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56K FAXMODEM
User’s Guide and Reference
This manual covers installation and operating instructions for the following modems:
3Com U.S. Robotics 56K* Faxmodem External
The material contained in this document is for information purposes only and is subject to change without notice. 3Com makes no representations or warranties with respect to the contents hereof and specifically disclaims any implied warranties of merchantability or fitness for any particular purpose. No part of this document may be reproduced, transmitted, transcribed, or stored in a retrieval system in any form or by any means, mechanical, magnetic, electronic, optical, chemical or otherwise, without the written permission of 3Com. 3Com assumes no responsibility for errors or omissions in this manual. Nor does 3Com make any commitment to update the information contained herein.
3Com, the 3Com logo, and U.S. Robotics are registered trademarks of 3Com Corporation. Windows is a registered trademark of Microsoft Corp. Any other trademarks, trade names, service marks, or service names owned or registered by any other company and used in this manual are the property of their respective owners.
Copyright
1998 3Com Corporation. All rights reserved.
* IMPORTANT! 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 56K technology, and an Internet provider or corporate host site with the ITU V.90 standard or
3Com 56K technology are necessary for these high-speed downloads. See http://www.3com.com/56k for details.
Table of Contents
External Modem Installation with Windows 95 and Windows 98
Determining Your Version of Windows 95
How to Connect the Modem to the Computer
Installing Modem Drivers with Windows 95:
Versions 950 and 950a (Moving Through the "New Hardware Found" Screens)
Version 950b (Using the Update Device Driver Wizard Screens)
Installing Modem Drivers with Windows 98
External Modem Installation with Windows 3.x
UART-Universal Asynchronous Receiver Transmitter
Table of Contents
Serial Interface Pin Definitions 74
Electromagnetic Compatibility 75
Safety (Low Voltage Directive) 75
Operation of pan-European modems 75
Welcome to 56K*Information Access
quickly upgrade their service to the ITU V.90
standard.
The International Telecommunication 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 3Com
U.S. Robotics modem, you can get 56K Internet access from any service provider who offers the
ITU V.90 standard or 3Com 56K technology.
3Com is working with providers everywhere to
∗
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 56K technology, and an
Internet provider or corporate host site with the
ITU V.90 standard or 3Com 56K technology are necessary for these high-speed downloads.
See http://www.3com.com/56k for details.
1
2
Modulation Schemes
ITU-T V.90
3Com 56K technology (Download up to 56kbps, and Upload using V.34)
ITU-T V.34 (Inc 33600)
ITU-T V.32 bis
ITU-T V.32
ITU-T V.22 bis
ITU-T V.22
ITU-T V.23
ITU-T V.21
Error Control and Data Compression
Schemes
ITU-T V.42
ITU-T V.42 bis
MNP 2-5
Product Features
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
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.32 bis 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
Flash ROM Upgradable
56K Faxmodem supports software download through flash memory. You can obtain the latest features by downloading updates quickly and easily.
Product Features
Front Panel Lights
PWR/Power
The modem is turned on.
CD/Carrier Detect
ON if modem receives a valid data signal (carrier) from a remote modem, indicating that data transmission is possible. Always ON if CD override is ON (&C0).
RD/Received Data
Flashes when modem sends result codes or passes received data bits from remote.
SD/Send Data
Flashes when computer sends a data bit to modem.
3
4
External Modem Installation with Windows 95 and Windows 98
You will need these items from your
3Com U.S. Robotics modem box:
modem power adaptor phone cord
Determining Your Version of
Windows 95
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 screen image). The number following the text “Microsoft Windows 95” will end with “950”, “950a”, or “950b”. This indicates your version of Windows 95.
serial modem cable
External Modem Installation with Windows 95 and Windows 98
Write down your version of Windows.
Windows 95 version _______
Click OK.
How to Connect the Modem to the Computer
1.
Turn off your computer and any attached devices, such as a printer, monitor, keyboard, and mouse.
2.
Connect the serial cable to the modem and to the computer. When looking for your serial port on the back of your computer, look for ports labeled COM, MODEM, RS-232, or SERIAL.
Do not select AUX, GAME, LPT, or
PARALLEL.
Remember which serial port you selected. This information will be necessary when installing your communications software.
3.
Plug one end of the phone cord into the
TELCO socket and the other end into a phone wallsocket.
The phone wall socket you use must be for an
ANALOGUE phone line. Most office phones are wired through DIGITAL lines. Be sure you know which type of line you have. The modem will be damaged if you use a digital phone line.
4.
Plug the power adaptor that came with the modem into a standard wall socket and insert its plug into the power socket on the modem.
5.
If you want to use a telephone on the same line, use a splitter arrangement. You cannot use the modem and a phone at the same time if they share the same telephone line.
5
6
External Modem Installation with Windows 95 and Windows 98
Installing Modem Drivers with Windows 95:
Versions 950 and 950a
Moving Through the “New Hardware Found”
Screens
1.
When Windows 95 restarts, it should detect the modem. If it does, you will see the following screen.
6.
Plug the power cords, cables, and peripherals back into the computer and turn on the computer.
7.
Start Windows 95.
External Modem Installation with Windows 95 and Windows 98
Click Driver from disk provided by
hardware manufacturer. Then click OK.
If this screen does not appear, refer to “If Plug and
Play Does Not Detect Your Modem” .
2.
When you see the Install from Disk screen,
•
If you have a disk that contains your modem’s drivers, insert the disk into your disk drive, usually A.
•
If you have a CD-ROM that contains your modem’s drivers, insert the CD-ROM into your CD-ROM drive, usually 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 install the drivers for your new modem.
7
External Modem Installation with Windows 95 and Windows 98
3.
Once Windows finishes loading the information from the disk or CD-ROM, 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).
8
External Modem Installation with Windows 95 and Windows 98
5.
In the “Modems Properties” screen, you should see a description for your modem.
If this screen does not appear, refer to “If Plug and
Play Does Not Detect Your Modem” on page 30.
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. You may need to know this setting when you install your communications software.
COM Port___________
This means the installation was a success.
9
External Modem Installation with Windows 95 and Windows 98
7.
Click More Info….
The modem’s status screens should appear in the box. Click OK.
Be sure to install software after the modem is installed.
Turn to “Software Installation” on page 20 for information about installing communications software.
Congratulations!
You are ready to start using your
3Com U.S. Robotics Faxmodem
10
External Modem Installation with Windows 95 and Windows 98
Installing Modem Drivers with Windows 95:
Version 950b
Using the Update Device Driver Wizard Screens
1.
When you see the following screen,
•
If you have a disk that contains your modem’s drivers, insert the disk into your disk drive, usually A.
•
If you have a CD-ROM that contains your modem’s drivers, insert the CD-ROM into your CD-ROM drive, usually D.
If your disk drive or CD-ROM drive is a different letter, type that letter instead of A or
D.
Click Next.
If this screen does not appear, refer to “If Plug and
Play Does Not Detect Your Modem” on page 30.
11
External Modem Installation with Windows 95 and Windows 98
2.
When you see the following screen, click
Finish.
Windows will copy files to your hard drive.
3.
When Windows is finished copying files, verify that the modem installation was a success.
Click the Windows Start button and point to
Settings. Then click Control Panel
.
12
External Modem Installation with Windows 95 and Windows 98
4.
Double-click the Modems icon (circled in the screen image below).
5.
In the “Modems Properties” screen, you should see a description of your modem.
This means the installation was a success.
13
External Modem Installation with Windows 95 and Windows 98
If this screen does not appear, refer to “If Plug and
Play Does Not Detect Your Modem” on page 30.
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. You may need to know this setting when you install your communications software.
COM Port_________
7.
Click More Info….
The modem’s status screens should appear in the box. Click OK.
Be sure to install software after the modem is installed.
Turn to “Software Installation” for information about installing communications software.
Congratulations!
You are ready to start using your
3Com U.S. Robotics Faxmodem
14
External Modem Installation with Windows 95 and Windows 98
Installing Modem Drivers with Windows 98
1.
When you see this screen, Windows has detected the modem.
2.
Click Next.
3.
When you see the following screen:
If this screen does not appear, refer to “If Plug and Play Does Not Detect Your Modem”.
15
External Modem Installation with Windows 95 and Windows 98
• if you have a CD-ROM that contains your modem’s drivers, check CD-ROM drives option and insert the CD-ROM into your
CD-ROM drive.
• if you have a disk that contains your modem’s drivers, check the Floppy disk
drives option and insert the disk into your disk drive.
4.
The next screen tells you that Windows has found the driver for your modem. Click Next.
5.
Click Finish.
6.
When Windows is finished copying files, you should verify that the modem installation was a success. Click the Windows Start button and point to Settings. Then click Control Panel.
7.
Double-click the Modems icon.
8.
In the “Modems Properties” screen, you should see a description of your modem. This means the installation was a success. Click OK.
16
External Modem Installation with Windows 95 and Windows 98
If you do not see your modem listed, the installation was unsuccessful. R efer to “If Plug and Play Does
Not Detect Your Modem”.
9.
Next, click the Diagnostics tab at the top of the
“Modems Properties” screen. Write down the
COM setting for your modem in the following space. You may need to know this setting when you install your communications software.
COM Port_________
Turn to “Software Installation” for information about installing communications software. Also refer to the manual of the communications software for instructions on installation.
After you install your communications software, you are ready to use the modem.
17
External Modem Installation with Windows 3.x
You will need these items from your
3Com U.S. Robotics modem box:
modem power adaptor serial modem cable phone cord
How to Connect the Modem to the Computer
1.
Turn off your computer and any attached devices, such as a printer, monitor, keyboard, mouse.
2.
Connect the serial cable to the modem and to the computer. When looking for the serial port on the back of your computer, look for ports labeled COM, MODEM, RS-232, or SERIAL.
Do not select AUX, GAME, LPT, or
PARALLEL.
Remember which serial port you selected. This information will be necessary when installing your communications software.
3.
Plug one end of the phone cord into the TELCO socket and the other end into a phone wall socket.
18
External Modem Installation with Windows 3.x
The phone socket you are going to use must be for an ANALOGUE phone line. Most office phones are wired through DIGITAL lines. Be sure you know what type of line you have. The modem will be damaged if you use a digital phone line.
4.
Plug the power adaptor that came with the modem into a standard wall socket and insert its plug into the power socket on the modem.
If you want to use a telephone on the same line, use a splitter arrangement. You cannot use the modem and a phone at the same time if they share the same telephone line.
6.
Plug the power cords, cables, and peripherals back into the computer and turn on the computer.
7.
Start Windows 3.x.
Be sure to install software after the modem is installed.
Turn to “Software Installation” for information about installing communications software.
Congratulations!
You are ready to start using your
3Com U.S. Robotics Faxmodem
19
Software Installation
Fax, Data, and Telecommunications Software
(communications software) allows you to send and receive 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, 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.
Windows 95
1.
Insert the communications software disk or
CD-ROM into your disk drive or CD-ROM drive.
2.
Go to the Windows Start menu and select Run.
3.
In the Run dialog box, type A:\install.exe or
D:\install.exe and press ENTER.
If your disk drive or CD-ROM drive is a different letter, type that letter instead of A or
D.
4.
Then click OK.
5.
Follow the on-screen instructions to install your
Fax, Data, and Telecommunications Software.
Windows 3.x
1.
Insert the communications software disk or
CD-ROM into your disk drive or CD-ROM drive.
2.
In Program Manager, click File and select
Run.
3.
In the text box, type A:\install.exe or
D:\install.exe and press ENTER.
If your disk drive or CD-ROM drive is a different letter, type that letter instead of A or
D.
4.
Then click OK.
20
Software Installation
5.
Follow the on-screen instructions to install your
Fax, Data, and Telecommunications Software.
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 communications software programs will ask you to select the type of modem you are using.
Select a 3Com U.S. Robotics high speed modem. If that selection is not listed, pick Courier Dual
Standard, V.32 bis, 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
.
Disable the type of flow control (hardware or software) that you are not using.
UART - Universal Asynchronous Receiver
Transmitter (External Modems Only)
If you are running Windows 3.x or you have upgraded your system from Windows 3.x to
Windows 95, you can run MSD to determine your
UART setting. In DOS, type MSD at the Windows directory and then press ENTER.
21
Software Installation
Follow the on-screen instructions to access the
COM port settings panel. In this panel you should find the UART chip used. Match the UART type listed in MSD with the serial rate listed in the chart. Select this serial rate in any fax/data programs you use.
If this is your UART...
Select this serial rate
16550
16450
8250
115.2 or 57.6 Kbps
38.4 Kbps
19.2 Kbps
Do not select a 28,800, 14,400, or 12,000 bps serial port rate if offered. Your modem will not work correctly with any of these settings. Fix or lock the serial port (baud) rate. If it’s referred to as
autobaud
, select OFF.
22
Congratulations!
You are now ready to start using your
3Com U.S. Robotics 56K Faxmodem
Troubleshooting
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 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 need to shut down the computer and uninstall the modem. Exit out of the Modems
Properties screen by clicking Cancel. Click Start, Shut Down, select the Shut down the computer? option, and then click Yes. When your computer has shut down, turn it off and unplug it from its power outlet. Unplug its serial cable from the computer’s COM port. Reinstall your modem following the directions in the “External Modem Installation with Windows 95” chapter, but use a different COM port.
5.
Click More Info. You should see a list of the modem’s ATI commands. Click OK and exit out of all open screens. If the ATI commands do not appear, your modem is not properly installed. Reinstall your modem following the directions in the “External Modem Installation with Windows 95” chapter.
23
Troubleshooting
PROBLEM
The computer or software will not recognise the modem.
POSSIBLE SOLUTION
Make sure the modem is plugged in and turned on. Use only the power adaptor included with your modem.
POSSIBLE SOLUTION
You may not be entering modem commands in the proper manner. Type in all upper case (AT) or all lower case (at).
POSSIBLE SOLUTION
The COM port may not be enabled. Refer to your computer’s manual for information about enabling COM ports (usually involves altering the bios settings, motherboard jumpers, and the operating system).
POSSIBLE SOLUTION
You may be using the wrong serial cable with your external faxmodem. Make sure you are using an RS-232 modem cable. You will need to make sure you are using a 25-pin male to 25-pin female if your COM port is a
25-pin port, or a 25-pin male to 9-pin female if your COM port is a 9-pin port.
24
Troubleshooting
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.
POSSIBLE SOLUTION
You might have a bad phone cord connection to your modem. The phone cord should be plugged into the phone socket on the modem and the wall phone socket. The phone cord should be no longer than 12 feet in length. Use the phone cord included with your modem if possible.
POSSIBLE SOLUTION
You may have devices between the modem and the wall socket. There should be no line splitters, fax machines, or other devices between the modem and the wall socket.
POSSIBLE SOLUTION
You may have a poor line connection. Place the call again. Calls are routed differently each time.
25
Troubleshooting
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.
POSSIBLE SOLUTION
You may be using the wrong power adaptor for your modem. Use only the power adaptor that came with your modem.
PROBLEM
Both modems sound like they are exchanging 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.
26
Troubleshooting
PROBLEM
Your 56K modem cannot achieve a 56K Internet connection.
POSSIBLE SOLUTION
Your modem is capable of receiving data at speeds up to 56 Kbps and sending data at speeds up to 31.2 Kbps.
However, the download speeds you experience may be lower due to varying line conditions. An analogue phone line compatible with ITU-T V.90 or 3Com 56K technology, and an Internet provider or corporate host site compatible with ITU-T V.90 or 3Com 56K technology are necessary for these high-speed downloads. Check
http://www.3com.com/56k for a list of ISPs that observe ITU-T V.90 and/or offer 3Com 56K technology.
POSSIBLE SOLUTION
Your phone line may not be capable of transferring data at the full 56K, but V.90 and 3Com 56K technology operate at a range of speeds and will use the highest speed possible.
POSSIBLE SOLUTION
You may have devices between the modem and the wall socket. There should be no line splitters, fax machines, or other devices between the modem and the wall socket.
27
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 then press ENTER.
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.
28
Troubleshooting
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 plugged in and turned on. Use only the power adaptor included with the modem.
29
Troubleshooting
PROBLEM
If Plug and Play (PNP) does not detect your modem. You have installed the modem and Windows has started, 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 Start and click Shut Down.
2.
When asked if you wish to shut down your computer, click Yes.
3.
When Windows indicates that it is safe to turn off your computer, turn it off.
4.
Wait 15 seconds before turning the computer back on.
5.
Windows 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, follow the on-screen instructions to install the modem.
•
If you do not see the new hardware screens, continue with step 6.
6.
Click Windows Start
30
Troubleshooting
7.
Point to Settings
8.
Click Control Panel.
9.
Double-click the System icon.
10.
Click the Device Manager tab on the “System Properties” screen.
11.
Look for “Other Devices” or “Unknown Devices” in the list that appears.
•
If you do not see either of these options in the list, contact customer support for technical assistance.
•
If you do see one of these options, double-click the option and continue with step 12.
12.
If the description that appears matches the modem you are trying to install, click Remove. If it does not, contact customer support for technical assistance.
13.
Click OK when Windows asks if you wish to remove the device.
14.
Restart the computer and continue with the on-screen instructions. If the computer does not detect the modem after this second restart, contact customer support for technical assistance.
31
Glossary
transmit/receive frequencies are the reverse of the
originating modem, which is in originate mode.
Cross references are printed in boldface. Cross references with items in the Data Commands found in the “Technical Reference” section, are printed in
italics.
application
A computer program designed to perform a specific function, such as a word processing or organizing data into a spreadsheet.
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.
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
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.
ASCII
American Standard Code for Information
Interchange is a code used to represent letters,
numbers, and special characters, such as $, !, and
/.
answer mode
The mode used by your modem when answering an incoming call from an originating modem. The
32
Glossary 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 certain number of rings. See
S-register S0 in the “Technical Reference” section.
autodial
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. Autodial 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
binary digit
A 0 or 1, which reflects the use of the binary numbering system. It is used because the computer recognizes either of two states, OFF or ON. The shortened form of binary digit is bit.
bit rate
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.
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.
33
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.
character
A representation, coded in binary digits, of a
letter, number, or other symbol.
Glossary 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, such as error-control
protocols, employ advanced techniques such as
longer transmission frames and data compression
to increase cps.
class 1 and 2.0
International standards used between fax
application programs and faxmodems for sending
and receiving faxes.
34
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 acknowledgment.
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.
Glossary 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.
Data Communications Equipment (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
35
dictionary
The term used for compression codes built by the
V.42 bis data 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.
Glossary duplex
Duplex indicates a communications channel capable of carrying signals in both directions. See
Electronic Industries Association (EIA)
This association is a group which defines electronic standards in the U.S.
error control
A variety of techniques that check the reliability of
characters (parity) or blocks of data. V.42 and
MNP error-control protocols use 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.
36
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 over one line. In microcomputer communications, may refer to the suppression of
Glossary half duplex
These signals will flow in both directions, but only one way at a time. In microcomputer communications, may refer to activation of the
online 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 cycles per second.
ITU-T
An international organization 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.
37
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
En
.
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
Glossary 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 some modems, 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 offhook) and replacing it (going on-hook).
38
online fall back/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.
Glossary 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
remote digital loopback
A test that checks the phone link and a remote modem's transmitter and receiver.
39
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.
ROM
Read Only Memory is permanent memory, which is not user-programmable.
serial transmission
The consecutive flow of data in a single channel.
Compare it to parallel transmissions where data flows simultaneously in multiple channels.
start/stop bits
These signaling bits are attached to a character before and after the character is transmitted during
asynchronous transmission.
Glossary 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
Software mode that allows direct communication with the modem. This mode 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.
40
V.17
An ITU-T standard for making facsimile connections at 14,400 bps, 12,000 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.
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.
Glossary
V.23
An ITU-T standard for modem communication at
1200 bps with a 75 bps back channel.
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.
41
V.32 bis
An ITU-T standard that extends the V.32
connection range: 4800, 7200, 9600, 12,000, and
14,400 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 28,800 bps and 33,600bps.
V.42
An ITU-T standard for modem communications that defines a two-stage process of detection and
negotiation for LAPM error control.
Glossary
V.42 bis
An extension of ITU-T V.42 that defines a specific data compression scheme for use during V.42
connections.
V.90
The ITU-T standard for 56 Kbps modem communications.
Xmodem
The first of a family of error control software
protocols used 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.
42
Glossary
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 the 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.
43
Technical Reference
Front Panel Lights
Symbol Meaning
PWR ........ Power
CD ........... Carrier Detect
RD ........... Received Data
SD ........... Send Data
Status
The modem is turned on.
ON if modem receives a valid data signal (carrier) from a remote modem, indicating that data transmission is possible. Always ON if CD override is ON (&C0).
Flashes when modem sends result codes or passes received data bits from remote.
Flashes when computer sends a data bit to modem.
44
Technical Reference
Typing Commands
•
In terminal mode, 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 because 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. This does not include the AT prefix, carriage returns, or spaces.
All defaults are based on the &F1
Hardware Flow Control template loaded in NVRAM when the modem is shipped. Defaults are listed in italics.
45
Technical Reference
Basic Data Commands
<control key>S
Stop or restart help screens.
<control key>C
or
<control key>K
Stop help screens.
$
Use in conjunction with
D
,
S
, or
&
commands (or just AT) to display a basic command list; online help.
A
A/
Manual Answer goes off hook in answer mode. Pressing any key aborts the operations.
Re-executes the last issued command.
Used mainly to redial. This does not require the AT prefix or a Carriage
Return.
A>
Re-executes the last issued command continuously, until the user intervenes or the command is executed forever. Does
46 not require the AT prefix or a Carriage
Return.
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.
Bn
Dn
U.S./ITU-T answer sequence
B0
B1
ITU-T answer sequence
U.S. answer tone
Dials the specified phone number, includes the following:
L
P
0-9 Numeric digits
#, * Extended touch-tone pad tones
R
Dials the last dialled number
Pulse (rotary) dial
Originates call using answer
(reverse) frequencies
S
n
T
Dials the phone number string stored at position
n
(
n
= 0
−
3).
Phone numbers are stored with the &Z
n
=s command
Tone dial
Technical Reference
Dn (Continued)
,
/
!
;
W
@
$
(Comma) Pause, see the definition of the S8 register to which it is linked
(Semicolon) Return to
Command mode after dialling
(Exclamation point) Flashes the switch hook
(Back Slash) Delays for 125 ms.
before proceeding with dial string
Waits for second dial tone (X2 or X4); linked to S6 register
(At Symbol) Dials, waits for quiet answer, and continues (X3 or higher)
(Dollar Sign) Displays a list of
Dial commands
47
En
Fn
Hn
Sets local echo
E0
E1
Echo OFF
Modem displays keyboard commands
Sets online local echo of transmitted data ON/OFF
F0
F1
Local echo ON; modem sends a copy of data, it sends to the remote system to your screen
Local echo OFF; receiving system may send a remote echo of data it receives
Controls ON/OFF hook
H0
H1
Hangs up (goes on hook)
Goes off hook
Technical Reference
In
Ln
Mn
Displays the following information:
I4
I5
I6
I7
I0
I1
I2
I3
I9
I11
Four-digit product code
Results of ROM checksum
Results of RAM checksum
Product type
Current modem settings
Stored memory settings
Link diagnostics
Product configuration
Plug and Play information
Extended link diagnostics
Speaker Volume
L0
L2
L3
Lowest Speaker Volume L1
Low Speaker Volume
Medium Speaker volume
High Speaker Volume
Operates speaker
M0
M1
M2
Speaker always OFF
Speaker ON until CONNECT
Speaker always ON
48
Technical Reference
M3 Speaker ON after dial, until
CONNECT
On
Qn
Returns online
O0
O1
Returns online
Returns online and retrains
Displays/suppresses result codes
Q0
Q1
Q2
Displays result codes
Quiet mode; no result codes
Displays result codes only in Originate mode
Sr.b=n Sets bit .b of register r to n (0/OFF or
1/ON)
Sr=n Sets register r to n
Sr?
Displays contents of S-Register r
S$
Vn
Displays a list of the S-Registers
Displays verbal/numeric result codes
V0
V1
Numeric codes
Verbal codes
49
50
Technical Reference
Xn Sets result code displayed, default is X4
X
n
Setting
Result Codes X0 X1 X2 X3 X4
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
• • • •
13/CONNECT 9600
• • • •
18/CONNECT 4800
• • • •
20/CONNECT 7200
• • • •
21/CONNECT 12000
• • • •
25/CONNECT 14400
43/CONNECT 16800
85/CONNECT 19200
• • • •
• • • •
• • • •
*Requires @ in dial string; replaces NO CARRIER
Technical Reference
Xn (Continued) X
n
Setting
Result Codes X0 X1 X2 X3 X4
91/CONNECT 21600
99/CONNECT 24000
103/CONNECT 26400
107/CONNECT 28800
151/CONNECT 31200
155/CONNECT 33600
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
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
51
Technical Reference
Xn (Continued) X
n
Setting
Result Codes X0 X1 X2 X3 X4
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
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Adaptive Dialling
Wait for 2nd Dial Tone (W)
Wait for Answer (@)
Fast Dial
•
•
•
•
• •
•
•
•
52
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
(&F0)
Use factory configuration 1
(&F1)
Use factory configuration 2
(&F2)
Technical Reference
Z Resets modem
Z0
Z1
Z2
Z3
Z4
Z5
Resets modem to profile selected by Y command
Resets modem to profile 0
Resets modem to 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)
53
Extended Data Commands
&$ Displays a list of ampersand
(&) commands
&An Enables/disables additional result code subsets, see Xn
&A0 ARQ result codes disabled
&A1 ARQ result codes enabled
&A2 Modulation indicator added
&A3 Protocol indicators added
LAPM/MNP/NONE (error control) and V.42
bis
/MNP5
(data compression)
&Bn Manages modem’s serial port rate
&B0 Variable, follows connection rate
&B1 Fixed serial port rate
&B2 Fixed in ARQ mode, variable in non-ARQ mode
Technical Reference
&Cn Controls Carrier Detect (CD) signal
&C0 CD override
&C1 Normal CD operations
&Dn Controls Data Terminal Ready
(DTR) operations
&D0 DTR override
&D1 DTR toggle causes online
Command mode
&D2 Normal DTR operations
&D3 Resets on receipt of DTR
&Fn Loads a read-only (nonprogrammable) factory configuration
&F0 Generic template; no flow control
&F1 Hardware flow control template
&F2 Software flow control template
54
Technical Reference
&Gn 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 Flow control disabled
&H1 Hardware flow control, Clear to
Send (CTS)
&H2 Software flow control, Xon/Xoff
&H3 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 Data compression disabled
&K1 Auto enable/disable
&K2 Data compression enabled
&K3 MNP5 compression disabled
55
&Mn Sets Error Control (ARQ) for connections at 1200 bps and higher
&M0 Normal mode, error control disabled
&M1 Reserved
&M2 Reserved
&M3 Reserved
&M4 Normal/ARQ
&M5 ARQ mode
&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.)
Note: &N17 through &N39 apply only to
V.90 products.
&N0 Connection speed is determined by the remote modem
56
Technical Reference
&N1 300 bps
&N2 1200 bps
&N3 2400 bps
&N4 4800 bps
&N5 7200 bps
&N6 9600 bps
&N7 12,000 bps
&N8 14,400 bps
&N9 16,800 bps
&N10 19,200 bps
&N11 21,600 bps
&N12 24,000 bps
&Nn (Continued)
&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
&N30 45,333 bps
&N31 46,666 bps
&N32 48,000 bps
&N33 49,333 bps
&N34 50,666 bps
Technical Reference
&N35 52,000 bps
&N36 53,333 bps
&N37 54,666 bps
&N38 56,000 bps
&Pn Sets pulse (rotary) dial make/break ratio
&P0 U.S./Canada ratio, 39%/61%
&P1 U.K. ratio, 33%/67%
&Rn Sets Receive Data (RD) hardware flow control, Request to Send (RTS), see also &Hn
&R0 Reserved
&R1 Modem ignores RTS
&R2 Received Data to computer only on RTS
&Sn Controls Data Set Ready (DSR) operations
&S0 DSR override; always ON
&S1 Modem controls DSR
57
Technical Reference
&Tn Begins test modes
&T0 Ends testing
&T1 Analogue Loopback
&T2 Reserved
&T3 Local Digital Loopback
&T4 Enables Remote Digital
Loopback
&T5 Prohibits Remote
Digital Loopback
&T6 Initiates Remote Digital
Loopback
&T7 Remote Digital with self-test and error detector
&T8 Analogue Loopback with selftest and error detector
58
Technical Reference
&Un When set above 0, the value chosen from the table sets the floor connect speed (the lowest acceptable connect speed). If a connection cannot be made at or above this speed, the modem will hang up. This command can also be used in conjunction with &Nn.
Note: &U17 through &U39 apply only to V.90 products.
&U=0
&U>0
&N=0
Connects at best possible speed between your modem and the remote modem.
Note: These factory default settings should be sufficient for most users.
Connects at any speed faster than the value
&U
n.
&N>0
Attempts a connection at the speed defined by &N
n
.
Connects at any speed between
&N
n
. and &U
n.
59
&Un (Continued)
&U0 No restrictions on the minimum speed for the connection
&U1 300 bps
&U2 1200 bps
&U3 2400 bps
&U4 4800 bps
&U5 7200 bps
&U6 9600 bps
&U7 12,000 bps
&U8 14,400 bps
&U9 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 28,000 bps
&U18 29,333 bps
&U19 30,666 bps
60
Technical Reference
&U20 32,000 bps
&U21 33,333 bps
&U22 34,666 bps
&U23 36,000 bps
&U24 37,333 bps
&U25 38,666 bps
&U26 40,000 bps
&U27 41,333 bps
&U28 42,666 bps
&U29 44,000 bps
&U30 45,333 bps
&U31 46,666 bps
&U32 48,000 bps
&U33 49,333 bps
&U34 50,666 bps
&U35 52,000 bps
&U36 53,333 bps
&U37 54,666 bps
&U38 56,000 bps
Technical Reference
&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 Destructive, but does not send break
&Y1 Destructive, expedited
&Y2 Nondestructive, expedited
&Y3 Nondestructive, unexpedited
&Zn=sWrites phone number string s at position n (n = 0
−−
3)
&Zn=L Writes last executed dial string at position n (n = 0
−−
3)
&Zn?
Displays the phone number stored at position n (n = 0
−−
3)
&ZL?
Displays the last executed dial string
#CID=n
Controls Caller ID feature
#CID=0 Caller ID disabled
#CID=1 Caller ID enabled with formatted information
#CID=2 Caller ID enabled with unformatted information
+++
Escapes to online-command mode
61
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
S1
S2
S3
S4
S5
S6
0
0
43
13
10
8
2
Sets the number of rings on which to answer in Auto Answer Mode
When set to 0, Auto Answer is disabled
Counts and stores the number of rings from an incoming call
S0 must be greater than 0
Stores the ASCII decimal code for the escape code character
Default character is
+
A value of 128 – 255 disables the escape code
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
Sets the number of seconds the modem waits before dialling
If X
n
is set to X2 or X4, this is the time-out length if there is not a dial tone
62
Technical Reference
Register Default Function
S7
S8
S9
S10
S11
S12
S13
72
50
0
60
2
6
14
Bit
2
3
0
1
4
Sets the number of seconds the modem waits for a carrier
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 modem
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
Sets the duration and spacing, in milliseconds, for tone dialling
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)
Value
4
8
1
2
16
Result
Reset when DTR drops
Reset non-MNP transmit buffer from 1.5K to 128 bytes*
Set backspace key to delete
On DTR signal, autodial the number stored at position 0
At power on/reset, autodial the number stored at position 0
63
Technical Reference
Register Default Function
S13 (Continued)
S14
S15
0
0
Bit Value Result
5
6
7
32
64
128
Reserved
Disable quick retrains
Disconnect on escape code
*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
Reserved
Bit-mapped register setup
To set the register, see instructions for S13
Bit Value Result
0
1
2
1
2
Disable ARQ/MNP for V.22
Disable ARQ/MNP for V.22 bis
4 Disable ARQ/MNP V.32/V.32 bis
64
Technical Reference
Register Default Function
S15 (Continued)
S16
S17
S18
S19
S20
S21
0
0
0
0
0
10
Bit Value Result
5
6
3
4
8
16
32
64
Disable MNP handshake
Disable MNP level 4
Disable MNP level 3
MNP incompatibility
7 128 Disable V.42 operation
To disable V.42 detect phase, select the total of the values for bits 3 and 7. (S15=136{the sum of values 8 and 128})
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
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
Reserved
Sets the length, in 10-millisecond units, of breaks sent from the modem to the computer; applies to MNP or V.42 mode only
65
Technical Reference
Register Default Function
S22
S23
S24
S25
S26
S27
17
19
0
20
0
0
Stores the ASCII decimal code for the Xon character
Stores the ASCII decimal code for the Xoff character
Reserved
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
Reserved
Bit-mapped register setup
To set the register, see instructions for S13
Bit Value Result
2
3
0
1
4
5
1
2
4
8
16
32
Enables ITU-T V.21 modulation at 300 bps for UK calls
Enables unencoded (non-trellis coded) modulation in V.32 mode
Disables V.32 modulation
Disables 2100 Hz answer tone to allow two V.42 modems to connect faster
Enables V.23 fallback mode
Disables V.32
bis
mode
66
Technical Reference
Register Default Function
S27 (Continued)
S28
S29
S30
S31
S32
0
8
255
20
0
128
2
Bit
2
3
0
1
Bit Value Result
6
7
64
128
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
Eliminates the V.32 answer tones for a faster connection
Default item, all times are in tenths of seconds
Disables all connections except V.32 at 9600 bps
Sets the duration, in tenths of a second, of the V.21 answer mode fallback timer
Reserved
Reserved
Bit-mapped register setup
To set the register, see the instructions for S13
Value
4
8
1
2
Result
V.8 Call Indicate enabled
Enables V.8 mode
Reserved
Disable V.34 modulation
67
Technical Reference
Register Default Function
S32 (Continued)
S33 0
S34 0
Bit Value Result
6
7
4
5
16
32
64
128
Disable 33,600 bps and 31,200bps in V.34 modulation
Disable 56K modulation
Disable V.90 modulation.
Reserved.
Bit-mapped register setup
To set the register, see the instructions for S13
Bit Value Result
6
7
4
5
2
3
0
1
1
2
4
8
16
32
64
128
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
Bit-mapped register setup
To set registers, see instructions for S13
Bit Value Result
0
1
1
2
Disable 8S-2D trellis encoding
Disable 16S-4D trellis encoding
68
Technical Reference
Register Default Function
S34 (Continued)
S35-S37
S38
S39-S40
S41
S42
0
0
0
Bit Value Result
4
5
2
3
4
8
16
32
Disable 32S-2D trellis encoding
Disable 64S-4D trellis encoding
Disable non-linear coding
Disable TX level deviation
6
7
64
128
Disable Pre-emphasis
Disable Pre-coding
Reserved
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.
Reserved
Reserved
Reserved
69
Technical Reference
Fax Commands
+FCLASS=n Sets the mode of operation
FCLASS=0 Data mode
FCLASS=1 Group 3 Facsimile Service Class 1mode
FCLASS=2.0
Group 3 Facsimile Service Class 2.0 mode
FCLASS?
+FCLASS=?
Displays the FCLASS mode options
(see mode descriptions above)
+FTS=n
Displays the current FCLASS mode
(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 the screen
Makes the modem wait for a specified length of silence before sending OK to
The pause is set in10 millisecond intervals. intervals that pass before OK appears. (
n
=0-255)
n
is the number of 10 millisecond silence is
Note: This command terminates with OK when either the specified amount of detected or when the user types anything (which is ignored).
70
Technical Reference
Fax Commands
(Continued)
+FTM=n
+FRM=n
+FTH=n
+FRH=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.
Transmits 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.
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.
71
Technical Reference
Screen Messages
Numeric Text
Message Message Description
0 OK The previous command has been processed successfully.
1 CONNECT The modem has just connected to another modem.
2 RING Reports the receipt of a network altering ring.
3 NO CARRIER No carrier is being received from the modem.
4 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 detected.
64 CONNECT/FAX (Optional) The modem has established a fax connection. This response is used only when the fax mode is selected.
72
Technical Reference
The Serial Interface
The serial interface is a standard developed by the Electronic Industries Association (EIA). It defines the signals and voltages used when data is exchanged between a computer and a modem or serial printer.
The entire standard covers many more functions than are used in most data communications applications.
Data is transmitted between the devices over a shielded serial cable with a 25-pin male (DB-25) connector to the modem and a 25-pin, 9-pin, 8-pin, or custom-built connector to the computer.
The use of a shielded cable when connecting a modem to a computer is recommended to ensure minimal interference with radio and television.
Pin assignments are factory-set in the U.S. Robotics modem to match the standard DB-25 assignments in the following table. DB-9 connectors for IBM/AT-compatible computers should be wired at the computer end of the cable as shown in the DB-9 column.
73
Technical Reference
Serial Interface Pin Definitions
DB-25
7
8
5
6
3
4
1
2
12
20
22
DB-9
5
1
8
6
2
7
3
—
4
—
9
Circuit
AA
BA
BB
CA
CB
CC
AB
CF
SCF
CD
CE
Function
Signal Source
Computer/Modem
Chassis Ground
Transmitted Data
Received Data
Request to Send
Clear to Send
Data Set Ready
Signal Ground
Carrier Detect
Both
Computer
Modem
Computer
Modem
Modem
Both
Modem
Speed Indicate
Data Terminal Ready
Modem
Computer
Ring Indicate Modem
74
Regulatory Information
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 73/23/EEC:
•
EN 60950/A4 3/97
•
EN 41003 08/93
The ports on this modem have the following safety status:
•
Telephone line connector = TNV-2
•
All other ports = SELV
These definitions are classified as per safety standard: EN 60950/A4 3/97
•
SELV: Safety Extra Low Voltage
75
Regulatory
Operation of pan-European approved modems
If your particular modem has pan-European approval, as indicated by the approval label on the bottom of the modem being as shown below: then the following notice should be observed:
This equipment has been approved to CTR 21 for pan-European single terminal connection to the
Public Switched Telephone Network (PSTN).
However, due to differences between the individual PSTNs provided in different countries the approval does not, of itself, give an unconditional assurance of successful operation on every PSTN network termination point.
In the event of problems, you should contact your equipment supplier in the first instance.
76
Limited Warranty
HARDWARE: 3Com Corporation warrants its hardware products to be free from defects in workmanship and materials, under normal use and service, for the following lengths of time from the date of purchase from 3Com or its authorized reseller:
56K Faxmodem
Network Interface Cards
Other hardware products
* unless otherwise specified above
Spare parts and spares kits
Lifetime
Lifetime
One year*
90 days
If a product does not operate as warranted above during the applicable warranty period, 3Com shall, at its option and expense, repair the defective product or part, deliver to Customer an equivalent product or part to replace the defective item, or refund to Customer the purchase price paid for the defective product. All products that are replaced will become the property of 3Com. Replacement products may be new or reconditioned. Any replaced or repaired product or part has a ninety
(90) day warranty or the remainder of the initial warranty period, whichever is longer.
SOFTWARE: 3Com Corporation warrants that the software programs licensed from it will perform in substantial conformance to the program specifications therefor for a period of ninety (90) days from the date of purchase from 3Com or its authorized reseller. 3Com warrants the media containing software against failure during the warranty period. No updates are provided. 3Com's sole obligation with respect to this express warranty shall be (at 3Com's discretion) to refund the purchase price paid by Customer for any defective software products, or to replace any defective media with software which substantially conforms to applicable 3Com published specifications. Customer assumes responsibility for the selection of the appropriate applications program and associated reference materials. 3Com makes no warranty or representation that its software products will meet Customer’s requirements or work in combination with any hardware or applications software products provided by third parties, that the operation of the software products will be uninterrupted or error free, or that all defects in the software products will be corrected. For any third party products listed in the 3Com software product documentation or specifications as being compatible
77
3Com will make reasonable efforts to provide compatibility, except where the non-compatibility is caused by a "bug" or defect in the third party's product.
YEAR 2000 WARRANTY. In addition to the
Hardware Products Warranty and Software
Products Warranty identified above, 3Com warrants that all Heritage 3Com products sold or licensed to Customer on and after January 1, 1998 that are date sensitive will continue performing properly with regard to such date data on and after
January 1, 2000, provided that all other products used by Customer in connection or combination with the 3Com products, including hardware, software, and firmware, accurately exchange date data with the 3Com products, with the exception of those products identified at 3Com’s Web site,
http://www.3com.com, as not meeting this standard. A product is considered a “Heritage
3Com product” if it is a member of a product family which was manufactured by 3Com prior to its merger with
78
Limited Warranty
US Robotics Corporation. This Year 2000 limited warranty does not apply to Heritage US Robotics
Corporation products. If it appears that any such product does not perform properly with regard to such date data on and after January 1, 2000, and
Customer notifies 3Com before the later of April 1,
2000, or ninety (90) days after purchase of the product from 3Com or its authorized reseller,
3Com shall, at its option and expense, provide a software update which would effect the proper performance of such product, repair such product, deliver to Customer an equivalent product to replace such product, or if none of the foregoing is feasible, refund to Customer the purchase price paid for such product.
Any software update or replaced or repaired product will carry a Year 2000 Warranty for ninety
(90) days or until April 1, 2000, whichever is later.
OBTAINING WARRANTY SERVICE:
Customer must contact 3Com’s Corporate Service
Center or an Authorized 3Com Service Center within the applicable warranty period to obtain warranty service authorization. Dated proof of purchase may be required. Products returned to
3Com's Corporate Service Center must be preauthorized by 3Com with a Return Material
Authorization (RMA) number marked on the outside of the package, and sent prepaid and packaged appropriately for safe shipment, and it is recommended that they be insured. The repaired or replaced item will be shipped to Customer, at
3Com's expense, not later than thirty (30) days after receipt of the defective product by 3Com.
Dead- or Defective-on-Arrival
. In the event a product completely fails to function or exhibits a defect in materials or workmanship within the first forty-eight (48) hours of installation but no later than thirty (30) days after the date of purchase, and this is verified by 3Com, it will be considered deador defective-on-arrival (DOA) and a replacement shall
Limited Warranty be provided by advance replacement. The replacement product will normally be shipped not later than three (3) business days after 3Com’s verification of the DOA product, but may be delayed due to export or import procedures. When an advance replacement is provided and Customer fails to return the defective product to 3Com within fifteen (15) days after shipment of the replacement,
3Com will charge Customer for the replacement product, at list price.
3Com shall not be responsible for any software, firmware, information, or memory data of
Customer contained in, stored on, or integrated with any products returned to 3Com for repair, whether under warranty or not.
WARRANTIES EXCLUSIVE: IF A 3COM
PRODUCT DOES NOT OPERATE AS
WARRANTED ABOVE, CUSTOMER'S SOLE
REMEDY FOR BREACH OF THAT
WARRANTY SHALL BE REPAIR,
REPLACEMENT, OR REFUND OF THE
PURCHASE PRICE PAID, AT 3COM'S OPTION.
TO THE FULL EXTENT ALLOWED BY LAW,
THE FOREGOING WARRANTIES AND
REMEDIES ARE
79
Limited Warranty
EXCLUSIVE AND ARE IN LIEU OF ALL
OTHER WARRANTIES, TERMS, OR
CONDITIONS, EXPRESS OR IMPLIED,
EITHER IN FACT OR BY OPERATION OF
LAW, STATUTORY OR OTHERWISE,
INCLUDING WARRANTIES, TERMS, OR
CONDITIONS OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, AND
SATISFACTORY QUALITY. 3COM NEITHER
ASSUMES NOR AUTHORIZES ANY OTHER
PERSON TO ASSUME FOR IT ANY OTHER
LIABILITY IN CONNECTION WITH THE
SALE, INSTALLATION, MAINTENANCE OR
USE OF ITS PRODUCTS.
3COM SHALL NOT BE LIABLE UNDER THIS
WARRANTY IF ITS TESTING AND
EXAMINATION DISCLOSE THAT THE
ALLEGED DEFECT IN THE PRODUCT DOES
NOT EXIST OR WAS CAUSED BY
CUSTOMER'S OR ANY THIRD PERSON'S
MISUSE, NEGLECT, IMPROPER
INSTALLATION OR TESTING,
UNAUTHORIZED ATTEMPTS TO REPAIR OR
MODIFY, OR ANY OTHER CAUSE BEYOND
THE RANGE OF THE INTENDED USE, OR BY
ACCIDENT, FIRE, LIGHTNING, OR OTHER
HAZARD.
80
LIMITATION OF LIABILITY. TO THE
FULL EXTENT ALLOWED BY LAW, 3COM
ALSO EXCLUDES FOR ITSELF AND ITS
SUPPLIERS ANY LIABILITY, WHETHER
BASED IN CONTRACT OR TORT (INCLUDING
NEGLIGENCE), FOR INCIDENTAL,
CONSEQUENTIAL, INDIRECT, SPECIAL, OR
PUNITIVE DAMAGES OF ANY KIND, OR FOR
LOSS OF REVENUE OR PROFITS, LOSS OF
BUSINESS, LOSS OF INFORMATION OR
DATA, OR OTHER FINANCIAL LOSS ARISING
OUT OF OR IN CONNECTION WITH THE
SALE, INSTALLATION, MAINTENANCE, USE,
PERFORMANCE, FAILURE, OR
INTERRUPTION OF ITS PRODUCTS, EVEN IF
3COM OR ITS AUTHORIZED RESELLER HAS
BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES, AND LIMITS ITS
LIABILITY TO REPAIR, REPLACEMENT, OR
REFUND OF THE PURCHASE PRICE PAID, AT
3COM'S OPTION. THIS DISCLAIMER OF
LIABILITY FOR DAMAGES WILL NOT BE
AFFECTED IF ANY REMEDY PROVIDED
HEREIN SHALL FAIL OF ITS ESSENTIAL
PURPOSE.
DISCLAIMER: Some countries, states, or provinces do not allow the exclusion or limitation of implied warranties or the limitation of incidental or consequential damages for certain products supplied to consumers or the limitation of liability for personal injury, so the above limitations and exclusions may be limited in their application to you. When the implied warranties are not allowed to be excluded in their entirety, they will be limited to the duration of the applicable written warranty.
This warranty gives you specific legal rights which may vary depending on local law.
Limited Warranty
GOVERNING LAW: This Limited Warranty shall be governed by the laws of the State of
California, U.S.A. excluding its conflicts of laws principles and excluding the United Nations
Convention on Contracts for the International Sale of Goods.
3Com Corporation
5400 Bayfront Plaza
Santa Clara, CA 95052-8145
+1 (408) 764-5000
C
ONTACT DETAILS
Phone : +44 (0) 870 844 4546
Fax : +44 (0) 870 844 4547
BBS : +44 (0) 118 969 2200
E-Mail : [email protected]
WWW : http://www.3com.co.uk
81
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