3Com U.S. Robotics 56K Voice Command Reference Manual Download Page 113

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ESTING

THE

ONNECTION

This chapter contains information about:

■

Testing the Business Modem using AT&T

■

Testing the Business Modem using S-Register 16

Overview

Your modem can perform digital and remote digital loopback tests. You
can use these tests to check the operations of the transmitter and
receiver, or to locate a problem with a remote device or a telephone line.

Testing is done by sending the AT&T

command or by setting Register

S16. Only one test can be performed at a given time. If you send a test
command while the modem is in test mode, you'll receive an ERROR
message.

All loopback testing conforms to ITU-T Recommendation V.54.

Summary of Contents for U.S. Robotics 56K Voice

Page 1: ...http www 3com com 3Com OfficeConnect 56K Business Modem Command Reference Published January 1999...

Page 2: ...mputer Software as defined in DFARS 252 227 7014 June 1995 or as a commercial item as defined in FAR 2 101 a and as such is provided with only such rights as are provided in 3Com s standard commercial...

Page 3: ...ur Internet Service Provider 1 2 Windows NT 4 0 and Later 1 8 What you need 1 9 Configuring Your modem 1 9 Setting up RAS 1 9 Determining if TCP IP is installed 1 10 Installing TCP IP 1 10 Configuring...

Page 4: ...S Register 2 3 Getting a list of S Registers 2 4 Understanding bit mapped S Registers 2 4 3 MODES OF OPERATION Command and Online Modes 3 1 Entering Online Command Mode 3 2 Returning to Online Mode 3...

Page 5: ...g with RAM and NVRAM 5 2 Saving a Phone Number to NVRAM 5 2 Displaying S Register Value Information 5 3 Saving a Command String to NVRAM 5 3 Working with Flash Memory 5 3 Saving ROM Templates to NVRAM...

Page 6: ...9 1 Other Remote Access Commands 9 3 Accessing the Host 9 3 At the Guest Device 9 3 Viewing and Changing the Host s Configuration 9 4 Remote Configuration Commands 9 5 Quitting a Remote Access Sessio...

Page 7: ...4 Lower speed V Protocols 12 5 Error Control 12 5 Error Control Commands 12 5 V 42 Error Control 12 7 MNP Error Control 12 7 Error Control and Flow Control 12 7 Data Compression 12 8 V 42bis versus MN...

Page 8: ...5 2 Double characters are appearing on your monitor 15 3 After you dial the Business Modem reports NO CARRIER and then hangs up 15 3 Hear ringing but the Business Modem won t answer 15 3 The Business...

Page 9: ...g Decimal Values A 3 Default S Register Settings A 3 A complete list of S Registers A 5 B ALPHABETIC COMMAND SUMMARY Basic Command Set B 1 Ampersand Command Set B 5 Percent Command Set B 11 Octothorpe...

Page 10: ...FAX INFORMATION FOR PROGRAMMERS Fax Service Class 1 Commands G 1 FAX Service Class 2 0 Commands G 1 Fax Mode Flow Control Setting G 2 FCC Notice G 2 Notes G 2 H VIEWING LEDS I S REGISTERS S Registers...

Page 11: ...this guide follow the instructions in the release notes Finding Specific Information in This Guide This table shows the location of specific information in this guide If you are looking for informatio...

Page 12: ...rm of a command in uppercase and lowercase letters However you can abbreviate commands by entering only the uppercase letters and the appropriate value Commands are not case sensitive Screen displays...

Page 13: ...Compliance For information on Year 2000 compliance and 3Com products visit the 3Com Year 2000 web page http www 3com com products yr2000 html Words in italicized type Italics emphasize a point or den...

Page 14: ...4 ABOUT THIS GUIDE...

Page 15: ...ll not recognize your modem What You Need You need Windows 95 98 with Dial Up Networking installed to configure your modem for Windows 95 98 Configuring Your modem with Plug and Play Plug and Play mod...

Page 16: ...u use the latest version of the modem software and information INF file from the 3Com U S Robotics Web site http www usr com home online Installing the Latest Software See Chapter 3 Upgrading your Mod...

Page 17: ...o the Control Panel and double click on Add Remove Programs to open the Add Remove Programs Properties window 4 Click Windows Setup tab 5 Double click on Communications The following window appears 6...

Page 18: ...ed 4 Type a name for the connection and click Next 5 Type a phone number for the connection and click Next 6 You should see a message indicating that a new connection was created successfully 7 Click...

Page 19: ...Windows 95 98 1 5 9 On the My Connection window click Server Type and deselect the following Log on to Network NetBEUI IPX SPX Compatible...

Page 20: ...uble click My Computer and double click Dial Up Networking to display all the connections you can customize 2 Right click the icon you created and select Properties to display the My Connection proper...

Page 21: ...dress Click Specify an IP address and enter the IP address provided by your ISP Does not give you a specific IP address Click Server assigned IP address If your ISP Do this Gives you specific name ser...

Page 22: ...for Windows NT users CAUTION Before you use these procedures contact your ISP to determine if they have any special requirements For you to Use this connection Use a dial up connection to connect over...

Page 23: ...1 Go to Start Settings Control Panel Modems 2 Click Add 3 Check Don t detect my modem I will select it from a list 4 Click Next 5 Click Have Disk 6 Place the diskette or CD ROM that was packaged with...

Page 24: ...ols to find TCP IP Protocol Adapter 4 If TCP IP Protocol is listed skip to section Configuring a PPP Connection If TCP IP Protocol is NOT listed move to the next section Installing TCP IP To install T...

Page 25: ...address provided by your ISP 6 Enter the primary DNS and secondary DNS server IP addresses in the appropriate name server address boxes 7 If your ISP requests that you use a specific frame size select...

Page 26: ...any authentication including clear text Make sure only the necessary network protocols are selected In the Connect to window after you click Dial there should be no domain set This is only for logging...

Page 27: ...siness Modem and 25 mhz Business Modem you first must install the Macintosh 230K High Speed Script and then configure Open Transport PPP Installing the script 1 Download the USRARA HQX file This file...

Page 28: ...system responds with a proper speed Configuring Open Transport PPP Selecting the correct modem 1 Go to Apple Menu Control Panels Modem 2 In the Modems Window choose the port that your modem is connec...

Page 29: ...ol Panel TCP IP 2 In the TCP IP window select PPP in the Connect via drop down box 3 Set the Configure drop down box to Using PPP Server 4 Type in your internet service providers Domain Name Server Ad...

Page 30: ...Panels PPP 2 In the PPP window select Registered User 3 Type in your Internet Service providers login name and your password in the name and password boxes 4 Put the phone number that you dial to conn...

Page 31: ...0 bps it is recommended that you use a third party communications software package If You Are Using MS DOS Because there is no communications software built in to MS DOS you must install and run a thi...

Page 32: ...1 18 CHAPTER 1 CONNECTING TO YOUR ISP...

Page 33: ...rminal mode what you type is sent directly to the modem General rules for using AT commands You must follow some general guidelines to send AT commands to your modem Type AT before each command and pr...

Page 34: ...ming parameters redefinitions of selected ASCII characters and other configuration settings are stored Initially the S Register settings for each of the NVRAM templates are the same You can overwrite...

Page 35: ...anually CAUTION If you do not write an S Register setting with W the setting will be retained only until the next reset or power off Example Sending ATS0 2 changes the setting for S Register 0 to 2 Th...

Page 36: ...it mapped S Register uses one number to describe a collection of settings Bit mapping allows us to pack a lot of information in a small space Bit mapped registers are in the form of Sr b n where r is...

Page 37: ...Set the modem to Use this command Control the modem using AT commands Command Mode Escape Code Your modem set to revert to Command Mode when the Escape Code is used ATS14 0 0 Your modem to Disconnect...

Page 38: ...ata 6 Type 7 Wait for OK to appear before typing any data You can change the characters used to revert to Command Mode or the wait time by resetting Register S2 or S12 For more information about reset...

Page 39: ...transmitted on your screen you can use the ATFn command Example Sending ATF0 will allow you to see what you are typing in the display window You may see the term duplex used in place of online local e...

Page 40: ...you exit the program Example Sending AT FCLASS 1 allows you to receive faxes from fax machines Class 1 and Class 2 0 Fax Modes refer to standards set by the Electronic Industries Association Telecomm...

Page 41: ...in Data or Fax mode use the AT FCLASS command Whenever the modem is reset using the ATZ command or by turning the power off and then on it will reset to Data Mode If the modem returns a value of This...

Page 42: ...3 6 CHAPTER 3 MODES OF OPERATION...

Page 43: ...d phone number and execute dial options DO NOT use spaces or dashes ATD phone number Tone dial ATDT Pulse dial ATDP Pause for the length of time specified by S Register 8 The default is 2 seconds ATD...

Page 44: ...ditional command IMPORTANT With the exception of the above Dial options your modem will ignore any commands issued after the D in the same command string Call a device that can only originate calls It...

Page 45: ...onds then redial Make a maximum of 10 attempts To stop the repeating press any key during the pause between dial attempts If you press any key while the modem is dialing that dial attempt is canceled...

Page 46: ...nection If there is no response within 60 seconds the Business Modem hangs up For more information about adjusting the 60 second wait for connection time using S Register 7 see Appendix A S Registers...

Page 47: ...or making analog international calls above 1200 bps Handshaking options The ATBn command controls the handshake options Example Sending ATB1 will allow your modem to use Bell answer tone selecting HST...

Page 48: ...Detection Call Detection allows the modem to recognize whether an incoming call is analog data or fax Call Detection is an optional Service Class 2 0 feature and is also implemented by 3Com for Fax C...

Page 49: ...associated with the calling party s telephone number in addition to the Basic service information The information the Business Modem actually receives depends on the service type to which you ve subsc...

Page 50: ...5 TIME 2038 NMBR 8475550001 NAME U S ROBOTICS OK Using the CID command described below you can have the Business Modem send the information to your computer between the first and second RING messages...

Page 51: ...al An Example of Formatted caller ID presentation RING DATE 1015 TIME 2038 NMBR 8475550001 NAME U S ROBOTICS RING An Example of Unformatted caller ID presentation RING 801E01083130313532303338020A3730...

Page 52: ...er is associated with a different ring pattern and devices that recognize distinctive ring like the Business Modem can be set to answer only on certain incoming ring patterns For example a fax machine...

Page 53: ...seconds off C 0 4 second on 0 2 second off 0 4 second on 0 2 second off 0 8 second on 4 0 seconds off D 0 3 second on 0 2 second off 1 0 second on 0 2 second off 0 3 second on 4 0 seconds off For you...

Page 54: ...ical to that of other 3Com modems that do not support distinctive ring If only one ring type is enabled the Business Modem will recognize only the enabled ring type and ignore all others It will send...

Page 55: ...ry RAM nonvolatile random access memory NVRAM and Flash memory Memory type Applies to Loss of power will Command RAM The current settings Cancel any changes you make To save settings before resetting...

Page 56: ...e example above you would send AT N8 W to the modem The new default setting for your Business Modem will only allow a 14400 bps connection to a remote device To restore NVRAM factory defaults use the...

Page 57: ...ash memory You can use the Fn command to load one of the three configuration templates from Flash memory into current memory Example Sending AT F1 to your modem will load the Hardware Flow Control Tem...

Page 58: ...tings When the Business Modem is turned on it loads the settings stored in NVRAM By default these settings are that same as the F1 template You can save any of the three templates or save modified ver...

Page 59: ...to Command Display result codes ATQ0 NOT display result codes ATQ1 NOT display result codes while in Answer mode See Chapter 4 Modes of Operation for a description of modes ATQ2 Display result codes...

Page 60: ...nd A3 you won t be able to distinguish A2 from A3 codes For your modem to Command Display only connection rate AT A0 Display connection rate and ARQ result codes AT A1 Display connection rate ARQ resu...

Page 61: ...stands for Recommended Standard For your modem to Command Ignore the state of DTR and act as if DTR is always present Use this command with equipment that cannot provide DTR AT D0 If issued before co...

Page 62: ...odem Command To send the DSR signal at all times AT S0 Default When originating a call to send the DSR signal after dialing when the Business Modem detects the remote analog device s answer tone AT S1...

Page 63: ...ends a Carrier Detect CD signal in response to establishing a connection with another modem You can use the AT Cn command to control how the Business Modem sends the CD signal For your modem to Comman...

Page 64: ...7 4 CHAPTER 7 CONTROLLING EIA 232 SIGNALING...

Page 65: ...tion rates Serial port rates pertain to data transferred between your computer and the Business Modem Connection rates pertain to data transferred between the Business Modem and the device at the othe...

Page 66: ...cify using your communications software for example 38 4 Kbps when the Business Modem connects in ARQ mode If the connection is not under error control the Business Modem behaves as if it was set to B...

Page 67: ...y allow connections with remote devices that are operating at 14 4 Kbps To allow your modem to Set connection rate as Command Negotiate for the highest possible rate Variable AT N0 Connect only if the...

Page 68: ...ighest Possible Connect Speed The N command when used in conjunction with the U command allows you to limit the highest possible connect speed If a remote modem attempts to connect to your Business Mo...

Page 69: ...does not connect to your Business Modem at a range between the speeds designated by the N and U commands your Business Modem will not allow it to connect The link speed associated with the U argument...

Page 70: ...k speeds and their associated indexes Link Speed Index Highest 0 300 1 1200 2 2400 3 4800 4 7200 5 9600 6 12000 7 14400 8 16800 9 19200 10 21600 11 24000 12 26400 13 28800 14 31200 15 33600 16 28000 1...

Page 71: ...TE rate of your Business Modem has been increased to 230 kbps to enhance throughput This command is only supported on Business Modems attached to high speed serial cards 46666 31 48000 32 49333 33 506...

Page 72: ...8 8 CHAPTER 8 CONTROLLING DATA RATES...

Page 73: ...ou should be familiar with these terms before you continue Setting Up Remote Access At the Host Business Modem 1 Prepare to send AT commands by putting your communications software in Terminal Mode Lo...

Page 74: ...wo remote access passwords You can set two passwords to allow different levels of access to each Business Modem Example Sending AT P1 corn will allow a remote user to log in with the password corn The...

Page 75: ...ce has enabled remote access and is set to auto answer ATS0 1 Know the password if you will need one 2 Call the host device although it doesn t matter which device originates the call 3 After a connec...

Page 76: ...remainder of the connection When the host accepts the password the following message and prompt will appear on your screen Remote Access granted Remote You may not be prompted for a password If you a...

Page 77: ...ess Modem s serial port rate to 9600 bps If you have this access privilege You can use View only Any of the inquiry ATI commands View and Configure Any of the Business Modem commands except those that...

Page 78: ...not be restored to their previous settings when you send the host AT C1 After you make changes to the host s configuration the remote access prompt changes from Remote to Remote To change the data fo...

Page 79: ...C or typing ATO After you ve entered the password you can quit by sending one of these commands Before you disconnect issue the ATI5 command to the remote modem and check its S41 setting Make sure S4...

Page 80: ...9 8 CHAPTER 9 ACCESSING AND CONFIGURING THE BUSINESS MODEM REMOTELY...

Page 81: ...unts one administrative account for you and nine accounts for guest users The account profiles are stored in the host Business Modem s nonvolatile random access memory NVRAM There are two forms of Dia...

Page 82: ...y method Enable Dial Security Activate the Dial Security settings 1 Set up an account for yourself Use any of the 40 available accounts numbered 0 39 for your account Use the AT An command to set up u...

Page 83: ...e sure to remember your administrative password If you enable Dial Security and then forget your administrative password you To make the host Business Modem Command Example Hang up and then dial back...

Page 84: ...p an account you can modify each field independently If a field is to remain unchanged from its original setting just insert a comma as shown AT A1 Y The command above allows the guest user to supply...

Page 85: ...Autopass and Password prompting When using Autopass Prompting When using Password Prompting Both the host and guest devices are made by 3Com and have Dial Security enabled Guest devices don t have to...

Page 86: ...or power off the Business Modem Dial Security will be disabled If you need a reference when setting these command you can use the ATI10 command See Appendix B Alphabetic Command Summary for more info...

Page 87: ...Remote Configuration Dial Security accounts may be configured remotely See Configuring Dial Security Remotely at the end of this chapter For your modem to Command Access accounts by disabling local s...

Page 88: ...strator asked you to use See Setting Up Dial Security earlier in this chapter for instructions b You need to assign the password as your Autopass password Example Sending AT V PW3 will assign the pass...

Page 89: ...ur remote access password Dialing In From the Remote Site 1 From the remote site connect to the host using Dial Security Once a connection is made follow the instructions for beginning a remote access...

Page 90: ...ING If you do not use the ATZ command to end a remote access session Dial Security will remain disabled at the host and anyone dialing in to the host for remote access will have access to the ATI10 sc...

Page 91: ...r and one for data received from the phone line Flow control provides a system for stopping and starting transmission depending on how full the buffers are Flow Control s purpose is to prevent overfil...

Page 92: ...ffer is 90 full and then sending special characters in the data stream to stop the flow of data When the buffer drops back to 50 full the Business Modem sends special characters in the data stream to...

Page 93: ...rfere with XON XOFF signaling between the remote computer and remote device see AT I2 AT I1 Force the Business Modem to act on your XON XOFF commands but remove them from the data stream instead of pa...

Page 94: ...e system The error control protocol enables the devices to control the flow of data on the phone link In non ARQ mode a Business Modem set to AT I5 operates as though flow control were disabled AT I0...

Page 95: ...Disable transmit data flow control AT H0 Enable Hardware flow control Requires that your computer and software support Clear to Send CTS at the EIA 232 interface AT H1 Enable Software flow control Re...

Page 96: ...11 6 CHAPTER 11 FLOW CONTROL...

Page 97: ...ssible speed when they attempt to connect with another modem 56 Kbps If the remote device is not V 34 capable a connection is made using the highest compatible modulation scheme x2 V 34 V FC V 32 terb...

Page 98: ...e following conditions for an x2 connection to be made A digital connection at one end ISPs or other online services must have a digital connection to the public switched telephone network PSTN Most m...

Page 99: ...stablish speeds up to 56K downstream Other Protocols x2 x2 client modems can receive data at speeds up to 56 kbps and send data at V 34 speeds To use x2 the client x2 modem must connect to a server x2...

Page 100: ...tone which is the prevalent standard in the U S and Canada for connections at 2400 bps and lower At higher speeds the Business Modem also recognizes the ITU answer tones necessary for connecting with...

Page 101: ...in answering older V 32 modems at 9600 bps Use Register S28 to modify the duration of the extra tones used in V 32 negotiations in the rare instance that this may be necessary See Appendix A S Regist...

Page 102: ...atibility Formatting data frames Detecting errors using Cyclic Redundancy Checking CRC Retransmitting corrupt data frames The Business Modem is set at the factory to try for an error control connectio...

Page 103: ...ed before an acknowledgment is required MNP Error Control The Microcom Networking Protocol MNP is supported by the ITU T V 42 Recommendation MNP is based on special protocol frames If the remote devic...

Page 104: ...in the CONNECT message if the modem is set to A3 V 42bis versus MNP5 Data Compression Business Modems using V 42bis compression negotiate the following options and report them in the ATI6 display Dict...

Page 105: ...by the remote modem When transferring such files it s best to set the modem to K3 See the information in data compression This allows V 42bis compression to work dynamically with the compressed data b...

Page 106: ...sion of ZMODEM file transfer protocol For example certain public domain file transfer protocols have the following effects The protocols listed above further reduce throughput when an error control co...

Page 107: ...also be used for non ARQ connections Leave the Business Modem at its M4 and K1 settings for both error control and data compression YMODEM G is another good choice but never use it unless both the lo...

Page 108: ...12 12 CHAPTER 12 HANDSHAKING ERROR CONTROL DATA COMPRESSION AND THROUGHPUT...

Page 109: ...current settings product code and call duration Querying Here is a complete list of ATIn commands Common Inquiry Commands For your modem to display Command Current settings ATI4 NVRAM settings ATI5 Li...

Page 110: ...stores information about link operations When the call is ended you can request a diagnostic summary The duration of the last call or the real time is displayed depending on the modem clock setting Fo...

Page 111: ...and options D S Registers S and the octothorpe command set To see the remainder of the screen for any given command press any key For your modem to display Command A partial summary of the basic comma...

Page 112: ...13 4 CHAPTER 13 DISPLAYING QUERYING AND HELP SCREENS...

Page 113: ...tests You can use these tests to check the operations of the transmitter and receiver or to locate a problem with a remote device or a telephone line Testing is done by sending the AT Tn command or b...

Page 114: ...d Summary before testing If the modem is detecting errors and retransmitting the affected data your results will be invalid For your modem to Command End testing AT T0 Enter analog loopback AL mode an...

Page 115: ...end the test by sending ATH or ATZ Be careful though because ATZ resets the modem in addition to ending the test In either case the modem responds with OK If the modem sends an ERROR message you have...

Page 116: ...mputer interface 1 Send AT M0 N3S14 0 0 to the modem prepare for testing This command disables error control fixes the connection rate at 2400 bps and makes the Business Modem return to command mode w...

Page 117: ...end the Business Modem the escape code to bring it back to Command mode 4 Send AT T3 to the modem to enter Digital Loopback mode 5 Have the remote user type a short message It will be looped back by y...

Page 118: ...eyboard data sent to the modem by returning it over the phone lines and displaying it on your screen Granting a Digital Loopback Test Request AT T4 Using AT T4 causes the Business Modem to grant a rem...

Page 119: ...remote digital loopback mode and the MR status light flashes 5 Type a short message It will be looped back to your modem by the remote device and to your screen for verification The remote user will n...

Page 120: ...opback request For example older 3Com modems need to be set to S16 8 4 Send AT T7 to the modem The modem enters remote digital loopback mode and the MR status light flashes The Business Modem sends it...

Page 121: ...e RDL Testing Using a Built in Test Pattern S16 4 1 Send AT M0 N3S14 0 0 to the modem to prepare for testing This command disables error control fixes the connection rate at 2400 bps and makes the Bus...

Page 122: ...device to enter remote digital loopback mode The MR status light flashes during this operation 5 Type a short message It will be looped back to your Business Modem by the remote device and to your scr...

Page 123: ...tern Ending Testing That Uses the Test Pattern Pressing any character key cancels all tests and hangs up the Business Modem If you used Register S16 be sure to reset Register S16 and return to the err...

Page 124: ...14 12 CHAPTER 14 TESTING THE CONNECTION...

Page 125: ...T For Windows users make sure that you set the correct COM port and IRQ in your communications software and if applicable in Windows Control Panel Ports For Macintosh users make sure that you set the...

Page 126: ...t the Business Modem If so see the chapter about Controlling EIA 232 Signaling Make sure that the phone line from your wall jack connects to JACK port of the Business Modem Make sure the Business Mode...

Page 127: ...u finish the call Hear ringing but the Business Modem won t answer Look at the TR LED to make sure that your terminal or computer is sending a DTR signal via the EIA 232 interface Send ATI4 to the Bus...

Page 128: ...n may be one of the following Your computer may not support the higher serial port rate If this is the case fix your software rate at 9600 bps If you use memory resident programs TSRs Terminate and St...

Page 129: ...g on whether the connection is to be made with a facsimile device or a data device See Chapter 2 Modes of Operation for information on switching between Fax and Data modes Make sure the proper bit rat...

Page 130: ...er serial port rate If your computer doesn t have a 16550 UART set your communications software to use a slower serial port You can also try running the program on a different PC An idiosyncrasy of an...

Page 131: ...nty of packing material b Be sure to include your SRO number inside the package along with your name and address Put your return address and your SRO number on the shipping label as well c Ship the pa...

Page 132: ...15 8 CHAPTER 15 TROUBLESHOOTING...

Page 133: ...perating software which are made publicly available from our Web site BBS and ftp site Checking Your Business Modem s Software Version Issuing the ATI7 command produces the following information ati7...

Page 134: ...are web page Call the 3Com Bulletin Board Service BBS at 847 262 6000 From the main menu select Files Select area 5 USR Business Modem Download the newest Business Modem file with the extension ZIP Re...

Page 135: ...your modem using the XMODEM Checksum or XMODEM CRC protocol Since this is a test the modem s existing software is not erased 4 After you ve completed the test transfer successfully use your communicat...

Page 136: ...1 Power your modem off The power switch is in the rear right corner of the back panel 2 While holding in the RESET button between the RS 232 and USB jacks turn the modem back on 3 Start your communica...

Page 137: ...Register as a decimal value between 0 and 255 The modem however understands the decimal value as a collection of binary digits bits How bits are mapped to decimal values Bits can be mapped into decima...

Page 138: ...to bits by finding the largest decimal equivalent that is less than the decimal value Subtract the decimal equivalent and mark the equivalent bit 1 Continue until the decimal value is zero See the ex...

Page 139: ...as the one in Using Bits above Default S Register Settings The table below lists all default values for S Register settings S Registers Function NVRAM Default Setting S0 Auto Answer 0 S1 Counts store...

Page 140: ...dshake time 100 ms 8 S29 V 21 handshake time 100 ms 20 S33 Bit mapped functions 0 S34 Bit mapped functions 0 S38 Disconnect wait time sec 0 S41 Allowable remote log in attempts 0 S42 Remote Access ASC...

Page 141: ...r of seconds the Business Modem waits for a dial tone S7 60 Sets the number of seconds the Business Modem waits for a carrier May be set for much longer duration if for example the Business Modem is o...

Page 142: ...Level 3 used for testing Level 2 7 128 Hardware reset works like powering off and then on S14 1 Bit mapped register See the beginning of this appendix for information about setting bit mapped registe...

Page 143: ...with X and Y modem type File Transfer Protocols without using flow control The 128 byte option allows remote users with slower modems to stop your transmitted data from scrolling off their screens Wh...

Page 144: ...s S27 0 Bit mapped register See the beginning of this appendix for information about setting bit mapped registers Bit Value Result 0 1 Enable ITU T V 21 modulation at 300 bps for overseas calls In V 2...

Page 145: ...n to be pushed in order to dial try lengthening the duration of the extra tones Setting S28 to zero eliminates the extra tones resulting in a faster connect time if for example the Business Modem is s...

Page 146: ...login attempts exceeds the limit set by this register the Business Modem returns online and any further login attempts during the remainder of that connection are refused S42 126 Stores the ASCII dec...

Page 147: ...able 2400 symbol rate 1 2 Disable 2743 symbol rate 2 4 Disable 2800 symbol rate 3 8 Disable 3000 symbol rate 4 16 Disable 3200 symbol rate 5 32 Disable 3429 symbol rate 6 64 Disable Call Indicate CI 7...

Page 148: ...ables Disables V 90 S69 0 Bit mapped register See the beginning of this appendix for information about setting bit mapped registers Bit Value Result 0 1 Disable Plug and Play signaling 1 2 Disable Mul...

Page 149: ...ait 1 second before typing any data When you type the modem will either hang up or stay on line depending on how you set S14 Repeat command If you include the repeat command in the Dial string the mod...

Page 150: ...ccepted The maximum number of characters allowed is 36 including the AT prefix punctuation and spaces Optional parameters P Dial using pulses Accepted but ignored T Dial using tones Accepted but ignor...

Page 151: ...de echo OFF Your typing will not appear on the screen E1 Command mode echo ON Your typing will appear on the screen Command Function Fn Online local echo If ON a modem displays on your screen the data...

Page 152: ...command and online modes O0 Return online normal O1 Return online and retrain Use O1 if there were errors in a non ARQ data transfer Qn Enable or disable the display of result codes Q0 Display result...

Page 153: ...Q result codes A2 In addition to ARQ result codes display HST V 32 V FC or V 34 modulation indicator A3 In addition to ARQ and modulation indicators display an error control indicator LAPM HST MNP or...

Page 154: ...that are stored permanently in read only memory Appendix C Flow Control Templates lists the settings for each template To load a template into current memory enter AT Fn To write a template to NVRAM e...

Page 155: ...ting for ARQ mode I3 Hewlett Packard Host mode Applies only to modems attached to an HP mainframe that uses the ENQ ACK protocol Use in ARQ mode only I4 Hewlett Packard Terminal mode Applies only to m...

Page 156: ...tes in Normal mode as though it were set to M0 Nn Sets fixed link speed Nn UN Sets highest and lowest link speeds n 1 Variable rate The modem negotiates with the remote device for the highest possible...

Page 157: ...0000 bps n 27 41333 bps n 28 42666 bps n 29 44000 bps n 30 45333 bps n 31 46666 bps n 32 48000 bps n 33 49333 bps n 34 50666 bps n 35 52000 bps n 36 53333 bps n 37 54666 bps n 38 56000 bps n 39 57333...

Page 158: ...without the CTS signal S4 Send the computer DSR at the same time as CD S5 Send DSR normally and follow CTS with CD Tn Test the modem T0 End testing T1 Enter Analog Loopback AL mode Your modem will sen...

Page 159: ...characters long including any Dial command options Example AT Z2 555 6789 In the following example M0 no error control is inserted before the Dial command AT M0 DS2 This command functions differently...

Page 160: ...Cn Remote configuration control C0 Defer configuration changes until the call is ended Changes take effect for ensuing connections C1 Cancel configuration changes and restore the original configuratio...

Page 161: ...tain software programs For example T could be used in a security program to identify incoming tone security codes To return the modem to Command mode press any key or drop the computer s or terminal s...

Page 162: ...B 14 APPENDIX B ALPHABETIC COMMAND SUMMARY...

Page 163: ...uring dial through connect Result codes Q0 Enabled Verbal or numeric result codes V1 Verbal result codes Result code subset X7 Extended Includes all codes except VOICE Protocol response codes A3 Full...

Page 164: ...em the AT W string Error control M4 Normal error control Link rate select N0 Variable Pulse dialing type P0 U S Canada Record data hardware flow control R2 Enabled Data Set Ready S0 Always on Remote D...

Page 165: ...lt code subset X7 Extended Includes all codes except VOICE Protocol response codes A3 Full protocol codes Serial port rate select B1 Serial port rate fixed higher than connect rate Carrier Detect C1 N...

Page 166: ...h 8 Parity 0 None DTE rate Kbps 19 2 _ NVRAM Options Setting Description NVRAM Options Setting Description Handshake option B0 ITU T answer sequence Transmitter C1 Enabled Command mode echo E1 Enabled...

Page 167: ...software flow control I0 Disabled Analog data compression K1 Enabled Normal lines L0 Normal lines Error control M4 Normal error control Link rate select N0 Variable Record data hardware flow control...

Page 168: ...C 6 APPENDIX C FLOW CONTROL TEMPLATE...

Page 169: ...ring the default 2 seconds set in Register S6 7 BUSY Busy signal detect modem hangs up 8 NO ANSWER After waiting 5 seconds for an answer modem hangs up returned instead of NO CARRIER when the option i...

Page 170: ...AL TONE 7 BUSY 8 NO ANSWER 10 CONNECT 2400 11 RINGING 12 VOICE 13 CONNECT 9600 18 CONNECT 4800 20 CONNECT 7200 21 CONNECT 12000 25 CONNECT 14400 43 CONNECT 16800 85 CONNECT 19200 91 CONNECT 21600 99 C...

Page 171: ...odulation TCM V FC 28 8 26 4 24 21 6 19 2 16 8 14 4 kbps asynchronous TCM V 32 terbo 21 6 19 2 16 8 14 4 12 kbps 9600 7200 bps asynchronous TCM 4800 bps asynchronous Quadrature Amplitude Modulation QA...

Page 172: ...Frequency Shift Keying FSK This modulation Supports This Supports ITU T V 42 LAPM error control 1200 bps and higher MNP Levels 2 3 and 4 error control level 5 data compression 1200 bps and higher HST...

Page 173: ...al speeds in V 32 bis Data format Binary serial defaults to 8 bit word length no parity and 1 stop bit Word Length Parity 1 Bit Stop Bits 7 Even odd mark space 1 7 None 2 8 None 1 Flow Control Buffers...

Page 174: ...B 25 to DB 9 Cable DB 9 connectors for PCs should be wired at the computer end of the cable as shown below Minimum Requirements Some computer terminal equipment supports only a few of your modem s EIA...

Page 175: ...w control R2 Pin 4 DB 25 or Pin 7 DB 9 is required For Macintosh Computers If you re connecting your modem to a Macintosh computer we strongly recommend that you purchase a hardware handshaking cable...

Page 176: ...E 6 APPENDIX E TECHNICAL INFORMATION Serial Ports Macintosh modem These are the signals generated or accepted by your modem s serial port...

Page 177: ...BS 40 28 72 48 H 104 68 h 09 09 HT 41 29 73 49 I 105 69 I 10 0A LF 42 2A 74 4A J 106 6A j 11 0B VT 43 2B 75 4B K 107 6B k 12 0C FF 44 2C 76 4C L 108 6C l 13 0D CR 45 2D 77 4D M 109 6D m 14 0E SO 46 2E...

Page 178: ...19 EM 57 39 9 89 59 Y 121 79 y 26 1A SUB 58 3A 90 5A Z 122 7A z 27 1B ESC 59 3B 91 5B 123 7B 28 1C FS 60 3C 92 5C 124 7C 29 1D GS 61 3D 93 5D 125 7D 30 1E RS 62 3E 94 5E 126 7E 31 1F US 63 3F 95 5F _...

Page 179: ...ms FRS n 0 255 Wait for silence 10 ms FTM n 3 24 48 72 73 74 96 121 122 145 146 Transmit data with carrier FRM n 3 24 48 72 73 74 96 121 122 145 146 Receive data with carrier FTH n 3 24 48 72 73 74 96...

Page 180: ...learly contains in a margin at the top or bottom of each transmitted page or on the first page of the transmission the date and time it is sent and an identification of the business other entity or in...

Page 181: ...x operation ARQ On Is making a data connection using an error control protocol Off Is making a data connection without using an error control protocol AA On Is ready to accept calls Blinking Has detec...

Page 182: ...istration CD On Has detected a carrier from a remote device or carrier detect has been forced on Off Has not detected a carrier RS On Has detected the Ready to Send RTS signal from your computer Off H...

Page 183: ...e is 0 127 S4 10 Stores the ASCII decimal code for the Line Feed character Valid range is 0 127 S5 8 Stores the ASCII decimal code for the Backspace character A value of 128 255 disables the Backspace...

Page 184: ...1 Using the AT Command Set for instructions about how to set bit mapped registers Bit Value Result 0 1 Reset when DTR drops 1 2 Reverse normal Auto Answer operation On incoming RING enter Originate M...

Page 185: ...r of errors during a call 5 32 Set Backspace key to delete 6 64 Some earlier 2400 bps MNP modems not made by 3Com U S Robotics or Microcom were not fully compatible with the MNP protocol If you have d...

Page 186: ...s sent from the Business Modem to the computer or terminal Applies to ARQ mode only S22 17 Stores the ASCII code for the XON character S23 19 Stores the ASCII code for the XOFF character S24 150 Sets...

Page 187: ...n phase S28 8 Sets the duration in tenths of a second of the extra 3000 600 Hz answer tones sent during V 32 hand shaking This gives V 32 modems additional time to connect in V 32 mode before timing o...

Page 188: ...s the number of allowable remote access login attempts thus enabling or disabling remote access The default setting of zero allows no remote login attempts thus disabling remote access A value of 1 or...

Page 189: ...Symbol rate bit mapped register used primarily by 3Com Technical Support for debugging purposes Bit Value Result 0 1 Disable 2400 symbol rate 1 2 Disable 2743 symbol rate 2 4 Disable 2800 symbol rate...

Page 190: ...e V FC S58 0 Bit mapped register primarily used by 3Com Technical Support for debugging purposes Bit Value Result 0 1 Disable x2 1 2 Reserved 2 4 Reserved 3 8 Reserved 4 16 Reserved 5 32 Disable V 90...

Page 191: ...3Com Replacement products may be new or reconditioned 3Com warrants any replaced or repaired product or part for ninety 90 days from shipment or the remainder of the initial warranty period whichever...

Page 192: ...o 3Com s Corporate Service Center must be pre authorized by 3Com with a Service Repair Order SRO number marked on the outside of the package and sent prepaid and packaged appropriately for safe shipme...

Page 193: ...LUDING 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 A...

Page 194: ...unications Commission helpful The CIB Interference Handbook and The CIB Telephone Interference Bulletin These documents are available on the Internet through the FCC Compliance and Interference Bureau...

Page 195: ...e equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures Reorient or relocate the receiving antenna Increase the separation between the...

Page 196: ...ce may be extended by means of a certified connector assembly telephone extension cord The customer should be aware that compliance with the above conditions may not prevent degradation of service in...

Page 197: ...eives at the low frequency The transmit receive frequencies are the re verse of the calling modem which is in originate mode application application program A computer program designed to perform a sp...

Page 198: ...ission of defective blocks of data See HST MNP and V 42 baud rate The number of discrete signal events per second occurring on a communications channel Although not technically accurate baud rate is c...

Page 199: ...ternational Telecommunication Union ITU Telecommunication standards are now covered under Telecommunications Standards Sector TSS ITU T replaces CCITT For example the Bell 212A standard for 1200 bps c...

Page 200: ...In the ARQ protocol implemented in 3Com high speed modems the receiving modem accepts no more data until a defective block is received correctly data communications A type of communications in which c...

Page 201: ...o the screen for verification digital signals Discrete uniform signals In this manual the term refers to the binary digits 0 and 1 DSR See data set ready DTE See Data Terminal Equipment duplex Indicat...

Page 202: ...ched The added information usually includes a frame number block size data error check codes and Start End indicators file transfer protocol FTP A TCP IP application that allows users of an internet t...

Page 203: ...r computer s expansion bus IP Internet Protocol IPX Novell s Internet Packet Exchange protocol IRQ See interrupt request ISA See Industry Standard Architecture ITU T International Telecommunication Un...

Page 204: ...anual originate Used when equipment other than the modem does the dialing In such installations the modem does not respond to AT commands but when taken off hook immediately goes into call originate m...

Page 205: ...character even or odd depending on which type of parity is used Plug Play ISA A variation of the standard ISA bus that attempts to automate the troublesome process of resolving the IRQ and COM port c...

Page 206: ...al Standard Order Code USOC standard for wiring a single line two wire phone network interface passing tip and ring signals typically from the public switched network ROM See Read Only Memory Serial L...

Page 207: ...essor Keyboard entries go directly to the modem whether the entry is a modem command or data to be transmitted over the phone lines Received data is output directly to the screen The more popular comm...

Page 208: ...communications Among other things V 25 specifies an answer tone different from the Bell answer tone All 3Com modems can be set with the B0 command so that they use the V 25 2100 Hz tone when answerin...

Page 209: ...of ITU T V 42 that defines a specific data compression scheme for use with V 42 error control V Fast Class V FC Proprietary modulation scheme developed by Rockwell International for data communication...

Page 210: ...14 GLOSSARY...

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