3Com Modem 10241644 00 User Manual

56K Voice Faxmodem Internal  
User’s Guide  
PN 1.024.1644-00  
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Table of Contents  
WELCOME TO 56K INFORMATION ACCESS......................................1  
PRODUCT FEATURES.......................................................................2  
INTERNAL MODEM INSTALLATION WITH WINDOWS 95...................5  
DETERMINING AVAILABLE RESOURCES ....................................................5  
DETERMINING YOUR VERSION OF WINDOWS 95.........................................6  
PLUG AND PLAY INSTALLATION............................................................7  
HOW TO PREPARE FOR PLUG AND PLAY INSTALLATION .............................7  
HOW TO INSERT THE MODEM INTO THE COMPUTER .....................................8  
INSTALLING MODEM DRIVERS WITH WINDOWS 95:  
Versions 950 and 950a (Moving Through the “New Hardware  
Found” Screens)...................................12  
Version 950b (Using the Update Device Driver Wizard Screens)....16  
INTERNAL MODEM INSTALLATION WITH WINDOWS 3.X ...............20  
A Word about COM Ports and IRQs............................................20  
How to Change the Modem’s Settings..........................................21  
How to Insert the Modem into the Computer.................................23  
SOFTWARE INSTALLATION ...........................................................29  
WINDOWS 95..................................................................................29  
WINDOWS 3.X.................................................................................29  
TYPE OF MODEM..............................................................................30  
INITIALISATION STRING ......................................................................30  
FLOW CONTROL..............................................................................30  
TROUBLESHOOTING......................................................................31  
SUPPORT RESOURCES..................................................................39  
ARE YOU STILL HAVING PROBLEMS?...................................................40  
IF YOU MUST RETURN THE MODEM TO US .............................................40  
GLOSSARY.....................................................................................41  
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Table of Contents  
TECHNICAL REFERENCE ................................................................51  
TYPING COMMANDS..........................................................................51  
BASIC DATA COMMANDS ..................................................................51  
EXTENDED DATA COMMANDS .............................................................57  
S-REGISTERS..................................................................................64  
FAX COMMANDS .............................................................................71  
THE SERIAL INTERFACE (CABLE INFORMATION) .......................................73  
REGULATORY (CE COMPLIANCE)...................................................74  
ELECTROMAGNETIC COMPATIBILITY ......................................................74  
RINGER EQUIVALENCE NUMBER...........................................................74  
LIMITED WARRANTY......................................................................75  
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Welcome to 56K*Information Access  
The International Telecommunications Union (ITU) decides the technical  
protocols that communications devices must use to operate with each  
other. Modems that comply with ITU standards can “talk” to other  
standards-compliant modems and fax machines worldwide.  
The ITU has determined a worldwide standard for 56K modem technology.  
With a U.S. Robotics modem, you can get 56K Internet access from any  
service provider who offers the ITU V.90 standard or 3Com’s proprietary  
56K technology. 3Com is working with providers everywhere to quickly  
upgrade their service to the ITU V.90 standard.  
* In accordance with the ITU standard for V.90 transmissions, this modem is capable of  
56 Kbps downloads. However, the download speeds you experience may be lower due  
to varying line conditions and other factors. Uploads from users to server equipment  
travel at speeds up to 31.2 Kbps. An analogue phone line compatible with the ITU V.90  
standard or 3Com’s proprietary 56K technology, and an Internet provider or corporate  
host site with the ITU V.90 standard or 3Com’s proprietary 56K technology are  
necessary for these high-speed downloads. The ITU V.90 standard was officially  
determined in February, 1998 and is expected to be ratified in September, 1998. See  
www.3com.com/56k for details.  
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Product Features  
Modulation Schemes  
ITU-T V.90  
x2™ technology (Download up to 56kbps, and Upload using V.34)  
ITU-T V.34+  
ITU-T V.34  
ITU-T V.32bis  
ITU-T V.32  
ITU-T V.23  
ITU-T V.22bis  
ITU-T V.22  
Bell 212A  
ITU-T V.21  
Bell 103  
Error Control and Data Compression Schemes  
ITU-T V.42  
ITU-T V.42bis  
MNP 2-5  
Fax Modulation Schemes  
ITU-T V.17  
ITU-T V.29  
ITU-T V.27ter  
ITU-T V.21  
Fax Standards  
EIA 578 Class 1 FAX  
EIA 592 Class 2.0 FAX  
Front Channel Link Rates (Download Speeds)  
28000, 29333, 30666, 32000, 33333, 34666, 36000, 37333, 38666, 40000,  
41333, 42666, 44000, 45333, 46666, 48000, 49333, 50666, 52000, 53333,  
54666, 56000, 57333  
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Product Features  
Back Channel Link Rates (Upload Speeds)  
4800, 7200, 9600, 12000, 14400, 16800, 19200, 21600, 24000, 26400,  
28800, 31200  
V.34+ Link Rates  
4800, 7200, 9600, 12000, 14400, 16800, 19200, 21600, 24000, 26400,  
28800, 31200, 33600  
V.32bis Link Rates  
4800, 7200, 9600, 12000, 14400  
Additional Link Rates  
300, 1200/75 (V.23), 1200, 2400  
Fax Link Rates  
2400, 4800, 7200, 9600, 12000, 14400  
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Product Features  
Flash ROM Upgradable  
56K Voice Faxmodem Internal supports software download through flash  
memory. You can obtain the latest features by downloading updates  
quickly and easily.  
Speakerphone*  
With the addition of an inexpensive set of externally powered speakers,  
your new voice modem provides all the convenience of a full-duplex  
speakerphone. Unlike many half-duplex speakerphones, your modem  
allows you to converse normally without annoying echoes and distortion.  
Simply plug the speakers and microphone into the jacks on the modem  
identified with the appropriate icons, and you are ready to go.  
Personal Voice Mail*  
Personal Voice Mail turns your modem into a full-featured messaging  
system. Enjoy the convenience of professional voice mail in your home or  
office for a fraction of the cost. With Personal Voice Mail, you can record  
custom greetings, receive messages, and set up multiple voice  
“mailboxes”. You can even access your voice messages remotely. Your  
modem will automatically detect incoming fax/voice/data calls and route  
them appropriately.  
* A headset, external powered speakers, or sound card (with audio cable)  
is required to utilise all voice features, including hands-free  
speakerphone.  
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Internal Modem Installation  
with Windows 95  
Before you start your installation, make sure that you have the following  
items:  
Modem  
U.S. Robotics Disk  
RJ-11 Phone Lead  
Tail Lead  
Microphone  
Analogue (Standard) Telephone Wall Socket  
Phillips Head Screwdriver or ¼” Hex Screwdriver  
Data/Fax/Voice Communications Software and Manual  
Determining Available Resources  
Your U.S. Roboticsâ modem is a Plug and Play device. Windowsâ 95  
can automatically identify a Plug and Play device and determine if your  
system has the resources necessary to support the device. However,  
Plug and Play will not work if you do not have resources available or if  
devices on your system are not reporting resource usage correctly. Here  
is how you can verify that your system has the necessary resources  
before installing the modem.  
1. Click the Windows 95 Start button, point to Settings, and then click  
Control Panel.  
2. Double-click the System icon.  
3. When the “System Properties” screen appears, click the Device  
Manager tab.  
4. Double-click Computer and the “Computer Properties” screen  
appears.  
5. Select the option at the top of the screen to show Interrupt Requests  
(IRQs).  
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Internal Modem Installation with Windows 95  
You will see the IRQs your system is currently using. If IRQs 3, 4, 5, and  
7 are being used, you need to free an IRQ before you begin installation.  
This process involves moving a device from the IRQ you want to use to a  
different (and usually higher) IRQ setting. Please read the documentation  
for (or contact the manufacturer of) the device that is currently using the  
IRQ you want to use for your modem, to learn more about what you  
should do to move the other device.  
Determining Your Version of Windows 95  
Follow these steps to determine your version of Windows 95. This  
information will be important during installation.  
1. Click the My Computer icon on your desktop with the right mouse  
button.  
2. Click Properties.  
3. In the “System Properties” screen, look at the system information  
under the General tab (circled in the following screen image). The  
number following the text “Microsoft Windows 95” will end with “950”,  
“950a”, or “950b”. This indicates your version of Windows 95.  
Windows 95 version  
Write down your version of Windows.  
Windows 95 version _______  
Click OK.  
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Internal Modem Installation with Windows 95  
Plug and Play Installation  
This modem’s factory default setting is “Plug and Play” operation. If you  
are using the Windows 95 environment, the COM port and IRQ will  
automatically be set to Windows as the environment. Since your new  
U.S. Robotics modem is a “Plug and Play” device, Windows 95 may be  
able to detect your modem automatically after you plug it into your  
computer. The operating system should do all the work of recognising the  
modem for you.  
How to Prepare for Plug and Play  
Installation  
1. Touch an unpainted metal part of your computer (the back is usually  
unpainted) to discharge static electricity. Static can damage your  
modem.  
2. Take the modem out of its plastic bag.  
5.3.Find the jumper shunts (small black plastic pieces) on the COM  
(serial) port and IRQ jumper pins on your modem. They should be in  
roughly the area indicated in the following illustration.  
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Internal Modem Installation with Windows 95  
4. When doing a “Plug and Play” installation, the jumper shunts should  
be placed so that they are hanging from single jumper pins rather than  
on pairs of pins. Move your jumper shunts so they are hanging as in  
the diagram.  
If you need to move the jumper shunts, grasp them with tweezers or  
needle-nosed pliers. DO NOT grasp too firmly, however, or you may crush  
the jumper shunts. If a jumper shunt seems stuck, try gently rocking it  
back and forth as you lift.  
How to Insert the Modem into the  
Computer  
1. Before installing your modem, write down your modem's serial number.  
The serial number is on the white label under the bar code on the  
modem and on the outside of the box.  
Serial Number_______________________  
Before you unplug any cords, label them or make a sketch of how they  
are connected. This can be helpful when you plug them back in later.  
2. Turn off your computer and unplug it from the electrical outlet.  
2.3.Unplug any peripheral devices (printer, monitor, keyboard, mouse,  
etc.) from the computer.  
CAUTION: To avoid risk of electric shock, make sure your computer  
and all peripheral devices are turned off and unplugged from electrical  
outlets.  
8
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Internal Modem Installation with Windows 95  
4. Remove the screws from your computer’s cover and then remove the  
cover, as shown in the following diagrams. Your computer may differ in  
appearance from these diagrams, but the basic principle for removing  
the cover should be the same. Refer to your computer manufacturer’s  
manual if you need further instructions.  
5. Find an empty ISA expansion slot that’s at least as long as the gold  
edge of your modem. (ISA slots are dark plastic grooves lined with  
metal.) Unscrew and remove the expansion slot cover. It is the long  
narrow piece of metal that keeps dust from entering through the  
opening perpendicular to the slot.  
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6. Holding the modem by each corner, align the gold edge with the empty  
expansion slot. Push down gently until the modem snaps into the slot.  
The diagram shows horizontally aligned expansion slots. Some  
computers have vertically aligned slots. The instructions apply to both  
styles.  
You need to apply a little pressure to seat the modem properly.  
Sometimes a gentle back and forth motion helps fit the modem all the  
way into the slot. If you feel resistance, the modem may not be  
properly lined up with the slot. Do not force it into the slot. Remove the  
modem and try again.  
7. Once the modem is inserted, fasten it firmly into place using the screw  
that you removed in step 5.  
8. Replace the computer’s cover and fasten it with the screws you  
removed in step 4.  
9. Locate the phone wall socket you plan to use for the modem. If you  
have a phone plugged into this wall socket, disconnect the telephone  
cord from the socket.  
The phone wall socket you use must be for an ANALOGUE phone line  
(the type found in most homes). Many office buildings have digital  
phone lines. Be sure you know which type of line you have. The  
modem will be damaged if you use a digital phone line.  
10. Plug one end of the phone cord included with the modem into the  
TELCO socket.  
11. Plug the other end of the cable into the phone wall socket.  
10  
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Internal Modem Installation with Windows 95  
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Internal Modem Installation with Windows 95  
You cannot use the modem and a phone at the same time if they  
share the same telephone line. If you want to use a telephone on the  
same line as the modem when the modem is not in use, plug your  
telephone cord into the modem’s PHONEsocket, using the supplied  
Tail Lead Adaptor.  
12. An external, powered speaker must be connected for speakerphone  
and voice mail usage. Plug a set of powered, magnetically-shielded,  
external speakers or a headset (not included) into the 3.5 mm SPKR  
socket on the modem.  
2. 13. Plug the supplied microphone into the 3.5 mm MIC socket on the  
modem.  
14. Plug the power cords, cables, and peripherals back into the computer  
and turn on the computer.  
15. Start Windows 95.  
12  
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Internal Modem Installation with Windows 95  
Installing Modem Drivers  
with Windows 95:  
Versions 950 and 950a  
Moving Through the “New Hardware Found” Screens  
1. When Windows 95 starts, it should detect the modem. If it does, you  
will see the following screen.  
Click Driver from disk provided by hardware manufacturer.  
Then click OK.  
If this screen does not appear, go to “If Plug and Play Does Not Detect  
Your Modem” on page 37.  
2. When you see the Install from Disk screen, insert the disk or the CD-  
ROM and type A:\ or D:\  
If your disk drive or CD-ROM drive is a different letter, type that letter  
instead of A or D.  
Click OK. Windows will load the modem’s drivers.  
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Internal Modem Installation with Windows 95  
3. Once Windows finishes loading the information from the disk, verify  
that the modem installation was a success. When your desktop  
returns, click the Windows Start button and point to Settings. Then  
click Control Panel.  
4. Double-click the Modems icon (circled in the screen image below).  
14  
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Internal Modem Installation with Windows 95  
5. In the “Modems Properties” screen, you should see a description for  
your modem.  
This means the installation was a success. Click OK.  
If you do not see your modem listed in the preceding screen, the Plug  
and Play installation was unsuccessful. Please refer to “If Plug and  
Play Does Not Detect Your Modem” on page 37.  
6. Next, click the Diagnostics tab at the top of the “Modems Properties”  
screen. Write down the COM setting for your modem in the space  
below. Your screen may show a different setting than that shown in  
the following screen. You will need to know this setting when you  
install your communications software.  
COM Port___________  
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Internal Modem Installation with Windows 95  
6. Click More Info….  
Click OK.  
Turn to “Software Installation” on page 29 for information about installing  
communications software.  
16  
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Internal Modem Installation with Windows 95  
Installing Modem Drivers  
with Windows 95:  
Version 950b  
Using the Update Device Driver Wizard Screens  
1. Start Windows. Insert the U.S. Robotics disk into your disk drive.  
Click Next.  
If this screen does not appear, go to “If Plug and Play Does Not Detect  
Your Modem” on page 37.  
2. When you see the following screen, click Finish.  
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Internal Modem Installation with Windows 95  
3. Now you should verify that the modem installation was a success.  
When your desktop returns, click the Windows Start button and point  
to Settings. Then click Control Panel.  
4. Double-click the Modems icon (circled in the screen image below).  
18  
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Internal Modem Installation with Windows 95  
5. In the “Modems Properties” screen, you should see a description of  
your modem.  
This means the installation was a success. Click OK.  
If you do not see your modem listed in the preceding screen, the Plug  
and Play installation was unsuccessful. Please refer to the “If Plug and  
Play Does Not Detect Your Modem” section on page 37.  
6. Next, click the Diagnostics tab at the top of the “Modems Properties”  
screen. Write down the COM setting for your modem in the space.  
Your screen may show a different setting than that shown in the  
following screen. You will need to know this setting when you install  
your communications software.  
COM Port_________  
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Internal Modem Installation with Windows 95  
7. Click More Info….  
Click OK.  
Turn to “Software Installation” on page 29 for information about installing  
communications software.  
20  
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Internal Modem Installation with  
Windows 3.x  
Before you start your installation, make sure that you have the following  
items:  
Modem  
U.S. Robotics Disk  
RJ-11 Phone Lead  
Tail Lead  
Microphone  
Analogue (Standard) Telephone Wall Socket  
Phillips Head Screwdriver or ¼” Hex Screwdriver  
Data/Fax/Voice Communications Software and Manual  
A Word about COM Ports and IRQs  
Most computer accessories — a mouse, sound card, enhanced graphics  
card, scanner, etc. — require a special connection through which they  
can communicate with the computer. For an internal modem, this  
connection is called a communications (or COM) port. Most computers  
have 1 or 2 COM ports, but they can have up to 4. Although internal  
modems do not connect to COM ports directly, they do require a COM  
port setting, which is determined by the setting on the modem’s COM  
jumper pins.  
Each COM port uses an interrupt request (IRQ). An accessory uses an  
IRQ to get the attention of your computer’s central processing unit (CPU)  
so that the accessory can perform a task.  
The computer stops what it is doing, depending on the priority of the  
request, to help the accessory perform its task. When two accessories  
share an IRQ, it is like two people asking different questions in unison to  
a third person. Just as the person being asked the two questions cannot  
understand either request, a computer can lock up or otherwise fail to  
communicate properly with your modem when there is an IRQ conflict.  
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Internal Modem Installation with Windows 3.x  
Accessories cannot share COM ports and should not share IRQs. When  
accessories try to share settings, they will either not work properly or not  
work at all.  
3Com has set your modem to a default Plug and Play setting geared  
towards Windows 95 users. In this configuration, the shunts used to set  
your modem’s COM port and IRQ settings are hanging from single jumper  
pins and will not affect your modem’s settings  
Some communications software programs require a particular setting for  
your modem. Now is a good time to read the software’s manual to  
determine what setting is required.  
How to Change the Modem’s Settings  
1. Always touch an unpainted metal part of your computer (the back is  
usually unpainted) to discharge static electricity before handling the  
modem. Static can damage your modem.  
2. Take the modem out of its plastic bag.  
3. Find the COM and IRQ jumper shunts (small black plastic pieces) on  
your modem’s jumper pins (refer to the diagram).  
22  
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The jumper shunts will be hanging from single jumper pins as shown in  
the following illustration.  
4. To change the COM port and IRQ settings, you need to reposition the  
jumper shunts on the COM port and IRQ pins. To do this, lift the  
jumper shunts off the pins.  
Grasp the jumper shunts with a tweezers or needle-nosed pliers. DO  
NOT grasp too firmly, as you may crush the shunts. If a jumper shunt  
seems stuck, gently rock it back and forth as you lift. Do not touch  
any other part of the modem or your computer with the  
tweezers/pliers. A shunt needs to be sitting on both jumper pins in  
order to effectively set the modem to the desired setting.  
5. Move the jumper shunt to the new setting.  
·
The COM port setting can involve one to three shunts. The four  
possible COM port settings are as follows:  
·
Unlike most COM port settings, the IRQ setting involves only one  
jumper shunt. Simply move the jumper shunt to the pins labelled  
with the IRQ you need.  
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The following are recommended combinations of COM port and IRQ  
settings when not using Plug and Play:  
COM 1, IRQ 4 or  
COM 2, IRQ 3  
Most computers provide you with COM1 and COM2. If you do not use  
either of these two ports, you may disable them either in your computer's  
BIOS or with jumpers (refer to the manual of your PC). Any device  
attached to a disabled COM port will not be useable anymore, so it is  
advisable to check your computer's configuration thoroughly before  
proceeding. Generally the serial mouse is on COM1.  
COM3 and COM4 may also be used. It is not recommended to assign  
these ports an IRQ already used by another device, e.g. an active COM1  
(IRQ4) or COM2 (IRQ3). If it is not possible to disable COM1 or COM2,  
you may use either IRQ5 or IRQ7. However, be aware that IRQ7 is  
generally used by the printer port LPT1 and may therefore not be  
available. (You may be able to disable this port, if it is not used.) You  
should also check if a sound card is installed in your PC, which usually is  
on IRQ5. A sound card can be reconfigured to use another IRQ, i.e. 10.  
Refer to your sound card manual.  
It is recommended that the modem be installed on COM2  
whenever possible.  
How to Insert the Modem into the  
Computer  
1. Before installing your modem, write down your modem's serial number.  
The serial number is on the white label under the bar code on the  
modem and on the outside of the box.  
Serial Number_______________________  
Before you unplug any cords, label them or make a sketch of how they  
are connected. This can be helpful when you plug them back in later.  
24  
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Internal Modem Installation with Windows 3.x  
2. Turn off your computer and unplug it from the electrical outlet.  
2.3.Unplug any peripheral devices (printer, monitor, keyboard, mouse,  
etc.) from the computer.  
CAUTION: To avoid risk of electric shock, make sure your computer  
and all peripheral devices are turned off and unplugged from electrical  
outlets.  
4. Remove the screws from your computer’s cover and then remove the  
cover, as shown in the following diagrams. Your computer may differ in  
appearance from these diagrams, but the basic principle for removing  
the cover should be the same. Refer to your computer manufacturer’s  
manual if you need further instructions.  
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Internal Modem Installation with Windows 3.x  
5. Find an empty ISA expansion slot that’s at least as long as the gold  
edge of your modem. (ISA slots are dark plastic grooves lined with  
metal.) Unscrew and remove the expansion slot cover. It is the long  
narrow piece of metal that keeps dust from entering through the  
opening perpendicular to the slot.  
6. Holding the modem by each corner, align the gold edge with the empty  
expansion slot. Push down gently until the modem snaps into the slot.  
The diagram shows horizontally aligned expansion slots. Some  
computers have vertically aligned slots. The instructions apply to both  
styles.  
You need to apply a little pressure to seat the modem properly.  
Sometimes a gentle back and forth motion helps fit the modem all the  
way into the slot. If you feel resistance, the modem may not be  
properly lined up with the slot. Do not force it into the slot. Remove the  
modem and try again.  
26  
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7. Once the modem is inserted, fasten it firmly into place using the screw  
that you removed in step 5.  
8. Replace the computer’s cover and fasten it with the screws you  
removed in step 4.  
9. Locate the phone wall socket you plan to use for the modem. If you  
have a phone plugged into this wall socket, disconnect the telephone  
cord from the socket.  
The phone wall socket you use must be for an ANALOGUE phone line  
(the type found in most homes). Many office buildings have digital  
phone lines. Be sure you know which type of line you have. The  
modem will be damaged if you use a digital phone line.  
10. Plug one end of the phone cord included with the modem into the  
TELCO socket.  
11. Plug the other end of the cable into the phone wall socket.  
You cannot use the modem and a phone at the same time if they  
share the same telephone line. If you want to use a telephone on the  
same line as the modem when the modem is not in use, plug your  
telephone cord into the modem’s PHONE socket, using the supplied  
Tail Lead Adaptor.  
12. An external, powered speaker must be connected for speakerphone  
and voice mail usage. Plug a set of powered, magnetically-shielded,  
external speakers or a headset (not included) into the 3.5 mm SPKR  
socket on the modem.  
12. 13. Plug the supplied microphone into the 3.5 mm MIC socket on the  
modem.  
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Internal Modem Installation with Windows 3.x  
14. Plug the power cords, cables, and peripherals back into the computer  
and turn on the computer.  
15. Start Windows 3.x.  
16. If you have your modem set to COM1/IRQ4 or COM2/IRQ3, go to  
“Software Installation” on page 29. If you have your modem configured  
to any other setting, open Program Manager and double-click the  
Main icon.  
17. Double-click the Control Panel icon.  
18. Double-click the Ports icon.  
19. If it is not already selected, click the COM port for your modem. Then  
click Settings.  
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Internal Modem Installation with Windows 3.x  
20. Set the Baud Rate to the highest option and Flow Control to Hardware.  
Then click Advanced.  
21. In the Interrupt Request Line (IRQ) box, select the IRQ.  
22. Click OK.  
23. You will see a screen prompting you to restart Windows. Click  
Restart Now.  
Turn to “Software Installation” on page 29 for information about installing  
communications software.  
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Software Installation  
Voice Fax, Data, and Telecommunications Software (communications  
software) allows sending and receiving faxes directly from your computer  
desktop. You can build your own fax directory, send faxes to specified  
groups of fax numbers, select individual cover pages when necessary, and  
send individual faxes without exiting your word processing program.  
Communications software allows you to change settings and issue  
commands to your modem.  
Additionally, voice communications software lets you connect to Bulletin  
Board Systems (BBS) and other online data providers. Take advantage of  
this access to enter a new world of information and entertainment.  
Be sure to install software after the modem is installed.  
Windows 95  
1. Insert the communications software disk into your disk drive.  
2. Go to the Windows Start menu and select Run.  
3. In the Run dialog box, type A:\setup.exe and press ENTER.  
If your disk drive is a different letter, enter that letter in place of A.  
4. Follow the on-screen instructions to install your Voice Fax, Data, and  
Telecommunications Software.  
Windows 3.x  
1. Insert the communications software disk into your disk drive.  
2. In Program Manager, click File and select Run.  
3. In the text box, type A:\setup.exe and press ENTER.  
If your disk drive is a different letter, type that letter instead of A.  
Then click OK.  
4. Follow the on-screen instructions to install your Voice Fax, Data, and  
Telecommunications Software.  
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Software Installation  
Refer to your software manual for the specific installation instructions. The  
software’s installation program will ask you questions about the modem you are  
using. You may need the following information when installing a  
communications software package.  
Type of Modem  
Most voice communications software programs will ask you to select the  
type of modem you are using. Select a U.S. Robotics high speed  
modem. If that selection is not listed, pick Courier Dual Standard,  
V.32bis, or V.34.  
Initialisation String  
For hardware flow control, a fixed serial port rate, and full result codes,  
type: AT&F1 and then press ENTER.  
If you must use software flow control, type: AT&F2 and then press  
ENTER.  
Flow Control  
For hardware flow control (highly recommended), select RTS/CTS.  
For software flow control, select XON/XOFF.  
You may need to disable the flow control (hardware or software) that you  
are not using.  
Congratulations!  
You are now ready to start using your  
3Com U.S. Robotics modem.  
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Software Installation  
Read This First!  
1. Click Windows Start, point to Settings, and click Control Panel.  
2. Double-click the Modems icon.  
3. Click the Diagnostics tab.  
4. Click on the COM port that your modem is assigned to, so that it is  
highlighted. (If you do not see your modem on this screen, you will  
need to shut down your computer and uninstall the modem. Reinstall  
the modem following the instructions in the Installation Guide.)  
5. Click More Info. You should see a list of the modem’s ATI  
commands. Click OK. (If you do not, your modem is not properly  
installed. Shut down your computer and uninstall the modem. Reinstall  
the modem following the instructions in the Installation Guide.)  
PROBLEM: The computer or software will not recognise the  
modem.  
POSSIBLE SOLUTION  
Make sure the modem turned on. An internal modem should turn on  
automatically when the computer is turned on.  
POSSIBLE SOLUTION  
You may not be entering modem commands in the proper manner. Type  
in all upper case (AT) or all lower case (at).  
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Troubleshooting  
POSSIBLE SOLUTION  
You may have a COM port/IRQ conflict. If you have an internal modem  
and a Windows 95 system, right-click on the My Computer icon on your  
desktop. Click Properties. Click the Device Manager tab. If you see a  
yellow exclamation point over your modem, you have a resource conflict,  
and it is probably an IRQ conflict. Click the modem’s name to select it.  
Then click Remove. You will be asked if you are sure you wish to remove  
the device. Click OK. When the modem has been removed, shut down  
and turn off your computer. Unplug the computer from its electrical outlet  
and remove the cover. Physically remove the modem from its ISA slot.  
Replace the cover, plug the computer back into the electrical outlet, and  
turn on the computer. When Windows restarts, once again right-click the  
My Computer icon on your desktop and click Properties. Click the  
Device Manager tab. Double-click Computer. Make sure the “Interrupt  
request (IRQ)” radio button at the top of the screen is checked. You can  
determine which IRQ settings are free on your system by looking for  
numbers that are not listed in the Setting column. One of the following  
IRQs needs to be free: 3, 4, 5, or 7 (or 9 if you have a Winmodem). If  
there are no IRQ settings free in this range, you need to move a device off  
of one of these IRQs in order to free it for use by your modem. We  
recommend removing other modems or disabling COM ports that may be  
using one of these IRQs. After you have made these changes, reinstall  
the modem using the instructions in the Installation Guide. Once your  
modem is properly installed, make sure you have the correct COM port  
and IRQ settings in your software and/or in the Windows Device Manager.  
PROBLEM: The modem will not go off hook to dial or does  
not answer the phone.  
POSSIBLE SOLUTION  
You may have plugged your modem’s phone cord into a digital line.  
Plugging your modem’s phone cord into a digital phone line can damage  
the modem. Call your phone company if you are unsure whether or not  
your phone line is digital.  
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Troubleshooting  
POSSIBLE SOLUTION  
You may have plugged your modem’s phone cord into the wrong jack on  
the modem. Make sure the phone cord is plugged into a jack labeled with  
the word TELCO (marked with a wall jack icon on externals).  
POSSIBLE SOLUTION  
You might have a bad phone cord connection to your modem. The phone  
cord should be plugged into the TELCO jack on the modem (marked with  
a wall jack icon on externals) and the wall phone jack. The phone cord  
should be no longer than 12 feet in length. Use the phone cord included  
with your modem if possible.  
POSSIBLE SOLUTION  
Your phone jack may have been wired incorrectly. Contact your telephone  
company. Ask them to make sure the tip and ring are on the inside pair of  
wires.  
POSSIBLE SOLUTION  
You may have devices between the modem and the phone jack. There  
should be no line splitters, fax machines, or other devices between the  
modem and the wall jack.  
POSSIBLE SOLUTION  
You may have a poor line connection. Place the call again. Calls are  
routed differently each time.  
POSSIBLE SOLUTION  
If you have voice mail, your dial tone may be altered because messages  
are waiting. Retrieve your voice mail messages to restore your normal dial  
tone.  
POSSIBLE SOLUTION  
Your software may not have auto answer enabled. Enable the auto answer  
feature. In your communication software’s terminal mode, type ATS0=1  
and press ENTER.  
You need to enable auto answer before every session unless you alter  
your software’s initialisation string to permanently enable auto answer.  
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Troubleshooting  
PROBLEM: Both modems sound like they are exchange  
carrier signals, but fail to establish a connection.  
POSSIBLE SOLUTION  
You may have a poor line connection. Place the call again. Calls are  
routed differently each time.  
POSSIBLE SOLUTION  
Your phone jack may have been wired incorrectly. Contact your telephone  
company. Ask them to make sure the tip and ring are on the inside pair of  
wires.  
PROBLEM: Your 56K modem cannot achieve a 56K Internet  
connection.  
POSSIBLE SOLUTION  
This modem is capable of 56 Kbps downloads. However, the download  
speeds you experience may be lower due to varying line conditions and  
other factors. Uploads from users to server equipment travel at speeds up  
to 31.2 Kbps. An analogue phone line compatible with the ITU V.90  
standard or 3Com’s proprietary 56K technology, and an Internet provider  
or corporate host site with the ITU V.90 standard or 3Com’s proprietary  
56K technology are necessary for these high-speed downloads. Check  
http://www.3com.com/56k for a list of ISPs that observe the 56K ITU  
standard and/or offer 3Com’s proprietary 56K technology.  
POSSIBLE SOLUTION  
The phone lines in your area may not be 56K compatible. Call your phone  
company to find out if your phone line is compatible with the ITU standard  
for 56K and/or is compatible with 3Com’s proprietary 56K technology.  
POSSIBLE SOLUTION  
You may have devices between the modem and the phone jack. There  
should be no line splitters, fax machines, or other devices between the  
modem and the wall jack.  
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Troubleshooting  
PROBLEM: Errors are constantly occurring in your V.17 fax  
transmissions.  
POSSIBLE SOLUTION  
Your modem initialisation string may be insufficient for fax transmissions.  
In terminal mode, type the following initialisation string:  
AT&F&H3&I2&R2S7=90 and then press ENTER. The standard string for  
faxing is AT&F1S36=0  
POSSIBLE SOLUTION  
There may be a Terminate and Stay Resident (TSR) program (such as a  
screen saver or virus scanner) running in the background, disrupting data  
communications. Disable any Terminate and Stay Resident (TSR)  
programs running in the background. If you have software running as a  
TSR, check the software’s manual for information about disabling its  
ability to operate as a TSR.  
POSSIBLE SOLUTION  
Your baud rate may be set too high. In your communications software,  
lower the baud rate to 9600, 7200, or 4800.  
POSSIBLE SOLUTION  
You may be trying to fax a compressed file. Decompress the file using  
the application with which it was compressed. Then open it in the  
application with which it was created. Select your fax software as the  
printer and then print the file.  
PROBLEM: Your communications software fails to initialise  
the modem.  
POSSIBLE SOLUTION  
Your software’s port settings may be incorrect. Make sure the software’s  
port settings match those for your modem.  
POSSIBLE SOLUTION  
Make sure the modem is turned on. An internal modem should turn on  
automatically when the computer is turned on.  
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Troubleshooting  
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Troubleshooting  
PROBLEM: If Plug and Play does not detect your modem.  
You have installed the modem and Windows has restarted,  
but you see only your normal desktop. You do not see any  
screens indicating new hardware has been detected.  
POSSIBLE SOLUTION  
The Plug and Play installation was not successful. Try the following:  
1. Click Windows 95 Start and click Shut Down. When asked if you  
wish to shut down your computer, click Yes. When Windows 95  
indicates that it is safe to turn off your computer, turn it off and wait 15  
seconds. Then turn the computer back on. Windows 95 may detect  
your modem upon this restart, even if it did not detect the modem  
during the initial installation. If you see screens indicating that new  
hardware has been detected by Windows 95, follow the on-screen  
instruction to install the modem. If you do not see the new hardware  
screens, continue with step 2 below.  
2. Click Windows 95 Start, point to Settings, and click Control Panel.  
Double-click the System icon and then click the Device Manager tab  
on the “System Properties” screen. Look for “Other Devices” or  
“Unknown Devices” in the list that appears. If you do not see either of  
these options in the list, please contact our technical support  
department. If you do see one of these options, double-click the  
option. If the description that appears matches the modem you are  
trying to install, click Remove. Click OK when Windows asks if you  
wish to remove the device. Next, restart the computer and continue  
with the on-screen instructions. If the computer does not detect the  
modem after this second restart, please contact our technical support  
department.  
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Support Resources  
Connecting to the 3Com Bulletin Board System (BBS)  
To connect to the 3Com BBS, dial 33320910308. If this is your first time  
connecting to our BBS, you will be asked to enter your name, create a  
password of your choice, and to fill out a questionnaire.  
Internet FTP  
The Internet FTP provides free library containing the same files as the  
BBS site. To access the FTP site type ftp.usr.com.  
Internet On Demand  
The Internet on Demand provides automatic technical support through a  
library containing product information, quick reference cards and  
installation help. To obtain an index of available documents, send a blank  
e-mail to [email protected]. To have a document e-mailed to you,  
place the document number in the subject field.  
World Wide Web  
A 3Com Home Page contains the same information as the Internet on  
Demand listing. To log on to our Web site, type http://www.3Com.com.  
CompuServe  
Through CompuServe access the same information as on the Internet FTP  
site. The 3Com forum address is GO THREECOM.  
America Online  
Go to the Keyword field and type 3COM to connect to the various 3Com  
resources, such as file libraries, message boards, online customer  
support, and product announcements.  
Fax and Technical Support Hotline  
Technical questions about 3Com modems can also be answered via fax  
or by technical support representatives.  
Hotline: +33 (0) 3 20 19 24 24  
Fax:  
+33 (0) 3 20 19 24 34  
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Support Resources  
Are You Still Having Problems?  
·
·
Review this manual.  
Contact your local reseller/dealer who may be able to provide you with  
the necessary assistance.  
·
If your reseller/dealer cannot help you, contact 3Com Customer  
Support. When you call, specify your modem serial number (found on  
the outside of the box), the software being used, and if possible, the  
contents of your ATI7 screen.  
Hotline:  
Fax:  
+33 (0) 3 20 19 24 24  
+33 (0) 3 20 19 24 34  
3Com BBS: +33 (0) 3 20 91 03 08  
CompuServe: GO THREECOM  
Internet::  
If You Must Return the Modem to Us  
·
·
Contact 3Com U.S. Robotics Customer Support to obtain a Return  
Materials Authorisation (RMA) number. You must have an RMA  
number before returning the modem to us.  
Phone : +33 (0) 3 20 87 04 97  
Fax :  
+33 (0) 3 20 87 06 94  
Ship the unit, postage paid, in a strong box made of corrugated  
cardboard with plenty of packing material  
Do not send the modem back in the original box.  
Send only the modem—not the power supply, manual,  
software, etc.  
·
·
·
·
·
Include your RMA number, name and address on the  
shipping label, as well as inside the package.  
If possible, send the package via a courier capable of  
tracking the progress of the package.  
Ship to the following address:  
3Com U.S. Robotics Logistics sarl  
European Repair Center  
RMA# ____________  
Rue Jules Verne  
Centre de Gros N°2  
F-59818 Lesquin Cedex  
France  
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Glossary  
Cross references are printed in boldface. Cross references with items in  
the Technical Reference section are printed in italics.  
analogue loopback  
A modem self-test in which data from the keyboard or an internal test  
pattern is sent to the modem's transmitter, turned into analogue form,  
looped back to the receiver, and converted back into digital form.  
analogue signals  
A variety of signals and wavelengths that can be transmitted over  
communications lines such as the sound of a voice over the phone line.  
These signals are in contrast with digital signals.  
answer mode  
The mode used by your modem when answering an incoming call from an  
originating modem. The transmit/receive frequencies are the reverse of the  
originating modem, which is in originate mode.  
application  
A computer program designed to perform a specific function, such as  
word processing or organising data into a spreadsheet.  
ARQ  
Automatic Repeat reQuest is a general term for a function that  
automatically allows your modem to detect flawed data and retransmit it.  
See MNP and V.42.  
ASCII  
American Standard Code for Information Interchange is a code used to  
represent letters, numbers, and special characters, such as $, !, and /  
asynchronous transmission  
Data transmission in which the length of time between transmitted  
characters may vary. Since the time lapses between transmitted  
characters are not uniform, the receiving modem must be signaled as to  
when the data bits of a character begin and then they end. The addition of  
start/stop bits to each character serves this purpose.  
auto answer  
In this setting the modem can pick up the phone line when it detects a  
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Glossary  
certain number of rings. See S-register (S0) in the Technical Reference  
section.  
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Glossary  
auto dial  
A process where your modem dials a call for you. The dialling process is  
initiated by sending an ATDT (dial tone) or ATDP (dial pulse) command  
followed by the telephone number to dial. Auto Dial is used to dial voice  
numbers. See command Dn.  
baud rate  
A term used to measure the speed of an analogue transmission from one  
point to another. Although not technically accurate, baud rate is  
commonly used to mean bit rate.  
binary digit (bit)  
A 0 or 1, which reflects the use of the binary numbering system. It is used  
because the computer recognises either of two states, OFF or ON.  
The shortened form of binary digit is bit.  
bit rate  
This refers to the number of binary digits, or bits, transmitted per second  
(bps). It is also referred to as transmission rate. Communications  
channels using telephone channel modems are established at set bit  
rates, commonly 2400, 4800, 9600, 14,400, 28,800 and higher, e.g. when  
using the Public Switched Telephone Network (PSTN).  
bits per second (BPS)  
This is the bits (binary digits) per second rate. Thousands of bits per  
second are expressed as kilobits per second or kbps.  
buffer  
A memory area set aside to be used as temporary storage during input  
and output operations. An example is the modem's command buffer.  
byte  
A group of binary digits stored and operated upon as a unit. In user  
documentation, the term usually refers to 8-bit units or characters. One  
kilobyte (KB) is equal to 1,024 bytes or characters; 640 KB indicates  
655,360 bytes or characters.  
carrier  
A tone signifying a connection the modem can alter to communicate data  
across telephone lines.  
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Glossary  
character  
A representation, coded in binary digits, of a letter, number, or other  
symbol.  
characters per second (CPS)  
A data transfer rate generally estimated from the bit rate and the  
character length. For example, at 2400 bps, 8-bit characters with start/  
stop bits (for a total of ten bits per character) will be transmitted at a rate  
of approximately 240 characters per second (cps). Some protocols, like  
error-control protocols, employ advanced techniques such as longer  
transmission framesand data compression to increase cps.  
Class 1 and 2.0  
International standards used between fax application programs and  
faxmodems for sending and receiving faxes.  
cyclic redundancy checking (CRC)  
An error-detection technique consisting of a test performed on each block  
or frame of data by both sending and receiving modems. The sending  
modem inserts the results of its tests in each data block in the form of a  
CRC code. The receiving modem compares its results with the received  
CRC code and responds with either a positive or negative  
acknowledgement.  
data communications  
A type of communications in which computers are able to exchange data  
over an electronic medium.  
data compression table  
A table containing values assigned for each character during a call under  
MNP5 data compression. Default values in the table are continually  
altered and built during each call: the longer the table, the more efficient  
throughput gained.  
data mode  
The mode in which the faxmodem is capable of sending and receiving  
data files. A standard modem without fax capabilities is always in data  
mode.  
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Glossary  
DCE  
Data Communications (or Circuit-Terminating) Equipment is equipment  
such as dial-up modems that establish and control the data link via the  
telephone network.  
default  
Any setting assumed, at startup or reset, by the computer's software and  
attached devices. The computer or software will use these settings until  
changed by the user or other software.  
detect phase  
In the ITU-T V.42 error-control protocol, the first stage in establishing if  
both modems attempting to connect have V.42 capability.  
dictionary  
The term used for compression codes built by the V.42 bisdata  
compression algorithm.  
digital loopback  
A test that checks the modem's RS-232 interface and the cable that  
connects the terminal (computer) and the modem. The modem receives  
data (in the form of digital signals) from the computer or terminal, and  
immediately returns the data to the screen for verification.  
digital signals  
Signals that are discrete and uniform. In this manual, the term refers to  
the binary digits 0 and 1. These signals are in contrast with analogue  
signals.  
DTE  
Data Terminal (or Terminating) Equipment is a computer that generates  
or is the final destination of data.  
duplex  
Duplex indicates a communications channel capable of carrying signals in  
both directions. See half duplex, full duplex.  
EIA  
Electronic Industries Association is a group which defines electronic  
standards in the U.S.  
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Glossary  
error control  
A variety of techniques that check the reliability of characters (parity) or  
blocks of data. V.42 and MNP error-control protocolsuse error detection  
(CRC) and retransmission of flawed frames (ARQ).  
facsimile  
A method for transmitting the image on a page from one point to another.  
This is commonly referred to as fax.  
fax mode  
The mode in which the faxmodem is capable of sending and receiving files  
in a facsimile format. See definitions for V.17, V.27ter, V.29.  
flow control  
A mechanism that compensates for differences in the flow of data into and  
out of a modem or other device. See commands &Hn, &In, &Rn.  
frame  
A data communications term for a block of data with header and trailer  
information attached. The added information usually includes a frame  
number, block size data, error-check codes, and Start/End indicators.  
full duplex  
These signals will flow in both directions at the same time. In  
microcomputer communications, may refer to the suppression of the on-  
line local echo.  
half duplex  
These signals will flow in both directions, but only one way at a time.  
microcomputer communications, may refer to activation of the online  
In  
local echo, which causes the modem to send a copy of the transmitted  
data to the screen of the sending computer.  
Hz  
Hertz is a frequency measurement unit used internationally to indicate  
one cycle per second.  
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Glossary  
ITU-T  
An international organisation that defines standards for telegraphic and  
telephone equipment. For example, the Bell 212A standard for 1200 bps  
communication in North America is observed internationally as ITU-T  
V.22. For 2400 bps communication, most U.S. manufacturers observe  
V.22 bis. The initials ITU-T represent the ‘International  
Telecommunications Union - Telecommunications sector’.  
LAPM  
Link Access Procedure for Modems is an error-control protocol defined in  
ITU-T Recommendation V.42. Like the MNP protocols, LAPM uses  
cyclic redundancy checking (CRC) and retransmission of corrupted  
data (ARQ) to ensure data reliability.  
local echo  
A modem feature that enables the modem to display keyboard  
commands and transmitted data on the screen. See command Hn.  
MNP  
Microcom Networking Protocol is an error-control protocol developed by  
Microcom, Inc., and now in the public domain. There are several different  
MNP protocols, but the most commonly used one ensures error-free  
transmission through error detection (CRC) and retransmission of erred  
frames.  
modem  
A device that transmits/receives computer data through a  
communications channel such as radio or telephone lines. It also  
changes signals received from the phone line back to digital signals  
before passing them to the receiving computer.  
nonvolatile memory (NVRAM)  
A user-programmable random access memory which retains data when  
power is turned off. On the 3Com U.S. Robotics modem it includes four  
stored phone numbers and the modem settings.  
OFF/ON hook  
Modem operations that are the equivalent of manually lifting a phone  
receiver (taking it off-hook) and replacing it (going on-hook).  
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Glossary  
online fallback/fall forward  
A feature that allows a high-speed, error-control modem to monitor line  
quality and fall back to the next lower speed in a defined range if line  
quality diminishes. As line conditions improve, the modem switches up to  
the next higher speed.  
originate mode  
The mode used by your modem when initiating an outgoing call to a  
destination modem. The transmit/receive frequencies are the reverse of  
the called modem, which is in answer mode.  
parity  
A simple error-detection method that checks the validity of a transmitted  
character. Character checking has been surpassed by more reliable and  
efficient forms of error checking, including V.42 and MNP 2-4 protocols.  
Either the same type of parity must be used by two communicating  
computers, or both may omit parity.  
protocol  
A system of rules and procedures governing communications between  
two or more devices. Protocols vary, but communicating devices must  
follow the same protocol in order to exchange data. The format of the  
data, readiness to receive or send, error detection and error correction are  
some of the operations that may be defined in protocols.  
RAM  
Random Access Memory is memory that is available for use when the  
modem is turned on, but that clears of all information when the power is  
turned off. The modem's RAM holds the current operational settings, a  
flow control buffer, and a command buffer.  
remote digital loopback  
A test that checks the phone link and a remote modem's transmitter and  
receiver.  
remote echo  
A copy of the data received by the remote system, returned to the  
sending system, and displayed on the screen. Remote echoing is a  
function of the remote system.  
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Glossary  
ROM  
Read Only Memory is permanent memory, which is not user-  
programmable.  
serial transmission  
The consecutive flow of data in a single channel. Compare to parallel  
transmissions where data flows simultaneously in multiple channels.  
start/stop bits  
These signalling bits attached to a character before and after the  
character is transmitted during asynchronous transmission.  
terminal  
A device whose keyboard and display are used for sending and receiving  
data over a communications link. This device differs from a microcomputer  
or a mainframe in that it has little or no internal processing capabilities.  
terminal mode  
A software mode that allows direct communication with the modem. This  
is also known as command mode.  
throughput  
The amount of actual user data transmitted per second without the  
overhead of protocol information such as start/stop bits or frame  
headers and trailers. Compare it with characters per second.  
V.8  
The ITU-T standard specification that covers the initial handshaking  
process.  
V.17 Fax  
An ITU-T standard for making facsimile connections at 14400 bps,  
12000 bps, 9600 bps, and 7200 bps.  
V.21  
An ITU-T standard for modems operating in asynchronous mode at  
speeds up to 300 bps, full-duplex, on public switched telephone  
networks.  
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Glossary  
V.22  
An ITU-T standard for modem communications at 1200 bps, compatible  
with the Bell 212A standard observed in the U.S. and Canada.  
V.22 bis  
An ITU-T standard for modem communications at 2400 bps.  
The standard includes an automatic link negotiation fallback to 1200 bps  
and compatibility with Bell 212A/V.22 modems.  
V.23  
An ITU-T standard for modem communication at 1200 bps with a 75 bps  
back channel. This standard is used in the U.K.  
V.27ter  
An ITU-T standard for facsimile operations that specifies modulation at  
4800 bps, with fallback to 2400 bps.  
V.29  
An ITU-T standard for facsimile operations that specifies modulation at  
9600 bps, with fallback to 7200 bps.  
V.32  
An ITU-T standard for modem communications at 9600 bps and  
4800  
bps. V.32 modems fall back to 4800 bps when line quality is impaired.  
V.32 bis  
An ITU-T standard that extends the V.32 connection range: 4800, 7200,  
9600, 12000, and 14400 bps. V.32 bis modems fall back to the next lower  
speed when line quality is impaired, fall back further as necessary, and  
also fall forward (switch back up) when line conditions improve.  
See online fall back/fall forward  
V.34  
An ITU-T standard that currently allows data rates as high as 28,800bps.  
V.34+  
This is an enhancement to V.34 that enables data transfer rates as high  
as 33,600 bps.  
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Glossary  
V.42  
An ITU-T standard for modem communications that defines a two-stage  
process of detection and negotiation for LAPM error control.  
V.42 bis  
An extension of ITU-T V.42 that defines a specific data compression  
scheme for use during V.42 connections.  
Xmodem  
The first of a family of error control software protocolsused to transfer  
files between modems. These protocols are in the public domain and are  
available from many bulletin board services.  
XON/XOFF  
Standard ASCII control characters used to tell an intelligent device to  
stop/resume transmitting data.  
Ymodem  
An error-checking protocol that can send several files of data at a time in  
1024-byte (1K) blocks. This protocol can use either checksums or CRC  
for error checking.  
Ymodem G  
This is similar to Ymodem, except it relies on the modem for error  
checking, which makes it faster.  
Zmodem  
This is similar to Xmodem and Ymodem, except it includes batch  
transfer, the ability to recover from a partially complete transfer, an  
autostart feature, and improved efficiency.  
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Technical Reference  
Typing Commands  
·
·
Type commands in either upper or lower case, not a combination.  
Use the Backspace key to delete errors. (You cannot delete the  
original AT command since it is stored in the modem buffer.)  
If a command has numeric options and you do not include a  
number, zero is assumed. For example, if you type ATB, the  
command ATB0 is assumed.  
·
·
Every command except A/, +++, and A> must begin with the  
AT prefix and be entered by pressing ENTER.  
The maximum command length is 58 characters. The modem does  
not count the AT prefix, carriage returns, or spaces.  
All defaults are based on the &F1¾Hardware Flow Control template  
loaded in NVRAM when the modem is shipped. Defaults are listed in  
italics.  
Basic Data Commands  
<control key>S  
Stop or restart help screens.  
<control key>C  
<control key>K  
or  
Stop help screens.  
$
Use in conjunction with D, S, or & commands (or just AT)  
to display a basic command list; online help.  
A
Manual Answer: goes off hook in answer mode. Pressing any  
key aborts the operations.  
A/  
A>  
Re-executes the last issued command. Used mainly to redial.  
Does not require the AT prefix or a Carriage Return.  
Re-executes the last issued command continuously, until the user  
intervenes or the command is executed. forever. Does not require  
the AT prefix or a Carriage Return.  
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Technical Reference  
Any key Aborts off-hook dial/answer operation and hangs up.  
AT  
Required command prefix, except with A/, +++, and A>. Use  
alone to test for OK result code.  
B
n
U.S./ITU-T answer sequence  
B0  
ITU-T answer sequence  
B1  
U.S. answer tone  
Dn  
Dials the specified phone number, includes the  
following:  
0-9  
#, *  
L
Numeric digits  
Extended touch-tone pad tones  
Dials the last dialed number  
P
Pulse (rotary) dial  
R
Sn  
Originates call using answer (reverse) frequencies  
Dials the phone number string stored in NVRAM at  
position n (n = 0-3); phone numbers are stored with the  
&Zn=s command  
T
,
;
Tone dial  
(Comma) Pause, See S8 definition; which it is linked to  
(Semicolon) Return to Command mode after dialing  
Dials the letters that follow (in an alphabetical phone  
number)  
!
/
W
@
$
(Exclamation point) Flashes the switch hook  
Delays for 125 ms. before proceeding with dial string  
Wait for second dial tone (X2 or X4); linked to S6 register  
Dials, waits for quiet answer, and continues (X3 or higher)  
Displays a list of Dial commands  
En  
Fn  
Sets local echo  
E0  
Echo OFF  
E1  
Modem displays keyboard commands  
Sets online local echo of transmitted data ON/OFF  
F0  
Local echo ON, modem sends a copy of data it sends to  
the remote system to your screen  
F1  
Local echo OFF, receiving system may send a  
remote echo of data it receives  
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Technical Reference  
Controls ON/OFF hook  
Hn  
In  
H0  
H1  
Hangs up (goes on hook)  
Goes off hook  
Displays the following information  
I0  
I1  
I2  
I3  
I4  
I5  
I6  
I7  
I9  
I11  
Four-digit product code  
Results of ROM checksum  
Results of RAM checksum  
Product type  
Current modem settings  
Nonvolatile memory (NVRAM) settings  
Link diagnostics  
Product configuration  
Plug and Play information  
Extended link diagnostics  
Ln  
Mn  
On  
Controls speaker volume (internals only)  
L0  
L1  
L2  
L3  
Low volume  
Low volume  
Medium volume  
High volume  
Operates speaker  
M0  
M1  
M2  
M3  
Speaker always OFF  
Speaker ON until CONNECT  
Speaker always ON  
Speaker ON after dial, until CONNECT  
Returns online  
O0  
O1  
Returns online  
Returns online and retrains  
P
Sets pulse dial (for phone lines that do not support  
touch-tone dialing)  
Qn  
Displays/suppresses result codes  
Q0  
Q1  
Q2  
Displays result codes  
Quiet mode; no result codes  
Displays result codes only in Originate mode  
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Technical Reference  
Sr.b=n Sets bit .b of register r to n (0/OFF or 1/ON)  
Sr=n Sets register r to n.  
Sr?  
S$  
T
Displays contents of S-Register r  
Displays a list of the S-Registers  
Sets tone dial  
Vn  
Displays verbal/numeric result codes  
V0  
Numeric codes  
V1  
Verbal codes  
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Technical Reference  
Xn  
Sets result code displayed, default is X4  
Xn Setting  
Result Codes  
X0  
X1  
X2  
X3  
X4  
0/OK  
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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  
13/CONNECT 9600  
18/CONNECT 4800  
20/CONNECT 7200  
21/CONNECT 12000  
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25/CONNECT 14400  
43/CONNECT 16800  
85/CONNECT 19200  
91/CONNECT 21600  
99/CONNECT 24000  
103/CONNECT 26400  
107/CONNECT 28800  
151/CONNECT 31200  
155/CONNECT 33600  
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Technical Reference  
Xn Setting  
Xn (Continued)  
Result Codes  
X0  
X1  
X2  
X3  
X4  
256/CONNECT 28000  
260/CONNECT 29333  
264/CONNECT 30666  
268/CONNECT 32000  
180/CONNECT 33333  
272/CONNECT 34666  
276/CONNECT 36000  
184/CONNECT 37333  
280/CONNECT 38666  
284/CONNECT 40000  
188/CONNECT 41333  
192/CONNECT 42666  
196/CONNECT 44000  
200/CONNECT 45333  
204/CONNECT 46666  
208/CONNECT 48000  
212/CONNECT 49333  
216/CONNECT 50666  
220/CONNECT 52000  
224/CONNECT 53333  
228/CONNECT 54666  
232/CONNECT 56000  
236/CONNECT 57333  
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Adaptive Dialing  
·
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Wait for 2nd Dial Tone (W)  
Wait for Answer (@)  
Fast Dial  
·
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*Requires @ in dial string; replaces NO CARRIER  
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Technical Reference  
Yn  
Selects power-on/reset default configuration  
Y0  
Y1  
Y2  
Y3  
Y4  
Use profile 0 setting in NVRAM  
Use profile 1 setting in NVRAM  
Use factory configuration 0  
Use factory configuration 1  
Use factory configuration 2  
Z
Resets modem  
Z0  
Resets modem to NVRAM profile selected by Y  
command or dip 7  
Z1  
Z2  
Z3  
Z4  
Z5  
Resets modem to NVRAM profile 0  
Resets modem to NVRAM profile 1  
Resets modem to factory default profile 0 (&F0)  
Resets modem to factory default profile 1 (&F1)  
Resets modem to factory default profile 2 (&F2)  
Extended Data Commands  
&$  
Displays a list of ampersand (&) commands  
&An  
Enables/disables additional result code subsets (see Xn)  
&A0  
&A1  
&A2  
&A3  
ARQ result codes disabled  
ARQ result codes enabled  
V.32 modulation indicator added  
Protocol indicators added LAPM/MNP/NONE (error  
control) and V42bis/MNP5 (data compression)  
&Bn  
&Cn  
Manages modem’s serial port rate  
&B0  
&B1  
&B2  
Variable, follows connection rate  
Fixed serial port rate  
Fixed in ARQ mode, variable in non-ARQ mode  
Controls Carrier Detect (CD) signal.  
&C0  
CD override  
&C1  
Normal CD operations  
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Technical Reference  
&Dn  
Controls Data Terminal Ready (DTR) operations  
&D0  
&D1  
&D2  
&D3  
DTR override  
DTR toggle causes online Command mode  
Normal DTR operations  
Resets on receipt of DTR  
&Fn  
&Gn  
Loads a read-only (non-programmable) factory configuration  
&F0  
&F1  
&F2  
Generic template  
Hardware flow control template  
Software flow control template  
Sets Guard Tone  
&G0  
No guard tone, U.S. and Canada  
&G1  
550 Hz guard tone, some European countries, requires  
B0 setting  
&G2  
1800 Hz guard tone, U.K., requires B0 setting  
&Hn  
Sets Transmit Data (TD) flow control (see also &Rn)  
&H0  
&H1  
&H2  
&H3  
Flow control disabled  
Hardware flow control, Clear to Send (CTS)  
Software flow control, XON/XOFF  
Hardware and software flow control  
&In  
Sets Receive Data (RD) software flow control (see also &Rn)  
&I0  
&I1  
&I2  
Software flow control disabled  
XON/XOFF signals to your modem and remote system  
XON/XOFF signals to your modem only  
&Kn  
Enables/disables data compression  
&K0  
&K1  
&K2  
&K3  
Data compression disabled  
Auto enable/disable  
Data compression enabled  
MNP5 compression disabled  
&Mn  
Sets Error Control (ARQ) for connections at 1200 bps and  
higher  
&M0  
&M1  
&M2  
&M3  
&M4  
&M5  
Normal mode, error control disabled  
Reserved  
Reserved  
Reserved  
Normal/ARQ  
ARQ mode  
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&Nn  
Sets connect speed, if connection cannot be made at  
this speed, the modem will hang up. When used in  
conjunction with &Un and &Un is greater than 0, &Nn  
sets the ceiling connect speed. &Un sets the floor  
connect speed. (See also the table in the &Un  
section.)  
&N0  
&N1  
&N2  
&N3  
&N4  
&N5  
&N6  
&N7  
&N8  
&N9  
Connection speed is determined by the remote modem  
300 bps  
1200 bps  
2400 bps  
4800 bps  
7200 bps  
9600 bps  
12,000 bps  
14,400 bps  
16,800 bps  
&N10 19,200 bps  
&N11 21,600 bps  
&N12 24,000 bps  
&N13 26,400 bps  
&N14 28,800 bps  
&N15 31,200 bps  
&N16 33,600 bps  
&N17 28,000 bps  
&N18 29,333 bps  
&N19 30,666 bps  
&N20 32,000 bps  
&N21 33,333 bps  
&N22 34,666 bps  
&N23 36,000 bps  
&N24 37,333 bps  
&N25 38,666 bps  
&N26 40,000 bps  
&N27 41,333 bps  
&N28 42,666 bps  
&N29 44,000 bps  
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Technical Reference  
&Nn  
(Continued)  
&N30 45,333 bps  
&N31 46,666 bps  
&N32 48,000 bps  
&N33 49,333 bps  
&N34 50,666 bps  
&N35 52,000 bps  
&N36 53,333 bps  
&N37 54,666 bps  
&N38 56,000 bps  
&N39 57,333 bps  
&Pn  
&Rn  
Sets pulse (rotary) dial make/break ratio  
&P0  
U.S./Canada ratio, 39%/61%  
&P1  
U.K. ratio, 33%/67%  
Sets Receive Data (RD) hardware flow control, Request to  
Send (RTS) (see also &Hn)  
&R0  
&R1  
&R2  
Reserved  
Modem ignores RTS  
Received Data to computer only on RTS  
&Sn  
&Tn  
Controls Data Set Ready (DSR) operations  
&S0  
DSR override; always ON  
&S1  
Modem controls DSR  
Begins test modes.  
&T0  
&T1  
&T2  
&T3  
&T4  
&T5  
&T6  
&T7  
&T8  
Ends testing  
Analog Loopback  
Reserved  
Local Digital Loopback  
Enables Remote Digital Loopback  
Prohibits Remote Digital Loopback  
Initiates Remote Digital Loopback  
Remote Digital with self-test and error detector  
Analog Loopback with self-test and error detector  
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Technical Reference  
&Un  
Sets floor connect speed when set above 0, if the  
connection cannot be established above this speed, the  
modem will hang up. When &Un is used in conjunction with  
&Nn and &Nn is greater than 0, &Nn is the ceiling connect  
speed.  
&N=0  
&N>0  
&U=0 Connects at best  
Connects at speed  
defined by &Nn. If the  
connection cannot be  
made above this speed,  
the modem will  
hang up.  
possible speed  
between your modem  
and the remote modem  
Note: These factory  
default settings should  
be sufficient for most users.  
&U>0 Connects at any speed  
faster than the value of &Un  
Connects at any speed  
between &Nn. and &Un  
&U0  
No restrictions on the minimum speed for the  
connection  
&U1  
&U2  
&U3  
&U4  
&U5  
&U6  
&U7  
&U8  
&U9  
300 bps  
1200 bps  
2400 bps  
4800 bps  
7200 bps  
9600 bps  
12,000 bps  
14,400 bps  
16,800 bps  
&U10 19,200 bps  
&U11 21,600 bps  
&U12 24,000 bps  
&U13 26,400 bps  
&U14 28,800 bps  
&U15 31,200 bps  
&U16 33,600 bps  
&U17 28000 bps  
&U18 29333 bps  
&U19 30666 bps  
&U20 32000 bps  
&U21 33,333 bps  
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Technical Reference  
&Un (Continued)  
&U22 34666 bps  
&U23 36000 bps  
&U24 37,333 bps  
&U25 38666 bps  
&U26 40000 bps  
&U27 41,333 bps  
&U28 42,666 bps  
&U29 44,000 bps  
&U30 45,333 bps  
&U31 46666 bps  
&U32 48000 bps  
&U33 49333 bps  
&U34 50666 bps  
&U35 52000 bps  
&U36 53333 bps  
&U37 54666 bps  
&U38 56000 bps  
&U39 57333 bps  
&Wn Writes current configuration to NVRAM templates  
&W0 Modifies the NVRAM 0 template (Y0)  
&W1 Modifies the NVRAM 1 template (Y1)  
&Yn  
Sets break handling  
&Y0  
&Y1  
&Y2  
&Y3  
Destructive, but does not send break  
Destructive, expedited  
Nondestructive, expedited  
Nondestructive, unexpedited  
&Zn=s  
&Zn=L  
Writes phone number string s to NVRAM at position  
n (n = 0-3)  
Writes last executed dial string to NVRAM at position  
n (n = 0-3)  
&Zn?  
&ZL?  
+++  
Displays the phone number stored at position n (n = 0-3)  
Displays the last executed dial string  
Escapes to online-command mode  
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Technical Reference  
S-Registers  
To change a setting, use the ATSr=n command, where r is the register and  
n is a decimal value from 0 - 255 (unless otherwise indicated).  
Register  
Default  
Function  
S0  
0
Sets the number of rings on which to answer in Auto  
Answer mode. When set to 0, Auto Answer is disabled.  
S1  
S2  
0
Counts and stores the number of rings from an incoming  
call. (S0 must be greater than 0.)  
43  
Stores the ASCII decimal code for the escape code  
character. Default character is +. A value of 128 255  
disables the escape code.  
S3  
S4  
S5  
13  
10  
8
Stores the ASCII code for the Carriage Return character.  
Valid range is 0 127.  
Stores the ASCII decimal code for the Line Feed character.  
Valid range is 0 127.  
Stores the ASCII decimal code for the Backspace  
character. A value of 128-255 disables the Backspace  
key’s delete function.  
S6  
S7  
2
Sets the number of seconds the modem waits before  
dialing. If Xnis set to X2 or X4, this is the time-out length if  
there is not a dial tone.  
60  
Sets the number of seconds the modem waits for a  
carrier. May be set for much longer duration if, for  
example, the modem is originating an international  
connection.  
S8  
S9  
2
6
Sets the duration, in seconds, for the pause (,) option in  
the Dial command.  
Sets the required duration, in tenths of a second, of the  
remote modem’s carrier signal before recognition by the  
U.S. Robotics modem.  
65  
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Technical Reference  
Function  
Register  
Default  
S10  
14  
Sets the duration, in tenths of a second, that the modem  
waits to hang up after loss of carrier. This guard time  
allows the modem to distinguish between a line  
disturbance from a true disconnect (hang up) by the  
remote modem.  
Note: If you set S10 = 255, the modem will not hang up  
when carrier is lost. Dropping DTR hangs up the modem.  
S11  
S12  
S13  
70  
50  
0
Sets the duration and spacing, in milliseconds, for tone  
dialing.  
Sets the duration, in fiftieths of a second, of the guard time  
for the escape code sequence (+++).  
Bit-mapped register. Select the bit(s) you want on and set  
S13 to the total of the values in the Value column. For  
example, ATS13 = 17 enables bit 0 (value is 1) and bit 4  
(value is 16).  
Bit  
0
1
Value  
1
2
Result  
Reset when DTR drops.  
Reset non-MNP transmit buffer from  
1.5K to 128 bytes.*  
2
3
4
8
Set backspace key to delete.  
On DTR signal, auto dial the number  
stored in NVRAM at position 0.  
At power on/reset, auto dial the  
number stored in NVRAM at position  
0.  
4
16  
5
6
7
32  
64  
128  
Reserved  
Disable quick retrains.  
Disconnect on escape code.  
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Technical Reference  
Function  
Register  
Default  
S13 (Continued)  
*
The 1.5K-byte non-ARQ buffer allows data transfer with Xmodem-and  
Ymodem-type file transfer protocols without using flow control.  
The 128-byte option lets remote users with slower modems keep data you  
are sending from scrolling off their screens. When remote users send your  
computer an XOFF (Ctrl-S) and you stop transmitting, the data in transit  
from your modem’s buffer does not exceed the size of their screen.  
This is also very helpful in situations when a remote modem/printer  
application is losing characters.  
S14  
S15  
0
0
Reserved  
Bit-mapped register setup. To set the register,  
see instructions for S13.  
Bit  
0
1
Value  
Result  
1
2
4
Disable ARQ/MNP for V.22.  
Disable ARQ/MNP for V.22bis.  
Disable ARQ/MNP  
2
V.32/V.32bis/V.32terbo.  
Disable MNP handshake.  
Disable MNP level 4.  
Disable MNP level 3.  
MNP incompatibility.  
Disable V.42 operation.  
3
4
5
6
7
8
16  
32  
64  
128  
To disable V.42 detect phase, select the total of the  
values for bits 3 and 7 (in other words S15 = 136 [the sum  
of values 8 and 128])  
S16  
S17  
S18  
0
0
0
Reserved  
Reserved  
Test timer for &T loopback testing. Sets the time in  
seconds of testing before the modem automatically times  
out and terminates the test. When set to 0, the timer is  
disabled. Valid range is 1-255.  
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Technical Reference  
Function  
Register  
Default  
S19  
0
Sets the duration, in minutes, for the inactivity timer. The  
timer activates when there is no data activity on the phone  
line; at time-out the modem hangs up. S19 = 0 disables  
the timer.  
S20  
S21  
0
Reserved  
10  
Sets the length, in 10-millisecond units, of breaks sent  
from the modem to the computer; applies to MNP or  
V.42 mode only.  
S22  
S23  
S24  
S25  
17  
19  
0
Stores the ASCII decimal code for the XON character.  
Stores the ASCII decimal code for the XOFF character.  
Reserved  
20  
Sets the duration, in hundredths of a second, that DTR  
must be dropped so that the modem does not interpret a  
random glitch as a DTR loss. (Most users will want to use  
the default; this register is useful for setting compatibility  
with older systems running under older operating software.)  
S26  
S27  
0
0
Reserved  
Bit-mapped register setup. To set the register,  
see instructions for S13.  
Bit  
Value  
Result  
0
1
Enables ITU-T V.21 modulation at 300  
bps for overseas calls; in V.21 mode,  
the modem answers both overseas  
and domestic (U.S. and Canada)  
calls, but only originates V.21 calls.  
(Default Bell 103)  
1
2
Enables unencoded (non-trellis  
coded) modulation in V.32 mode.  
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Technical Reference  
Function  
Register  
Default  
S27 (Continued)  
Bit  
2
Value  
4
Result  
Disables V.32 modulation.  
Disables 2100 Hz answer tone to  
allow two V.42 modems to connect  
faster.  
3
8
4
5
6
7
16  
32  
64  
128  
Enables V.23 fallback mode.  
Disables V.32bis mode.  
Disable V.42 selective reject.  
Software compatibility mode. This  
setting disables the codes and  
displays the 9600 code instead. The  
actual rate of the call can be viewed on  
the ATI6 screen. Used for unusual  
software incompatibilities. Some  
software may not accept 7200,  
12,000, and 14,400 bps or greater  
result codes.  
S28  
0
8
Eliminates the V.32 answer tones for a faster connection.  
Default item, all times are in tenths of seconds.  
255  
20  
Disables all connections except V.32 at 9600 bps.  
S29  
Sets the duration, in tenths of a second, of the V.21  
answer mode fallback timer.  
S30  
S31  
0
Reserved  
Reserved  
128  
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Technical Reference  
Function  
Register  
Default  
S32  
2
Bit-mapped register setup. To set the register,  
see the instructions for S13.  
Bit  
0
1
Value  
1
2
Result  
V.8 Call Indicate enabled.  
Enables V.8 mode.  
Reserved.  
2
4
3
4
5
6
8
Disable V.34 modulation.  
Disable V.34+ modulation.  
Disable 56K modulation.  
Disable V.90 modulation.  
Reserved.  
16  
32  
64  
128  
7
S33  
0
Bit-mapped register setup. To set the register, see the  
instructions for S13.  
Bit  
0
1
2
3
4
5
6
7
Value  
1
2
4
8
16  
32  
64  
128  
Result  
Disable 2400 symbol rate.  
Disable 2743 symbol rate.  
Disable 2800 symbol rate.  
Disable 3000 symbol rate.  
Disable 3200 symbol rate.  
Disable 3429 symbol rate.  
Reserved  
Disable shaping.  
S34  
0
Bit-mapped register setup. To set registers, see  
instructions for S13.  
Bit  
0
1
2
3
Value  
1
2
4
8
16  
Result  
Disable 8S-2D trellis encoding.  
Disable 16S-4D trellis encoding.  
Disable 32S-2D trellis encoding.  
Disable 64S-4D trellis encoding.  
Disable non-linear coding.  
4
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Technical Reference  
Register  
Default  
Function  
Value Result  
S34 (Continued)Bit  
5
6
7
32  
64  
128  
Disable TX level deviation.  
Disable Pre-emphasis.  
Disable Pre-coding.  
S35-S37  
Reserved  
S38  
0
Sets an optional delay, in seconds, before a forced hang-  
up and clearing of the Transmit buffer when DTR drops  
during an ARQ call. This allows time for a remote modem  
to acknowledge receipt of all transmitted data before it is  
disconnected. The modem immediately hangs up when  
DTR drops.  
This option only applies to connections terminated by  
dropping DTR. If the modem receives the ATH command,  
it ignores S38 and immediately hangs up.  
S39-S40  
S41  
Reserved  
0
Bit-mapped register setup. To set registers, see  
instructions for S13.  
Bit  
0
Value  
1
Result  
Reserved.  
1
2
Speakerphone connect message  
override (voice products only).  
Reserved.  
Message waiting (voice  
products only).  
Reserved.  
Reserved.  
Reserved.  
Reserved.  
2
3
4
8
4
5
6
7
16  
32  
64  
128  
S42  
0
Reserved  
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Technical Reference  
Fax Commands  
+FCLASS=n  
Sets the mode of operation  
FCLASS=0  
Data mode  
FCLASS=1  
Group 3 Facsimile Service Class 1  
mode  
FCLASS?  
+FCLASS=?  
+FTS=n  
Displays the current FCLASS mode  
(See mode descriptions above)  
Displays the FCLASS mode options  
(See mode descriptions above)  
Stops the fax transmission. Then the modem waits for  
a specified time before OK appears on screen. The  
pause is set in 10 millisecond intervals. n is the number  
of 10 millisecond intervals that pass before OK appears.  
(n=0-255)  
+FRS=n  
Makes the modem wait for a specified length of silence  
before sending OK to the screen. The pause is set in10  
millisecond intervals. n is the number of 10 millisecond  
intervals that pass before OK appears.(n=0-255)  
Note: This command terminates with OK when either  
the specified amount of silence is detected or when the  
user types anything (which is ignored).  
+FTM=n  
+FRM=n  
Transmits data using the modulation specified by  
n.(n = 3, 24, 48, 72, 96, 97, 98, 121, 122, 145, or 146)  
Note: See the “Screen Messages” table at the end of  
this section for an explanation of messages that appear  
in response to this command.  
Receives data using the modulation specified by  
n.(n = 3, 24, 48, 72, 96, 97, 98, 121, 122, 145, or 146)  
Note: See the “Screen Messages” table at the end of  
this section for an explanation of messages that  
appear in response to this command.  
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Technical Reference  
+FTH=n  
+FRH=n  
Transmits data framed in the HDLC protocol using the  
modulation specified by n.(n = 3, 24, 48, 72, 96, 97, 98,  
121, 22, 145, or 146)  
Note: See the “Screen Messages” table at the end of  
this section for an explanation of messages that appear  
in response to this command.  
Receives data framed in the HDLC protocol using the  
modulation specified by n.(n = 3, 24, 48, 72, 96, 97, 98,  
121, 122, 145, or 146)  
Note: See the “Screen Messages” table at the end of  
this section for an explanation of messages that appear  
in response to this command.  
Screen Messages  
Displayed  
Displayed  
as a number in words  
Description  
0
1
2
3
4
OK  
The previous command has been  
processed successfully.  
CONNECT  
The modem has just connected to  
another modem.  
RING  
altering ring.  
Reports the receipt of a network  
NO CARRIER No carrier is being received from the  
modem.  
ERROR  
The previous command line has not  
been recognized or was completed  
abnormally.  
5
NO DIAL  
TONE  
(Optional) Dial tone was not received  
within the time-out period.  
6
BUSY  
(Optional) A busy signal was deleted.  
64  
CONNECT/  
FAX  
(Optional) The modem has established  
a fax connection. This response is used  
only when the fax mode is selected.  
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Regulatory  
CE Compliance  
Electromagnetic Compatibility  
This device complies with the following standards in accordance with the  
European Directives 89/336/EEC.  
· Immunity EN 50082-1 06/92  
· Emission EN 55022 class B 08/87  
Safety (Low Voltage Directive)  
This device complies with the following standards in accordance with  
European Directives 91/263/EEC and 91/263/EEC:  
·
·
EN 60950/A2 10/93  
EN 41003 08/93  
The ports on this modem have the following safety status:  
· Telephone line connector = TNV  
· All other ports = SELV  
These definitions are classified as per safety standard:  
· EN 60950/A2 10/93  
· SELV: Safety Extra Low Voltage  
· TNV: Telecommunications Network Voltage, voltages in  
compliance with standard EN 41003 08/93 criteria.  
Ringer Equivalence Number (REN)  
The modem's REN (Ringer Equivalence Number) is 1.  
The total of the RENs of all items connected to one telephone line must  
not exceed 4. As long as the total is 4 or less, the ringing characteristics  
of the connected items should not be affected.  
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Limited Warranty  
U.S. Robotics Access Corp., a subsidiary of 3Com Corporation, warrants  
to the original end-user purchaser that this product will be free from  
defects in materials and workmanship for the life of the modem. During  
the limited warranty period, and upon proof of purchase, the product will  
be repaired or replaced (with the same or a similar model, which may be a  
refurbished model) at U.S. Robotics’ option, without charge for either parts  
or labour. This limited warranty shall not apply if the product is modified,  
tampered with, misused, or subjected to abnormal working conditions  
(including, but not limited to, lightning and water damage).  
THIS LIMITED WARRANTY DOES NOT GUARANTEE YOU  
UNINTERRUPTED SERVICE. REPAIR OR REPLACEMENT AS  
PROVIDED UNDER THIS LIMITED WARRANTY IS THE EXCLUSIVE  
REMEDY OF THE PURCHASER. THIS LIMITED WARRANTY IS IN LIEU  
OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING,  
BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF  
MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE OR  
PURPOSE. U.S. ROBOTICS SHALL IN NO EVENT BE LIABLE FOR  
ANY SPECIAL, INDIRECT, INCIDENTAL, PUNITIVE OR  
CONSEQUENTIAL DAMAGES OF ANY KIND OR CHARACTER,  
INCLUDING, WITHOUT LIMITATION, LOSS OF REVENUE OR PROFITS,  
FAILURE TO REALIZE SAVINGS OR OTHER BENEFITS, LOSS OF  
DATA OR USE, DAMAGE TO EQUIPMENT, AND CLAIMS AGAINST  
THE PURCHASER BY ANY THIRD PERSON, EVEN IF U.S. ROBOTICS  
HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.  
This limited warranty gives you specific legal rights. You may have others,  
which vary from nation to nation. Some nations do not allow limitations on  
duration of an implied warranty, or the exclusion or limitation of incidental  
or consequential damages, so the above exclusion or limitation may not  
apply to you.  
56K Voice Faxmodem Internal - User’s Guide  
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