data if XON/XOFF (-S, -Q) characters occur in the data stream from other sources. They may, for example, come from the remote system: an XON from the remote system, after your modem has sent an XOFF, can result in buffer overflow. -S (XOFF) and -Q (XON) characters also occur in binary files, and are used by Xmodem-type protocols. You risk having these characters misinterpreted as modem flow control characters and dropped from the data stream. If you cannot use hardware flow control and if you're transferring non-text (binary) files, or using an Xmodem-type protocol, disable flow control entirely (&H0). In addition, be sure the modem is set to &B0 and &N0, so that the serial port and connection rates are equal. Transmit Data Buffer Sizes The Transmit Data refers to the data from the computer, which the modem is to transmit over the phone line. The size of the Transmit data buffer depends on whether the connection is under error control or not, as follows. * ARQ connections: 3.25K bytes. * Non-ARQ connections: 1.5K bytes, allowing use of error control file transfer protocols such as Xmodem and Ymodem without flow control. If bit 3 of Register S15 is turned on, the non-ARQ buffer size is reduced to 128 bytes, for the convenience of BBS operators taking calls from remote users of slower modems. See S-Register Summary, S15, in Appendix B. Received Data Buffer Size Received Data refers to the data the modem receives over the phone link, which the modem passes on to the attached computer. The size of this buffer remains constant at 2K bytes. Transmit Data Flow Control &Hn This type of flow control is for data transmitted to the modem by its attached computer or terminal. The modem monitors its buffer as data comes from the computer or modem. If the buffer approaches 90% capacity, the modem signals the computer or terminal to stop transmitting. When the modem has sent enough data over the link to half empty the buffer, it signals the computer or terminal to resume transmitting. &H0 Transmit Data flow control disabled. &H1 Hardware flow control. Default. Requires that your computer or terminal and software support Clear to Send (CTS) at the RS-232 interface. &H2 Software flow control. Requires that your software support XON/XOFF signaling. &H3 Use both hardware and software flow control. If you are unsure about what your equipment supports, select this option. But keep the warning, above, in mind about software flow control. Received Data Flow Control Separate commands, &Rn (hardware) and &In (software), control the flow of Received Data passed by the Courier to your computer or terminal. Your software and machine must support whichever type you select, although we recommend hardware flow control, if possible. Hardware Control(&Rn) &R0 Delay Clear to Send Response after Request to Send signal (RTS/CTS delay). The delay is required by some synchronous mainframes and does not apply to asynchronous calls. &R1 The modem ignores RTS. This setting is required if your computer or terminal or software does not support RTS. &R2 Hardware flow control of received data enabled. Default. The modem sends data to the computer or terminal only on receipt of the RTS signal. Software Control (&In) WARNING: In ordinary operation, the only characters the modem recognizes during a call are the three pluses (+++) of the escape code. But when software flow control is enabled, the modem also looks for -S or -Q characters. If these characters occur in a file or as part of a protocol, the modem reads them as XON/XOFF characters and acts on them. In some cases, the modem drops them from the data stream. &I0 Disables XON/XOFF flow control of received data. Default. Recommended for non-ARQ (Normal mode) calls, but see &I5. The I0 option provides transparency for all characters except the escape code sequence (+++), because at this setting the modem does not look for control characters. NOTE: Because of the risk described in the above warning, the settings that follow are only recommended for users whose data does not include XON/XOFF control characters. &I1 The Courier acts on your typed XON/XOFF commands, -S or -Q, and passes them to the remote computer. Use in ARQ mode only, but keep in mind that the XON/XOFF characters sent to the remote computer may interfere with XON/XOFF signaling between the remote computer and remote modem. See &I2. &I2 The Courier acts on your XON/XOFF commands, but removes them from the data stream instead of passing them to the remote computer. This ensures that the remote computer does not confuse your XON/XOFF characters with those from its attached modem. This is the recommended setting for ARQ mode. However, if the call is not in ARQ mode, there is no flow control on the phone link. If you send an XOFF to your modem and it stops passing data, it has no way to tell the remote computer and modem to stop sending for a while, and your modem's buffer may overflow. For more reliable control in non-ARQ mode, see &I5. &I3 Hewlett PackardSYMBOL 190 \f "Symbol"Host mode. Applies only to modems attached to an HP mainframe that uses the ENQ/ACK protocol. Use in ARQ mode only. See Appendix G. &I4 Hewlett PackardSYMBOL 190 \f "Symbol"Terminal mode. Applies only to modems attached to terminals in an HP system that uses the ENQ/ACK protocol. Use in ARQ mode only. See Appendix G. &I5 This setting is designed to enable flow control on the phone link when the connection is not under error control. For this to work for you, the remote modem must also have &I5 capability. In ARQ mode, a Courier set to &I5 operates the same as it does when set to &I2. It acts on your XON/XOFF commands, but does not pass them to the remote system. The error control protocol enables the modems to control the flow of data on the phone link. In non-ARQ mode, a Courier set to &I5 operates as though flow control were disabled (&I0); it does not look for your typed XON/XOFF commands. However, it looks for XON/XOFF characters coming in over the phone link. When the remote operator sends XON/XOFF commands, the Courier either resumes or stops transmitting data over the link and drops the characters from the data stream. If both modems are set to &I5, operators at each end can signal the remote modem to stop sending, thereby controlling the data flow on the phone link and preventing their own modem's buffer from overflowing. At the computer or terminal/modem interfaces, the modems independently control the flow of data through their Transmit Data (&H) settings. Guidelines Use of software flow control may prove satisfactory if you're only transferring text files. However, if you're transferring non-text (binary) files, or using an Xmodem-type protocol, disable flow control entirely (&R1, &I0). In addition, set the modem to &B0 and &N0, so that the serial port and connection rates are equal. *********** S-REGISTERS The S-Registers are used to set various timing parameters, redefine selected ASCII characters, and other configuration options. A detailed summary of the S-register functions is in Appendix B. A less detailed summary is in the Quick-Reference card. Sr=n Set S-Register value: r is any S-Register; n must be a decimal number between 0 and 255. Sr.b=n Alternative command for setting bit-mapped registers: r is the bit-mapped register; .b is the bit; n is 0 (off) or 1 (on). Sr? Query contents of register r. **************** INQUIRY AND HELP The modem displays information such as the current modem settings, product code, and call duration. It also displays summary information for every command that the modem supports. For more information on Inquiry and Help commands, including sample displays, see Chapter 6. ******* TESTING The modem can perform a number of tests including Analog Loopback, Digital Loopback, and Remote Digital Loopback. These tests can be used to check the operations of the modem's transmitter and receiver, or to locate a problem with a remote modem or telephone channel. Error control must be disabled for these tests. See Appendix H for more information. ******************* INTERNATIONAL CALLS There are three commands that apply to international calls above 1200 bps--Bn, &Gn, &Pn. Bn is described earlier in this chapter. &Gn This setting applies only to overseas calls at 2400 or 1200 bps. British phone switching systems require the modem to send an 1800 Hz guard tone after it sends an answer tone. Some other European phone networks require a 550 Hz guard tone. Guard tones are not used in the United States or Canada. &G0 No guard tone. This is used in the U.S. and in Canada. Default. &G1 This sets a 550 Hz guard tone, and is used in some European countries. &G2 This sets an 1800 Hz guard tone, and is used in the U.K. and some Commonwealth countries. &G2 requires the B0 setting. &Pn This command sets the ratio of the off-hook/on-hook (make/break) interval for pulse dialing. The default sets the modem for use in North America. The ratio must be changed if the modem is used in the United Kingdom and some Commonwealth countries. &P0 Make/break ratio, U.S./Canada: 39%/61%. Default. &P1 Make/break ratio, United Kingdom, some Commonwealth countries: 33%/67%. ********************** MISCELLANEOUS COMMANDS Cn Transmitter enabled/disabled. C0 Transmitter disabled; receive-only condition. C1 Transmitter enabled. Default. Kn Modem clock operation: Call-duration or Real-time mode. Displayed with ATI3 and ATI6 commands. K0 Display current call-duration if online. Display last call-duration if offline. Default. K1 Return actual time at ATI3. Clock is set using ATI3=HH:MM:SS K1. &Yn Break handling. This command allows you to send a break to abort data transfer without disconnecting from the phone link. &Y0 Destructive, don't send Break. &Y1 Destructive, expedited (Default). &Y2 Nondestructive, expedited. &Y3 Nondestructive, unexpedited; modem sends Break in sequence with data received from computer or terminal. NOTE: If the call is under MNP5 data compression, destructive Breaks cause both modems to reset their data compression tables. When transmission resumes, the modems build new tables, and the result is lower than normal throughput. &ZC=s Write the following command string s to NVRAM. The command string may be up to 30 characters long; spaces are not counted. This command can be used so that you can call another modem without loading your communications software. After storing a command, you can program the voice/data switch to execute the stored command string when pressed. The following example assigns a command string that displays the link diagnostics screen when you press the voice/data switch. AT&ZC=I6 The function of the voice/data switch is determined by the setting of Register S32, as described in Appendix G. Set the voice/data switch function to execute stored command string by setting Register S32 to 9 with the following command: ATS32=9 Note that you can reset the voice/data switch at any time to one of the other available functions. Additionally, you can overwrite the stored command string with a new one at any time. Once you've stored your command string and set Register S32, all you need to do is press the voice/data switch whenever you want the command string executed. &ZC? Display the stored command string. %T Enables the modem, when off hook, to detect the tone frequencies of dialing modems. %T is meant primarily for use with network applications, but may also be integrated into certain software programs. For example, %T could be used in a security program to identify incoming tone security codes. To enable %T, type ATH1 to force the modem off hook. Then type AT%T . To return the modem to Command mode, press any key or drop the computer's or terminal's DTR signal. The modem responds OK. Chapter 5--Fax Operations and Call Detection ************* Compatibility The Courier modem provides Group III-compatibility when combined with Class 1 or Class 2.0 fax software. In addition, the modem adheres to the following standards. NOTE: The International Telecommunication Union (ITU-T) was formerly the International Telegraph and Telephone Consultative Committee (CCITT). TIA/EIA-578 Service Class 1 Asynchronous Facsimile DCE Control Standard TIA/EIA-592 Service Class 2.0 Asynchronous Facsimile DCE Control Standard ITU-T V.17 14.4K/12K bps ITU-T V.29 9600/7200 bps ITU-T V.27 ter 4800/2400 bps ITU-T V.21 300 bps ******************** Fax Modem Guidelines Fax operations require facsimile-compatible software that can send or receive Group III faxes. Follow the instructions in your fax software manual. The modem's normal operating mode is Data mode. If your fax software is typical, it automatically switches the modem to Fax mode when you run the program, and resets the modem to Data mode when you exit the program. If you have a problem, however, and think the modem may be in the wrong mode, you can use one of the following AT commands to manually switch the modem: AT+FCLASS=0 (Switch to Data mode) AT+FCLASS=1 (Switch to Class 1 Fax mode) AT+FCLASS=2.0 (Switch to Class 2.0 Fax mode) If you are not sure whether the modem is in Data or Fax mode, type the following command. AT+FCLASS? The modem returns a value of 0 to indicate Data mode, 1 to indicate Class 1 Fax mode, or 2.0 to indicate Class 2.0 Fax mode. NOTE: Whenever the fax modem is reset using the ATZ command, by toggling the DTR signal, or by turning the power off and on, the modem will be set to Data mode. ***************************** Fax Mode Flow Control Setting Many facsimile software products use software flow control when the modem is in Fax mode. Throughout our documentation, we recommend that you use hardware flow control for Data mode (factory setting). However, to allow compatibility with software products that use software flow control by default, U.S. Robotics fax modems now automatically change to software flow control when entering Fax mode. ********** FCC Notice FCC part 68, rules regarding fax operation, has been amended as follows: Telephone facsimile machines--identification of the sender of the message: It shall be unlawful for any person within the United States to use a computer or other electronic device to send any message via a telephone facsimile machine unless such a message clearly contains, in a margin at the top or bottom of each transmitted page or on the first page of the transmission, the date and time it is sent and an identification of the business, other entity, or individual sending the message and the telephone number of the sending machine or of such business, other entity, or individual. Telephone facsimile machines manufactured on and after December 20, 1992 must clearly mark such identifying information on each transmitted page. ******************** Notes to Programmers Lists of supported Class 1 fax commands and optional Class 2.0 commands are in Appendix K. If you want to know more about the supported Class 1 fax commands, refer to the standard for the Service Class 1 fax protocol. ANSI/EIA/TIA-578-1990 (EIA-578) Asynchronous Facsimile DCE Control Standard November, 1990 Approved: October 22, 1990 For more information on Class 2.0, refer to the standard for the Service Class 2.0 fax protocol. ANSI/EIA/TIA-592-1993 (EIA-592) Asynchronous Facsimile DCE Control Standard May, 1993 You can obtain copies of these standards by contacting Global Engineering Documents, at 1-800-854-7179. ************** Call Detection Courier High Speed modems support Call Detection, which is a method of reporting whether an incoming call is Data, Fax Class 1, or Fax Class 2.0. It is especially useful for Bulletin Board systems, as it automates recognition of different calls from multiple users. Call Detection is an optional Service Class 2.0 feature, and is also implemented by U.S. Robotics for Fax Class 1 applications. To obtain a copy of the technical specification of U.S. Robotics' implementation of Call Detection for Fax Class 1, call our BBS at (708) 982-5092 and download the file CALLSEL.TXT. For information on implementing Fax Class 2.0 Call Detection, see the standard listed above. For a list of the optional Fax Class 2.0 commands supported by U.S. Robotics, see Appendix K. Chapter 6--Queries and Help Screens ******************* User Inquiries (In) The Inquiry command has 11 options. The most commonly used options display the following information: ATI3 Call duration ATI4 Current settings ATI5 NVRAM settings ATI6 Link diagnostics summary I0 The modem returns a 4-digit product code. If you have a problem and call U.S. Robotics' Technical Support Department, you may be asked for this product code. I1 The modem performs a checksum of its read-only memory (ROM) and returns the result to the screen. This function is used only in factory testing. The modem should always read the same number. I2 The modem performs a test of its random access memory (RAM) and returns either the OK (0) or ERROR (4) result code, followed by OK when the test is completed. You may want to use this command as a checkpoint if the modem appears to be malfunctioning. I3 The modem returns the duration of the last call if set to K0. It displays the actual time if set to K1. See the description of the Kn command in Chapter 4. I4 The modem displays its current configuration. Figure 6.1 below is an example. Figure 6.1--Sample Result of ATI4 Command ati4 USRobotics Courier Dual Standard V.34 Fax Settings... B0 C1 E1 F1 M1 Q0 V1 X1 BAUD=57600 PARITY=N WORDLEN=8 DIAL=PULSE ON HOOK TIMER &A1 &B0 &C1 &D2 &G0 &H0 &I0 &K1 &L0 &M4 &N0 &P0 &R1 &S0 &T5 &X0 &Y1 %N6 S00=000 S01=000 S02=043 S03=013 S04=010 S05=008 S06=002 S07=060 S08=002 S09=006 S10=007 S11=070 S12=050 S13=000 S14=000 S15=000 S16=000 S17=000 S18=000 S19=000 S20=000 S21=010 S22=017 S23=019 S24=150 S25=005 S26=001 S27=000 S28=008 S29=020 S30=000 S31=000 S32=009 S33=000 S34=000 S35=000 S36=000 S37=000 S38=000 S39=000 S40=000 S41=000 S42=126 S43=200 S44=015 S45=000 S46=000 S47=000 S48=000 S49=000 S50=000 S51=000 S52=000 S53=000 S54=000 S55=000 S56=000 S57=000 LAST DIALED #: OK I5 The modem displays the configuration stored in nonvolatile random access memory (NVRAM), as in the following example. If your modem connects to a modem that has Dial Security and local access enabled, you cannot view the stored phone numbers. Figure 6.2--Sample NVRAM Settings Screen ati5 USRobotics Courier Dual Standard V.34 Fax NVRAM Settings... DIAL=PULSE B0 F1 M1 X7 BAUD=57600 PARITY=N WORDLEN=8 &A3 &B1 &G0 &H1 &I0 &K3 &L0 &M4 &N0 &P0 &R2 &S0 &T5 &X0 &Y1 %N6 S00=001 S02=043 S03=013 S04=010 S05=008 S06=002 S07=060 S08=002 S09=006 S10=007 S11=040 S12=050 S13=000 S15=000 S19=000 S21=010 S22=017 S23=019 S24=150 S25=005 S26=001 S27=000 S28=008 S29=020 S31=000 S32=009 S33=000 S34=000 S35=000 S36=000 S37=000 S38=000 S39=000 S40=000 S41=000 S42=126 S43=200 S44=015 S51=000 S53=000 S54=000 S55=000 S56=000 S57=000 STORED PHONE NUMBERS 0: 1: 2: 3: 4: 5: 6: 7: 8: 9: STORED COMMAND = OK I6 During a connection, the modem monitors and stores information about link operations. When the call is ended, you can request a diagnostic summary, as in the following example. The duration of the last call or real time is displayed depending on the Kn setting. Figure 6.3--Sample Link Diagnostics Screen (ATI6) ati6 USRobotics Courier Dual Standard V.34 Fax Link Diagnostics... Chars sent 0 Chars Received 0 Chars lost 0 Octets sent 0 Octets Received 0 Blocks sent 0 Blocks Received 0 Blocks resent 0 Retrains Requested 0 Retrains Granted 0 Line Reversals 0 Blers 0 Link Timeouts 0 Link Naks 0 Data Compression NONE Equalization Long Fallback Disabled Last Call 00:00:00 Disconnect Reason is Keypress Abort OK For calls under data compression, the number of characters sent may be less than the number of octets sent, due to buffering operations. Line Reversals only apply to HST-mode operations, when the modems switch the high and low speed channels. At this time, online fallback is only reported Enabled in HST-mode. Most terms used in the display are self-explanatory except for the following: Octets: Compressed data units. If the number of octets is greater than the number of characters sent, the modems probably used MNP5 compression on an already compressed file, and the result was expanded data. Line Reversals: The number of times HST-mode modems switched the high and low speed channels. Blers: Errors in data and protocol blocks. If there were many block errors, your receiver may have experienced problems on the line. Blocks Resent: These represent blocks the remote modem resent due to the previous category, Blers. Link Timeouts: Protocol detection problems: communications were severed momentarily, and the modems probably recovered. This does not indicate the retry timeout. Link Naks: Negative acknowledgments (one or more blocks). Data Compression: Indicates the type of data compression negotiated for the call (V42BIS or MNP5) or NONE. A V42BIS response includes the size of the dictionary and the maximum string length used, for example, 2048/32. See Appendix A for more information. Equalization Long/Short: Status of S15 bit 0; long if bit 0=0, short if bit 0=1. Short equalization applies only to HST modems. Fallback: Enabled/Disabled: indicates whether or not the modems negotiated online fallback during the connection sequence. Protocol: indicates the error control protocol negotiated (LAPM, ST, MNP, NONE) or SYNC for a synchronous call. Speed: The last rates at which the receiver/transmitter were operating before disconnecting. Disconnect Reason: Possible reasons the modem hung up are as follows: A Rootless Tree: The modem received an invalid V.42 bis (compression) frame. Break Timeout: Incompatible processing of a Break signal occurred. DISC: The remote modem sent a V.42 Disconnect frame. DTR dropped: The computer or terminal dropped the Data Terminal Ready signal, terminating the call. Escape code: The operator sent the modem the +++ escape code. Extra Stepup: The modem received an invalid V.42 bis (compression) frame. GSTN (General Switch Telephone Network) Clear Down: The connection was non-ARQ and DTR was dropped from one side of the connection, or the DISC frame was corrupted due to noise. Illegal Command Code: The modem received an invalid V.42 bis (compression) frame. Inactivity timeout: The modem detected no activity on the line for the duration specified in Register S19 (default is 0, timer disabled). Invalid Codeword: The modem received an invalid V.42 bis (compression) frame. Invalid speed: The modem is set to &N1 or higher, for a fixed link rate, and the remote modem is not operating at the same rate. LD received: The remote modem sent an MNP error control Link Disconnect request. Loop loss disconnect: The modem detected a loss of current on the loop connecting it with the telephone company central office. This usually occurs because the remote modem has hung up: the central office drops current momentarily when there is a disconnect at the other end of a call. Unless Register S38 is set higher than zero, the modem immediately hangs up at loop loss. Loss of carrier: The modem detected loss of the remote modem's carrier and waited the duration specified in Register S10 (default is 0.7 seconds). MNP incompatibility: The modem is set to &M5 and the remote modem does not have MNP capability, or there was an MNP negotiation procedure error. Retransmit limit: The modems reached the maximum of twelve attempts to transfer a data frame without error. SABME Timeout (Set Asynchronous Balance Mode Extended): The modems failed this part of V.42 link negotiation. Unable to Retrain: After several attempts, disturbances on the phone line prevented the modems from retraining, and they could no longer transmit or receive data. XID Timeout: The modems failed to negotiate the V.42 Detection (XID Exchange) phase. Dial Security Disconnect Reason: Possible reasons the answering modem may have hung up during a Dial Security session are as follows: Security Abort: The modem hung up because it received an invalid password three times. Prompting Not Enabled: The modem hung up because the originating modem did not send an autopass password, and prompting wasn't enabled. No Prompting in Sync: The originating modem did not send an autopass password, and the answering modem cannot prompt for a password in any synchronous mode. Non-ARQ Mode: The modem hung up because the originating modem was set for error control and the answering modem was set for non-error control. Mode Incompatible: The modem hung up because both modems were not set to the same error control setting. No Prompting in Non-ARQ: Prompting was enabled, but the modem hung up because the originating modem was set for error control, and the answering modem was set for non-error control. The answering modem cannot prompt when it is set for non-error control. I7 The modem returns a product configuration. If you have a problem and call U.S. Robotics' Technical Support staff, you may be asked to read this screen. I8 Not used I9 Not used I10 View Dial Security Account status. For security administrators only, unless local security is disabled, S53=0 or S53.2=0. Figure 6.4--Sample Dial Security Account Status Screen ati10 USRobotics Courier Dual Standard V.34 Fax DIAL SECURITY STATUS DIAL SECURITY ENABLED:[N] LOCAL SECURITY ENABLED:[N] PROMPTING ENABLED:[N] FORCED AUTOPASS:[N] LOCAL ACCESS PASSWORD:[NO PSW] AUTOPASS PASSWORD:[NO PSW] ACCOUNT PSW ACCT/E DIAL/B NEW_# PHONE # #0 [NO PSW] [N] [N] [N] #1 [NO PSW] [N] [N] [N] #2 [NO PSW] [N] [N] [N] #3 [NO PSW] [N] [N] [N] #4 [NO PSW] [N] [N] [N] #5 [NO PSW] [N] [N] [N] #6 [NO PSW] [N] [N] [N] #7 [NO PSW] [N] [N] [N] #8 [NO PSW] [N] [N] [N] #9 [NO PSW] [N] [N] [N] OK I11 Connection report used for debugging purposes. A U.S. Robotics Technical Support representative may ask you for information provided on this screen. ********************** S-Register Query (Sr?) This command allows you to view the contents of a particular S-Register, as in the following example that requests the contents of Register S0 ("On what ring will the modem answer?"): ATS0? ************************* Phone Number Query (&Zn?) At this command, the modem returns the phone number stored in NVRAM at position n, as in the following example that includes a sample modem response: AT&Z3? 5551234 ****************************** Last-Dialed Number Query (DL?) At this command the modem displays the number stored in the last-dialed number buffer: ATDL? ********************************** Stored Command String Query (&ZC?) At this command the modem displays the command string stored in NVRAM with the &ZC=s command: AT&ZC? ************ HELP Screens Courier modems provide five Help screens: summaries of the basic AT command set, extended ampersand (&) command set, Dial command options, S-Register functions, and percent (%) command set. NOTE: The Help screens are not available when the modem makes a connection in synchronous mode: &M1, &M6, or &M7. Stop/Restart Display The following command stops the display. Hold down the Control key and type "S": -S To restart the display, use the same command or press any key. Cancel Display Either of the following commands cancels the display. -C -K ********************* Basic Command Set ($) At AT$, the Courier displays a screen that shows a partial summary of the command set. A second screen, activated by pressing any key, shows the remaining commands. The first screen is shown in Figure 6.5. Figure 6.5--Sample Basic Commands HELP Screen at$ HELP, Command Quick Reference (CTRL-S to Stop, CTRL-C to Cancel) &$ HELP, Ampersand Commands Kn n=0 Call Duration Mode %$ HELP, Percent Commands n=1 Real Time Clock Mode A/ Repeat Last Command Mn n=0 Speaker Off A> Continuously Repeat Command n=1 Speaker On Until CD AT Command Mode Prefix n=2 Speaker Always On A Answer Call n=3 Speaker Off During Dial Bn n=0 V.32 originate mode On n=0 Return Online n=1 HST originate mode n=1 Return Online & Retrain Cn n=0 Transmitter Off n=2 Return Online & Speed Shift n=1 Transmitter On P Pulse Dial Dn Dial a Telephone Number Qn n=0 Result Codes Sent n=0..9#*TPR,;"W@!()- n=1 Quiet (No Result Codes) DL Dial Last Phone Number n=2 Verbose/Quiet On Answer DSn Dial Stored Phone Number Sr=n Sets Register "r" to "n" D$ HELP, Dial Commands Sr? Query Register "r" En n=0 No Command Echo S$ HELP, S Registers n=1 Echo Command Chars T Tone Dial Fn n=0 Online Echo Vn n=0 Numeric Responses n=1 No Online Echo n=1 Verbal Responses Strike a key when ready . . ************************* Extended Command Set (&$) At AT&$, the Courier displays a screen that shows a partial summary of the extended ampersand command set. A second screen, activated by pressing any key, shows the remaining command set. The first screen is shown in Figure 6.6. Figure 6.6--Sample Ampersand Commands HELP Screen at&$ HELP, Ampersand Commands (CTRL-S to Stop, CTRL-C to Cancel) &An n=0 Disable /ARQ Result Codes &Nn n=0 Highest Link Speed n=1 Enable /ARQ Result Codes n=1 300 bps n=2 Enable /Modulation Codes n=2 1200 bps n=3 Enable /Extra Result Codes n=3 2400 bps &Bn n=0 Floating DTE Speed n=4 4800 bps n=1 Fixed DTE Speed n=5 7200 bps n=2 DTE Speed Fixed When ARQ n=6 9600 bps &Cn n=0 CD Always On n=7 12000 bps n=1 Modem Controls CD n=8 14400 bps &Dn n=0 Ignore DTR n=9 16800 bps n=1 On-Line Command Mode n=10 19200 bps n=2 DTE Controls DTR &Pn n=0 N.American Pulse Dial &Fn n=0 Load Factory Configuration n=1 UK Pulse Dial n=1 Hardware Flow Control Cnfg. &Rn n=0 CTS Follows RTS n=2 Software Flow Control Cnfg. n=1 Ignore RTS n=3 HST/Cellular w/ HW FC Cnfg. n=2 RX to DTE/RTS high &Gn n=0 No Guard Tone &Sn n=0 DSR Always On n=1 550 Hz Guard Tone n=1 Modem Controls DSR n=2 1800 Hz Guard Tone n=2 Pulse DSR, CTS=CD Strike any key when ready . . . ************* Dialing (D$) At ATD$, the Courier displays this Dial command summary: Figure 6.7--Sample Dial Command HELP Screen atd$ HELP, Dial Commands (CTRL-S to Stop, CTRL-C to Cancel) 0-9 Digits to Dial * Auxiliary Tone Dial Digit # Auxiliary Tone Dial Digit T Tone Dialing P Pulse Dialing R Call an Originate Only Modem , Pause (Wait for S8 Time) ; Remain in Command Mode After Dialing " Used to Dial Alpha Phone #'s W Wait for 2nd Dial Tone (X3-X7) @ Wait for an Answer (X3-X7) ! Flash Switch Hook OK ************************* S-Register Functions (S$) At ATS$, the Courier displays a screen that shows a partial summary of the S-Register functions. More screens, activated by pressing any key, show the remaining registers. The first screen is as follows. Figure 6.8--Sample S-Register HELP Screen ats$ HELP, S Register Functions (CTRL-S to Stop, CTRL-C to Cancel) S0 Ring to Answer On S33 Reserved S1 Counts # of Rings S34 Bit Mapped S2 Escape Code Char 1 = Disable V32bis S3 Carriage Return Char 2 = Disable Enhanced V32 mode S4 Line Feed Char 4 = Disable Quick V32 retrain S5 Backspace Char 8 = Enable V23 Fallback S6 Wait Time/Dial Tone (sec) 16 = Change MR to DSR S7 Wait Time/Carrier (sec) 32 = Enable MI/MIC S8 Comma Time (sec) 64 = Disable RA Busy Msg S9 Carrier Detect Time (1/10sec) 128 = Disable Terbo S10 Carrier Loss Time (1/10sec) S35 Reserved S11 Dial Tone Spacing (msec) S36 Reserved S12 Escape Code Time (1/50sec) S37 Reserved S13 Bit Mapped S38 Disconnect Wait Time (sec) 1 = Reset On DTR Loss S39 Reserved 2 = Do Originate in Auto Answer S40 Reserved 4 = No Pause Before Result Codes S41 # of Allowed Login Attempts 8 = Do DS0 On DTR S42 Remote Escape Code Char 16 = Do DS0 On Reset S43 Remote Escape Code Time (1/50sec) Strike a key when ready . . . ********************* Percent Commands (%$) At AT%$, the Courier displays a screen that shows a partial summary of the percent command functions. A second screen, activated by pressing any key, shows the remaining registers. The first screen is as follows. Figure 6.9--Sample Percent HELP Screen at%$ HELP, Percent Commands (CTRL-S to Stop, CTRL-C to Cancel) %An= Security Account Information %Fn Remote DTE Data Format Command Structure n=0 8, No parity %An= PW,ACCT E,DIAL B,NEW#,PH# n=1 7, Mark parity n = (0-9) n=2 7, Odd parity PW = Password n=3 7, Even parity ACCT E = Account Enable %L=PWn Security Local Access Psw DIAL B = Dial Back Enable PWn = (0-9) NEW# = New Dial Back # %Nn V.25bis Synchronous Clock Rate PH# = Dial Back Phone # n=0 RESERVED %Bn Remote DTE Data Rate n=1 RESERVED n=0 110 bps n=2 1200 bps n=1 300 bps n=3 2400 bps n=2 600 bps n=4 4800 bps n=3 1200 bps n=5 7200 bps n=4 2400 bps n=6 9600 bps n=5 4800 bps n=7 12000 bps n=6 9600 bps n=8 14400 bps n=7 19200 bps n=9 16800 bps n=8 38400 bps n=10 19200 bps Strike a key when ready . . . Appendix A--Link Negotiation (Handshaking) and Error Control This appendix includes information on how U.S. Robotics modems negotiate with remote modems for the rate and other characteristics of each connection. In addition, you'll find information on error control and, especially useful, some statistics and guidelines on using the modem for the best throughput. Some of the following text includes the term ARQ, which means Automatic Repeat Request. ARQ is a method used in many error control protocols to ensure that any data that has been corrupted in transit is retransmitted. We use the term in our documentation to designate a connection under error control. NOTE: High speed calls are highly vulnerable to errors unless the data is protected by error control. The V. protocol operations described below take place even if one of the modems is not set for error control, thereby prohibiting error control for the call. If your modem connects with a modem at high speed but without error control, and if you are not using an error con