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Troubleshooting

A-7

Issue 2    May 1995

Table A-4. Connection Problems while Placing a Call (3 of 3)

Symptom

Action

Modem establishes
and disconnects a
call

You may have a poor telephone line connection.
Try dialing again.

The remote modem may have encountered an
error control disconnect, where the modem is
configured to establish a call using error
correction. If the modems cannot negotiate error
control, then a disconnect occurs. Try using
Normal (\N0) or Direct Mode (\N1).

Your telephone may have Call Waiting enabled.
Refer to your local phone book for procedures to
disable this feature.

Perform a Local Analog Loopback (&T1) test to
check the modem’s hardware operation.

Summary of Contents for KeepInTouch 3765

Page 1: ...y of AT T Any reference to AT T Paradyne is amended to read Paradyne Corporation AREA CODE CHANGE Please note that the area code for Paradyne Corporation in Largo Florida has changed from 813 to 727 F...

Page 2: ...3765 A2 GB90 10 Issue 2 May 1995 KeepInTouch PCMCIA Modem Models 3765 and 3766 User s Guide Printed on recycled paper Member Company...

Page 3: ...ies of merchantability or fitness for a particular purpose Further AT T Paradyne Corporation reserves the right to revise this publication and to make changes from time to time in the contents hereof...

Page 4: ...tered trademarks of their respective owners Warranty A limited warranty is provided with this product Refer to the enclosed Warranty Card for more information Important Safety Instructions 1 Read and...

Page 5: ...ed at the network interface Use caution when installing or modifying telephone lines Avoid using a telephone other than a cordless type during an electrical storm There may be a remote risk of electri...

Page 6: ...y modifications in order to maintain uninterrupted service 6 If your modem needs to be returned for repair or replacement follow the return policy as indicated on your warranty card 7 No repairs may b...

Page 7: ...the receiving antenna G Increase the separation between the equipment and receiver G Connect the equipment into an outlet on a circuit different from that to which the receiver is connected G Consult...

Page 8: ...e by an authorized Canadian maintenance facility designated by the supplier Any repairs or alterations made by the user to this equipment or equipment malfunctions may give the telecommunications comp...

Page 9: ...Important Regulatory Information G Issue 2 May 1995 This page intentionally left blank...

Page 10: ...allation G Installing Your KeepInTouch PCMCIA Modem 2 1 Connection to a Telephone Outlet 2 2 G Using the KIT Utilities 2 4 G Installing Fax Software 2 5 3 Using Your Modem G What is a Modem 3 1 G Unde...

Page 11: ...ory Settings Command F 3 12 Reload Settings from a User Profile Y 3 13 Reset Modem and Load User Profile Z 3 13 G An Overview of File Transfers and Fax Operation 3 14 File Transfers 3 14 Fax Operation...

Page 12: ...4 G Connecting with Non ETC Modems D 5 G Tips for Successful Cellular Operation D 6 G Overview of Cellular Networks D 7 E Advanced Modem Concepts G Changing Modem Data Rates and Modulations E 1 G Err...

Page 13: ...oduction G 1 1 Supplied Equipment 1 2 2 Installation G 2 1 Modem Installation 2 2 3 Using Your Modem G 3 1 Dial Data Network 3 2 E Advanced Modem Concepts G E 1 Modem to Computer Flow Control E 5 G E...

Page 14: ...ction Problems while Placing a Call A 5 G A 5 Online Operation A 8 G A 6 Fax Operation A 8 B Technical Specifications G B 1 Technical Specifications B 1 C Response Codes G C 1 X Commands Effect on CON...

Page 15: ...cond It is compatible with a variety of modem standards allowing it to communicate with slower modems To ensure error free data transfers the KeepInTouch PCMCIA modem employs V 42 and MNPr Levels 4 2...

Page 16: ...r more information about cellular operation refer to Appendix D Cellular Communications The Hayesr AutoSync feature is also supported For more information on Hayes AutoSync refer to the Using Hayes Au...

Page 17: ...es diskette high density 3 5 containing software for installing enabling upgrading and testing your modem The diskette also contains help text files with information on using your modem and its AT com...

Page 18: ...PC to control the modem if not supplied with your modem This software application allows you to transfer files to and from your PC receive electronic mail e mail dial into bulletin boards etc G If you...

Page 19: ...a BBS telephone number on your warranty card or other enclosed documentation The BBS contains the latest version of the KIT Utilities which include the help text files You can view the help text files...

Page 20: ...tall your modem 1 Locate an unused PCMCIA socket on your PC Refer to your PC s user s guide for more information about the PCMCIA socket 2 Hold the modem so that the product logo label is facing up an...

Page 21: ...e If however you want to connect to a cellular telephone supported in Model 3766 only refer to Appendix D Cellular Communications 1 Plug the modular cord s 2 pin connector into the modem s 2 pin rear...

Page 22: ...he KIT Utilities describes this process NOTE If your PC has Card and Socket Services installed you can use your modem without installing the KIT Utilities However to upgrade your modem s firmware or p...

Page 23: ...d AT command usage To use the Kit Utilities first install the software on your PC Once installed the KIT Utilities menus and messages guide you through the available options and provide help along the...

Page 24: ...ilities software when the modem is enabled Record this information for setting up your communications and fax software applications Installing Fax Software Some KeepInTouch PCMCIA modems ship with sof...

Page 25: ...ther computers Picture the modem as a telephone for your computer it performs many of the same functions as a telephone such as dialing answering calls and hanging up Information is sent over telephon...

Page 26: ...ing a communications software package and your computer s keyboard Once two modems are connected also known as online they automatically switch to Data mode In Data mode any information sent from the...

Page 27: ...e you have installed the modem in the computer as described in Chapter 2 Installation and that you have a communications software package installed and running on your computer The software must be se...

Page 28: ...an be entered one at a time or in strings several commands at once for example AT FS0 0 W Strings can have up to 60 characters after the AT prefix G Commands described in this manual that end with the...

Page 29: ...ifier tells the modem to perform additional tasks when dialing a telephone number The following example shows the elements of a dial command string Dial Modifiers The following can be used as dial mod...

Page 30: ...used when calling an originate only modem This modifier is the last character in the dialing string e g ATDT 123 4567R S n Dial Stored Telephone Number Causes the modem to dial the telephone number w...

Page 31: ...he telephone number 555 1234 TYPE ATDT9W555 1234 PRESS Enter Dialing a Stored Telephone Number This example shows how to dial a number which has been stored in the memory of the modem You can use the...

Page 32: ...ibed on pages 3 3 and 3 9 TYPE ATH To issue the command to hang up PRESS Enter The modem disconnects The second and more subtle approach to hanging up a call is to make sure that the D command is set...

Page 33: ...ree plus signs When typing the escape sequence you must allow some amount of idle time before and after typing the signs This amount of time is called the escape guard time For example if the escape g...

Page 34: ...m is first turned on the contents of one of the two memory areas are retrieved into an area of memory known as the Active Profile The Y command determines which of the two user profiles will be retrie...

Page 35: ...tive Profile User Profile 1 and any stored telephone numbers PRESS Enter Save Write to Memory Command W After you make changes to the modem s configuration options you can save your changes in either...

Page 36: ...re loaded into the Active User Profile and the modem is set up for Data mode These are some of the features and functions available to you when the factory settings are loaded G V 34 operation with a...

Page 37: ...the Y command TYPE AT Yn where n is 0 for User Profile 0 or 1 for User Profile 1 PRESS Enter Reset Modem and Load User Profile Z Use the Z command to reset the modem and load the contents of User Pro...

Page 38: ...must G Have your modem and PC set up for modem operation before executing your communications software G Have communications software that is operating and in terminal mode G Have your modem online wi...

Page 39: ...ther PC Also documents created on your PC can typically be faxed to a remote fax machine or PC Similar to your communications software your fax software uses basic AT commands for functions such as di...

Page 40: ...r DOSr by Attachmate must be used The M option described on page 4 13 must be set to M4 when using Hayes AutoSync After using the Hayes AutoSync feature it is recommended that you reload your modem s...

Page 41: ...o your modem via your communications software When a modem receives a command it responds with a message known as a response code that displays on your monitor Response codes are described in Appendix...

Page 42: ...is command selects a CCITT or Bell communications standard When CCITT V 23 is selected this command also selects the send and receive data rates For more information refer to the B command S Registers...

Page 43: ...ly stored in the modem s memory with the AT Zn x command T Tone Dial Configures the mode to use DTMF tones to dial a telephone number W Wait for Dial Tone Causes the modem to wait for a dial tone Paus...

Page 44: ...your modem I0 Displays product code 240 I1 Displays firmware revision number first three digits only see I19 for full display I2 Performs a checksum which verifies the integrity of the firmware runnin...

Page 45: ...cribed in Table 4 2 which begins on page 4 20 n the number of the S Register you want to change x the new value for S Register n in decimal format Sn VIEW S REGISTER This command displays the contents...

Page 46: ...des are enabled CONNECT messages include the data rate and may also be set to include information on error control and data compression Extended result codes also report reasons why a connection faile...

Page 47: ...te X5 Enabled Enabled Enabled CONNECT line rate REL X6 Enabled Enabled Enabled CONNECT line rate protocol X7 Enabled Enabled Enabled CONNECT dte rate Zn RESET AND LOAD STORED PROFILE This command caus...

Page 48: ...ERING This command determines whether or not the modem buffers data received while it is negotiating the type of connection to be used with a remote modem Buffering means the data is held in a tempora...

Page 49: ...Using this command is not recommended unless your communications software supports the Break character and your application requires you to send or receive break signals This command controls three d...

Page 50: ...s not buffered Errors in the data transmission may occur The DTE PC to modem speed must match the modem to modem speed N2 MNP or Disconnect Reliable Mode The modem attempts to connect using MNP error...

Page 51: ...hardware flow control CTS Q3 Enables two way hardware flow control RTS CTS Tn SET INACTIVITY TIMER This command forces the modem to disconnect if no data is transmitted or received within a specified...

Page 52: ...mode when an on to off transition of DTR is detected An ATO returns the modem to Data mode D2 The modem hangs up and switches to Command mode when an on to off DTR transition is detected Auto answer i...

Page 53: ...r level used by the modem to transmit data over the telephone line The transmit output level can range from 10 dBm to 25 dBm I 10 10 dBm I18 18 dBm I 11 11 dBm I19 19 dBm I 12 12 dBm I20 20 dBm I 13 1...

Page 54: ...t or idle modes DSR remains on until the call is disconnected This mode is sometimes referred to as Standard RS 232 operation Tn TESTS The T command allows you to perform diagnostic tests on your mode...

Page 55: ...T5 Rejects Remote Digital Loopback RDL test requests This command causes the modem to reject a remote modem s request for a remote digital loopback test See T6 for more information on remote digital l...

Page 56: ...file User Profile 1 and Telephone Directory Wn WRITE SAVE CHANGES TO MEMORY This command allows you to save the Active Profile configuration options command and S Register settings in a User Profile T...

Page 57: ...rectory entry of 40 characters or four directory entries that total up to 30 characters combined An SET ERROR CONTROL FALLBACK CHARACTER This command allows you to change the ASCII value of the error...

Page 58: ...Registers S76 and S78 and Appendix E Advanced Modem Concepts Bn Max Rate Modulation B300 300 bps V 21 if B0 or Bell 103J if B1 B1200 1200 bps V 22 if B0 or Bell 212A if B1 or V 23 if B2 or B3 B2400 24...

Page 59: ...when the modem is directly connected to the cellular telephone with a Cellular Direct Connect cable The effects of this command are automatically saved you do not need to use the W command C0 Motorol...

Page 60: ...cter S3 n CARRIAGE RETURN CHARACTER This S Register determines the ASCII value used as the carriage return Enter key This character is used in asynchronous operation only n 0 127 Factory setting is 13...

Page 61: ...ating modem waits before abandoning a call when no answer tone is received This register is not associated with the W dial modifier n 1 255 seconds Factory setting is 60 seconds S8 n PAUSE TIME DIAL M...

Page 62: ...d S18 n TEST TIMER This S Register sets the duration in seconds for modem loopback tests issued by the T command After this timer expires the modem returns to Command mode Setting S18 to zero disables...

Page 63: ...ly detect the remote modem s modulation when establishing a connection Automoding is highly recommended for most applications The following modulations can be detected when automoding is enabled V 34...

Page 64: ...wing much greater throughput when using error control and data compression If enabled the serial port speed DTE automatically changes to match the modem connection DCE speed NOTE This command should o...

Page 65: ...rmation on using the KIT Utilities NOTE To locate the KIT Utilities and the help text files refer to the section Where to Find Additional Information on page 1 5 If you are experiencing problems while...

Page 66: ...ct your modem or PC dealer See page 1 5 for information on locating technical support telephone numbers Use Table A 1 to check basic modem installation Table A 1 Modem Installation Symptom Action Mode...

Page 67: ...used by any other COM ports Make sure that the communications software is set to a DTE speed allowed by the modem Make sure that all AT commands are terminated with a carriage return Use your communi...

Page 68: ...the computer is providing DTR to the modem Set the modem s DTR Control to Ignore D0 Modem goes off hook answers but does not connect Verify that the originating modem supports your modem s modulation...

Page 69: ...one should stop as the touch tone signals or dialing pulses are sent If the dial tone does not break check the setting of S11 Refer to Making a Call with Your Modem beginning on page 3 5 to verify tha...

Page 70: ...ocal phone book for procedures to disable this feature If the modem passes the above tests and a problem still exists then the problem is likely not with your modem High error rates occur when running...

Page 71: ...dem may have encountered an error control disconnect where the modem is configured to establish a call using error correction If the modems cannot negotiate error control then a disconnect occurs Try...

Page 72: ...ted data character formats Garbage characters appear on your monitor when your modem connects to another modem Your modem is not using error control and the other modem is using error control The garb...

Page 73: ...0 COMPATIBILITY Dial Line Modulations Fax Modulations ITU V 34 28 800 bps 2400 bps V 32 terbo 19 200 16 800 bps CCITT V 32bis 14 400 12 000 9600 7200 4800 bps CCITT V 32 9600 4800 bps CCITT V 22bis 24...

Page 74: ...in cellular telephone direct connector DIMENSIONS Height Width Length 0 196 inches 5 0 mm 2 126 inches 54 0 mm 3 370 inches 85 6 mm TRANSMIT LEVEL 10 dBm DATA RATES Dial Line Computer Data Rates 28 80...

Page 75: ...and X The Q command is used to turn response codes on or off When Q0 is set response codes are turned on enabled When Q1 is set response codes are turned off disabled Refer to page 4 5 for more infor...

Page 76: ...4 n X5 n n X6 n n n X7 n For example if you have X1 set you may see a response message such as CONNECT 57600 If you have X5 set however the response for that same connection if error control is used w...

Page 77: ...d command entered The command does not exist or it has a syntax error or a parameter variable which is out of the allowed range Tables C 3 and C 4 list the Extended response codes Table C 3 describes...

Page 78: ...T 7200 Connection with 7200 bps DTE or DCE rate 16 CONNECT 12000 Connection with 12 000 bps DTE or DCE rate 17 CONNECT 16800 Connection with 16 800 bps DTE or DCE rate 18 CONNECT 1200 75 Connection us...

Page 79: ...ely NOTE Cellular operations are supported in Model 3766 only Model 3765 modems do not support cellular connections For information on the models of cellular telephones which can be directly connected...

Page 80: ...to work with a specific set of Motorola cellular telephones Other telephones are also supported by using a C command specific to your model of cellular telephone Refer to the help text file cellv34 t...

Page 81: ...is automatically downloaded when this number is called If you must connect to a modem that does not support ETC refer to the sections Using Cellular Modem Pools and Connecting with Non ETC Modems in t...

Page 82: ...ns in Table D 1 automatically switch back to their non cellular settings Using Cellular Modem Pools Many cellular carriers now offer Cellular Modem Pools which support the ETC protocol These Cellular...

Page 83: ...protocols then configure the mobile site modem to operate at 4800 bps by using the B4800 command G If the remote land line modem is not an ETC modem but it does support the V 22bis protocol then confi...

Page 84: ...G Cellular communications within a building may not be possible due to the number of obstructions within a building If you are having problems while trying to transfer or receive data from inside a bu...

Page 85: ...ing VOX G The remote modem should use V 42 error correction at a minimum If this is not possible then the remote modem should use Reliable mode Overview of Cellular Networks A cellular network consist...

Page 86: ...ength G Heavy phone traffic especially during peak periods such as rush hour and lunch hour and contention for an available frequency can determine if your data call connects G Hand offs the passing o...

Page 87: ...m data rate and modulation that may be used Two S Registers that also affect the data rate and modulation are S76 Autorate control and S78 Automode control The B command sets the modulation and maximu...

Page 88: ...ing rules controls which modulation is selected G If Automoding is on the modem may select either modulation depending on negotiations with the remote modem G If Automoding is off only the higher of t...

Page 89: ...since the non error control modem interprets these characters as data instead of part of the error control handshaking process Data Compression Data compression minimizes the amount of data sent over...

Page 90: ...from the computer To prevent the buffer from filling and overflowing which would result in data loss and errors the modem tells the computer to stop sending data When the modem s buffer is almost full...

Page 91: ...turn Modem B can use V 42 or MNP flow control techniques if using error control or it can send an XOFF to Modem C to stop data flow if using modem to modem flow control This is illustrated in link B...

Page 92: ...s situation the modems are configured to ignore and pass through any XON XOFF characters they may receive To resume data flow Computer A issues an XON character For this type of flow control the compu...

Page 93: ...d is generating an answer tone beginning the handshaking process with the calling modem asynchronous transmission A data transmission that is synchronized by a transmission start bit at the beginning...

Page 94: ...A signal between the local and remote ends of a network indicating energy exists on the transmission circuit command line Contains the command s instructing the modem to perform a function Command lin...

Page 95: ...hat is eliminated is restored after the data is received Data mode One of two operating modes When in Data mode the modem considers any input from the computer to be data and transmits it across the t...

Page 96: ...provides or creates data In this guide the term DTE refers to the computer in which the modem is installed DTR Data Terminal Ready A signal from the computer to the modem that indicates the computer...

Page 97: ...data in a network to avoid losing data Also see page NO TAG H handshaking The exchange of predetermined codes and signals tones to establish a connection between two modems The handshaking process oc...

Page 98: ...d by poor telephone line conditions Level 5 includes data compression modem MOdulator DEModulator A device used to convert data from a digital signal to an analog signal so that data can be transmitte...

Page 99: ...of checking data accuracy by counting the number of bits that have a value of one PBX Telephone switching equipment Private Branch Exchange dedicated to one customer A PBX connects private telephones...

Page 100: ...emory to buffer temporarily store data register A part of the modem s memory that contains values that determine the modem s operating characteristics response code An asynchronous message in either n...

Page 101: ...synchronized by timing signals Characters are sent at a fixed rate This type of transmission is more efficient than asynchronous transmission T tone dialing One of two dialing methods in which telepho...

Page 102: ...s its contents when the device is powered down Also see RAM V 17 A standard for modems operating in fax mode full duplex with asynchronous or synchronous data at 14 400 bps over dial telephone lines V...

Page 103: ...s data over dial or leased telephone lines at 14 400 12 000 9600 7200 or 4800 bps V 34 A standard for modems operating full duplex with asynchronous or synchronous data at 28 800 bps over dial telepho...

Page 104: ...ffering 4 8 G modem to modem flow control 4 9 K break control 4 9 N error control mode 4 10 Q serial port flow control 3 15 4 11 T inactivity timer 4 11 X XON XOFF passthrough flow control 4 11 C CD c...

Page 105: ...ter format 3 4 data compression 4 10 4 19 E 3 data mode 3 2 3 9 data mode return to O 4 4 data rate selection B 4 18 data rates B 1 destructive mode 4 9 diagnostic program A 1 dial modifiers 3 5 4 3 d...

Page 106: ...ommands M help text files 1 5 hook control H 4 4 I inactivity timer T 4 11 install program A 1 IRQ setting 2 4 2 5 A 3 L line feed character S4 4 20 loading a User profile after a reset Z 4 7 on power...

Page 107: ...dial modifier 4 21 S10 no carrier disconnect timer 4 21 S11 DTMF tone timer 4 22 S12 escape guard time 3 9 4 22 S18 test timer 4 22 S25 DTR detection 4 22 S76 autorate control 4 23 S78 automode contr...

Page 108: ...dex IN 5 Issue 2 May 1995 loading on power up 4 16 V V 17 fax See fax V 42 MNP 5 data compression C 4 19 W W dial modifier wait for dial tone 4 3 X XON XOFF passthrough flow control X 4 11 Z ZMODEM 3...

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