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MODEM USER GUIDE Issue RC1.3

1. file C MODULAR Manual txt 30 of 102 12 03 02 11 35 28 file C MODULAR Manual txt CHAPTER 6 AT COMMANDS All the Modems AT commands are described and listed alphabetically in this chapter For commands with parameters the value range and default values are also shown The value range used shows the variations of selections The default values tak ffect when your Modem is issued with the amp F command The commands are listed alphabetically by the first letter of the command mnemonic Note Rules for typing commands are provided in Chapter 4 Your Modem recognises commands in both upper and lower case characters A Manual Answer Parameters None Purpose To manually answer a call by putting the Modem off hook to generate answer tone and wait for a carrier Object To transfer a voice call to a data call After completing the voice portion of the call the operator types the ATA command and presses RETURN and the other individual types the ATD command The A command can also be used to manually answer a call by typing ATA after the modem has output a RING message You will receive a CONNECT response if a data connection is made otherwise your Modem hangs up sends you a NO CARRIER response and returns to Command Mode The Modem will not execute commands which appear after A on the command line therefore type any additional commands before the A command
2. DEVICEHIGH C CARDTALK CTALKCS EXE Loads Card Services DEVICEHIGH C CARDTALK CARDTALK SYS SERIAL 4 COM4IRQ 3 A IOW MEMW NOSHARE This line loads the modem utility here with COM 3 There is no DATABOOK DOS utility to query card status but there is a WINDOWS utility its icon is a stylised letter D file C MODULAR Manual txt 16 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt PHOENIX The following lines are required in the CONFIG SYS DEVICE C PCM3 CNFIGNAM EXE DEFAULT DEVICE C PCM3 PCMSSDB EXE Loads Socket Services in this case for DATABOOK hardware DEVICE C PCM3 PCMCS EXE Loads Card Services DEVICE C PCM3 PCMRMAN SYS DEVICE C PCM3 PCMSCD EXE With the Phoenix suite loaded type PCM at the DOS prompt for a utility which reads the CIS and identifies the card type s detected in the PC PHOENIX also has a WINDOWS utility which allows the user to confirm cards inserted identifying manufacturer and model number etc It is invoked by double clicking on the icon which depicts a PCMCIA card with a large Arrow on its upper surface AMICARDZ The following lines are required in the CONFIG SYS DEVICE C PCMCIA SSVADEM SYS Loads Socket Services for VADEM chipset in this example DEVICE C PCMCIA AMICS SYS Loads Card Services DEVICE C PCMCIA PCBE SYS DEVICE C PCMCIA PCMODEM SYS DEVICE C AICARD29 EXE There is no AMIC
3. Example 1 Test Timer Disabled Test performed with no errors file C MODULAR Manual txt 64 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Terminal Modem Terminal Modem Terminal Modem Example 2 Terminal Modem Terminal Modem Terminal Modem Example 3 Terminal Modem Terminal Modem Modem Example 4 Terminal Modem Terminal Modem Modem Note were with the returned data pattern OK ATS 18 0 amp T7 CONNECT AT amp TO 000 OK OK ATS 18 0 amp T7 CONNECT AT amp TO 001 OK Test timer set to 10 seconds OK ATS 18 10 amp T CONNECT 000 OK OK ATS 18 10 amp T7 CONNECT OK Escape sequence Acknowledges Start test End test No errors Acknowledgement Escape sequence Acknowledges Start test End test Test completed with 1 error Escape sequence Acknowledges Start test Test completed with no errors Escape sequence Acknowledges Start test Timer expired Test completed with 19 errors An error count of 255 indicates 255 or more errors detected or that no synchronisation was achieved file C MODULAR Manual txt 65 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt amp T3 Local Digital Loopback Test The Local Digital Loopback Test is used to loop the data stream received from the remote modem back to
4. The SE1l setting causes the modem to try several retrain attemps if unsuccessful the call will be dropped file C MODULAR Manual txt 35 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt file C MODULAR Manual txt 36 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt amp G Parameters Default Purpose G Parameters Default Purpose Object H Parameters Default Purpose Object Parameters Purpose Select Guard Tone amp GO disable guard tone amp Gl As amp G0 amp G2 Select 1800Hz guard tone amp G2 The modem will use the guard tone selected by the parameter supplied Always use amp G2 for operation in the UK Modem to Modem Flow Control GO Disable modem to modem flow control G1 Enable modem to modem flow control GO Set modem modem flow control during non rror corrected calls connection only The G1 command allows the modem to generate and recognise XON XOFF characters for flow control On an error corrected link the G setting is ignored On Hook or Off Hook HO Goes on hook H1 Goes off hook HO On Hook This is equivalent to your telephone handset resting on its hook i e the modem is hung up Off Hook This is equivalent to your telephone handset off its hook i e the modem is online using the telephone line The OH indicator goes ON on the front panel wh
5. 1 TERMINAL SPEED DATA FORMAT By default the modem will automatically work out what speed the PC is using the word length and the parity each time it receives an AT command from the terminal As the Modem features a constant speed interface it does not matter if the PC port speed is different from the line speed In fact it is generally more efficient to run the port at a higher speed than the intended line speed This is particularly important if you intend to use MNP or V 42 with or without data compression As a guide the port speed should be at least twice the line speed when using error control When using data compression the port speed should be four times the line speed For instance when using the modem at V 32bis 14400bps the port speed should be 57600 However if you intend to operate the PC at a speed higher than 19 2kbps it is important that your COM port hardware is a buffered UART or If in doubt run MSD from the DOS prompt on your PC to verify the COM port characteristics any ports identified as 8250 should not be run higher than 19200 2s FLOW CONTROL Whilst the modem s default is to use file C MODULAR Manual txt 10 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt RTS CTS hardware flow control your particular system or application may require the use of XON XOFF software flow control This may be selected using the AT amp K4 command or adding
6. A Repeat Last Command Parameters None Purpose To x xecute a lengthy command line without retyping Object The A command instructs your Modem to repeat the last executed line You need not type AT or press RETURN when sending the A command as you do for other commands AT Attention Characters Parameters Designates transmission speed character format and parity file C MODULAR Manual txt 31 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt Object Typed in upper or lower case letters at the beginning of a command line to inform your Modem of the transmission speed character format and t equipment is set for he parity your Executing a command line without AT at the start results in no response at all file C MODULAR Manual txt 32 of 102 12 03 02 11 35 28 file C MODULAR Manual txt A Parameters Default Purpose Object Bn Parameters Default Purpose Object ole C Parameters Default Object amp C Parameters Default Maximum MNP Block Size AO Sets the maximum block size to 64 characters Al Sets the maximum block size to 128 characters A2 Sets the maximum block size to 192 characters A3 Sets the maximum block size to 256 characters A3 To set the maximum MNP block size Class 4 and Class 5 operation This command has no effect on Class 3 and lower operations
7. V 22 A B 1200bps V 22bis 2400bps V 32 fallback 4800bps V 32bis fallback 7200bps V 32 9600bps V 32bis 12000bps V 32bis 14400bps G Modem Modem Flow control H On Off Hook I Indentification amp K Flow Control 0 1 us AT MS instead Restore Factory Profile 0 Disable Guard Tone Same as 0 Select 1800Hz guard tone Disable Enable non ECC connections only Hang up Go off hook Product code Pre computed checksum from firmware Firmware checksum calculation and comparison with pre computed value returns OK or ERROR Base Firmware revision level Overall level of firmware DSP hardware type and revision level Disable Flow Control Enable RTS CTS flow control Enable XON XOFF flow control Enable transparent XON XOFF flow control Enable both RTS CTS and XON XOFF file C MODULAR Manual txt 93 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt K Break handling K MNP 10 Extended Servic 0 Disable V 42 to MNP conversion 1 Enable V 42 to MNP conversion L Volume 0 Low speaker volume 1 Medium speaker volume 2 High speaker volume SL Shows the Rx signal level file C MODULAR Manual txt 94 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt L MNP mode 0 Stream mode for MNP connections 1 Block mode M Loudspeaker 0 Speaker off MS Speaker ON until carrier detect 2 Speaker ON continuously SE Speaker ON only during an
8. which limit the maximum block size to 64 characters This command should be used to transmit smaller blocks of data when communicating over poor quality telephone lines to avoid retransmission of data and improve throughput Send Break Signal 9 Non error corrected links only Send break to remote system The B command is equivalent to pressing the break key on a terminal keyboard For standard non error corrected connections type a number from 1 to 9 after this command to indicate how long the modem is to provide the break signal The number will be multiplied by 100 ms and the break signal provided for that duration For error corrected operation the break is always 300 milliseconds Data Compression SCO Disable data compression C1 Enable MNP 5 data compression negotiation scil Enable or disable data compression If disabled the modem will operate with error correction only DCD Option amp C0 DCD always on amp C1 DCD on if valid carrier amp C1 amp C0 in 144 models file C MODULAR Manual txt 33 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt Purpose Object Control use of DCD pin 8 on the V 24 RS232C interface Certain software applications wish to know when a carrier is present i e modem is connected to a remote modem The DCD pin on the RS232C interface is used for this file C MODULAR Manual txt 34 of 102 12 03 02 11 35 28 fi
9. To store a telephone number in non volatile memory A stored phone number may be conveniently used in dialling e g ATDS 2 dial stored number 2 Four numbers may be stored i e m 0 to 3 e g AT amp Z2 5551212 stores number 5551212 in location 2 See AT amp V to view stored numbers file C MODULAR Manual txt 51 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt CHAPTER 7 REGISTERS The Modem has Special Registers which control many operating parameters These are known as S registers The remainder of this chapter lists the registers which are available for user access Many other registers are used by the modem for its operating parameters and writing values directly to any registers other than those which follow could result in unpredictable behaviour by the modem Reading a Value To read the current value of a register use the Sr command with r indicating the register number required The Modem then sends you the decimal value of the register For example to read the current value in Register SO type AT S0 and press the RETURN key 003 This value indicates that Modem automatically answers calls after three rings OK The Modem completed the command and waits for your next command Changing a Value To change a register value use the Sr n command with r indicating the register number 0 95 and RUR indicating the new decimal value In
10. 255 varies with register To change the value of an Modem register The ntire procedure is described in Chapter 7 Return to Command Mode after Dialling None Typed at the end of a Dial command line to instruct your Modem to return to Command Mode after dialling without going on hook Allows data to be sent as Touch Tones to services such as the telephone order service of banks which recognise Touch Tones as data DSR Options amp S0 DSR always on amp S1 DSR follows V 24 RS232C Specification amp SO Allow control of DSR amp S0 may be used for terminals and PCs that require DSR to be ON permanently Touch Tone Dialling None o tone dial the digits which follow T ina Dial Command Line Type the T command anywhere even between digits in a dial command line to cause the modem to tone dial Test Mode Enable Disable amp TO End Self test mode amp T1 Local Analog loopback amp T3 Local digital loopback amp T4 Grant RDL request amp T5 Deny RDL request amp T6 Remote digital loopback amp T7 Remote digital with self test amp T8 Local Analog loopback with self test amp TO amp T4 To enable disable the self test mode details of the Self test and diagnostic functions are discussed in Chapter 8 Diagnostics and Testing Full file C MODULAR Manual txt 48 of 102 12 03 02 11 35 29 file C MODULAR Manual txt V Word or Di
11. 32 amp V 32bis with or without Trellis CCITT V 34 file C MODULAR Manual txt 74 of 102 12 03 02 11 35 29 file C MODULAR Manual txt Receiver Dynamic Range Transmitter Level Line Synchronisation Self test and Loopbacks Telephone Lin REN Telephone Handset Serial Data Interface Desktop versions Power Supply Desktop versions Physical Dimensions Environmental Operating Relative humidity Storage Asynchronous signalling rates at 1200 amp 2400 are 1 and 2 5 NOTE FSK Frequency Shift Keying DPSK Differential Phase Shift Keying QAM Quadrature Amplitude Modulation 0 to 45 dB full duplex 11 dB Automatic Adaptive Equalisation receiver Fixed Compromise Equalisation transmitter Modem performs Local Analog amp Digital Loopback test or Remote Digital Loopback test on command or from the V24 RS 232 interface 600 ohm balanced dial up telephone interface meeting British Telecom specifications One BS6312 type plug 1 0 4 wire 600 ohm balanced telephone interface meeting British Telecom specifications One BS6312 type socket 25 pin RS232 V 24 interface with female DB 25 connector on modem rear panel wired as a DCE Plug top 240 V AC 50 Hz supplying 9Vac 700mA 116 mm wide x 32 mm high x 170mm deep Desktop 20mm wide x 106mm high x 135mm deep PC Cards The modem meets specification requiremen
12. Manual txt Notes If you are using software which uses the N and S37 x commands then support is provided at 14400 bps and lower speeds in which case the reported MS subparameters will be modified to reflect the N and S37 x settings However this method is not generally recommended because of the speed limitation and because S37 is not updated by the MS command Examples AT MS 2 Instructs the modem to assume V 22bis mode for future connections attms 74 Sets the modem up as a V Fast modem lt automode gt is an optional numeric value which enables or disables automatic modulation negotiation The options are 0 Automode disabled 1 Automode enabled using V 8 or V 32 Annex A The default value is 1 which enables automode Note however there are modulations for which there is no automatic negotiation e g Bell 212 lt mod gt 69 For lt automode gt 0 automode disabled i e fixed modulation a If lt max_rate gt is within the rates supported by the selected modulation the selected rate is that specified by lt max_rate gt For example MS 9 0 1200 4800 selects V 32 4800 bps fixed rate If lt max_rate gt is greater than the highest speed supported by the modulation specified by lt mod gt the starting rate is the highest rate supported by the selected modulation For example t MS 9 0 2400 14400 selects V 32 9600 or 4800 bps To force a specifi
13. WBA WwW OW GBS PBR ooo WN FR ooo Now oo co N 66 67 69 70 77 80 Gl MEANING Command line executed successfully Remote carrier detected Incoming ring detected Remote carrier lost or not detected Command line contains error The modem cannot recognise the command Remote carrier detected A dialton xpected but not found Remote line is busy The remote modem did not answer the call or answered incorrectly Connection established at 600bps Connection established at 2400bps Connection established at 4800bps Connection established at 9600bps Connection established at 7200bps Connection established at 12000bps Connection established at 14400bps Connection established at 19200bps Connection established at 38400bps Connection established at 57600bps V 23 connection established V 23 connection established was Remote carrier detected at V 21 Remote carrier detected at V 23 Remote carrier detected at V 23 Remote carrier detected at V 22 Remote carrier detected at V 22bis Remote carrier detected at V 32 Remote carrier detected at V 32 Remote carrier detected at V 32 Remote carrier detected at V 32bis Remote carrier detected at V 32bis Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier
14. and your Modem connects to another modem it determines the transmission speed of the remote system from the carrier signal of the modem originating the call this speed could be different from that currently in use between your terminal and the modem The Modem will then select an interface speed to match that of the line remote modem A connect message showing the new speed is firstly issued at the previous interface speed then the interface speed changes to the new rate file C MODULAR Manual txt 21 of 102 12 03 02 11 35 28 file C MODULAR Manual txt CHAPTER 4 COMMANDS AND RESPONSES This chapter offers guide lines to follow when sending commands to your Modem and describes the responses sent by your Modem in reply to your commands Executing Commands When your Modem is in Command Mode explained in Chapter 3 you can use your keyboard to send your modem a command Commands are sent in the form of mnemonics to specify the requested operation the Modem will then respond with an appropriate response The remainder of this chapter describes how to use each of the command sets to control the modem Using AT commands Use the following guide lines when typing AT commands iy With your Modem in Command Mode the letters AT in upper or lower case must appear at the start of every command line 2a Type the command mnemonics in upper case or lower case letters note that many m
15. are ignored file C MODULAR Manual txt 66 of 102 12 03 02 11 35 29 file C MODULAR Manual txt CHAPTER 9 STATUTORY INFORMATION FOR THE MODEMS The purpose of these modems is to allow terminals PCs and other computers to interconnect via the Public telecommunications network The modems ar quipped with the following ports Description of Port Types PC card Modem Type of Circuit Port Location Port Description TNV Rear Panel PSTN NTTP Line connection TNV Rear Panel Associated Handset Connection SELV PC Edge Connector PC Bus and Power connections Description of Port Types Desktop Modem Type of Circuit Port Location Port Description TNV Rear Panel PSTN NTTP Line connection TNV Rear Panel Associated Handset Connection SELV Rear Panel DTE PC connection Do not connect unapproved telephone handsets to the Associated Handset connection Do not operate the modem in modes which are not intended for use outside the UK The UK configuration for the appropriate commands are ATBO AT amp G2 and refer to these commands in chapter 6 for more detail These modems have been approved for use with direct exchange lines and compatible PABXs The user should be aware that it is the modem and not the host which has been approved Ringer Equivalence Number REN REN is a value given to all apparatus which can be connected to the PSTN The REN is used to cal
16. command mode file C MODULAR Manual txt 20 of 102 12 03 02 11 35 28 file C MODULAR Manual txt Resetting your Modem Ts Turn your Modem off then on 2 Type ATZ and press RETURN key Either step resets your Modem causing the following to occur 1 The commands assigned specific parameters will return to default values 2n Registers S0 through S19 return to default values 3 4 Your modem goes on hook if it was off hook 4 The last executed command is deleted from memory Iz Your Modem remains in Command Mode 6 Your Modem sends you the OK respons Speed Requirements Baud Rate When sending commands to your Modem from your PC or terminal be sure that the speed of the connection is 300 600 1200 2400 4800 9600 or 19200 bps 38400 57600 bps or 115 2Kbps Use the appropriate software command to set the transmission speed of your computer or terminal to match or exceed that of the remote system Consult your manual to see how to set the speed it can be set to any combination of the following software Data 7 or 8 databits per character Stop Bits I or 2 Parity Odd Even or None Also Mark or Space but see note below The use of Mark or Space parity will be accepted and transmitted by the modem as follows Terminal Computer Modem 7 bit Mark 7 bit None 7 bit Space 8 bit None 8 bit Mark 8 bit None 8 bit Space 8 bit Even When in Direct or unbuffered mode AT N1
17. data calls When a compatible modem answers your data call the Modem automatically makes the data connection If your software is able to operate with AT commands i e it expects a Hayes compatible modem you can use such commands to dial calls automatically Auto Answering Although the Modem is preset to answer calls automatically you can disable this by entering the ATSO 0 command see chapter 7 Operating Modes Two basic operating modes Command Mode and Data Mode are supported on the Modem In Command Mode you can send keyboard instructions to the Modem to respond to a variety of dialling and answering functions In Data Mode you can exchange data across the telephone line with a modem at a remote location Do not send commands when in Data Mode as the modem assumes everything it receives from the computer or terminal is data and will send it across the telephone lin Command Mode The Modem automatically enters Command Mode when Tg You turn on the modem Dix You touch any key on the keyboard while the modem is dialling answering or training causing it to hang up 3 Either modem fails to detect the other s carrier Signal due to a hang up or telephone line noise and breaks the data connection file C MODULAR Manual txt 19 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt Command Sets The Modem supports a command set or language for control of its operation AT com
18. detected at V 34 MNP 5 Data Compression in operation V 42bis Data Compression in operation No Data Compression No Error Correction Protocol LAPM V 42 Error Correction Protocol MNP 4 Error Correction Protocol 1 AT COMMAND RESPONSES file C MODULAR Manual txt 24 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt Modem Control Strings Communications and Fax software packages generally have strings which are used at different times to control the modem operation Each string is made up of selected AT commands which is described in detail in Chapter 6 RESET each of This is likely to be issued when the software tries to recover from an unknown state Usually simply an ATZ command INITIALISATION Its job is to change the modem from whatever state it has been left in toa known state that is compatible with your fax or comms software The modem is very straightforward without any unusual features which your software would have to take account of so the most simple of Initialisation strings will be sufficient eg AT amp F which will select th modem s factory defaults DIAL Simply ATD for the modem range HANGUP Use ATH to hangup file C MODULAR Manual txt 25 of 102 12 03 02 11 35 28 file C MODULAR Manual txt CHAPTER 5 DIALLING The dialling commands available on your Modem are detailed in this chapter The Modem is designed to di
19. established was Remote carrier detected at V 21 Remote carrier detected at V 23 Remote carrier detected at V 23 Remote carrier detected at V 22 Remote carrier detected at V 22bis Remote carrier detected at V 32 Remote carrier detected at V 32 Remote carrier detected at V 32 Remote carrier detected at V 32bis Remote carrier detected at V 32bis Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier detected at V 34 Remote carrier detected at v 34 MNP 5 Data Compression in operation V 42bis Data Compression in operation No Data Compression LAPM V 42 Error Correction Protocol MNP 4 Error Correction Protocol MNP 10 Cellular Power Protocol FUNCTION Ring number to auto answer calls file C MODULAR Manual txt 100 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt S1 0 255 rings 0 Count number of incoming rings S2 01 127 ASCII 43 Escape character 53 0O 127 ASCII 13 Carriage return character S4 0 127 ASCII 10 Line feed character 55 0 127 ASCII 8 Backspace character S6 5 6 seconds 5 Wait for dial tone period S7 0 58 seconds 50 Wait for remote carrier period S8 3 10 seconds 3 Wait for dial pause S9 0O 255 100ms 6 Carrier detect repons time S10 O 255 100ms 14 Carrier loss reponse ti
20. file C MODULAR Manual txt Register S6 Wait Time For Dial Tone Range 5 6 seconds Default 5 seconds Register S6 determines the time delay your Modem makes after accessing the telephone line before dialling the first digit in the dial command The delay allows time for a dial tone to be provided on the line The default of 5 seconds is the minimum delay time If you can assign a value less than 5 your Modem still waits 5 seconds You may want to increase the value in this register if you have trouble receiving a dial tone within 5 seconds Register S7 Wait Time For Remote Carrier Signal Range 0 58 seconds Default 40 or 50 seconds depending on model Register S7 determines the number of seconds your Modem waits for a remote modem s carrier signal before hanging up The timer starts when the modem completes dialling The default delay value is usually enough time However you can assign a value from 0 to 58 NOTE There is a statutory requirement that this wait time does not exceed 59 seconds Register S8 Pause Time for Comma in Dial Commands Range 3 10 seconds Default 3 seconds Your Modem pauses for each comma it encounters in a Dial command line The comma is generally used when dialling through a PBX or other special telephone service Register S8 determines how long to pause for each comma The 3 second default value is usually enough time
21. for most applications file C MODULAR Manual txt 56 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Register S9 Carrier Detect Response Tim Range 0 255 x 100ms Default ll Oy 600ms Register S9 sets the carrier detect response tim This is the time taken for a carrier from a remote modem to be present on the telephone line before the DCD signal is asserted S9 must have a value less than S10 fora connection to occur Setting the register value below 6 might result in noise on the telephone line being confused with a carrier signal Register S10 Carrier Detect Loss Time Range 0 255 x 100ms Default 14 1 4 seconds Register S10 sets the carrier detect loss time This is the time taken for an absence of carrier during a connection with a remote modem to signify that the connection has ended S10 must have a value greater than S9 for a connection to occur Register S12 Escape Guard Time Range 0s 255 x 20ms Default 50 1 second Register S12 sets th scape guard time the time delay required both before and after entering the escape characters It also determines the maximum inter character time The guard time prevents your Modem from misinterpreting the escape characters as data If you assign a value of 0 timing will not be a factor you will be able to enter t s he thr scape characters without concern for timing onsiderations You must
22. intervention S The ability of a modem to dial telephone numbers under software control and thereby originate telephone calls without manual intervention The term baud rate refers to the rate at which a modem modulates the digital signal for transmission This rate is often confused with the bits per second transfer rate though the two may be different The term is taken from the name of Frenchman Louis Baudot binary synchronous communications bit BSC A type of protocol that synchronises both ends of the communication line then transmits binary data across the line The name given to the smallest unit of information that can be stored in file C MODULAR Manual txt 80 of 102 12 03 02 11 35 29 file C MODULAR Manual txt a computer An acronym derived from binary digit break This is a signal that communicating devices normal operation The of a series of 0 bits is used by to interrupt signal consists which must be present for longer than the period of a normal character file C MODULAR Manual txt 81 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt British Approvals Board for Telecommunications BABT buffer byte carrier signal Clear To Send CTS communications software Data Carrier Detect DCD Data Communications Equipment DCE data compression Data Set Ready DSR Is the
23. is greater than 0 The value in register S1 adds up with each incoming ring received by your Modem It clears if no rings occur within approximately eight seconds after the last ring You will rarely use the S1 register but you can read or set it If the telephone does not ring this value clears to zero after eight seconds Register S2 Escape Character Range 0O 255 ASCII Default 43 ASCII Register S2 identifies the decimal value of the ASCII characters used to perform th scape feature described in Chapter 3 The default value decimal 43 is the ASCII character although you can change this register to most values from 0O to 127 Values greater than 127 disable the escape feature preventing you from sending a HANG UP command since you cannot return from Data Mode to Command Mode while keeping the data connection To disconnect in this instance either the remote modem must hang up or you must de assert Data Terminal Ready DTR on pin 20 the Modem s DTE interface see AT amp D command Register S3 Carriage Return Characters Range 0 127 ASCII Default Ls CTRL M Register S3 identifies the character used to end and execute a command line and the character you receive following a modem response Normally you will want to use the default value of 13 However you may want to change this value if using file C MODULAR Manual txt 53 of 102 12 03 02 11 35 29 fi
24. modem transmitter to test the remote modem circuits See also Remote Digital Loopback with Self Test Your Modem may be conditioned to accept a request from a remote modem for a remote digital loopback with the amp T command factory setting or it can be programmed to refuse such a request by issuing the amp T5 command file C MODULAR Manual txt 63 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt The Remote Digital Loopback test is also able to be initiated from the V 24 RS 232 interface by the DTE asserting RL on pin 21 circuit 140 The modem asserts the TI signal pin 25 to acknowledge the application of the test The following is an example using the Remote Digital Loopback Test Assume starting from an on line state The local data terminal equipment must be set to expect characters to be echoed and your Modem is set to echo commands received from the local data terminal Example 1 Test timer disabled Terminal Escape sequence Modem OK Acknowledges Terminal ATS 18 0 amp T6 Start test Modem CONNECT Modem now in test mode Type the test The silent hawk caught confirm no errors Message the sleepy chicken in echoed message Terminal Escape Sequence Modem OK Acknowledges Terminal AT amp TO End test Modem OK Test terminated The local terminal equipment the local and remote modems and the telepho
25. on your keyboard your Modem then hangs up sends on OK response while dialling or NO CARRIER response when waiting for carrier then returns to Command Mode file C MODULAR Manual txt 29 of 102 12 03 02 11 35 28 file CVMODULAR Manual txt Hanging Up At the end of a call put your Modem in Command Mode using the escape characters if necessary type ATH and press the RETURN key The modem then hangs up the call sends an OK response and returns to Command Mode Your Modem may also disconnect a call when the RS232C signal DTR pin 20 changes See the AT amp D command which controls the use of this feature Stored Numbers Your Modem has the capability of saving 4 telephone numbers in its internal memory These numbers are protected from reset or power failure so will be available for use even after your Modem has been switched off In order to save a stored number use a command such as AT amp Z3 5551212 This command saves the telephone number 5551212 in the third memory location The stored number can be recalled during a dial command with the S command followed by the memory location e g ATDS 3 Manual dialling Plug a telephone handset into the socket on the rear of the modem You can then dial numbers with the telephone When you hear the answertone from the remote modem type ATD lt RETURN gt Replace the receiver immediately afterwards and the Modem will take over the dialled call
26. the remote modem is able to respond to V 54 loop requests The remote modem will loop its receive stream back to the line and hence to the local data station The local data terminal can then compare the received stream of data with its transmitted message to verify the connection If the data pattern which is received does not match the information transmitted then either the local data terminal the local or remote modem or the telephone circuit is at fault If this is the case both the local and remote stations may individually initiate local analogue loopback tests to further isolate the cause of the problem Note The Remote Digital Loopback with or without self test and Local Digital Loopback can only be performed when your Modem is connected with a remote modem and operating a non error corrected call If not an ERROR message will be received You can initiate the Remote Digital Loopback test by Ts Establishing a dialled connection 2ye Returning to the command mode by issuing the escape sequence 3 Issuing the amp T6 command once in the command state The local modem requests a digital loopback with the remote modem through a special CCITT standard handshake sequence s CCITT Recommendation V 54 for details The remote modem automatically acknowledges the request if it has been conditioned to do so The remote modem then loops the output of the modem receiver into the input of the
27. 03 02 11 35 29 file CV MODULAR Manual txt Q Parameters Default Purpose Object amp Q Purpose Object amp R Parameters Default Purpose Sr Parameters Purpose Suppress Modem Responses Q0 Sends responses Ql Does not send responses Qo To enable or disable the result codes from the modem The Modem sends responses when executing commands and at other times during its operation If you do not want to receive modem responses send the Q1 command One such situation is when a printer is connected to your Modem and you do not want the modem responses printed Async Operating Mode Identical to the amp M command to control the connection modes allowed See amp M RTS Operation amp RO CTS follows RTS after delay specified by S26 amp R1 RTS transitions are ignored CTS always ON amp RO This controls how the modem will operate in synchronous mode Read Register r r 0 95 To read the value of the modem s register The ntire procedure is described in Chapter 7 file C MODULAR Manual txt 47 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Sr n Parameters Purpose Semicolon Parameters Object amp S Parameters Default Purpose Object T Parameters Purpose Object amp T Test Parameters Default Purpose Set Register r to Value n Goa A0 95 n 0
28. 2 12 03 02 11 35 29 file C MODULAR Manual txt APPENDIX G AT Command Summary e Data Mode Escape A Manual Answer A MNP Max block size 0 64 Characters 1 128 Characters 2 192 Characters 3 256 Characters A Repeats Last Command AT Attention Characters B Transmits Break De 9 Break length in 100ms units length can be specified only on non EC calls SC Compression 0 Disable EC and Data compression 1 Enable MNP negotiation 2 Enable V 42bis 3 Enable V 42bis and MNP amp C DCD Options 0 DCD always ON 1 DCD determined from line G Remote password n a in 288 336 modem Enter the remote configuration password for this modem D Dial Dial modifiers A Pause F Return to Command Mode after dialling T Touch Tone Dialling W Wait for a Second Dial Tone L Redial Last number 5 Disable Call Tone amp D DTR Options 0 Ignores DTR Go to Command State when DTR ON OFF 2 Hang up Go to Command State when DTR ON OFF 3 Power Up Reset when DTR ON OFF E Echo 0 No Command Echo 1 Command Echo file C MODULAR Manual txt 92 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt SE Retrain 0 1 F Line Modulation 0 1 2 on a 4 5 Oo 7 8 9 10 ATF not supported on 288 336 modem amp F Restores Factory Defaults amp G Guard Tone bh Disable auto retrain Enable auto retrain Auto mode V 21 300bps ignored OK response V 23 1200 75 bps
29. 2400 CONNECT 1275 CONNECT 7512 X2 Extended result code with Dialtone detect X3 Extended result code with BUSY signal detection X4 Extended response set with BUSY signal and Dialtone detection x4 Use basic responses X0 when the CONNECT response is suitable for data connection at all speeds Send the X1 command when you require the CONNECT response to include the connection speed If busy and or dialtone detection is required use X2 X3 or X4 See also S register 95 for messag nhancements Select Profile amp Y0 Select Profile 0 amp Y1l Select Profile 1 amp YO Select Profile for power up reset By default stored Profile 0 is used after a reset for the active profile settings Use this command to cause Profile 1 to be used file C MODULAR Manual txt 50 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Parameters Default Purpose Object amp Zm Parameters Purpose Object Fetch Profile ZO Fetch Profile 0 Z1 Fetch Profile 1 Z0 Reset your Modem to one of two stored profiles Sending the Z command to reset your Modem causes the modem to Hang up if off hook Registers are fetched from the selected stored profile Delete the last executed command from memory The user should wait at least one half second after receiving OK before sending another command Store Telephone Number amp Zm 123456
30. 3 lt min_rate gt is an optional number which specifies the lowest rate at which the modem may establish a connection The value is decimal coded in units of bps e g 2400 specifies the lowest rate to be 2400 bps The default is 300 for 300 bps 4 lt max_rate gt is an optional number which specifies the highest rate at which the modem may establish a connection The value is decimal coded in units of bps e g 14400 specifies the highest rate to be 14400 bps The default is 33600bps Note that the modem will assume that the lt max_rate gt will not be greater than the current DTE terminal speed Reporting Selected Options The user is able to view the selected MS options by issuing the following command AT MS The response is MS lt mod gt lt automode gt lt min_rate gt lt max_rate gt For example MS 11 1 300 33600 shows default values Reporting Supported Options This command allows the user to query which possible modes are supported on the modem the command is AT MS The response is MS list of supported lt mod gt values list of supported lt automode gt values list of supported lt min_rate gt values list of supported lt max_rate gt values For example FMS AOp Dye 2 35 8 95 LOr 135 64 69 TEN 0 1 300 33600 300 33600 N Automode Enable This command enables or disables automode detection The parameter value if vali
31. ARDZ DOS utility to query card status but there is a WINDOWS utility IBM As the IBM software is only designed for IBM machines there are fewer options There is a DOS utility which queries and displays card status On later IBM ThinkPads with the plug and play facility there is no configuration required file C MODULAR Manual txt 17 of 102 12 03 02 11 35 28 file C MODULAR Manual txt WINDOWS 95 Windows 95 installations are different from the above as Microsoft include Card and Socket Services within Windows 95 The following method is required to inform the PC that an M5134 LT modem is installed From the Control Panel select Add New Hardware then Modem Now ensure the modem is plugged into either PCMCIA slot Insert the manual driver disc and choose the modem type as an Enhanced Modem PCMCIA type The PC will now test the modem and identify it as being present file C MODULAR Manual txt 18 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt CHAPTER 3 OPERATION This chapter describes the functions which are supported on the Modem These functions allow you to set your Modem to dial automatically and also automatically to answer an incoming call The Command and Data operational modes are also discussed in this chapter together with control characters reset procedures and baud rate options Auto Dialling The Modem automatically dials both voice and
32. Digits supported are gg 9 Symbols and Touch Tone only T Use the Touch Tone dialling method semi colon Return to Command Mode after dialling l Causes the modem to perform a timed break recall Hook Flash at this point in the dialling operation Some PABX systems allow the caller to break off from a call and obtain dial tone once more Recall this is normally used to facilitate such operations as transfering a call or accessing special functions etc One method of achieving Recall is to break the connection to line for a specified amount of time hence Timed Break Recall The break time can be set using S29 Check if the PABX supports this method of recall before attempting to utilise the command W Causes your Modem to wait for dial tone for the period specified by register S6 If a busy tone is detected your Modem will go on hook and display a BUSY signal A keyboard input will subsequently be accepted and an on hook will occur with an OK response An ERROR response will occur if the W command is not in the dial string NOTE Only one consecutive W command may be inserted into a dial string at any one time comma Causes a short pause for 3 seconds Contents of S register 8 S n Dial stored number n where n is 0 to l TABLE 5 1 DIAL COMMANDS The Pause Command When you wish to dial a call through a Private Branch Exchange PABX you must first dia
33. ICATORS file C MODULAR Manual txt 9 of 102 12 03 02 11 35 28 Register SO value set to 0 ON when your Modem is using the telephone line off hook OFF when your Modem is not using the telephone lin on hook ON when the Modem is in a test mode file CV MODULAR Manual txt INITIAL SETUP When first configuring the Modem for use with your own system it is best to put it into a known state by ensuring the Factory profile is loaded This may be achieved by entering t he AT amp F command The most important of the Factory settings hat will be loaded ar The most important of the Factory settings that will be loaded are FEATURE SETTING Terminal type Asynchronous amp M0 Terminal speed data format Auto detect on entry of AT command Command echo ON E1 Flow Control RTS and CTS amp K3 CTS signal Follow RTS amp R0 DTR signal Active amp D2 amp D0 on 144 modems DSR signal Always ON amp S0 DCD signal Active amp Cl amp CO on 144 modems Result codes Verbose V1 Connect codes Extended X4 Dialling method Tone Auto answer Enabled S0 2 Speaker ON until connect M1 Volume Medium L2 Having loaded the Factory settings and put the modem into a known state you may now proceed to change particular settings as required by your application GENERAL REQUIREMENTS Typical settings that may be important for any type of application are
34. PCMCIA slots there are two additional device drivers which must run on the PC In logical terms these drivers known as CARD SERVICES and SOCKET SERVICES provide an interface between the hardware ie the slot in the PC and any comms or fax software running on the PC If the Lap top PC has been prepared modem ready by the manufacturer these utilities will already have been installed loaded and you will be able to insert the modem and use it directly If you experience difficulty getting a PCMCIA modem to operate correctly these drivers and their configuration should be checked Both drivers are invariably loaded from the CONFIG SYS file To date the modems have been tested with the following types of driver CARDSOFT PHOENIX DATABOOK AMICARDZ IBM Each lap top computer manufacturer generally pre installs one of the above the only exception being IBM which has developed its own drivers Lap top PCs running Windows 95 are a special case as the Card and Socket Services are included within Windows 95 Each requires different lines in the CONFIG SYS file to load the various parts The remainder of this chapter shows those which have been found to operate with the modem In order to check the CONFIG SYS file you should type the following at the DOS prompt c gt EDIT C CONFIG SYS You will then be able to compare the file with the lines on the following pages and make changes where necessar
35. R CARRIER CARRIER CARRIER CARRIER CARRIER CARRIER CARRIER CARRIER CARRIER CARRIER 31200 CARRIER 33600 COMPRESSION CLASS 5 COMPRESSION V 42BIS 600 2400 4800 9600 7200 12000 14400 19200 38400 57600 75TX 1200RX 1200TX 75RX 300 75 1200 1200 75 1200 2400 4800 7200 9600 12000 14400 16800 19200 21600 24000 26400 28800 COMPRESSION NONE PROTOCOL LAPM PROTOCOL ALT PROTOCOL ALT CELLULAR REGISTER RANGE So 0 255 DIGIT RESPONSI e UU NHO Oo CDCOWDAIADAWNOWNWAATA BFWBNEF CO Qo WBA WwW OW GBS PBR ooo WN FR awn on wo o Nx oU amp 66 67 69 TE 80 81 rings ea DEFAULT MEANING Command line executed successfully Remote carrier detected Incoming ring detected Remote carrier lost or not detected Command line contains error The modem cannot recognise the command Remote carrier detected A dialton xpected but not found Remote line is busy The remote modem did not answer the call or answered incorrectly Connection established at 600bps Connection established at 2400bps Connection established at 4800bps Connection established at 9600bps Connection established at 7200bps Connection established at 12000bps Connection established at 14400bps Connection established at 19200bps Connection established at 38400bps Connection established at 57600bps V 23 connection established V 23 connection
36. R indicator on the front panel will illuminate b If your PC is connected and ready to communicate the TR indicator will also be lit file C MODULAR Manual txt 7 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt LED Indicators The front panel of your Modem contains nine LED indicators which show your current operating status From left to right the indicators are as described in Table 2 2 LEGEND V 24 SIGNAL MEANING FUNCTION MR DSR Modem Ready ON when modem is READY TR DTR Terminal Ready ON when your computer or terminal is sending its DTR signal CD DCD Carrier Detect ON when your Modem detects a remote modem s carrier signal OFF when remote carrier signal is not detected or remote modem hangs up SD TXD Send Data Flashes when your computer or terminal sends a command to your Modem or when your Modem sends data to the remote modem RD RXD Receive Data Flashes when your Modem receives data from the remote location or when your Modem sends data or responses to your computer or terminal HS High Speed ON for V 22 bis operation or faster OFF at 300 amp 1200 bps operation AA Auto Answer ON when your Modem receives an incoming call and is set up to automatically answer calls OFF when set up to ignore calls file C MODULAR Manual txt 8 of 102 12 03 02 11 35 28 file C MODULAR Manual txt OH Off Hook TST Test TABLE 2 2 LED IND
37. STING If failures in a communications link occur the Modem s diagnostic and test facilities assist you to determine the source of the difficulty Problems occasionally encountered are usually characterized by slow throughput spurious characters or a total inability to communicate Problems can be encountered in either the local or remote data terminal equipment the local or remote modem or the telephone circuit and the Modem s diagnostics are designed to help you find the cause of the problem Five diagnostic tests are supported on your Modem These tests are Local Analogue Loopback V 54 loop 3 which tests the communications path between your Modem and local data terminal equipment including Local Analogue with Self Test which tests your Modem s status Remote Digital Loopback V 54 loop 2 which tests the communications path between your data terminal equipment the Modem then telephone circuit and a remote modem Remote Digital Loopback with Self Test which tests the circuit with pre defined data Local Digital Loopback which allows a remote modem without remote digital loopback capabilities to test the telephone circuit A To determine if a failure is due to a faulty telephone circuit Perform the local analogue loopback with self test If both modems pass this test but the remote digital loopback with self test fails this is good indication the telephone circuit is at fault However
38. ady to communicate file C MODULAR Manual txt 82 of 102 12 03 02 11 35 29 file C MODULAR Manual txt Data Terminal Equipment DTE 7 Data Terminal Ready DTR downloading A term used to describe communications equipment which either originates data or receives data for its own use usually a terminal An RS232C signal that is generated by DTEs when they are ready to communicate The process of receiving a file from a remote information service or computer file C MODULAR Manual txt 83 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt EBCDIC code Extended Binary Coded Decimal Interchange Code A code used by IBM that represents each letter number special character and control character as an 8 bit binary number error control A term used to describe the process of adding extra information to transmitted data in order that the receiver can detect that errors have occurred and thereby request re transmission of the affected data file transfer protocol A protocol that only exchanges disk files with the host This type of protocol does not allow you to communicate interactively with the host flow control A term describing the use of software or hardware signals to control the flow of data between two devices Also known as handshaking file C MODULAR Manual txt 84 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt frequency modulat
39. al automatically originate telephone calls without requiring additional or auxiliary equipment such as a telephone Dial Commands Table 5 1 is a complete summary of available DIAL commands and their functions which are supported on your Modem when you are originating a call Internal Speaker Control You can use your Modem s internal speaker to listen for a dial tone busy signal ringing and carrier Dialling Procedure and D Commands The D command instructs your Modem to dial a telephone number An example of a typical Dial Command might be AT D 5551212 This command line instructs your Modem to ss Wait the number of seconds specified in register S6 for a dial tone S6 default is 5 seconds 23s Dial the telephone number 5551212 3s Wait the number of seconds specified in register S7 for the remote modem carrier tone S7 default is 40 seconds If the Modem detects the carrier tone within the allowable time it makes the data connection and sends a CONNECT response and enters data mode If the modem detects the busy signal and X3 or X4 response set is selected it goes back on hook and sends a BUSY response If the modem does not detect carrier tone it hangs up sends a NO CARRIER response and returns to Command Mode file C MODULAR Manual txt 26 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt COMMAND SYNTAX AT FUNCTION D Your Modem dials a number in the originate mode
40. amp K4 to the modem s initialisation string file C MODULAR Manual txt 11 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt CENTRAL SITE OPERATION 1 If your host system echoes user commands or data AT ANY TIME it is essential that you change the escap sequence by entering ATS2 nn where nn is an ascii code for a character other than If you do not when a user types your modem will hang To avoid being repeatedly disturbed by incoming calls you should disable the speaker using the ATMO command As the serial ports on host systems usually echo characters you should use ATQ1EO to disable Result codes and prevent character echo For example this prevents RING messages being echoed by the host which would in turn prevent the modem from answering an incoming call If host system is activated when the DSR signal is taken high by the modem then DSR should be set to follow DCD This is carried out by entering the AT amp S2 command Telephone Line Interferenc The modem is supplied with a standard modular jack lead permanently fitted to the port marked LINE on the rear of the modem This should be plugged directly into the BT type 600 telephone wall socket If you are using an associated telephone handset this should now be plugged into the socket marked TEL on the rear of the modem If you experience telephone line tro
41. arameters originate is 75Tx 1200Rx answer is default No Automode fixed handshake to Fn command Automode detection enabled file C MODULAR Manual txt 96 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Shows active modem configuration Buffered connection no EC Unbuffered no EC Enable V 42 or MNP EC conection Enable V 42 MNP or non EC connection Enable V 42 only Enable MNP only Go back online Initiate retrain Send command responses No responses Shows the Line Quality value 128 0 7 good line See amp M0 3 CTS follows RTS by delay in S26 Ignore RTS CTS remains ON Value n DSR always on DSR follows RS232C specification 144 v32bis modem End test mode analogue loopback ocal digital loopback Grant RDL request Deny RDL request iocal Remote digital loopback Remote digital with self test ocal analogue loop with self N EC Mode 0 1 2 3 4 5 O On line 0 al Q Responses 0 1 SQ 0 amp Q Sync Async Mode 0 amp R RTS CTS 0 1 Sr Reads Register Sr n Sets Register to amp S DSR Options 0 al s only amp T Test Modes 0 1 3 4 5 6 7 8 V Responses 0 1 amp V Shows Profiles W EC Messages 0 1 2 amp W Stores Profile 0 test Send numeric digit responses Send word responses CONNECT message indicates the DTE speed Modem reports line speed prot
42. before reporting a problem with the circuit you should confirm that there are also problems when operating with a telephone handset Note Should you experience continuous connection failures you should report the problem in the first instance to your modem supplier B To determine if failure is due to data terminal equipment Perform the local analogue loopback test This test will verify both the modem and the data terminal equipment If the local analogue loopback with self test proves satisfactory but the local analogue loopback test fails this probably indicates the data terminal equipment is at fault Important Note All diagnostic tests should be initiated from the Command Mode with a Standard AT NO or Direct AT N1 connection S18 Test Timer file C MODULAR Manual txt 59 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Register S18 when set to a non zero value establishes the durations of your Modem s diagnostics tests When a test is active for a period equal to the value chosen for this register from 1 to 255 seconds the modem will automatically halt the test and return to the command state Loading S18 with zero disables the test timer factory setting file C MODULAR Manual txt 60 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt amp T1 Local Analogue Loopback Test The Local Analogue Loopback Test is used to verify the integ
43. body that is licensed by the Department of Trade and Industry to administer the approval of equipment designed for connection to the PSTN This includes modems telephones PBXs etc An area of memory inside a computer or other electronic device that is used to store data temporarily Unit of information stored within a computer usually consists of 8 bits A single frequency tone which is generated by a modem during communication to carry the data and to inform the remote modem of the correct speed at which to operate A V 24 RS232C interface signal that is generated by Data Communications Equipment to indicate that it is ready to receive data from the DTE to which it is attached Used to provide hardware flow control The term used to describe a program running on a personal computer that allows it to be used as if it were a terminal connected to another computer An RS232C interface signal used by modems to inform the terminal to which they are attached that they have connected to a carrier signal from a remote modem A term used to describe communications equipment through which data passes usually a modem The generic term describing the use of various techniques to reduce the size of a computer file for storage or transmission purposes MNP5 and V 42bis are both methods of compression that can be incorporated into intelligent modems A V 24 RS232C signal that is generated by modems when they ar re
44. c modem to modem speed ie select fixed mode operation specify the lt max_rate gt and lt min_rate gt both to be the same speed and lt mod gt to be the modulation for that speed For example MS 11 0 16800 16800 selects V 34 16800 bps fixed mode no comparable S37 command MS 9 0 12000 12000 selects V 32bis 12000 bps fixed mode same as NOS37 10 For lt automode gt 1 automod nabled i e automatically selected speed and modulation When a call is made the modems negotiate and connect at the highest possible rate supported by both modems The scheme for this negotiation is either V 8 or V 32bis Annex A If lt max_rate gt is greater than the highest rate supported by the modulation specified by lt mod gt the modem automodes file C MODULAR Manual txt 42 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt down from the highest rate of the selected modulation For example MS 10 1 1200 24000 selects automoding down starting at V 32bis 14400 bps file C MODULAR Manual txt 43 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt b To set the modem for a wide range of negotiation automode specify the initial modulation and rate using lt mod gt and lt max_rate gt respectively Set lt min_rate gt to 300bps For example MS 11 1 300 16800 selects automode starting at V 34 16800 bps MS 9 1 300 12000 selects automode starting at V 32bis 12000 bps
45. cedure Modems requiring adjustments not covered below should be returned to your dealer for service WARNING Do not remove the modem from its case The modem has no parts within the case that you can service Removing the modem from its case will invalidate your warranty and approval to connect Sending and receiving data requires more than a modem Your PC is part of a system that includes a telephone line and another computer system You can solve some operating problems by checking your programs and adjusting your modem you cannot solve problems caused by the telephone line or the other computer system The Quick Fix List You can solve most problems by checking the following things Recheck each cable even though you may be sure that they are plugged in properly Do not try to clean jacks or connectors 1 Check to see that all cables connected to the modem are securely connected at both ends isd RS232 cable connected to the modem and to the correct serial port on your PC or terminal Modem Power cable connected to the modem and the plug pack plugged into the wall power outlet Is the wall plug switched on x Telephone cable the one supplied with the modem connected to the modem and the telephone wall socket p 2a Check to see that the PC program and the remote computer system hav ach selcted the same data bit selection either 7 or 8 bits and parity S Check the following Do
46. culate the number of pieces of apparatus which may be connected simultaneously to a single PSTN line without impairing the performance of the standard bell circuit The RENs of all simultaneously connected apparatus should not exceed 4 0 on any single PSTN line B T telephones can be assumed to have an REN of 1 0 unless otherwise marked file C MODULAR Manual txt 67 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt These modems have a REN of 1 0 file C MODULAR Manual txt 68 of 102 12 03 02 11 35 29 file C MODULAR Manual txt Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix APP ENDICES Data Communications for Beginners Technical Specifications Cable Specification Troubleshooting Tips Glossary PABX Notes Command Summary Fax Operation file C MODULAR Manual txt 69 of 102 12 03 02 11 35 29 file C MODULAR Manual txt APPENDIX A Data Communications For Beginners Here is a brief summary of key data communications concepts that you should understand Equipment Data Communications is the exchange of information between two or more locations Typically one of the locations is a computer and the other locations are computer terminals In the case of a PC both locations the PC and the host are computers From here on we ll call it the terminal whether it is a PC or a non intelligent terminal There are two
47. d is written to Register S31 bit 1 Default is N1 See also MS for the 288 336 modem NO Automode detection is disabled A subsequent handshake will be conducted according to the contents of Register S37 file C MODULAR Manual txt 44 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt N1 Automode detection is enabled A subsequent handshake will be started according to the contents of Register S37 or if S37 is zero starting the highest speed supported on the modem file C MODULAR Manual txt 45 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt N Parameter Default Purpose O Parameters Object Error Correction Operating Mode NO Standard operation non error corrected buffered data N1 Direct operation non error corrected data not buffered N2 Reliable operation MNP If the modem fails to negotiate a reliable connection it will drop the call N3 Auto Reliable operation V 42 or MNP If the modem fails to negotiate a reliable connection it will adopt a standard connection as fallback N4 Enable V42 error correction only N5 Enable MNP error correction only N3 To specify which error correction negotiation will occur after carrier is established On Line None To return your Modem to Data Mode after the characters switched it to Command Mode file C MODULAR Manual txt 46 of 102 12
48. e K command determines the action performed by the modem when it receives a break from the DTE port the modem port or from a B command The way in which the modem reacts to these options is summarised in the following table Loudspeaker Volume L1 Low volume L2 Medium volume 3 High volume L2 To set the volume level on the integral loudspeaker Loudspeaker Control MO Speaker OFF M1 Speaker ON until carrier detected M2 Speaker ON continuously M3 Speaker ON only during answering phase M1 To allow manual control of your Modem s internal speaker file C MODULAR Manual txt 39 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Object amp M amp MO amp M1 amp M3 Parameters Default amp MO Purpose If you do not want to use the speaker to monitor calls send the MO command Async Sync Mode Direct Asynchronous operation Reserved To allow selection of sync async modes and support automatic dialling in sync mode Note that Synchronous modes are supported on desktop modems only MS This extended format command is available onl Select Modulation y on the 288 336 V 34 modem It selects the modulation be used for future connections can enable or disable automode lowest and highest speeds using format is Not all subparameters have to b modem modem speed to In addition the MS command and optionall
49. ed by the service being used file C MODULAR Manual txt 28 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt COMMAND MEANING MODEM TO BE ENTERED RESPONSE ATD5551212 Dial telephone number 555 1212 OK then return for command ATD123435 Send I D number 123435 OK then return for command ATD1232 Send password 1232 OK then return for command ATD218 100 Send transaction number 218 10 OK then return for command ATH Hang up terminate call OK TABLE 5 2 TOUCH TONE COMMANDS Auto Dialling Voice Calls Plug a simple telephone handset into the socket on the rear of the modem You can then type the command at the end of a Dial command line when using your Modem as an auto dialler For example typing ATDT9 5551212 and pressing RETURN instructs your Modem to Touch Tone T dial and digit 9 pause dial 5551212 and return to Command Mode When you hear the ringing of the remote telephone through your Modem s internal speaker pick up your telephone handset and send the Hang Up command type ATH and press RETURN Then talk to the person at the other end of the line You could also send a Dial command line by omitting the semi colon waiting for the remote telephone to ring then lifting the receiver and pressing any key Cancelling a Call To cancel a call after pressing the RETURN key press any key
50. en the modem is off hook Usually the default HO is used This allows the Modem to go back on hook when the modem terminates a call Identification TO Send product code Tis Send checksum testing only T2 verify PROM checksum OK response I3 PROM Device I4 Modem Capabilities To provide information on the modem s identity file C MODULAR Manual txt 37 of 102 12 03 02 11 35 29 file C MODULAR Manual txt Object This command allows you to interrogate the modem to check its firmware and configuration codes file C MODULAR Manual txt 38 of 102 12 03 02 11 35 29 file C MODULAR Manual txt amp K Parameters Default Purpose Object K Parameters Default Purpose Object L Parameters Default Purpose M Parameters Default Purpose Flow Control amp KO Disable DTE flow control amp K3 Enable Bi directional RTS CTS interface signals Modem uses CTS line to control data from DTE DTE uses RTS line to control data from modem amp K4 XON XOFF Modem uses XOFF character to stop data from DTE and XON character to resume transmission DTE also uses XOFF to stop modem from sending data and XON to resume transmission amp K3 Set DTE port flow control Ensures that the same method of flow control is set on the modem and DTE terminal device or PC Break Control Or S K5 Th
51. es do not specifically mention class 1 or 2 in which case the Rockwell TR29 interface should be file C MODULAR Manual txt 101 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt selected APPENDIX I Voice Operation Certain of the Modems are able to send and receive voice messages when used with a computer and suitable software To determine if your modem has the voice facility issue the AT command AT FCLASS If the modem s response includes 80 then voice facilities are available The voice command interface conforms to Rockwell standard so ensure that any voice software which you plan to use is able to operate with Rockwell voice modems file C MODULAR Manual txt 102 of 102 12 03 02 11 35 29
52. es the modem turn on Does the MR LED light Does it accept any commands Does it respond to the A command Does it display messages Does it send or receive data Does the problem repeat or is it intermittent file C MODULAR Manual txt 78 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Can the modem continue to process commands file C MODULAR Manual txt 79 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt What happens to the command message or data that fails to work correctly What was the last correct action just before failure What was the last screen message displayed Check over what you ve learned about the problem Do you have a modem problem or is it really a problem with something else You will solve most problems by checking all the cables and by checking the PC program GLOSSARY analogue signal ASCII code asynchronous auto answer auto dial baud rate APPENDIX E A signal that varies continuously over time T American Standard Code for Information Interchange A standard way of representing each letter number special character and control character as a 7 bit binary number A method of data transfer that uses START and STOP bits to separate individual characters within the data stream The ability of a modem to detect ring signals on the telephone lin and thereby answer incoming calls without manual
53. file CV MODULAR Manual txt MODEM USER GUIDE Issue RC1 3 file C MODULAR Manual txt 1 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt CONGRATULATIONS You have purchased one of our modems which will give you many years of trouble free operation The modems in this series are microprocessor based and incorporate high speed data communications capabilities They work with computers and terminals equipped with a V24 or RS232C ports for on line communication with other computers Your modem is completely compatible with CCITT V 21 V 22 V 22bis V 23 V32 and V 32bis standards and can operate at port speeds from 300 bps to 57 600bps The 288 336 versions also support V 34 modes and speeds up to 115 2Kbps Both auto answer and auto dial are available as normal functions The modem supports V 42 amp V 42bis in addition to MNP up to classes 4 amp 5 for error correction and data compression to ensure the maximum integrity and throughput for your data If you find that technical manuals such as this guide are more than you can handle initially and want to try out the modem Go ahead As it works with most PCs and terminals you may not need to read further than this if your software will lead you through the procedures required You won t cause any damage to your computer modem or phone if it doesn t work the first time You should however first read the conditions of approval for connection to telephone li
54. git Responses Parameters vO Digit responses Vl Word responses Default V1 Purpose To define whether the modem responds with words e g NO CARRIER or numeric codes Object V1 is preferred so you can recognise problems and remain updated with the modem s current operating status If your software package does not handle character strings efficiently ither end the V0 command or Q1 command amp V Show Profile Parameter amp V Displays active profile stored profile 0 amp V1L Displays active profile stored profile 1 Purpose Display settings of all parameters Object Use this command to display the current settings of your Modem The active profile two stored profiles and stored telephone numbers are displayed file C MODULAR Manual txt 49 of 102 12 03 02 11 35 29 file C MODULAR Manual txt amp W Parameters Purpose Object X Parameters Default Object amp Y Parameters Default Purpose Object Store Modem Profile amp W0 Store Profile 0 amp W1 Store Profile 1 Store active settings in non volatile memory The Modem allows storage of the active settings a profile of important parameters into two stored profiles 0 and 1 These profiles are stored in non volatile memory so survive power off Select Result Code Set X0 Basic result code set code 0 4 X1 Extended result code test displays CONNECT CONNECT 1200 CONNECT
55. he mouse is on COM2 then the modem should be changed to COM3 see below for switch settings Communications software generally uses IRQ4 for COM1 and COM3 and IRQ3 for COM2 and COM4 iv Once installed the telephone jack lead should be plugged into your telephone wall socket Additionally you may wish to plug a telephone into the socket marked TEL on the rear panel of the modem If you are not happy at the prospect of dismantling your computer to install the modem arrange for your dealer or a qualified engineer to do it for you For example to use conventional interrupt settings for COM ports use the following table COM1 INT4 All switches should be OFF except 34 DE COM2 INT3 2 5 amp 8 COM3 INT4 3 6 amp 7 COM4 INT3 2 6 amp 8 FUNCTION SWITCH ADDRESS COM SELECTION SW5 SW6 SW7 Sws COM1 Set INT4 also ON OFF ON OFF 3F8 COM2 Set INT3 also ON OFF OFF ON 2F8 COM3 normally INT4 OFF ON ON OFF 3E8 COM4 normally INT 3 OFF ON OFF ON 2E8 INTERRUPT SELECTION INT9 Special software SW1 ON SW 2 3 4 OFF INT3 SW2 ON SW 1 3 4 OFF INT4 SW3 ON SW 1 2 4 OFF file C MODULAR Manual txt 13 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt INT5 Special software SW4 ON SW 1 2 3 OFF file C MODULAR Manual txt 14 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt Installing the PCMCIA modem On laptop PCs with
56. ion full duplex half duplex hardware handshaking host intelligent modem interactive protocol International Telecommunications Union ITU Kermit Microcom Networking Protocol MNP An early modulation technique that uses different signal frequencies to represent binary data The term used to describe two way simultaneous communication The term used to describe systems that allow communication in two directions but not at the same time The use of hardware signals such as RTS and CTS to provide flow control during communication The computer that is in control ina data communications network The host may be a mainframe mini or micro computer A type of modem which by virtue of having its own micro processor can be controlled by software commands from the terminal to which it is attached rather than manually by switches A protocol that lets you communicate interactively with the host In this kind of protocol part or all of the contents of the screen display are sent to the host when you press RETURN you do not have to communicate with the host by sending it disk files Is the international body that governs the definition of standards such as the V series for use in international telecommunications Formally CCITT An error control protocol developed for use in connecting micro computers to mainframes The protocol has various levels and the par
57. its that represent each character following one after another 23 Parallel data is sent with all the bits for one character going in parallel down different pins on the connector Nearly all data communication uses serial transfer this is always so where you use modems to connect over the telephon network Some computers come with serial ports built in and some do not You must determine if your computer has such a serial port check if there is a serial connector on the back of your machine If you cannot find this connector on your PC it is likely that you will have to buy one separately For example the IBM PC and the APPLE may not come with an RS 232 port You may need to buy add on cards that provide this facility Nearly every terminal or glass teletype has a DB25 RS232 connector plus a facility to select various options for the RS232 serial output DTE amp DCE Also there are two types of RS 232 connections One type called the Data Communications Equipment DCE and the other is called Data Terminal Equipment DTE It will be necessary for you to know which type is fitted to your computer so that you can purchase or construct the proper type of cable The cable will be used to connect your machine to your modem WARNING PCs often use a female DB25 connector as their parallel printer connection point Never connect your modem to the parallel printer port of a PC as you run the risk of da
58. k with Self Test The primary purpose of the Local Analogue Loopback with Self Test is to verify the integrity of the modem If both modems individually pass the test the Remote Digital Loopback with Self Test may then be performed to verify the complete modem to modem communication path The following are examples using the Local Analogue Loopback with Self Test Example 1 Terminal ATS18 06T8 Modem CONNECT Terminal AT amp TO Modem 000 Test performed with no errors Example 2 Terminal ATS18 06T8 Modem CONNECT Terminal AT amp TO Modem O12 OK Test performed with 12 errors Example 3 Test time set to 10 seconds Terminal ATS18 106 T8 Modem CONNECT Modem 000 OK Test performed with no errors Start Test Modem now in TEST mode End Test OK Acknowledgement Start Test Modem now in TEST mode End Test 12 errors Acknowledgement Start Test Modem now in TEST mode Timer expired Test completed file C MODULAR Manual txt 62 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Example 4 Terminal ATS18 10 amp T8 Start Test Modem CONNECT Modem now in TEST mode Modem 007 Timer expired OK Test completed Test performed with 7 errors amp T6 Remote Digital Loopback Test The Remote Digital Loopback test is used to test the local data terminal equipment the local and remote modem and the telephone circuit The test can only be carried out if
59. l an access code usually the digit 9 to reach an outside line The comma command instructs your Modem to pause for up to 11 seconds file C MODULAR Manual txt 27 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt The use of the comma and the W commands should be restricted to single insertions within a dial string Longer delays can be created by increasing the value of registers S6 and S8 The maximum pause permitted is 11 seconds A typical Dial command line containing the comma command might be ATD9 5551212 which instructs your Modem to dial 9 pause then dial the remaining digits Return to Command Mode after Dialling The semi colon command at the end of a command line instructs your Modem to return to Command mode after dialling without hanging up This feature lets you call locations such as telephone order services or banks which recognised Touch Tone as data The command also lets you perform voice calls using your Modem Note Pressing the RETURN key after typing a command line instructs your Modem to wait for a carrier signal from the remote modem The modem returns to Command Mode and hangs up if no carrier is detected within the specified time normally 40 seconds Sending Touch Tones as Data When calling a service which interprets Touch Tone as data use the command sequence in Table 5 2 below as an example guide The use of and codes will be defin
60. le CV MODULAR Manual txt Object amp D Parameters Default Purpose Object E Parameters Default Purpose Object ole E Parameters Default Purpose Object Dial The D command is used in conjunction with the digits 0 to 9 the and symbols and the Dial commands such as T and see Chapter 5 to dial a call DTR Options Qh DO Ignore DTR D1 Go to Command State when DTR ON OFF D2 DTR drop causes modem to hang up auto answer inhibited amp D3 Soft Reset when DTR ON OFF ATZ command action Q Qh Qh D2 amp D0 in 144 models Allows control of response to DTR transitions The DTR signal of the V 24 RS232C Interface Pin 20 or line control register for integral modem is normally ON when a terminal or PC is connected to your Modem and when communication software is running This command allows special actions to be taken when the DTR signal goes from ON to OFF Echo Commands E0 Does not echo commands El Echoes commands El During operation command characters are echoed to your screen as they are sent to your Modem This permits you to view the correct PLOC rr command line which is being sent Use the EO command when your Modem is connected to echopl quipment or host computer ports Auto retrain SEO Disable auto retrain SE1 Enable auto retrain SEL To allow better adaption to a poor quality line
61. le CV MODULAR Manual txt non standard equipment file C MODULAR Manual txt 54 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Register S4 Line Feed Characters Range 0 127 ASCII Default 10 CTRL J Register S4 identifies the line feed character output after the carriage return when receiving word responses from your Modem V1 command If you neither want nor require a line feed character you can change the value in this register to select a null character but you cannot disable line feeds Register S5 Backspace Character Range 0 255 ASCIT Default 8 CTRL H Register S5 indicates the BACKSPACE key character and the character echoed to move the cursor back one position Pressing the BACKSPACE key does the following T Echoes the keystroke to your computer or terminal Zi Moves the cursor back over the last character entered 3 Deletes the last character in your Modem s memory 4 Causes your Modem to send an ASCII space blank to erase the character on the screen The space moves the cursor to the next position with the result the modem just sends another backspace character to back up the cursor again As two extra characters are sent after the backspace the response is somewhat slow A repeat key on terminals may not work properly when used to backspace A value greater than 32 disables this feature file C MODULAR Manual txt 55 of 102 12 03 02 11 35 29
62. maging your equipment file C MODULAR Manual txt 72 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt APPENDIX B Technical Specifications Characteristic Data Format DTE Interface Speed Operating Modes Dialling Communication Mode Visual Monitor Desktop versions only Audio Monitor Intelligence Modulation amp Compatibility Description Serial binary asynchronous 7 or 8 data bits parity odd even none 300 600 1200 2400 4800 9600 19200 also 1200 75 38400 and 57600 16800 21600 28800 amp 115200 24000 26400 on 288 336 only The operating modes are as follows Manual originate Automatic originate Manual answer Automatic answer Manual dial Automatic dial Touch tone DTMF dialling Full amp half duplex on two wire switched telephone channels 9 lights LED Light Emitting Diodes to display MR Modem Ready DSR signal TR Terminal Ready DTR signal CD Carrier Detect DCD signal SD Send Data RD Received Data HS High Speed AA Auto Answer OH Off Hook TST Self Test Mode In built speaker Microprocessor with integrated ROM amp RAM ITU V 21 FSK ITU V 22 Mode A i ii and Mode B i ii iii iv DPSK L file C MODULAR Manual txt 73 of 102 12 03 02 11 35 29 file C MODULAR Manual txt ITU V 23 Mode 1 amp 2 FSK ITU V 22 bis QAM ITU V
63. mands provide the modem with Hayes compatibility In this command set all commands are entered in asynchronous mode and each command begin with the letters AT or at Data Mode Characters The Modem lets you switch from Data Mode to Command Mode without losing the data connection to a remote modem by use of th characters This could be convenient when you want to check or change a setting and then return to sending data The following procedure shows how to return to Command Mode without losing a data connection which was already established Ty Make the data connection with your Modem either by dialling out or answering an incoming call Qe Wait at least one second without typing anything This wait time is determined by Register S12 ie Type three plus characters If you desire you can use characters other than S th description of Register S2 4 Wait at least one second again set by Register 12 The Modem will respond with an OK and enters Command Mode while maintaining the data connection unless the remote modem disconnects or drops the telephone connection You can then use commands to check a setting change a register value or have time to consult a manual To leave Command Mode and resume sending data type ATO AT command and press the RETURN key Alternatively you can terminate the call by typing ATH and pressing RETURN The modem then stays in
64. me 12 O 255 20ms 50 Escape guard time S18 0 255 seconds 0 Test Timer 25 0 255 seconds 5 DTR off timer S26 0 255 10ms 1 CTS delay S29 5 9 seconds 5 Hook Flash delay S30 0 255 minutes 0 Inactivity timer S37 bit mapped 0 Desired modem modem speed S38 0 255 seconds 20 Delay before forced hangup S48 077 128 7 V 42 negotiation control APPENDIX H Fax Operation These Modems are able to send and receive CCITT Group 3 fax images he fax interface conforms to EIA 578 Class 1 and EIA 592 operates at 19200bps Class 2 certain modems only The interfac when in fax mode All models are able ton through 14400 V 17 9600 V29 4800 V To determine if your modem has the Class 2 AT command AT FCLASS If the modem s response includes 2 then In order to take advantage of the fax facil it is necessary to use an applications package computer gotiate fax speeds 27ter and 2400 V 22bis commands issue the class 2 is available lities on the modem on your which expects a fax modem conforming to either Class 1 or Class 2 The applications package will fax control signalling and negotiation encoding tasks thus allowing you to send from directly from a terminal and T 4 perform the T 30 fax and receive faxes Choose either Class 1 on you fax applications package in order to operate with the modem Certain applications packag
65. ne circuit are all proved to the OK if your Modem choes the test message back to the local data terminal exactly as it was transmitted amp T7 Remote Digital Loopback with Self Test The Remote Digital Loopback with Self Test is used to test the local and remote modem and the telephone circuit Your Modem sends a standard test message to the remote modem The remot modem when properly conditioned loops its receive stream back to the local modem The local modem examines the receive pattern and increments an internal error counter each time an error is detected At the end of the test your Modem returns a three digit error count representing the errors accumulated during the testing interval If the error count is 000 both the local and remote modem and the telephone circuit test correctly If errors were encountered you may want to initiate local analogue loopback with self test to further isolate the source of the problem After escaping from on line state to command mode you can initiate the Remote Digital Loopback with Self Test by issuing the amp T7 command once in the command mode The following are examples using the Remote Digital Loopback with Self Test Assuming that you start from the on line state with a non error corrected call established local data terminal equipment set to expect characters to be echoed and Modem is set to echo commands received from the local data terminal
66. nemonics are prefixed by symbols e g amp etc Include any parameters required by the command The command line must contain no more than 127 characters 3 After typing the command s press the RETURN key to execute the command line The modem sends a response often OK when it executes the command line 4 Always wait for the OK response before typing the AT prefix of the next command line Sas If you type a character by mistake you can erase it by typing a backspace 6z You can abort a command line at any point by typing CTRL X 7 You can place multiple commands on a single line by omitting AT from all except the first command Spaces may be used between commands to improve readability Your Modem saves the last executed command line in memory you can then use the A or a to re execute that command line see Chapters 6 and 7 This is the only command not precede with an AT If your command line was not executed or if you did not receive any response refer to the section on Troubleshooting in this chapter file C MODULAR Manual txt 22 of 102 12 03 02 11 35 28 file CVMODULAR Manual txt Troubleshooting AT Commands If your Modem did not execute the command line when you pressed RETURN check the following items iis Was your modem in Command Mode see Chapter 3 25 Did AT appear at the beginning of the command line og Check that the TR LED in ON This will indicate that y
67. nes given in Chapter 9 If this is your first modem and you are new to computing it could take a few hours of use before you get the feel of what is required to make it work It is also recommended you learn the etiquettes of modem use where you are sharing facilities such as bulletin boards They often restrict access to a certain amount of time per day MNP is acknowledged as a trademark of Microcom Inc file C MODULAR Manual txt 2 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt Chapter Chapter Chapter Chapter Chapter Chapter Chapter Chapter Chapter Appendix Appendix Appendix Appendix Appendix Appendix Appendix Appendix CONTENTS OMNIA OA BWN EF Zara AVA wD PY Introduction Installation Operation Commands and Responses Dialling AT Commands Registers Diagnostics and Testing Statutory Information for the Modems Data Communications for Beginners Technical Specifications Cable Specification Troubleshooting Tips Glossary PABX Notes Command Summary Fax Operation file C MODULAR Manual txt 3 of 102 12 03 02 11 35 28 file C MODULAR Manual txt CHAPTER 1 INTRODUCTION There are six modems in the series covered by this guide Desktop PC card and PCMCIA format each with maximum operating speeds of 14400bps or 28800 33600bps Each Modem is a communications device designed to work with a terminal or personal computer The modem o
68. ns AC outlet Location Your Modem is designed to fit neatly on a desk or shelf and should be placed near a 220 240V AC power source such as a wall outlet The length of your RS 232C cable determines th distance between your modem and the computer printer or terminal that you wish to interface with You should be able to s the LED indicator lights on the front panel clearly and be able to hear the internal speaker when dialling calls PC Connection Requirements The following components are required to connect your Modem to a personal computer Ty An RS 232C or V 24 serial port in the computer Ze A cable with a male connector to connect to your Modem the gender of the connector on the other end depends on your computer requirements 25 pin female for most PCs See Appendix C for cable descriptions 33 The appropriate software usually a COMMS package or terminal emulator to operate the computer to modem interface eg Terminal in MS Windows When connecting your Modem to a computer printer or terminal not equipped with a DB 25 connector you will need to obtain an adapter cable See your computer dealer for the appropriate cable file C MODULAR Manual txt 6 of 102 12 03 02 11 35 28 file C MODULAR Manual txt Connection Procedure To a PC or Terminal Complete the following steps to connect your Modem to a computer printer or terminal Ey Plug the male DB 25 connect
69. nternal telephone systems protocol A set of rules for sending and receiving data on a communications line Public Switched Telephone Network PSTN This is the technical term used to describe the dial up telephon networks run by British Telecom and Kingston Communications Request To Send RTS An RS232C interface signal that is generated by Data Terminal Equipment to indicate that it has data ready for transmission Used to provide hardware flow control Ring Indicator RI An RS232C signal that is generated by DCEs when they detect an incoming RING signal on the telephone lin RS232 cable Any cable that is wired in accordance with the RS232 or ITU V 24 standard which is the world wide standard data communications interface standard serial interface A type of interface such as RS232C that permits the transmission of data in serial fashion i e one bit after another down a single wire Other wires may also be used to provide control signals and a return data path simplex a The term used to describe systems which allow communication in one direction only file C MODULAR Manual txt 87 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt software handshaking The use of software signals such as XON and XOFF to provide flow control during communication start bit z A high bit that is inserted at the beginning of each character transmitted during as
70. ocol and DTE speed when a connection is made CONNECT message indicates line speed Store active configuration as profile 0 Store active configuration as profile 1 file C MODULAR Manual txt 97 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt W Split Speed 0 Disable split speed Enable split speed and V 23 sets ATF3 144 only m file C MODULAR Manual txt 98 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt X Result Codes 0 Basic result code set code 0 4 1 Principal result codes 0 5 8 23 2 Principal codes and dialtone detection 3 Principal codes with BUSY signal detection 4 Extended 0 80 codes with BUSY signal and dialtone detection Y Long Space 0 Disable long space disconnect 1 Enable long space disconnect amp Y Select Profile 0 Profile 0 loaded after hard reset 1 Profile 1 loaded after hard reset Z Fetch Profile 0 Profile 0 1 Profile 1 amp Zm nnnn Store Number nnnn in memory store m m can be 0 3 nnnn can be up to 40 digits file C MODULAR Manual txt 99 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt WORD RESPONSE OK CONNECT RING NO CARRIER ERROR CONNECT 1200 NO DIALTONE BUSY NO ANSWER CONNECT CONNECT CONNECT CONNECT CONNECT CONNECT CONNECT CONNECT CONNECT CONNECT CONNECT CONNECT CARRIER CARRIER CARRIER CARRIER CARRIER CARRIER CARRIE
71. ons programs for microcomputers Files for transmission are split into fixed length blocks which are checksummed and requests re transmission of the block concerned if errors have occurred S Zmodem ASCII characters usually 17 and 19 which are used to provide software flow control An error control protocol for file transfer often found in communications programs for microcomputers An error control protocol for file transfer often found in communications programs for microcomputers Similar to XMODEM file C MODULAR Manual txt 89 of 102 12 03 02 11 35 29 file C MODULAR Manual txt but more advanced because it uses variable length blocks file C MODULAR Manual txt 90 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt APPENDIX F PABXs amp Switchboards Lis Always use a direct outside telephone line if you can They are much cleaner e g no operator interrupts disconnects etc If you must go through a PABX or Switchboard then you need to bear these points in mind a Don t forget to put the 0 or 9 at the front of the number you re dialling if required b If it takes a while to get an outside line put in a delay comma in the dial string to make sure that you get a line before dialling e g ATD9 1234567 lt CR gt The comma indicates to the Modem that a pause of approximately three default seconds is required file C MODULAR Manual txt 91 of 10
72. or on your cable into the connector marked DTE INTERFACE on the back of your Modem Figure 2 1 Zee Plug the other end of the cable into the V 24 connector on your computer If you need assistance consult the manual which came with your PC or contact your computer dealer Connection Procedure to telephone line Complete the following steps to connect your Modem to your telephone lin i If you have not yet provided British Telecom PLC with the information described under BABT Regulations refer to chapter 9 please do so at this time 22 Make sure you have one of the British Telecom line standard jacks unit 601A S32 If you are using your modem without a telephone simply plug the modem cable into the wall jack 4 If you want to have your telephone connected alongside your modem connect the telephone handset to the socket on the modem s rear panel Connection Procedure for a telephone The modem may share a telephone line with a telephone This facility is only suitable for simple telephones and the connection should be made by plugging the connector on the telephone line cord into the socket marked PHONE on the modem s rear panel Refer to Chapter 9 for points on the use of this facility Connection Procedure to an AC outlet Plug the mains plug into a 220 240V AC outlet to complete the installation When power has been connected you should notice the following a The M
73. our terminal is active and that the Modem is waiting for commands If the TR LED is OFF then the modem is not expecting to receive commands or the terminal is not active If you received an ERROR response after pressing the RETURN key check the following items die That your equipment is sending commands at 300 600 1200 2400 4800 9600 19200 38400 57600 or 115200 for the 288 336 modem command line contains no more than Lie That your command line contains no more than 127 characters including AT and any spaces 3 That the command syntax was correct i e the o correct symbols e g amp etc were used and that numeric and alpha characters were used where required Deleting AT Commands Use the BACKSPACE key if you make a mistake while typing a command line Pressing BACKSPACE deletes the last character you entered Note that BACKSPACE will not delete the AT prefix If necessary the backspace character may be changed to another ASCII character by assigning a new value in the S5 register see Chapter 7 To delete th ntire command line press CTRL X which will cause the command line to be aborted AT Commands Responses Your Modem sends responses in reply to commands from your keyboard Responses can appear as words or digits default is words You will most likely want to receive word responses to monitor modem operation Certain software packages may require numeric responses u
74. peration is based on ITU V 21 V 22 V 22 bis V 23 V 32 and V32bis The 288 336 models also have V 34 operation The Modem can touch tone dial telephone numbers and is approved in the United Kingdom For details of the BABT aspects please see Chapter 9 Using standard commands you can instruct your modem to dial or answer calls from a terminal or a computer set up for terminal emulation Program commands also allow you to change your modem s effects and many operating parameters The Modem will reply to each command you send and will keep you informed of your modem s current state Indicators LEDs on the front panel of the desktop Modem provide you with a visual check of your modem s operations Inside your Modem accessible only by authorised technicians a small speaker allows you to listen to the status of dialled calls Three modes of operation a Command Mode Fax and Data Mode and optional Voice mode are supported These are further discussed in Chapter 4 Operating Modes a Data In this mode your modem can connect to bulletin boards Internet or other service providers for browsing or uploading downloading files b Fax In this mode the modem is able to send or receive faxes from any fax machine provided your computer is equipped with suitable software Cc Voice Where supported on the modem this facility allows the modem to send or receive voice calls provided your computer i
75. rity of the communications path The test path includes your Modem and the local data terminal equipment s also Local analogue Loopback with Self Test amp T8 The following is an example using the Local Analogue Loopback Test When in the test the local Modem will echo characters received from the local data terminal The TST LED illuminates when in a test mode The TST LED will briefly extinguish each time an error is received when running self tests amp T8 and amp T7 The Local Analogue Loopback test is also able to be initiated from the V 24 RS 232 interface by the DTE asserting LL on pin 18 circuit 141 The modem asserts the TI signal pin 25 to acknowledge the application of the test Example 1 Terminal AT NO amp T1 Start test CONNECT Modem now in TEST mode The silent hawk Type in test messag caught the sleepy Confirm that all the chicken characters are received correctly F ey ce Escape sequence Modem OK Acknowledges Terminal AT amp TO End Test Modem OK Test terminates The test is passed if your Modem echoes the test message back to the local data terminal exactly as it was transmitted file C MODULAR Manual txt 61 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Note For the Local Analogue Loopback to be performed with or without self test your Modem should not have a call established amp T8 Local Analogue Loopbac
76. s equipped with suitable software Your Modem incorporates an internal speaker which allows you to monitor the dialled calls you can hear the establishment of carrier The sound depends on the modulation scheme i e V 23 V 34 etc being used This enables you to hear a dialling tone busy signal detect and connection problem and determine when a wrong number has been reached Standard Features The following components are included in your Modem package file C MODULAR Manual txt 4 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt Before proceeding please confirm for yourself that all components listed below are in your package Your Modem This User s Guide Modem Power Supply for desktop modems Line Cord for connecting modem to wall socket A wN file C MODULAR Manual txt 5 of 102 12 03 02 11 35 28 file C MODULAR Manual txt CHAPTER 2 INSTALLATION Your Modem is designed for use with PCs or terminals This chapter contains instructions on how to install your modem Turn to page 2 9 for instructions on the initial installation of the PC card modem Installation procedure for the desktop Modem To install your Modem you should complete the following steps der Find a suitable location to place your Modem 2 Connect your Modem to your computer printer or terminal 3 Connect your Modem to the telephone lin 4 Connect your power supply to the modem and to a mai
77. s like the signal from any other terminal Asynchronous protocols generally transmit the data as it is entered from the keyboard Bits are wrapped around the data to tell the modem to start prepare for the character to come and to stop and wait for the next Some protocols communicate interactively others transfer files When you use an interactive protocol each character is transmitted as you type it or when you press RETURN or ENTER file C MODULAR Manual txt 70 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt When you use file transfer protocols you must prepare the data in advance and save it in files on disk them as a batch to the host then transmit You can use file transfer protocols to send one or a series of files from one personal computer to another The data in each file must still be prepared in advance by your word processor spreadsheet or database program file C MODULAR Manual txt 71 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt With synchronous protocols the equipment at both ends of the communications line must synchronize with each other before data can be transmitted or received This makes it possible for the equipment at the receiving end to distinguish individual data bits in the continuous stream of data sent by the equipment at the other end Serial and Parallel Peripheral devices can receive data sent in two ways Ts Serial data has the b
78. se the ATVO command to receive such digit numeric responses Word responses are preceded and followed by a carriage return and line feed Digit responses are followed by a carriage return Responses can come from a basic response set or an extended response set default The basic responses do not indicate the speed of connection If you need to know the speed of a data connection use the X4 command to select th xtended response set Table 4 1 on the following page lists all possible word and digit responses file C MODULAR Manual txt 23 of 102 12 03 02 11 35 28 That your file CV MODULAR Manual txt WORD R ESPONSE OK CONNECT R ING NO CARRIER ERROR CONNECT 1200 NO DIALTONE BUSY NO ANSWER CONNECT 600 CONNECT 2400 CONNECT 4800 CONNECT 9600 CONNECT 7200 CONNECT 12000 CONNECT 14400 CONNECT 19200 CONNECT 38400 CONNECT 57600 CONNECT 75TX 1200RX CONNECT 1200TX 75RX CARRIER 300 CARRIER 75 1200 CARRIER 1200 75 CARRIER 1200 CARRIER 2400 CARRIER 4800 CARRIER 7200 CARRIER 9600 CARRIER 12000 CARRIER 14400 CARRIER 16800 CARRIER 19200 CARRIER 21600 CARRIER 24000 CARRIER 26400 CARRIER 28800 CARRIER 31200 CARRIER 33600 COMPRESSION CLASS 5 COMPRESSION V 42BIS COMPRESSION NONE PROTOCOL NONE PROTOCOL LAPM PROTOCOL MNP TABLE 4 DIGIT RESPONSI e UU NHO Oo CDCOWDAIADAWNOWNWAATA BFWBNEF CO Qo
79. swering amp M Operating Modes 0 Async mode 1 AT commands r Sync mode 1 with async command dialling until connection established Call dropped and return to async when DTR lowered 2 Sync mode 2 when DTR is raised modem calls the first stored number in memory When DTR goes low modem returns to async command mode 3 Sync mode 3 where DTR acts as a Talk Data switch A call is dialled manually then DTR is raised to start handshake training sequence Modem hangs when DTR goes low M MNP 10 Power 0 Power level not adjusted during link negotiation 1 Power Level adjusted MS Modulation mode 288 modems only MS lt mod gt lt automode gt lt min_rate gt lt max_rate gt lt CR gt lt mod gt Modulation Possible rates bps see note 1 0 V 21 300 1 V22 1200 2 V22bis 2400 or 1200 3 V23 1200 see note 2 9 V32 9600 or 4800 10 V32bis 14400 12000 9600 7200 4800 11 V34 33600 31200 28800 26400 24000 21600 19200 16800 14400 12000 9600 7200 4800 or 2400 see note 3 file C MODULAR Manual txt 95 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt 64 Bell 103 69 Bell 212 74 V Fast Note I lt max_rate gt 23 75Rx Bs For V 23 1200Tx lt mod gt 11 is the Automode 300 not UK 1200 not UK 28800 26400 24000 21600 19200 16800 or 14400 See optional lt automode gt lt min_rate gt and p
80. the previous example the S0 register value was 1 for the Modem to answer an incoming call after the first ring To cause your Modem to answer the call automatically after five rings type AT S0 5 and press RETURN When your Modem executes the command it sends the OK respons Setting Pointer The Modem places a pointer at the last register whose value was read or changed The pointer is a shortened access technique to a chosen register chosen You can also use the S command and omit the and to set the pointer without reading or changing value for example by typing AT SO and pressing RETURN sets a pointer to the S0 register immediately You can then read S0 value by typing AT file C MODULAR Manual txt 52 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt and pressing RETURN the S command is unnecessary and is the register number Similarly typing AT 8 Changes the value of the SO register to 8 Note The pointer remains set at the last register you accessed Register SO in the abov xamples until you use the S command to access and move the pointer to a different register Register SO Auto Answer Ring Number Range 0 255 rings Default 2 rings Assigning a value from 1 to 255 in Register SO automatically instructs your Modem to answer incoming calls A value of 0 disables auto answer Register S1 Count Incoming Rings The S1 register works only when the SO value
81. the remote modem The remote data terminal by transmitting a known data pattern to its local modem and comparing this pattern with that of the received data stream can verify the integrity of both the local and remote modem which is not CCITT V 54 compatible to engage in a remote digital loopback test with your Modem Your Modem must in the on line state prior to issuing the test command Example 1 Terminal a hae as u Escape Sequence Modem OK Acknowledges Terminal ATS 18 06 amp T3 Start test Modem CONNECT Loopback ON When the remote operator notifies you e g by voice telephone that the test is complete you then use the following command to terminate the digital loopback Terminal AT amp TO End test Modem OK Test terminated amp T4 Grant Remote Digital Loopback Request Condition your Modem to grant a request from the remote modem for a remote digital loopback test default setting amp T5 Deny Remote Digital Loopback Request Prevent your Modem from granting a request from a remote digital loopback test amp TO Ending a Test A test may be terminated from the command mode at any time by issuing the amp TO command to your Modem If the Local Analogue Loopback or Remote Digital Loopback test are being performed it is necessary to issue th scape sequence to return to the command mode prior to sending the amp TO command Commands which follow amp TO in a command line
82. though still enter the haracters consecutively Note If you assign small values to this register you may be unable to enter the thr scap characters fast enough be sure to take into account the time it takes to send one character at the current transmission speed Register S18 Test Timer Range 0 255 seconds Default 0 Register S18 sets the duration of the test modes A value of 0 will cause the test to run continuously file C MODULAR Manual txt 57 of 102 12 03 02 11 35 29 file C MODULAR Manual txt Register S25 DTR off Delay Range O 255 x 10ms The modem ignores an OFF condition of DTR for a period of less than this register value Applicable for synchronous operation only Register S29 Hook Flash Time Range 5 9 x 10ms Default ll ol 50ms The modem will go back on hook for this time period when it encounters a character in the dial string Register S30 Inactivity Timer Range 0 255 x minutes Default 0 disabled S30 contains the length of time for which it will stay on line with no data activity A value of 0 disables the Inactivity Timeout feature When in non error corrected mode transmit data activity refreshes the timer when in rror corrected mode both transmit and receive activity refresh the timer file C MODULAR Manual txt 58 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt CHAPTER 8 DIAGNOSTICS AND TE
83. ticular level used is determined by negotiation when the two devices connect An error control protocol developed by Microcom for use on network systems but now commonly used in modems file C MODULAR Manual txt 85 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt modem z The name modem is derived from the two words modulator and demodulator and describes the action of a modem during the transfer of data In simple terms a modem converts modulates digital signals from a computer to produce an analogue signal that can be transmitted over the telephone system The receiving modem demodulates the analogue signal to reproduce the digital data that was originally transmitted file C MODULAR Manual txt 86 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt parallel interfac A type of interface such as Centronics that permits the transmission of data parallel fashion i e two or more bits at a time with as many wires as necessary for the number of data bits per unit of data transmitted usually 8 parity bit An extra bit that may be appended to each character during asynchronous data transmission to provide a primitive form of error detection Prestel British Telecom s Videotex Viewdata service and the name of all services that use the BT protocol Private Automatic Branch Exchange PABX The term used to describe the central control equipment used to manage i
84. ts when operated under the following conditions Ambient temperature 0 to 40 deg Celsius 80 max with no condensation 20 to 65 Ambient temperatur deg Celsius file C MODULAR Manual txt 75 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt Relative humidity 95 max with no condensation file C MODULAR Manual txt 76 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt APPENDIX C REAR PANEL CONNECTIONS V 24 RS232 On desktop modems the port labelled V 24 RS232 is a 25 pin D socket which provides the main serial interface for connection to asynchronous terminals or PCs PIN SIGNAL ACRONYM DIRECTION 2 Transmit Data TxD Input from terminal 3 Receive Data RxD Output to terminal 4 Request to Send RTS Input from terminal 5 Clear to Send CTS Output to terminal 6 Data Set Ready DSR Output to terminal 7 Signal Ground GND N A 8 Data Carrier Detect DCD Output to terminal 20 Data Terminal Ready DTR Input from terminal 22 Ring Indicator RI Output to terminal Composite connector for mic speakers or for combinined earpiece mic tip mic input lst ring speaker earpiece output 2nd ring common file C MODULAR Manual txt 77 of 102 12 03 02 11 35 29 file C MODULAR Manual txt APPENDIX D Troubleshooting Tips Most of the problems with your modem will occur during installation Check this carefully IMPORTANT This is not a repair pro
85. uble after installing the Modem disconnect the modem from the line and test the line for function i e does it dial answer and quality i e do you get clear connections using an ordinary telephone handset The telephone company is not responsible for disturbances caused by non telephone company equipment the modem file C MODULAR Manual txt 12 of 102 12 03 02 11 35 28 file C MODULAR Manual txt Installation of PC card version of modem Refer to Chapter 9 Statutory Information before attempting to install the modem card in your PC i Ensure that your PC is switched off and remove the mains lead from the wall socket The PC Modem must be installed within your personal computer consult your PC User Manual for details on how to install expansion cards You must install your modem board in a free ISA 8 bit expansion slot ii iii When installing the modem the configuration switches must be set to ensure that the modem is compatible with your PC Your computer will probably be equipped with COM1 and COM2 serial ports in which case the modem will have to be set to either COM3 or COM4 as no two ports are allowed to have the same address The Interrupt or IRQ number also needs to be consideredas COM1 and COM3 generally share IRQ4 and for COM2 and COM4 it s IRQ3 If you have a serial mouse on COM1 then the modem should be set to COM4 factory setting to avoid using the mouse s interrupt Where t
86. ways to connect computers for communication de Hard Wire sometimes called Direct Connect wher the computer and the terminal are in relatively close proximity within 15 metres With a hard wire connection the computers are connected by a cable 2 Remote telephone or modem connection where the computers are connected via a telephone line A modem is needed for this type of connection so that the digital data can be transmitted over the telephone lines When connection is via a modem 5 The modem converts the digital data that comes to it from the computer into analog sound signals that can travel over the telephone line and converts the analog signals that come to it from the telephone lines into digital data that can be received by the computer lephone lines carry the data in the form of analog sound signals from one modem to another The telephon lines may be standard switched leased or privately owned Telephone lines may also interconnect to digital packet data networks Protocols There are several sets of rules for how to communicate with the host Each set of rules is called a protocol The protocol determines how data is sent across the communications line between two locations The PC is able to communicate with the host by emulating imitating the protocol used by terminals normally connected to the host The signal coming from the PC then look
87. y Usually the drivers have a user interface which can allow the user to ascertain that a modem card is present details of this interface are mentioned overleaf for each software driver All PCMCIA devices interface to the PC via an area of common memory known as the CIS Table The CIS table holds a series of operating parameters including the card s manufacturer and the type of card eg modem model number etc The PCMCIA modem identifies itself with ROCKWELL as the manufacturer the modem type being either RC144DPL or RC288DPL file C MODULAR Manual txt 15 of 102 12 03 02 11 35 28 file CV MODULAR Manual txt CARDSOFT The following lines are required in the CONFIG SYS DEVICE C CARDSOFT SSCIRRUS EXE This line to SOCKET SERVICE will vary depending on the hardware chips used in the laptop s slot DEVICE C CARDSOFT CS EXE This line loads CARD SERVICES DEVICEHIGH C CARDSOFT CSALLOC EXE Loads a plug and play card manager DEVICEHIGH C CARDSOFT CARDID EXE CARDSOFT has a WINDOWS control panel which allows the user to confirm cards inserted identifying manufacturer and model number etc It is invoked by double clicking on the icon which depicts red and blue PCMCIA cards DATABOOK The following lines are required in the CONFIG SYS DEVICEHIGH C CARDTALK TMB240 SYS i0 240 Loads Socket services her for a DATABOOK TMB240 adaptor
88. y specifies the extra parameters The command MS lt mod gt lt automode gt lt min_rate gt lt max_rate gt lt CR gt ntered enter a comma only or lt CR gt to skip the last parameter unspecified parameters at their Subparameter Definitions eld lt mod gt modulation automode disabled answering a call table to use lt mod gt Modulation Va AA V22 V22bis V23 V32 V32bis V34 PrRoOWNEF Fr oO Possible rates This action will leave current values A decimal number which specifies the preferred automode enabled or the only modulation dialling OX in originating The options are listed in the following bps see note 1 300 1200 2400 or 1200 1200 9600 or 4800 14400 33600 31200 28800 19200 9600 see note 2 12000 9600 7200 4800 26400 24000 16800 14400 12000 7200 4800 or 2400 21600 see note 3 64 69 74 Bell 103 Bell 212 V Fast Notes Le See optional lt automode gt parameters For V 23 300 1200 28800 19200 originate is 75Tx not UK not UK 26400 16800 24000 21600 or 14400 lt min_rate gt and lt max_rate gt 1200Rx answer is 75Rx file C MODULAR Manual txt 40 of 102 12 03 02 11 35 29 file CV MODULAR Manual txt L200 lt mod gt 11 is the default file C MODULAR Manual txt 41 of 102 12 03 02 11 35 29 file CV MODULAR
89. ynchronous communication to indicate of that character file C MODULAR Manual txt 88 of 102 12 03 02 11 35 29 the start file CV MODULAR Manual txt stop bit z synchronous mode Teletex E uploading Videotex Viewdata word length Xmodem XON XOFF Ymodem zmodem A low bit that is inserted after each character transmitted during asynchronous communication to indicate the end of that character One or two stop bits may be used A method of transmitting data without the use of start and stop bits to delineate characters within the data stream Instead timing information is superimposed on the data in order that the receiving device can correctly separate incoming characters A videocast TV transmitted Videotex system that generally lacks the interactive nature or high volume data base aspects of Videotex The process of transmitting a file to a remote information service or computer On line interactive colour graphic information retrieval system Users complete enquiries by entering simple commands and by accepting options displayed on menus Now frequently linked gateways to other computer data base systems The number of data bits making up the characters transmitted during asynchronous communication This can usually be set to 7 or 8 and does not include the start and stop bits An error control protocol for file transfer often found in communicati

MODEM USER GUIDE Issue RC1.3

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