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12

F

LOW

 

CONTROL

This chapter contains information about

■

Hardware and software flow control

■

Received-data flow control

■

Transmit-data flow control

Overview

The Courier V.Everything modem has two buffers, one for data 
transmitted from your computer, and one for data received from the 
phone line.

Flow control provides a system for stopping and starting transmissio
depending on how full the buffers are. Flow control’s purpose is to 
prevent overfilling the buffers, which may cause data to be lost.

We recommend that you use hardware flow control. If you do, 
depending on your communications software, you will also need to 
enable hardware flow control in your communications software.

Summary of Contents for Courier

Page 1: ... http www 3com com CourierTM V Everything Modem Command Reference Part No 1 024 2129 01 Published June 2000 ...

Page 2: ...or on the removable media in a directory file named LICENSE TXT or LICENSE TXT If you are unable to locate a copy please contact 3Com and a copy will be provided to you UNITED STATES GOVERNMENT LEGEND If you are a United States government agency then this documentation and the software described herein are provided to you subject to the following All technical data and computer software are commer...

Page 3: ...Dial Up Networking is Installed 1 3 Step Two Installing Dial Up TCP IP Support1 Step Three Setting Up a Connection to Yo ur ISP1 5 Step Four Customizing the TCP IP Sett ings1 7 Windows NT 4 01 9 1 9 What you ne ed1 10 Configuring Your mo dem1 10 Setting up RA S1 10 Determining if TCP IP is installe d1 1 Installing TCP I P1 11 Configuring a PPP connectio n1 1 Configuring a SLIP connect ion1 1 Troub...

Page 4: ...ur Courier V Everything Modem s Software Ve rsion3 1 Getting New Operating Softwa re3 2 Sending New Software to your mod em3 2 If Your Modem Doesn t Respon d3 3 Remote Flash 3 3 MODES OF OPERATION Command and Online M odes4 1 Entering Online Command Mode4 2 Returning to Online M ode4 2 Controlling Local Ec ho4 2 Command Mode Local Echo 4 2 Online Mode Local Echo4 3 Data and Fax Mode s4 3 DIALING A...

Page 5: ...rt5 9 Command s5 1 Result Code s5 12 WORKING WITH MEMORY Overview 6 1 6 2 Working with RAM and NVRA M6 2 Saving a Phone Number to NVR AM6 2 Displaying S Register Value Informatio n6 3 Saving a Command String to NV RAM6 3 Programming the Voice Data switch 6 3 Working with Flash Memory 6 4 Saving ROMTemplates to NVRAM 6 4 Default Settin gs6 5 CONTROLLING RESULT CODE DISPLAYS Result Code Display Comm...

Page 6: ...mma nds9 5 Quitting a Remote Access Sessi on9 7 CONTROLLING DATA RATES Overview 10 1 Serial Port Rates 10 1 Connection Ra tes10 3 Controlling Link Speeds with N a nd U10 4 Controlling Link Spe eds10 4 Specifying the Connect Sp eed10 4 10 4 Limiting a Range of Possible Connect Spe e ds10 4 N and U Command Val ues10 5 Configuring the High Speed L ED10 6 Setting DTE Rate to 230 K bps10 7 DIAL SECURIT...

Page 7: ...w Contro l12 3 Transmit Data Flow Contro l12 5 HANDSHAKING ERROR CONTROL DATA COMPRESSION AND THROUGHPUT Handshakin g13 1 Selective Reject 1 3 1 Attaining Speeds Above 28 8 Kbp s13 2 Attaining 56 K Connectio ns13 2 Controlling the V 8 Call Indicate Tone13 2 V 34 13 3 V 90 Capabilitie s13 3 Other Protocols 13 3 x2 13 3 Fast Class V FC Handshakin g13 3 HST 13 4 USR V 32terbo to USR V 32ter bo13 4 Lo...

Page 8: ... T 815 4 Digital Loopback Testing AT T3 15 5 15 5 Remote Digital Loopback Testing AT T6 AT T7 15 6 Granting a Digital Loopback Test Request A T T4 15 6 Canceling All Digital Loopback Test Requests T5 15 6 Testing Using Keyboard Data AT T6 15 7 Testing Using a Built inTest Pattern AT T7 15 8 DEDICATED LEASED LINE AND SYNCHRONOUS APPLICATIONS Overview 16 1 Requirement s16 2 A Device with a Synchrono...

Page 9: ...s up 17 3 Hear ringing but the Courier V Everything modem won t an swer17 The CourierV Everything modem acts as though a data link has been established but no call was receive d 17 3 The CourierV Everything modem behaves as if Enter were pressed when you don t press any keys 17 3 Problems that Occur After Connect ing17 4 Your screen displays random or garbage chara cters17 4 Many CRC errors 1 7 4 ...

Page 10: ...c Command S etB 1 Ampersand Command SetB 5 Percent Command Set B 12 Octothorpe Command S etB 1 FLOW CONTROL TEMPLATE Hardware Flow Contro lC 1 Software Flow control C 3 No Flow Contro lC 4 RESULT CODE MEANINGS AND SETS Result Code Meanin gsD Result Codes Sets for Xn Values D 2 New Connect Message sD 3 V 25BIS REFERENCE Command sF 1 Dial Options F 2 Result Code sF 2 Commands and Result Codes NOT Su...

Page 11: ...ASCII CHART FAX INFORMATION FOR PROGRAMMERS Fax Service Class 1 Comman dsH 1 FAX Service Class 2 0 Comman dsH 1 Fax Mode Flow Control Setti ngH 2 FCC Noti ceH 2 Notes H 2 GLOSSARY ...

Page 12: ......

Page 13: ...ide Table 1 Notice Icons Icon Notice Type Description Information note Important features or instructions Caution Information to alert you to potential damage to a program system or device Warning Information to alert you to potential personal injury Table 2 Text Conventio n Convention Description Syntax The word syntax means you must evaluate the syntax provided and supply the appropriate values ...

Page 14: ...the screen The words enter and type When you see the word enter in this guide you must type something and then press the Return or Enter key Do not press the Return or Enter key when an instruction simply says type continued Key names Key names appear in text in one of two ways Referred to by their labels such as the Return key or the Escape key Written with brackets such as Return or Esc If you m...

Page 15: ...5 98 will not recognise your modem What You Need You need Windows 95 98 with Dial Up Networking installed to configure your modem for Windows 95 98 ConfiguringYour modem with Plug and Play Plug and Play mode allows Windows 95 98 to automatically detect your modem and determine which modem configuration file called an INF file to use Follow the steps below to install the INF file for Windows 95 98 ...

Page 16: ...ECTING TO YOUR ISP 3 When the following window appears insert your Connections CD ROM change the default drive in Copy Manufacturer sfiles from to D or the correct path of your CD ROM and click OK to install the INF file ...

Page 17: ...a Networks LANs using Windows 95 98 Dial U Networking To access Internet Service Providers ISPs or remote LANs you must do the following Step One Determine if Dial Up Networking is Installed 1 Click Start Settings Control Pane 2 On the Control Panel double click Network The Network window will appear 3 Return to the Control Panel and double click Add Remove Programs to open the Add Remove Programs...

Page 18: ...tep Two Installing Dial Up TCP IP Support 1 Click Start Settings Control Panel 2 On Control Panel double click the Network to display the Network window 3 Determine if the TCP IP Dial Up Adapter is installed IF TCP IP Dial Up Adapter Do this Is not listed Click Add Protocol Microsoft TCP IP OK Insert your Windows 95 98 Setup diskette or CD ROM when you are prompted and Windows 95 98 installs TCP I...

Page 19: ... Select the correct modem if not already selected 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 Finish Is listed Go to Step Three Setting Up a Connection to Your ISP below IF TCP IP Dial Up Adapter Do this ...

Page 20: ...con you have just created an click the right mouse button Select Properties on the menu to display the following window The following screen may vary slightly depending on the version of Windows 95 98 you are using 9 On the My Connection window click the ServerType tab and deselect the following Log on to Network NetBEUI IPX SPX Compatible ...

Page 21: ...y Computer and double click Dial Up Networking to display all the connections you can customise 2 Right click the icon you created and select Properties to display the My Connectio properties window 3 On the My Connection properties window click the ServerType tab 4 Click TCP IP Settings If your ISP Do this Gives you a specific IP or Domain Name server addresses Go to Step Four Customising TCP IP ...

Page 22: ...s you a specific IP address 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 server addresses Click Specify name server addresses and enter the server address es provided by your ISP Does not give you specific name server addresses Click Server assigned serv...

Page 23: ...P account Your ISP s telephone number Does your ISP supply a static or dynamic IP address Your ISP s primary and secondary DNS servers INF file for Windows NT ConfiguringYour modem Since Windows NT is not Plug and Play compliant it is necessary to install the modem in Modem Properties For you to Use this connection Use a dial up connection to connect over the Internet SLIP only allows you to conne...

Page 24: ...lete Windows NT will request that yo restart your computer Select Yes Setting up RA 1 Right click the Network Neighborhood icon on your desktop and select Properties 2 Click the Services tab 3 Select Remote Access Service and click Properties 4 Click Add 5 Select your Courier V Everything modem s COM port and click OK 6 Highlight your Courier V Everything modem and click Configure 7 Select the fun...

Page 25: ...rotocol from the list Configuring a PP connection To configure the CourierV Everything modem for a PPP connection perform the following actions 1 Go to Start Programs Accessories Dial Up Networking 2 Click New 3 Select the Server tab and select PPP in the Dial up server type box 4 Select TCP IP 5 Deselect NetBEUI and IPX 6 If you are connecting to an ISP uncheck Enable PPP LCP Extensions If you ar...

Page 26: ...ot than Win95 Dial U Networking there are a finite number of problems that one runs into on a daily basis and the majority of these are caused by misconfiguration Most connection problems can be solved by following these steps In the Basi tab make sure that the phone book entry settings are correct Make sur Use Telephony Dialing Properties is unchecked Make sur Use another port if busy is unchecke...

Page 27: ...install the communications software package that is included on the Connections CD ROM Because Windows Terminal only supports speeds up to 19200 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 yo must install and run a third party communications software package t operate your mo...

Page 28: ...1 14 CHAPTER 1 CONNECTING TO YOUR ISP ...

Page 29: ...erminal mode what you type is sent directly to the modem General rules for usingAT commands You must follow some general guidelines to send AT commands to your modem Type AT before each command and press Enter after each command The exceptions are A A and which require neither AT nor Enter Leave zeroes off the end of AT commands A missing numeric parameter is assumed to be a zero For example ATE i...

Page 30: ...imin 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 an S Register s stored value See the default values listed in Appendix A S Registers for a complete listing of the initial settings AT Attention a command follows K3 Disable MNP5 data compression use ...

Page 31: ...ly 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 This setting will cause the Courier V Everything modem to answer in Auto Answer Mode on the second ring In the command ATSr n r is the register s number and n is a decimal value from 0 255 unless otherwise i...

Page 32: ...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 the bit mapped register b is the bit n is 0 off or 1 on See Appendix A S Registers to see how bits are mapped into decimal values and for information about setting bit mapped S Registers To display Co...

Page 33: ...our terminal screen ati7 3Com Courier V Everything Configuration Profile Product type US Canada External Product ID XX345300 Options HST V32bis Terbo VFC V34 x2 V90 Fax Options Class 1 Class 2 0 Clock Freq 25 Mhz Flash ROM 1024k Ram 256k Supervisor date 12 16 99 DSP date 12 14 99 Supervisor rev 9 9 9 DSP rev 9 9 9 DAA rev 0012 Serial Number 000000000001 OK Check the Supervisor and Digital Signal P...

Page 34: ... settings if necessary so you can send AT to your modem and get an OK response 2 Enter ATXMODEM The modem should respond as follows atxmodem Firmware Update Options 1 Read firmware 2 Write firmware ESCape Exits 3 Select 2 to begin updating the code The modem will respond with Ready to receive firmware update 4 Send the file to your modem using the XMODEM Checksum or XMODEM CRC protocol 5 After the...

Page 35: ...ype AT and press Enter If the CourierV Everything modem reports bootmodem it is corrupt Issue the ATXMODEM command and repeat the flash process found on the previous page 3 Power your modem off 4 Set the DIP switches to their previous settings 5 Power your modem on Remote Flash In order to upgrade the modem located at a remote site you need to ensure that the remote modem is enabled for remote acc...

Page 36: ...3 4 CHAPTER 3 UPGRADING YOUR MODEM ...

Page 37: ... the escape code will return the Courier V Everything modem to Command Mode or hang up To be able to change operating modes without losing connections set DIP switch 9 down Command Mode Escape Code Your modem set to revert to Command Mode when the Escape Code is used DIP switch 9 DOWN Your modem to Disconnect when the Escape Code is used DIP switch 9 UP Return to your connection after an Online Co...

Page 38: ...hese S Registers see Appendix A S Registers Returning to Online Mode There are two ways to return online using the ATOn command Example Sending ATO1 will allow you to resynchronise if you experienced errors during a non ARQ data transfer Controlling Local Echo There are two local echo settings one for Command Mode and one for Online Mode Command Mod Local Echo You can configure your modem to displ...

Page 39: ...software manual The modems default operating mode is Data Mode Most fax software automatically switches the device to Fax mode when you run the program and resets the device to Data mode when you exit the progra Example Sending AT FCLASS 1 allows you to receive faxes from fax machines As the modem transmits data to a remote system Command The modem sends a copy of the data to the screen Online loc...

Page 40: ...d for computer faxmodem interface Class 2 0 Fax Mode refers to the extended computer faxmodem interface If you are not sure whether your modem is 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 indicates 0 Data Mode 1 Class 1 Fax Mode 2 0 Class 2 0...

Page 41: ...fied 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 Comma Pause for 125 milliseconds ATD Slash Wait for a second dial tone before continuing dialing This command only works only if the X3 or higher command has been issued see Chapter 7 Controlling R...

Page 42: ...dditional 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 forces the modem to dial out at the answer frequency or Reverse frequencies You can put the R either before or after the number ATDR Display different sets of result codes See Chapter 7 Controlling ...

Page 43: ...alls Dial a number wait 60 seconds for a connection and then hang up Wait two seconds 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 but the cycle will continue Dial the last dialed number and repeat it just as the command does Also can be used to repe...

Page 44: ... response within 60 seconds the Courier V Everything mode hangs up For more information about adjusting the 60 second wait for connectio time using S Register 7 see Appendix A S Registers When a call is disconnected the Courier V Everything modem hangs up and returns the NO CARRIER result code If S0 0 Auto Answer is disabled To determine if Auto Answer is NOT disabled send the comman ATI4 and be s...

Page 45: ... AT Gn command only applies to analogue international calls at 240 or 1200 bps If you set G2 you must also sen ATB0 to the modem This setting allows the Courier V Everything modem to answer all calls from overseas If you want your modem Command To answer all V 34 type calls as well as calls from abroad use ITU T formerly CCITT answer sequence ATB0 Default NOT to answer V 34 type calls Use Bell ans...

Page 46: ...the date and time of the call and the calling party s telephone number Extended service provides the billing name associated with the calling party s telephone number in addition to the Basic service information The information the Courier V Everything modem actually receives depends on the service type to which you ve subscribed the information that the calling party s telephone company provides ...

Page 47: ...R 8475550001 NAME 3Com OK Using the CID command described below you can have the Courier V Everything modem send the information to your computer between the first and second RING messages The Caller ID information is displayed only once RING DATE 1015 TIME 2038 NMBR 8475550001 NAME 3Com RING The information remains in memory until either you reset the modem or until it receives another valid Call...

Page 48: ...n of the Caller ID signal An Example of Formatted Caller ID presentation RING DATE 1015 TIME 2038 NMBR 8475550001 NAME 3Com RING An Example of Unformatted Caller ID presentation RING 801E01083130313532303338020A37303835353530303031070C552E532E 524F424F5449435322 RING Commands The following table describes the AT CID n settings Caller ID Action Command Disable Caller ID detection and reporting AT C...

Page 49: ...gnment of multiple phone numbers to one line Each phone number is associated with a different ring pattern and devices that recognise distinctive ring like the Courier V Everything modem can be set to answer only on certain incoming ring patterns For example a fax machine answering machine telephone and modem could all share the same line Each device would have its own phone number and respond onl...

Page 50: ...g type is enabled the CourierV Everything modem will recognise only the enabled ring type and ignore all others It will send the result code RING only when it detects the ring type that s enabled Ring Description A 1 2 to 2 0 seconds on 4 0 seconds off B 0 8 second on 0 4 second off 0 8 second on 4 0 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 ...

Page 51: ...ns Ring Description A Telstra DR0 0 4 second on 0 2 second off 0 4 second on B Telstra DR3 0 2 second on 0 2 second off 0 4 second on C Telstra DR6 0 2 second on 0 2 second off 0 2 second on 0 2 second off 0 4 second on D Telstra DR7 0 2 second on 0 2 second off 0 2 second on 0 2 second off 0 2 second on Ring Description A 0 4 second on 0 2 second off 0 4 second on B 0 4 second on 0 2 second off 1...

Page 52: ...5 12 CHAPTER 5 DIALING ANSWERING AND HANGING UP Result Codes Verbal Numeric RING A 170 RING B 171 RING C 172 RING D 173 RING E 174 ...

Page 53: ...mory RAM nonvolatile rando 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 the modem use W See the section Working with RA for more detailed information ATI4 NVRAM Saved settings any configurations you can store retrieve and change NOT affect your settings ATI5 Flash Three ...

Page 54: ...om the example above you would send AT N8 W to the modem The new default setting for your CourierV Everything modem will only allow a 14400 bps connection to a remote device To restore NVRAM factory defaults use the AT Fn command See Appendix B Alphabetic Command Summar for more information on setting Fn Saving a Phone Number to NVRA CAUTION Do not include modem commands in AT Zn s Example To stor...

Page 55: ...gramming th Voice Data switch After storing a command to NVRAM you can program the voice data switch to execute the stored command string when pressed The function of the voice data switch is determined by the setting of S Register 32 1 Open your communications software program 2 Store a command to NVRAM using the AT ZC string command see the table above 3 Send ATS32 9 to your modem This command w...

Page 56: ...atio templates or prepared sets of commands in Flash 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 ControlTemplate into RAM Memory DIP switch settings override AT commands at power on You can set DIP switch 10 to ON and reset the Courier V Everything modem to l...

Page 57: ...efault these settings are that same as the F1 template You can save any of the three templates or save modified versions of them in NVRAM for use as power on defaults See Appendix C Flow Control Templates for a complete listing of the default values For your modem to Command Example Display NVRAM settings F1 settings ATI5 ATI5 Substitute a template other than F1 AT F2 W AT F2 W Save modified versi...

Page 58: ...6 6 CHAPTER 6 WORKING WITH MEMORY ...

Page 59: ...2 overrides Vn setting and DIP switch 7 overrides the S14 1 n setting If you want the modem 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 in numeric form ATV0 Display result codes in verbal form ATV1 Display result codes when originating answering...

Page 60: ... be compatible with some software For your modem to Command NOT display ARQ result codes This setting pertains only to the display of codes and not to ARQ function AT A0 Display ARQ result codes If the CourierV Everything modem is set to X0 and the connection rate is 1200 bps 56 Kbps a result code is displayed AT A1 Display modulation indicators HST V32 VFC V34 or DIGITAL If your software cannot h...

Page 61: ...mmended 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 Enter online Command Mode during a call by dropping DTR If issued before connecting with another device Most communications software packages have a method for toggling DTR Refer to your software s manual for details AT D1 Respond norm...

Page 62: ...modem will not accept commands until your computer sends a DTR signal The call will end when the DTR signal is dropped To change the DTR recognition time set S Register 25 See Appendix A S Registers for more information AT D3 For your modem to Command For your modem 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 Couri...

Page 63: ...n with another modem You can use the AT Cn command to control how the CourierV Everything modem sends the CD signal DIP switch 6 overrides the Dn setting at power on or reset To send DSR normally with CTS after sending CD In order to change the DSR pulse time in 20 second increments set S Register 24 See Appendix B Alphabetic Command Summary AT S5 For your modem Command For your modem to Command H...

Page 64: ...8 4 CHAPTER 8 CONTROLLING EIA 232 SIGNALING ...

Page 65: ...ould be familiar with these terms before you continue Setting Up Remote Acces At the Host Courier V Everything Modem 1 Prepare to send AT commands by putting your communications software in Terminal Mode Local The device that is directly connected to the computer you are using Remote The device at the other end of a telephone connection Host The CourierV Everything mode that will be accessed and c...

Page 66: ...apter 16 Dedicated Leased Line and Synchronous Applications 3 Set one or two remote access passwords You can set two passwords to allow different levels of access to eac Courier V Everything modem Example Sending AT P1 corn will allow a remote user to log in wit the password corn The user can view and change the Courier V Everything modem s configuration Remote access passwords can be up to eight ...

Page 67: ...st device 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 connection is established do this a Pause 4 seconds b Type 4 tildes c Pause 4 seconds The administrator of the host device can change the remote access character using S Register 42 and the pause dur...

Page 68: ...e 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 aren t passwor security is not active The following prompt appears on your screen after you type the four tildes Remote Access granted query only Remote During a remote access session the maximum numb...

Page 69: ...thing 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 CourierV Everything mode commands except those that cannot be used while online for example ATD or ATA You can also use remote configuration commands See the next section for examples To change the host CourierV Everything modem s serial p...

Page 70: ... will 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 format to Command No Parity 8 data bits AT F0 Mark parity 7 data bits AT F1 Odd Parity 7 data bits AT F2 Even parity 7 data bits AT F3 For your modem to Command Defer configuration changes to when ...

Page 71: ...rl 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 S41 is set for a value of 1 or greater If S41 is set to 0 when you disconnect you will not be able to access the remote modem again To prevent this sendATS41 1 W before yo disconnect To end the remote...

Page 72: ...9 8 CHAPTER 9 ACCESSING AND CONFIGURING THE COURIER V EVERYTHING MODEM REMOTELY ...

Page 73: ...le connection rates Serial port rates pertain to data transferred between your computer and the CourierV Everything Connection rates pertain to data transferred between the Courier V Everything modem and the device at the other end of a connection Serial Port Rates You set a fixed serial port rate to get the highest possible throughput an the best performance Set a variable rate to allow the Couri...

Page 74: ...communications software for example 38 4 Kbps when the Courier V Everything modem connects in ARQ mode If the connection is not under error control the Courier V Everything modem behaves as if it was set to B0 and switches its serial port rates to match the connection rate of each call Fixed for ARQ calls and AT B2 To implement this feature first set your software to the desired rate Then send AT ...

Page 75: ...y See below Fixed AT N1 AT N16 To connect at this rate Command To connect at this rate Command 300 bps AT N1 33 333 Kbps AT N21 1200 bps AT N2 34 666 Kbps AT N22 2400 bps AT N3 36 0 Kbps AT N23 4800 bps AT N4 37 333 Kbps AT N24 7200 bps AT N5 38 666 Kbps AT N25 9600 bps AT N6 40 0 Kbps AT N26 12 0 Kbps AT N7 41 333 Kbps AT N27 14 4 Kbps AT N8 42 666 Kbps AT N28 16 8 Kbps AT N9 44 000 Kbps AT N29 1...

Page 76: ...mote modem attempts to connect to your Courier V Everything modem at a speed different from N your Courier V Everything modem will not allow it to connect For a complete list of connect speeds see the table in section N and Command Values Limiting a Range of Possible Connect Speeds By setting N and U values you can limit the range of speeds at which your CourierV Everything modem connects If a rem...

Page 77: ...s an their associated indexes If U And N Then your modem Equals zero Equals zero Connects at the highest possible speed Equals zero Is greater than zero Connects at the N speed only Is greater than zero Is greater than zero and greater than U Connects at the highest possible speed in the range from U to N Is greater than zero Equals zero Not allowed Link Speed Index Highest 0 300 1 1200 2 2400 3 4...

Page 78: ... S69 setting to configure the HS High Speed LED 28000 17 29333 18 30666 19 32000 20 33333 21 34666 22 36000 23 37333 24 38666 25 40000 26 41333 27 42666 28 44000 29 45333 30 46666 31 48000 32 49333 33 50666 34 52000 35 53333 36 54666 37 56000 38 57333 39 Link Speed Index To do this Command Configure the HS LED to turn red when your modem reaches speeds over 33 3 kbps ATS69 12 ...

Page 79: ...e DTE rate of your Courier V Everything modem has been increased to 230 kbps to enhance throughput Your modem must be attached to a serial port capable of this speed to achieve this rate This command is only supported with modems attached to high speed serial cards ...

Page 80: ...10 8 CHAPTER 10 CONTROLLING DATA RATES ...

Page 81: ... administrative account for you and nine accounts for guest users The account profiles are stored in the host CourierV Everything modem s nonvolatile random access memory NVRAM There are two forms of Dial Security each will be explained later in this chapter Autopass Password Promptin Local The device that is directly connected to the computer you are using Remote The device at the other end of a ...

Page 82: ...10 available accounts numbered 0 9 for your account Use the AT An command to set up user accounts See the figure below for the five fields to concern yourself with The AT An command is automatically written to NVRAM It does not require you to send W WARNING Do not insert spaces between commas or between fields and commas Spaces will invalidate the command AT A0 password y y n 5551000 A command Acc...

Page 83: ...iles unless you enter the correct administrative password To make the host Courier V Everything modem Command Example Hang up and then dial back a guest device at a specified number Expect a pause of approximately 1 5 minutes before the modem dials back You cannot alter the duration of the pause AT A0 password y y n 1 area code and phone number AT A0 corn y y n 1 8 475555555 Prompt you to enter a ...

Page 84: ...w their passwords and the log in procedure Modifying Accounts After you have set up 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 a dialback number that is different from the one stored in the original account record 4 Enable Local Security WARNING...

Page 85: ...w is a comparison between 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 support 3Com Dial Security The connection between the Courier V Everything modem or modems is under V 42 error control See Appendix B Alphabetic Command Summary for informati...

Page 86: ...more information about theATI10 command 7 Send ATZ or ATZ to activate the Dial Security settings For all CourierV Everything modems except the PC card version make sure that DIP switch 10 is OFF so the modem loads the settings stored in NVRAM If DIP switch 10 is ON the settings in ROM F0 are loaded disabling dial security You can retreive the dial security settings by setting DIP switch 10 OFF and...

Page 87: ...r example ATI10 to view accounts an ACCESS DENIED message is displayed 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 security AT S administrative password View account information once access has been granted Remote users may only use this command ...

Page 88: ...t s administrator asked you to use See Setting Up Dial Securit 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 password as an Autopass password for account 3 c Check to see that you set your Autopass password correctly by using the ATI10 command Your Autopass password appears beside AUTOPASS PASSWORD if y...

Page 89: ...assword as your 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 session as described in Chapter 9 Accessing an Configuring the Courier V Everything modem remotel 2 When remote access has been granted use the AT S command t access the Dial Security ac...

Page 90: ...er know there had been a call coming The DTMF security status and password are shown in the ati10 screen DTMF security is enabled by setting the S53 bit 3 e g S53 8 or S53 3 1 Using the D command sets the DTMF security password AT D PWn n 0 39 Make sure to disable that account so no one can use the DTMF password as the Dial Security account For example to set local modem DTMF security password you...

Page 91: ...computer and one for data received from the phone line Flow control provides a system for stopping and starting transmissio depending on how full the buffers are Flow control s purpose is to prevent overfilling the buffers which may cause data to be lost We recommend that you use hardware flow control If you do depending on your communications software you will also need to enable hardware flow co...

Page 92: ...etecting that a buffer 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 CourierV Everything modem sends special characters in the data stream to restart the flow of data The problem with software flow control is that the characters used to stop Ctrl Q and start Ctrl S the flow of data can occur naturally in the dat...

Page 93: ...r V Everything modem is online the only characters it recognises are the escape code AT I0 Default Enable software XON XOFF flow control Use in ARQ mode only Note The XON XOFF characters sent to the remote computer may interfere with XON XOFF signaling between the remote computer and remote device see AT I2 AT I1 Force the modem to act on your XON XOFF commands but remove them from the data stream...

Page 94: ...he remote device must also have AT I5 capability In ARQ mode a modem set to AT I5 operates the same as it does when set to I2 It acts on your XON XOFF commands but does not pass them to the remote system The error control protocol enables the devices to control the flow of data on the phone link In non ARQ mode a modem set to AT I5 operates as though flow control were disabled AT I0 it does not lo...

Page 95: ...Command 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 Requires that your software support XON XOFF signaling AT H2 Use both hardware and software flow control If you are unsure about what your equipment supports select this option AT H3 ...

Page 96: ...12 6 CHAPTER 12 FLOW CONTROL ...

Page 97: ...est possible 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 terbo V 32 bis and so on down to as low as Bell 103 or 300 bps Selective Reject The Courier V Everything modem supports Selective Reject for analogue calls Selective Reject improves performance on n...

Page 98: ...g conditions for anV 90 connection to be made A digital connection at one en d ISPs or other online services must have a digital connection to the public switched telephone network PSTN Most major online services have a digital connection to the PSTN Only one digital to analogue convers i o n There can be only one digital to analogue conversion in the telephone network between the V 90 server mode...

Page 99: ...s to establish speeds up to 56 K 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 modem If clients attempt to connect to ISPs that do not use x2 the client modem will negotiate the next available modulation For example an x2 client modem calling into an ISP that only suppor...

Page 100: ...a Bell answer tone which is the prevalent standard in the U S and Canada for connections at 2400 bps and lower At higher speeds the Courier V Everything modem also recognises the ITU answer tones necessary for connecting with V protocol modems and adjusts to the answering device However when answering a call a Courier sending out the Bell answer tone B1 won t be recognised by V protocol modems The...

Page 101: ... 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 Registers Error Control Courier V Everything modems can employ error control techniques during data connections High speed data calls are vulnerable to errors unless the data is protecte by error control If your Courier V Every...

Page 102: ...mes The Courier V Everything modem is set at the factory to try for a error control connection and if that isn t possible to proceed with the call in Normal mode This means that M4 is set For your modem to Command Have no error control Normal Mode Due to the nature of phone line channels this is never recommended for analogue calls above 2400 bps AT M0 Enter Online Synchronous Mode without V 25 bi...

Page 103: ...blocks allowed 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 device doesn t recognize an MNP Link Request error control isn t possible In HST asymmetrical mode 3Com devices use a proprietary scheme similar to MNP Error Control and Flow Control Flow contr...

Page 104: ...in the CONNECT message if the modem is set to A3 V 42 bis versus MNP5 Data Compression Courier V Everything modems using V 4 bis compression negotiate the following options and report them in the ATI6 display Dictionary size that is the amount of memory available for compression table entries Entries are codes devised for redundant data The data is packed into shorter data units called code words ...

Page 105: ... modem When transferring such files it s best to set the modem to K3 See the information in data compression This allows V 42 bis compression to work dynamically with the compressed data but disables MNP5 Getting Maximum Throughput The following guidelines should help you to make the most of the Courier V Everything modem s advanced performance features In many instances experimentation and experi...

Page 106: ...ersion 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 connection is established The accuracy of the data is checke both by the file transfer protocol and the Courier V Everything modem To avoid redundancy use the above protocols only for non ARQ connecti...

Page 107: ... be used for non ARQ connections Leave the Courier V Everything 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 local and remote devices are using error control if YMODEM G detects an error it aborts the transfer Do not use either protocol with software flow control XON XOFF signaling ...

Page 108: ...13 12 CHAPTER 13 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 Link diagnostics summary ATI6 For your modem to Command Display a four digit product code ATI0 Perform a checksum of the modem s read only memory ROM and display the results This function is used only ...

Page 110: ...n request a diagnostic summary The duration of the last call or the real time is displayed depending on the modem clock setting For calls under data compression the number of characters sent may be less than the number of octets sent due to data compression operations ATI6 Display the product configuration ATI7 Lists phone numbers with redial instructions ATI8 Displays modem s Plug and Play ID ATI...

Page 111: ...n using M6 or M7 To see the remainder of the screen for any given command press any key Display a connection report that 3Com Technical Support representatives use to help you solve problems ATI17 For your modem to Command For your modem to display Command A partial summary of the basic command set AT A partial summary of the ampersand command set AT A partial summary of S Register functions ATS A...

Page 112: ...14 4 CHAPTER 14 DISPLAYING QUERYING AND HELP SCREENS ...

Page 113: ...se tests to check the operations of the transmitter an receiver or to locate a problem with a remote device or a telephone line Testing is done by sending theAT Tn 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 will receive an ERROR message All loopback testing conforms to ITU T Recommendation V 54 If...

Page 114: ...or a remote digital loopback test of your Courier V Everything modem Disable error control using the M0 command see Appendix B Alphabetic Command 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 test AT T0 local digital loopback AT T1 local analogue loopback AT T2 not used error AT T3 Grant Remot...

Page 115: ...to end the test Alternatively you can end the test by sendin 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 issued an invalid command 5 Send AT M4 unless you used a reset command ATZ If the CourierV Everything modem is in online mode still connected to a remote modem and...

Page 116: ...ter 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 Courier V Everything modem return to command mode when you type 2 Send AT T8 to begin the test The Courier V Everything modem enters analogue loopback AL mode and sends a CONNECT message The MR status light flashes The V Everything modem then...

Page 117: ...g 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 your Courier V Everything modem s transmitter for verification on the remote user s screen You will not see the message or any other data 6 When the remote user has completed the test send the escape code and then AT T0 to end the test Alternative...

Page 118: ...nd displaying it on your screen Granting a Digital LoopbackTest Request AT T4 Using AT T4 causes the CourierV Everything modem to grant a remote device s request for a remote digital loop back test Canceling All Digital LoopbackTest Requests T5 Using AT T5 cancels AT T4 and the Courier V Everything modem fails to acknowledge remote digital loopback test requests This is the default so that your Co...

Page 119: ... loopback mode and if the modem is an external model 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 not see your data 6 Send the escape code and the AT T0 to end the test Alternatively you can end the test by sendin ATH ATZ or ATZ Be careful because ATZ and ATZ reset the Courier V...

Page 120: ...dge the remote digital loopback 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 if the modem is an external model the MR status light flashes The Courier V Everything modem sends its built in test pattern to the remote device which loops it back to your Courier V Everything modem You will not see the data on ...

Page 121: ...Testing the Courier V Everything Modem using AT Tn 15 9 Data errors indicate a problem with the remote device or with the phone link 6 Send AT M4 unless you used a reset command ATZ orATZ ...

Page 122: ...15 10 CHAPTER 15 TESTING THE CONNECTION ...

Page 123: ... with devices that communicate using synchronous protocols i e mainframe computers The Courier V Everything modem must be connected to a synchronous serial port There are two ways to operate your modem in analogue synchronous mode Dial Using Means V 25bis Software Configuring the modem to enter synchronous mode when you power it on Then running communications software that uses the V 25 bis protoc...

Page 124: ...hrough its serial port Transmit and Receive synchronous timing pins are required at the EIA 232 interface so pins 15 and 17 are required The modem transmits timing signals through pin 15 and receives timing signals through pin 17 Note The serial cable included with your modem only supports asynchronous mode Communications Softwar The devices at both ends of the link must use the same synchronous p...

Page 125: ...s are in the process of connecting or reconnecting the Courier V Everything modem interprets any keyboard dataentry including an accidental key stroke as a key press abort and hangs up Delaying CTS until after carrier detection prevents this from happening However you have to set the Courier V Everything modem for hardware flow control by sending AT H1 If your software or machine does not support ...

Page 126: ...ever you may need to call your telephone company to have them check your line Dial Using V 25 bis Software To make synchronous connections using V 25 bis communications software you must first configure your modem using AT commands Once the modem is configured run your communications software Configuring th CourierV Everything Modem Before you attempt to connect to a synchronous network you must f...

Page 127: ...unications device when the Courier V Everything modem is online If Nn is set for 2 10 the Courier V Everything modem ignores the N rate and uses the Nn rate as the online connection rate For an offline clock speed of Command 1200 bps AT N2 2400 bps AT N3 4800 bps AT N4 7200 bps AT N5 9600 bps AT N6 Default 12000bps AT N7 14400 bps AT N8 16800 bps AT N9 19200 bps AT N10 To set the connection rate t...

Page 128: ...t codes Extended result codes provide more detailed information Don t be concerned if synchronous result codes do not appear on your screen they are intended for your communications software By default your modem is set to X1 for extended result codes To change to normal result codes send ATX0 to the modem Example Sending ATX1 W selects extended result codes 5 Your modem is able to answer calls au...

Page 129: ...nd the modem is in synchronous mode V 2 bis commands are no longer necessary and are ignored For dialing instructions refer to the manual included with your communications software Hanging Up Since your modem cannot accept commands once it is connected in synchronous mode you cannot use the ATH hang up command or the escape code The only way for the modem to disconnect is to drop its Data Terminal...

Page 130: ...32 Signaling Configuring th CourierV Everything Modem 1 If your communications software isn t running load the program and start Terminal mode see your software user s guide for instructions 2 Send AT F0B0 X0 to the modem The device you are calling should also be set to the equivalent of B0 which tells the modem to use the V 25 answer sequence and X0 which identifies the modem as the source of syn...

Page 131: ...e auto answer incoming calls switch to online synchronous mode after connection and then dial 555 1234 Dialing There are two methods of autodialing a stored telephone number Yo can have the modem dial the stored number either when it receives the Data Terminal Ready DTR signal from your computer or at power on reset 1 Store a telephone number to memory position 0 using the AT Z0 n command For exam...

Page 132: ...verything mode switches to synchronous mode and starts sending synchronous timing signals to your computer Configuring th CourierV Everything Modem 1 If your communications software isn t running load the program and start Terminal mode see your software user s guide for instructions 2 Send AT F0B0 W to the modem The device that you are calling should also be set to the equivalent of B0 which tell...

Page 133: ...dem sends receiver clock timing signals which are looped to the transmit clock and sent to the DTE over the serial interface Typical use systems that require synchronisation of data flowing in both directions AT X2 For your modem to Command Command Rate Command Rate AT N0 Variable default AT N8 14 4 Kbps AT N1 Reserved AT N9 16 8 Kbps AT N2 1200 bps AT N10 19 2 Kbps AT N3 2400 bps AT N11 21 6 Kbps...

Page 134: ...tion 0 using AT Z0 phone numbe For example to store 847 555 1111 and tone dial type AT Z0 T18475551111 8 Select a method to use to autodial the stored number You can have the Courier V Everything modem dial the stored number when it receives the Data Terminal Ready DTR signal from your computer at power on reset or when you press the Voice Data switch Use the following table to determine which com...

Page 135: ...u set the correct COM port and IRQ in your communications software and if applicable in Windows Control Panel Ports Make sure that your communications software is in Terminal mode Be sure that your communications software is set to the correct bit rate and word length 7 bits with or without a parity bit or 8 bits and no parity Check that DIP switch 8 is ON for act on AT commands If DIP switch 8 is...

Page 136: ... 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 Courier V Everything modem Make sure the Courier V Everything modem is connected to a standard analogue phone line and not to a digital system typically found in offices and hotels If the CourierV Everything modem responds NO DIAL TONE when you attempt to dial m...

Page 137: ...ter you finish the call Hear ringing but the Courier V Everything modem won t answer For external Courier V Everything modems 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 Courier V Everything modem and check that S0 is set to a value higher than 0 Also check that DIP switch 5 is OFF Set F1 and S0 1 then try again ...

Page 138: ...h the device you first tried to call If the modem is set to a fixed serial port rate B1 and your software is fixed at 19 2K 38 4K 57 6K or 115 2K bps the reason 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 Stay Resident programs or disk caching prog...

Page 139: ...is in the correct mode fax or data depending 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 rate word length parity and number of Sto bits have been selected Synchronous operations review the instructions in Chapter 12 Dedicated Leased Line and Synchro...

Page 140: ...the second device accepts your call the problem may lie with the device you first tried to call Errors during software download Try performing the XMODEM file transfer at a slower serial port rate If your computer doesn t have a 16550UART set your communications software to use a slower serial port If You Still Have Problems The problems described above are by far the most common ones that users e...

Page 141: ...our name and address Put your return address and your USO number on the shipping label as well c Ship the package to the following address 3Com Corporation Attn Receiving Dock 15 USO _______________ 1800 West Central Mount Prospect IL 6005 3Com will not accept packages sent COD so be sure to send the modem postage paid 3Com will repair or replace your CourierV Everything modem and return it to you...

Page 142: ...17 8 CHAPTER 17 TROUBLESHOOTING ...

Page 143: ... 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 decimal values Each bit can be either on 1 or off 0 Eight bits create 256 unique combinations of 1s and 0s Each of the eight bits can be assigned a number corresponding to its position b b b b b b b b 7 6 ...

Page 144: ...ues 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 example below 11 113 64 49 01 49 32 17 01 17 16 0111 1 1 0 01110001 Setting Bit Mappe S Registers You can set bit mapped S Registers using either bits or decimal values While it may be simpler for yo...

Page 145: ... as the one in Using Bits above Default S Register Settings The table below lists all default values for S Register settings ψ S Registers Function NVRAM Default Setting S0 Auto Answer 0 S1 Counts stores rings from incoming calls 0 S2 Escape code character 43 S3 Carriage Return character 13 S4 Line Feed character 10 S5 Backspace character 8 S7 Carrier wait time sec 60 S8 Dial pause sec 2 S9 Carrie...

Page 146: ...pped functions 0 S28 V 32 handshake time 100 ms 8 S29 V 21 handshake time 100 ms 20 S32 Voice data switch external modems 9 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 ASCII character 126 S43 Remote guard time 200 ms 200 S44 Leased line delay timer 15 S51 Bit mapped functions 0 S53 Bit mapped function...

Page 147: ...econds theCourierV Everything modem waits for a carrier May be set for much longer duration if for example the CourierV Everything mode is originating an international connection S8 2 Sets the duration in seconds for the pause option in the Dial command and the pause between command reexecutions and A commands S9 6 Sets the required duration in tenths of a second of the remote device s carrier sig...

Page 148: ... register See the beginning of this appendix for information about setting bit mapped registers Bit Value Result 0 1 Disconnect on escape code S15 0 Bit mapped register See the beginning of this appendix for information about setting bit mapped registers Bit Value Result 0 1 Disable the CourierV Everything modem s extra high frequency equalisation if it causes problems on shorter link calls for HS...

Page 149: ...esn t exceed the size of their screen S16 0 Bit mapped register See the beginning of this appendix for information about setting bit mapped registers For testing see Chapter 15 Testing Bit Value Result 1 2 Dial Test 2 4 Test pattern 3 8 Remote digital loopback S18 0 Test timer for software initiated loopback testing Tn disabled when S18 is set to 0 Used to set the duration of testing in seconds be...

Page 150: ...y originates V 21 calls 1 2 Enable unencoded non trelliscoded modulation in V 32 mode this option is part of the ITU T V 32 recommendation but is rarely used 2 4 Disable V 32 modulation used for testing HST modulation 3 8 Disable 2100 Hz answer tone to allow two V 42 devices to connect more quickly 4 16 See next page 5 32 See next page 6 48 Disable V 42 Detect Phase 7 128 Unusual software incompat...

Page 151: ...dulation 1200 bps S29 20 Sets the duration in tenths of a second of the V 21 answer tone S32 9 For External modems only Assign Voice Data switch function Value Function 0 Disabled 1 Voice Data originate mode 2 Voice Data answer mode 3 Redial last number 4 Dial number stored at position 0 5 Auto answer on off toggle 6 Reset modem 7 Initiate remote digital loopback 8 Busy out the phone line toggle 9...

Page 152: ...mber of unsuccessful login attempts exceeds the limit set by this register the CourierV Everything modem returns online and any further login attempts during the remainder of that connection are refused S42 126 Stores the ASCII decimal code for the remote access escape character The default character is a tilde S43 200 Sets the duration in fiftieths of a second of the guard time for the remote acc...

Page 153: ...sable 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 7 128 Disable V 8 S55 0 Trellis code bit mapped register used primarily by 3Com Technical Support for debugging purposes Bit Value Result 0 1 Disable 8S 2D mapping 1 2 Disable 16S 4D mapping 2 4 Disab...

Page 154: ...itor 5 32 Enables Disables V 90 S59 0 Bit mapped register See the beginning of this appendix for information about setting bit mapped registers Bit Value Result 0 1 Enhanced V 42bis 1 2 Alternate Caller ID timing S69 0 Bit mapped register See the beginning of this appendix for information about setting bit mapped registers Bit Value Result 0 1 External Plug and Play 1 2 Auto Redial 2 4 Reserved 3 ...

Page 155: ...ng of this appendix for information about setting bit mapped registers Bit Value Result 0 1 Enable recognition of Ring A 1 2 Enable recognition of Ring B 2 4 Enable recognition of Ring C 3 8 Enable recognition of Ring D 4 16 Enable recognition of Ring E Register Default Function ...

Page 156: ...A 14 APPENDIX A S REGISTERS ...

Page 157: ...Wait 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 modem will dial the number and wait 60 seconds for a carrier If the line is busy the modem will pause for 2 seconds and then redial The modem makes a maximum of 10 attempts A Reexecute the last issued c...

Page 158: ...er optional commands The numbers 0 9 are accepted 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 ignored Comma Pause for 2 seconds or the time in S Register 8 Accepted but ignored Semicolon Remain in Command mode after dialing Dial the letters that follow W Wa...

Page 159: ...mode 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 that it is transmitting to another modem F0 Online echo ON Sometimes called half duplex F1 Online echo OFF Sometimes called full duplex Hn Go on or off hook H0 Go on hook hang up H1 Go off hook pic...

Page 160: ... until the call is negotiated M2 The speaker is always on M3 The speaker turns on after the last digit is dialed and stays on until the call is negotiated On Return online Use with the escape code to toggle between 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 ...

Page 161: ...tting revert to the settings in NVRAM If DIP switch 1 is OFF reset to the F0 configuration template no flow control Z Complete hardware reset Command Function Display help for the ampersand command set An Enable or disable the display of additional result code subsets Also see the Xn command A0 Do not display ARQ result codes A1 Display ARQ result codes A2 In addition to ARQ result codes display H...

Page 162: ...er online Command mode during a call by dropping DTR D1 functions similarly to the escape code Return online with the On command or hang up with the Hn command D2 Normal DTR operations The modem will not accept commands unless your computer sends a DTR signal Dropping DTR ends a call D3 Modem resets with DTR toggle Fn Load one of the three configuration templates that are stored permanently in rea...

Page 163: ...nt supports select this option In Received data software flow XON OFF control I0 Disables XON XOFF flow control of received data I1 The modem acts on your typed XON XOFF commands Ctrl S or Ctrl Q and passes them to the remote device I2 The modem acts on your XON XOFF commands but removes them from the data stream instead of passing them to the remote device This is the recommended setting for ARQ ...

Page 164: ...oth your modem and the remote device must use the same protocol M0 Normal mode no error control Due to the nature of phone line channels this is never recommended for calls above 2400 bps M1 Use for online synchronous mode without V 25 bis This setting is exclusive of the modems error control M4 Normal ARQ mode If an ARQ connection isn t made the modem operates in Normal mode as though it were set...

Page 165: ...wer than or equal to the serial port rate n 1 300 bps n 2 1200 bps n 3 2400 bps n 4 4800 bps n 5 7200 bps n 6 9600 bps n 7 12000 bps n 8 14400 bps n 9 16800 bps n 10 19200 bps n 11 21600 bps n 12 24000 bps n 13 26400 bps n 14 28800 bps n 15 31200 bps n 16 33600 bps n 17 28000 bps n 18 29333 bps n 19 30666 bps n 20 32000 bps n 21 33333 bps n 22 34666 bps n 23 36000 bps n 24 37333 bps n 25 38666 bps...

Page 166: ...em sends data to the computer only upon receipt of the RTS signal Sn Send the computer a Data Set Ready DSR signal via the EIA 232 interface S0 DSR is always ON override S1 In Originate mode Send DSR after dialing on detection of the remote device s answer tone In Answer mode Send DSR after sending an answer tone S2 When Carrier is lost send a pulsed DSR signal with Clear to Send CTS following Car...

Page 167: ... Everything modem sends transmit clock timing signals to the DTE over the serial interface DTE rate follows the connection rate X1 The DTE sends transmit clock timing signals to the modem over the serial interface Typical use multiplexed leased lines X2 The Courier V Everything modem sends receiver clock timing signals which are looped to the transmit clock and sent to the DTE over the serial inte...

Page 168: ... include modem settings in the Zn string If the call requires a special setting insert it in the command string before the DS command Zn L Stores the last dialed number in position n Zn Display the phone number stored in NVRAM at position n where n 0 9 ZC s Store command string s in NVRAM The command string can be up to 30 characters long spaced do not count This command is used so you can call an...

Page 169: ...at you wrote to NVRAM with W or forced with C2 C2 Force configuration changes to take effect immediately Command Function D Set a DTMF password E n Erase security settings E 1 Erase local access password E 2 Erase Autopass password E 3 Erase passwords in accounts 0 9 E 4 Erase phone numbers in accounts 0 9 E 5 Disable Account Dialback and New Number fields in accounts 0 9 Fn Remotely configure ano...

Page 170: ...arily for use with network applications but may also be integrated into certain software programs For example T could be used in a security program to identify incoming tone security codes To return the modem to Command mode press any key or drop the computer s or terminal s DTR signal The modem responds OK V PWn Assign the password in account n in your modem s security account as your Autopass pa...

Page 171: ...B 15 CID 4 Enable caller ID but do not transmit the information to your computer retain it in the modem s memory CID Display the current caller ID settings CID Display the caller ID actions that are available Command Funtion ...

Page 172: ...B 16 APPENDIX B ALPHABETIC COMMAND SUMMARY ...

Page 173: ... 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 protocol codes Serial port rate select B1 Serial port rate fixed higher than connect rate Carrier Detect C1 Normal operations Data Terminal Ready D2 Normal operations Guard tone G0 U S Canada Transmit data...

Page 174: ...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 Digital Loopback RDL T5 Deny RDL Externals Only Synchronous transmit clock source X0 Courier Break handling Y1 Clear buffer send immediately Stored telephone number Z0 9 0 Blank EXTERNALS ONLY Synch Clock Speed N6 9600 bps Caller ID CID 0 Caller ID d...

Page 175: ...esult codes Result 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 Normal operations Guard tone G0 U S Canada Transmit data hardware flow control H2 Software flow control Record data software flow control I2 Enabled Analogue data compression K1 Enabled...

Page 176: ...ed telephone number Z0 9 0 Blank Externals only V 25 bis clock speed N6 9600 bps Caller ID CID 0 Caller ID disabled Word length 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 Online local echo F1 Disabled Training tone volume L2 Medium Speaker cont...

Page 177: ...ontrol H0 Disabled Record data software flow control I0 Disabled Analogue data compression K1 Enabled Normal or leased lines L0 Normal lines Error control sync M4 Normal error control Link rate select N0 Variable Record data hardware flow control R1 Disabled Data Set Ready S0 Always on Remote Digital Loopback RDL T5 Deny RDL Break handling Y1 Clear buffer send immediately Stored telephone number Z...

Page 178: ...C 6 APPENDIX C FLOW CONTROL TEMPLATE ...

Page 179: ...Register S6 7 BUSY Busy signal detect modem hangs up 8 NO ANSWER After waiting 5 seconds for an answer modem hangs up returned instead of NO CARRIER when the option is used 11 RINGING The modem has dialed remote phone line is ringing 12 VOICE Voice answer at remote site modem hangs up 170 RING A Incoming distinctive ring detected 171 RING B Incoming distinctive ring detected 172 RING C Incoming di...

Page 180: ...NE 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 CONNECT 24000 103 CONNECT 26400 107 CONNECT 28800 151 CONNECT 31200 155 CONNECT 33600 170 RING A 171 RING B 172 RING C 173 RING D 174 RING E Functions Wait for 2nd Dial Tone W Wait for Answer ...

Page 181: ... 41333 V90 292 30666 V90 266 41333 ARQ V90 293 30666 ARQ V90 267 42666 V90 294 32000 268 42666 ARQ V90 295 32000 ARQ 269 44000 V90 296 32000 V90 270 44000 ARQ V90 297 32000 ARQ V90 271 45333 V90 298 34666 272 45333 ARQ V90 299 34666 ARQ 273 46666 V90 300 34666 V90 274 46666 ARQ V90 301 34666 ARQ V90 275 48000 V90 302 36000 276 48000 ARQ V90 303 36000 ARQ 277 49333 V90 304 36000 V90 278 49333 ARQ V...

Page 182: ...313 61333 326 56000 V90 314 61333 ARQ 327 56000 ARQ V90 315 61333 V90 328 57333 V90 316 61333 ARQ V90 329 57333 ARQ V90 317 62666 330 58666 318 62666 ARQ 331 58666 ARQ 319 62666 V90 332 58666 V90 320 62666 ARQ V90 333 58666 ARQ V90 321 64000 V90 334 60000 322 64000 ARQ V90 335 Message Message ...

Page 183: ...mmand Example CRN18005551234 CRS Call Request with memory location Instructs the Courier V Everything mode to dial a number stored in memory Example CRS3 DIC Disregard incoming call Instructs the Courier V Everything mode to disregard an incoming call overrides auto answer for this call PRNn Program number Stores a number in NVRAM Example PRN3 18005551234 RFN Request list of forbidden numbers Inst...

Page 184: ...Appendix D Result Code Meanings and Sets 0 9 Digits Flash Wait for dial tone Greater Than separator Pause Equal Sign separator P Pulse T Tone Period separator Minus separator CFI Call failed CFRT Ringing CNX Connect INC Incoming call INV Invalid action LS List of numbers LSF List of forbidden numbers LSN List of stored numbers VAL Valid ...

Page 185: ... modem busy CFET Remote device busy CFFC Forbidden call CFNS Number not stored CFNT Answer tone not detected INVCU Command unknown INVMS Message syntax error INVPS Parameter syntax error INVPV Parameter value error CRI Call request with identification number PRI Program identifier RLD List of delayed call numbers RLI Request list of identification numbers ...

Page 186: ...E 4 APPENDIX E V 25 BIS REFERENCE ...

Page 187: ...8 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 78 4E N 110 6E n 15 0F SI 47 2F 79 4F O 111 6F o 16 10 DLE 48 30 0 80 50 P 112 70 p 17 11 XON 49 31 1 81 51 Q 113 71 q 18 12 DC2 50 32 2 82 52 R 114 72 r 19 13 XOF F 51 33 3 83 53 S 115 73 s 20 14 ...

Page 188: ... 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 à 126 7E 31 1F US 63 3F 95 5F _ 127 7F DEL Dec Hex Char Dec Hex Char Dec Hex Char Dec Hex Char ...

Page 189: ...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 96 121 122 145 146 Transmit HDLC data with carrier FRH n 3 24 48 72 73 74 96 121 122 145 146 Receive HDLC data with carrier FNS 0 1 Pass through non standard negotiation byte string FCR 0 1 Capability t...

Page 190: ...clearly contains in a margin at the top or bottom of each transmitted page or on the first page of the transmission the date and time it is sent and an identification of the business other entity or individual sending the message and the telephone number of the sending machine or of such business other entity or individual Telephone facsimile machines manufactured on and after December 20 1992 mus...

Page 191: ... receives at the low frequency The transmit receive frequencies are the reverse of the calling modem which is in originate mode application application program A computer program designed to perform a specific function such as a word processor or a spreadsheet ARQ See Automatic Repeat Request ASCII American Standard Code for Information Interchange A 7 bit binary code 0 s 1 s used to represent let...

Page 192: ...ee HST MNP and V 42 baud rat The number of discrete signal events per second occurring on a communications channel Although not technically accurate baud rate is commonly used to mean bit rate binary digit bit A 0 or 1 reflecting the use of a binary numbering system only tw digits Used because the computer recognises either of two states OFF or ON Shortened form of binary digit is bit BISYNC Binar...

Page 193: ...n carrying signal Carriers are generated and maintained by modems via the transmission lines of the telephone companies CCITT Formerly an international organisation that defined standards for telegraphic and telephone equipment It has been incorporated into its parent organisation International Telecommunication Union ITU Telecommunication standards are now covered under Telecommunications Standar...

Page 194: ...rmed on each block or frame of data by both sending and receiving modems The sending modem inserts the results of its computation in each data block in the form of a CRC code The receiving mode compares its results with the received CRC code and responds with either a positive or negative acknowledgment In the ARQ protocol implemented in 3Com high speed modems the receiving modem accepts no more d...

Page 195: ...t startup or reset by the computer s software and attached devices and operational until changed by the user digital loopbac A test that checks the modem s EIA 232 interface and the cable that connects the terminal or computer and the modem The mode receives data in the form of digital signals from the computer or terminal and immediately returns the data to the screen for verification digital sig...

Page 196: ... mode The mode in which the fax modem is capable of sending and receiving files in a facsimile format Flash memory A form of memory that can be electrically erased and reprogrammed without the need to remove it from the circuit board flow control A mechanism that compensates for differences in the flow of data input to and output from a modem or other device fram A data communications term for a b...

Page 197: ... proprietary signaling scheme design and error control protocol for high speed modems HST incorporates trellis coded modulation for greater immunity from variable phone line conditions and asymmetrical modulation for more efficient use of the phone channel at speeds of 4800 bps and above HST also incorporates MNP compatible error control procedures adapted to asymmetrical modulation Hz Hertz A fre...

Page 198: ...ough the ATE1 command The command causes the modem to display your typed commands When the modem is online to another system the local echo is invoked through the ATF0 command This command causes the modem to display the data it transmits to the remote system MB Megabyte One million bytes Microcom Networking Protocol MNP An asynchronous error control protocol developed by Microcom Inc and now in t...

Page 199: ...Serial Transmission parity An error detection method that checks the validity of a transmitted character Character checking has been surpassed by more reliable and efficient forms of block checking including Xmodem type protocols and the ARQ protocol implemented in Courier V Everything modems The same type of parity must be used by two communicating computers or both may omit parity When parity is...

Page 200: ... its transmitter and returned to the local screen for verification 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 result code Another way of saying status message The Courier V Everything modem sends result codes to your terminal for example to indicate the status of a connect...

Page 201: ...e format of data frames exchange between modems over a phone line See BISYNC Protocol HDLC synchronous transmission A form of transmission in which blocks of data are sent at strictly timed intervals Because the timing is uniform no Start or Stop bits are required Compare Asynchronous Transmission Some mainframes only support synchronous communications unless their owners have installed a synchron...

Page 202: ...ion that defines procedures for starting and endin sessions of data transmission V 17 An ITU T standard for facsimile operations that specifies modulation at 14 4 Kbps with fallback to 12 Kbps V 21 Fax An ITU T standard for facsimile operations at 300 bps V 21 Modem An ITU T standard for modem communications at 300 bps Modems made in the U S or Canada follow the Bell 103 standard However the modem...

Page 203: ...ne quality is impaired and fall back further as necessary They fall forward to the next higher speed when line quality improves V 32 terbo Modulation scheme that extends the V 32 connection range 4800 7200 9600 12K 14 4K 16 8K 19 2K and 21 6 Kbps V 32 terbo modems fall back to the next lower speed when line quality is impaired and fall back further as necessary They fall forward to the next higher...

Page 204: ...e XOFF character Some devices including the CourierV Everything modem understand Ctrl Q as XON others interpret the pressing of any key after Ctrl S as XON YMODEM An error correcting file transfer protocol that is related to but faster than XMODEM ZMODEM An error correcting file transfer protocol that is related to but faster than XMODEM or YMODEM ...

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