Toshiba V.90 User Manual Download Page 74 | Manualshive

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MNP and V.42

Flow control

55

The modem card has two kinds of flow control:

❖

Serial port flow control

❖

Modem port flow control (only in reliable mode)

Flow control

Serial port flow control

Serial port data flow is controlled by the modem in its
communication with a personal computer.

If the serial port speed is higher than the modem port speed, this
control function sends a transmission halt request to the personal
computer before the buffers in the modem are about to become
full. When the buffers have room to receive data again, the
transmission halt request is canceled and data transmission from
the personal computer is resumed.

The internal modem provides three kinds of serial port flow
control: one determined by software and two determined by
hardware.

Computer

DTE

Receive

Buffer

Buffer

Modem

DCE

Phone
Circuit

Modem port
flow control

flow control

Serial port

Transmi

t

Phone line

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Summary of Contents for V.90

Page 1: ...V 9056K InternalModem User sGuide TOSHIBA C500 0601M2 ...

Page 2: ...orient or relocate the receiving antenna Increase the separation between the equipment and receiver Connect the equipment to an outlet on a circuit different from that to which the receiver is connected Consult the dealer or an experienced radio TV technician for help NOTE Only peripherals complying with the FCC Class B limits may be attached to this modem Operation with non compliant peripherals ...

Page 3: ... The modem connects to the telephone line by means of a standard jack called the USOC RJ11C Type of service Your modem is designed to be used on standard device telephone lines Connection to telephone company provided coin service central office implemented systems is prohibited Connection to party lines service is subject to state tariffs If you have any questions about your telephone line such a...

Page 4: ...other electronic device to send any message via a telephone fax machine unless such message clearly contains in a margin at the top or bottom of each transmitted page or on the first page of the transmission the date and time it is sent and an identification of the business other entity or individual sending the message and the telephone number of the sending machine or such business other entity ...

Page 5: ...must contain the equipment s Ringer Equivalence Number REN and an explanation notice similar to the following The Ringer Equivalence Number REN of this device can vary For the REN number of your modem refer to your computer s user s guide NOTICE The Ringer Equivalence Number REN assigned to each terminal device provides an indication of the maximum number of terminals allowed to be connected to a ...

Page 6: ...The instructions and descriptions it contains are accurate for the Toshiba internal modem at the time of this user s guide s production However succeeding products and user s guides are subject to change without notice Toshiba assumes no liability for damages incurred directly or indirectly from errors omissions or discrepancies between the modem and the user s guide Trademarks Microsoft MS DOS an...

Page 7: ...Introduction xii Chapter 1 Setup 1 Hardware Setup 1 Function check 2 Chapter 2 Using the Internal Modem 5 Connection procedures 5 Analog or digital 5 Connecting the internal modem 6 Disconnecting the internal modem 7 Basic operation 7 Connecting to a telephone line 8 ...

Page 8: ... 16 In Request ID information 17 Ln Monitor speaker volume 20 Mn Monitor speaker mode 20 Nn Modulation handshake 21 On Return online to data mode 21 P Select pulse dialing 22 Qn Result code control 22 T Select tone dialing 22 Vn DCE response format 23 Wn Result Code Option 23 Xn Result code selection call progress monitoring 23 Extended result codes 24 Dial tone detect 24 Busy tone detect 24 Zn Re...

Page 9: ...ntrol 33 V 90 n 33 MS Command 34 MS carrier automode 0 max_rate 0 max_rx_rate 35 MS 35 MS 35 Chapter 4 S Registers 39 S Register values 40 S0 Auto answer ring number 40 S1 Ring counter 40 S2 AT escape character user defined 41 S3 Command line termination character user defined 41 S4 Response formatting character user defined 41 S5 Command line editing character user defined 41 S6 Wait before diali...

Page 10: ...es 53 Normal mode 53 Reliable mode 53 Commands Nn 54 Flow control 54 Serial port flow control 55 XON XOFF flow control software 56 CTS RTS two way flow control hardware 56 Commands Qn Kn 56 Modem port flow control 56 Data compression 57 Commands Cn 57 Chapter 6 Test Function 59 Test description 59 Testing procedure 60 Appendix A Specifications 63 Appendix B Communication Conditions 66 Glossary 69 ...

Page 11: ...Features xiii Function charts xv ...

Page 12: ...d computer to computer data communications The internal modemhas a modem port RJ11 for connectingtoan analog telephone line CAUTION Connect the internal modem ONLY to an analog line not to a digital line For more information see Connection procedures on page 5 Due to FCC limitations speeds of 53 kbps are the maximum permissible transmission rates during downloads Actual data transmission speeds wi...

Page 13: ... or phone line conditions prevent the V 90 connection In this case the maximum connect rate will be 33 600 bits second This section of the user s guide describes features of the internal modem Features 56K data communication The internal modem uses the V 90 protocol to connect at data rates of up to 53 000 bits per second bps to other modems employing the V 90 protocol For connection to non V 90 m...

Page 14: ...42bis data compression protocols Serial port access The internal modem frees your computer s serial port for connection of a serial mouse serial printer or other serial device Ring indicator The computer can be powered on automatically when the modem answers a call This feature is available only when the computer is in Resume Standby mode Refer to your computer s documentation for details on ring ...

Page 15: ...m 32 Kbps to 56 Kbps V 34 From 2400 bps to 33 6 Kbps V 32bis 4800 7200 9600 bps 12 14 4 Kbps V 32 4800 9600 bps V 22bis 1200 2400 bps V 22 1200 bps V 23 75 600 1200 bps V 21 300 bps BELL212A 1200 bps BELL103 300 bps MNP5 Data compression MNP4 Error control V 42bis Data compression V 42 Error control Fax V 17 7200 9600 bps 12 14 4 Kbps Note bps stands for bits per second ...

Page 16: ...es basic operations including connecting the modem and country selection Chapter 3 AT Commands explains the meanings of the AT commands that control your internal modem Chapter 4 S Registers explains the meanings of the registers that contain the settings for many of the internal modem functions Chapter 5 MNP and V 42 explains error correction flow control and data compression V 29 7200 9600 bps V...

Page 17: ... enclosed in parentheses following their definition For example Read Only Memory ROM Acronyms are also defined in the Glossary Keys The keyboard keys are used in the text to describe many computer operations A distinctive typeface identifies the key top symbols as they appear on the keyboard For example Enter identifies the Enter key Key operation Some operations require you to simultaneously use ...

Page 18: ...that improper use of equipment or failure to follow instructions may cause data loss or damage your equipment NOTE Please read A note is a hint or advice that helps you make best use of your equipment ATDT Text you are to type in is represented in the type face you see to the left ABC Text generated by the computer that appears on its display screen is presented in the type face you see to the lef...

Page 19: ...Chapter 1 Hardware Setup 1 Function check 2 ...

Page 20: ...for some reason need to set up the modem again Some procedures may vary slightly for users who have a preinstalled modem Hardware Setup Use the MS DOS or TSETUP program to set the COM port I O address port and IRQ level Refer to your computer s documentation The default settings are Device Configuration All devices Built in Modem Com 2 2F8H IRQ3 ...

Page 21: ...ic function accessible in the Modems Properties window to check the functions of your internal modem To run the diagnostics 1 Click the Diagnostics tab in the Modems Properties window Modem Properties window 2 Select the COM Port for Toshiba Internal V 90 Modem This is the COM port for the Toshiba internal modem ...

Page 22: ...tup Function check 3 3 Click More Info The system executes an automatic operations test If the test does not run or if an error message appears repeat the setup procedures Diagnostics tab More Info window ...

Page 23: ...Chapter 2 Connection procedures 5 Basic operation 7 ...

Page 24: ...signed for use with a standard analog telephone line Do not connect the modem to a digital telephone line A digital line will damage the modem Analog or digital If you are not sure which type of line a particular line jack offers assume that it is digital and do not connect the internal modem to it If the wall jack is known to be connected to a PBX Private Branch Exchange system then the line is d...

Page 25: ...iliar RJ11 connector as shown below If you are not sure that an RJ11 jack terminates an analog phone line do not connect the modem to it Connecting the internal modem CAUTION In the event of a lightning storm unplug the modem cable from the telephone jack A standard modular cable is supplied with the internal modem Follow the steps below to connect the internal modem to a telephone jack 1 Turn the...

Page 26: ... cable from the wall jack 2 Disconnect the modular cable from the computer s modem port Basic operation After you connect the modular cable to your internal modem and a telephone line you are ready to run your communication software Refer to your software documentation for instructions on operating your internal modem As examples this section describes how to execute basic modem operations by typi...

Page 27: ...on line If you are calling from an extension line such as in an office building and need to dial nine or another number to gain external access follow the steps below To place a call using tone dialing enter ATDT 9 and press Enter The nine or other number is for line access the comma is for a pause about 2 seconds with the default setting to give time for a connection The asterisks indicate the nu...

Page 28: ... the number of rings before the internal modem automatically answers the phone set the S0 register as follows ATS0 and press Enter The asterisk indicates the number of rings See S Register values on page 40 for more details Terminating a call The methods for terminating a call depend on the status of the connection If the internal modem is dialing or has not yet gone online you can terminate a cal...

Page 29: ...42 on page 52 CTS RTS control This control method is hardware dependent To control data flow the modem and computer transmit Clear To Send Request To Send signals to each other To set CTS RTS control enter the following AT command AT Q3 XON XOFF control This control method is managed by software The start stop signals that is transfer on transfer off are included in the data stream To set XON XOFF...

Page 30: ...on 11 Facsimiles Fax communication uses EIA 578 Class 1 commands and requires fax software Communication is controlled by the fax software NOTE Use only software compatible with EIA 578 Class 1 Do not use EIA 592 Class 2 compatible software ...

Page 31: ...Chapter 3 AT command formats 13 ...

Page 32: ...t for entering AT commands is ATXn where X is the AT command and n is the specific value for some of the commands After you type in the command press Enter Any command issued is acknowledged with a response in either text or numeric values known as result codes All commands and command values accepted by the modem are described in this section any entry other than those listed results in an error ...

Page 33: ...ters can be sent to the modem This pause prevents the modem from interpreting the escape sequence as data The value of the escape sequence character may be changed using register S2 A Repeat last command This command repeats the last command string entered Do not precede this command with an AT prefix nor conclude it by pressing Enter A Answer command This command instructs the modem to go off hoo...

Page 34: ...ay be used as phone number modifiers B0 Selects CCITT V 22 mode when the modem is at 1200 bps B1 Selects Bell 212A when the modem is at 1200 bps B2 Unselects V 23 reverse channel B3 Unselects V 23 reverse channel B15 Selects V 21 when the modem is at 300 bps B16 Selects Bell 103J when the modem is at 300 bps OK n 0 1 2 3 15 16 ERROR Otherwise P Pulse dialing S n Dial using the string saved by Zn c...

Page 35: ...ds of silence after dialing the number If silence is not detected the modem sends a NO ANSWER result code back to the caller Hook flash Causes the modem to go on hook for 0 5 seconds and then return to off hook Return to command mode Causes the modem to return to command mode after dialing a number without disconnecting the call L Redials last number Should be the first character following ATD ign...

Page 36: ...Returns modem identity string and driver version number same as I0 I4 Returns firmware version for data pump I5 Returns the code ver board ID country ID and subsystem vendor ID I6 8 Returns OK for compatibility I9 Returns country ID in English I11 The ATI11 result has two pages you must hit a key to get the second page See the following example ATI11 Description V 90 1 Last Connection V 90 2 Initi...

Page 37: ...eam rate 4 Current or final upstream rate 5 Current or final downstream rate 7 Data Compression Result V42bis 8 Estimated Noise Level 152 9 Receive Signal Power Level dBm 25 10 Transmit Signal Power Level dBm 16 11 Round Trip Delay msec 4 Press any key to continue Esc to quit 12 Near Echo Level dBm NA 13 Far Echo level dBm NA 14 Transmit Frame Count 3 15 Transmit Frame Error Count 0 16 Receive Fra...

Page 38: ... different locations Only valid during a call 10 Upstream transmit signal power 11 Round trip delay in millliseconds 12 Echo levels are valid for V 34 only 13 Echo levels are valid for V 34 only 14 Number of LAPM frames sent upstream during this call Count wraps around at 65535 15 Number of REJ frames received at the analog client modem 16 Number of LAPM frames received by client during this call ...

Page 39: ...nly the downstream digital loss Result Codes Ln Monitor speaker volume This command sets speaker volume to low medium or high Result Codes Mn Monitor speaker mode This command turns the speaker on or off As described n 0 1 2 3 4 5 6 7 8 9 11 ERROR Otherwise L0 Low volume L1 Low volume Same as L0 L2 Medium volume default L3 High volume OK n 0 1 2 3 ERROR Otherwise M0 The speaker is off M1 The speak...

Page 40: ...off hook OK n 0 1 2 ERROR Otherwise N0 When originating or answering this is for handshake only at the communication standard specified by S37 and the ATB command N1 When originating or answering begin the handshake at the communication standard specified by S37 and the ATB command default During handshake a lower transmission speed may be selected OK n 0 1 ERROR Otherwise O0 Instructs the modem t...

Page 41: ...codes are OK CONNECT RING NO CARRIER and ERROR The ATQ command allows the user to turn result codes on or off Result Codes T Select tone dialing This command instructs the modem to send DTMF tones while dialing Dialed digits are tone dialed until a P command or dial modifier is received This is the default setting O3 This command issues a rate renegotiation before returning to online data mode OK ...

Page 42: ...ing This command sets detection options for dial tones and busy signals which is its primary function However it also enables or disables extended result codes V0 Displays result codes as digits V1 Displays result codes as text default OK n 0 1 ERROR Otherwise W0 CONNECT result code reports DTE speed Disable protocol result codes W1 CONNECT result code reports DTE speed Enable protocol result code...

Page 43: ...only the basic result codes OK CONNECT RING NO CARRIER and ERROR Enabled Displays basic result codes along with the connect message and the modem s data rate and an indication of the modem s error correction and data compression operation Disabled The modem dials a call regardless of whether it detects a dial tone The period of time the modem waits before dialing is specified in register S6 Enable...

Page 44: ...rom the modem to the computer indicating that a carrier signal is being received from a remote modem DCD normally turns off when the modem no longer detects the carrier signal Result Codes Enabled The modem monitors for busy tones Result Codes OK n 0 1 2 3 4 5 6 7 ERROR Otherwise OK n 0 1 ERROR Otherwise C0 The state of the carrier from the remote modem is ignored DCD circuit is always on C1 DCD t...

Page 45: ...l This command determines which guard tone if any to transmit while transmitting in the high band answer mode This D0 Ignore The modem ignores the true status of DTR and treats it as always on This should only be used if your communication software does not provide DTR to the modem D1 If the DTR signal is not detected while in online data mode the modem enters command mode issues an OK result code...

Page 46: ...al Make Break Ratio G0 Guard tone disabled default G1 Sets guard tone to 550 Hz G2 Sets guard tone to 1800 Hz OK n 0 1 2 ERROR Otherwise K0 Disables flow control K3 Enables RTS CTS flow control default K4 Enables XON XOFF flow control OK n 0 3 4 ERROR Otherwise P0 Selects 39 61 make break ratio at 10 pulses per second P1 Selects 33 67 make break ratio at 10 pulses per second P2 Selects 33 67 make ...

Page 47: ... your computer s monitor For example OK n 0 to 2 ERROR Otherwise T0 Abort Stops any test in progress T1 Local analog loop This test verifies modem operation as well as the connection between the modem and computer Any data entered at the local DTE is modulated then demodulated and returned to the local DTE To work properly the modem must be offline OK n 0 CONNECT n 1 ERROR Otherwise V View active ...

Page 48: ...ble X Dial Tone Detect Enable X Busy Tone Detect Enable X LSD Action Standard RS 232C C DTR Action Ignore D Option Selection AT Command V 22b Guard Tone Disable G Flow Control Hardware K Error Control Mode V 42 MNP Buffer N Data Compression Enable C Auto AnswerRing 0 S0 AT Escape Char 43 S2 CarriageRtn Char 13 S3 Linefeed Char 10 S4 Backspace Char 8 S5 Blind Dial Pause 2 sec S6 NoAnswer Timeout 50...

Page 49: ...on comprises a list of storable parameters illustrated in the V command These settings are restored to the active configuration upon receiving a Zn command or at power up Refer to the V command Result Codes Option Selection AT Command No Carrier Disc 2000 msec S10 DTMF Dial Speed 95 msec S11 Escape GuardTime 1000 msec S12 Data Calling Tone Disabled S35 Line Rate 33600 S37 W Stores the current conf...

Page 50: ...the modem when sending or receiving data OK n 0 1 2 3 ERROR Otherwise N0 Buffer mode No error control Also known as Normal Mode N1 Same as N0 N2 MNP or disconnect mode The modem attempts to connect using MNP2 4 error control procedures If this fails the modem disconnects This is also known as MNP reliable mode N3 V 42 MNP or buffer default The modem attempts to connect in V 42 error control mode I...

Page 51: ...P or Buffer same as N3 N7 V 42 MNP or Buffer same as N3 OK n 0 1 2 3 4 5 7 ERROR Otherwise Q0 Disable flow control Q1 XON XOFF software flow control Q3 RTS CTS to DTE default OK n 0 1 3 ERROR Otherwise V0 Disable protocol result code appended to DCE speed V1 Enable protocol result code appended to DCE speed default OK n 0 1 ERROR Otherwise ...

Page 52: ...bles disables V 90 and changes the downstream rate Possible values of n C0 V 42bis MNP 5 disabled No data compression C1 V 42bis MNP 5 enabled Data compression enabled default OK n 0 1 ERROR Otherwise V90 0 Disables V 90 V90 1 Enables V 90 Auto rate default value V90 X Controls the downstream rate V90 Shows the current value V90 Shows the range 0 21 AT V90 X Downstream Rate 0 V 90 disabled 1 Auto ...

Page 53: ...mand can also be used to provide information concerning the current modem protocol settings and maximum connection speed settings In addition it can be used to indicate all the possible settings available for the modem 5 32000 bps 6 33333 bps 7 34666 bps 8 36000 bps 9 37333 bps 10 38666 bps 11 40000 bps 12 41333 bps 13 42666 bps 14 44000 bps 15 45333 bps 16 46666 bps 17 48000 bps 18 49333 bps 19 5...

Page 54: ... parameter settings MS This command returns a listing of all supported values for each sub parameter For the current modem driver the response is the following carrier A modem connect protocol string such as V 90 or 56K automode 0 Disables automatic modulation negotiation 1 Enables automatic modulation negotiation max_rate The maximum transmit rate If set to 0 then the max rate will be determined ...

Page 55: ...or max_rx_rate for the different carriers are Value Meaning V90C or V90 V90 K56 K56flex V34 V34 V32 V32 V32B V32bis V22 V22 V22B V22bis V23 V23 V21 V21 Value Meaning V90 K56 V34 2400 33600 in steps of 2400 V32bis 4800 19200 in steps of 2400 V32 4800 14400 in steps of 2400 V22bis 2400 V22 2200 V23 1200 V21 300 Value Meaning V90 28000 56000 in steps of 1333 K56 32000 56000 in steps of 2000 V34 2400 ...

Page 56: ...AT Commands AT command formats 37 V32bis 4800 19200 in steps of 2400 V32 4800 14400 V22bis 2400 V22 2200 V23 1200 V21 300 ...

Page 57: ...Chapter 4 S Register values 40 AT command set result codes 46 ...

Page 58: ... can also customize certain AT commands such as the escape sequence and command line termination The contents of the registers are changed automatically when you modify corresponding settings inyour communication software If you choose however you can display and edit the contents of the registers manually when the modem is in command mode If the value is outside the acceptable range an error is g...

Page 59: ...register number and its new value press Enter S0 Auto answer ring number This register determines the number of rings the modem will count before automatically answering a call Enter 0 zero if you do not want the modem to automatically answer at all When disabled the modem can only answer with an ATA command S1 Ring counter This register is read only The value of S1 is incremented with each ring I...

Page 60: ...ge return character This character is used to end command lines and result codes S4 Response formatting character user defined This register determines the ASCII value used as the line feed character The modem uses a line feed character in command mode when it responds to the computer S5 Command line editing character user defined This register sets the character recognized as a backspace and pert...

Page 61: ...one number The modem always pauses for a minimum of two seconds even if the value of S6 is less than two seconds The wait for dial tone call progress feature W dial modifier in the dial string will override the value in register S6 S7 Connection completion time out This register sets the time in seconds that the modem must wait before hanging up because the carrier is not detected The timer is sta...

Page 62: ...This register sets the length of time in tenths of a second that the modem waits before hanging up after a loss of carrier This allows for temporary carrier loss without causing the local modem to disconnect The actual interval the modem waits before disconnection is the value in register S10 Range 1 255 Default 50 Units seconds Range 0 65 Default 2 Units seconds Range 1 254 Default 20 Units 1 sec...

Page 63: ...required pause after the escape sequence default 1 second S37 Dial line rate Range 50 150 Default 95 Units 001 seconds Range 0 255 Default 50 Units 02 seconds S37 0 default maximum modem speed S37 1 reserved S37 2 1200 75 bps S37 3 300 bps S37 4 reserved S37 5 1200 bps S37 6 2400 bps S37 7 4800 bps S37 8 7200 bps S37 9 9600 bps S37 10 12000 bps S37 11 14400 bps S37 12 16800 bps ...

Page 64: ...e S register S38 S38 0 disables 56K and may allow a more reliable V 34 connection S38 1 default allows the modem to select the downstream rate automatically Other values of S38 force the downstream rate with fallback to V 34 if unsuccessful at the configured rate S37 13 19200 bps S37 14 21600 bps S37 15 24000 bps S37 16 26400 bps S37 17 28800 bps S37 18 31200 bps S37 19 33600 bps S38 0 56K disable...

Page 65: ...ted CONNECT 1 Modem connected to line RING 2 A ring signal has been detected NO CARRIER 3 Modem lost carrier signal or does not detect carrier signal or does not detect answer tone EC appears only when the Extended Result Codes configuration option is enabled EC is replaced by one of the following symbols depending upon the error control method used V 42bis V 42 error control and V 42bis data comp...

Page 66: ...600 EC 55 Connection at 21600 bps CONNECT 24000 EC 56 Connection at 24000 bps CONNECT 26400 EC 57 Connection at 26400 bps CONNECT 28800 EC 58 Connection at 28800 bps CONNECT 31200 EC 59 Connection at 31200 bps CONNECT 33600 EC 60 Connection at 33600 bps CONNECT 38400 EC 28 Connection at 38400 bps DTE rate Command Set Result Codes Table Continued Result Code Numeric Description EC appears only when...

Page 67: ...de CONNECT 44000 EC 76 Connection at 44000 bps 56K mode or V 90 CONNECT 46000 EC 77 Connection at 46000 bps 56K mode CONNECT 48000 EC 78 Connection at 48000 bps 56K mode or V 90 CONNECT 50000 EC 79 Connection at 50000 bps 56K mode Command Set Result Codes Table Continued Result Code Numeric Description EC appears only when the Extended Result Codes configuration option is enabled EC is replaced by...

Page 68: ...de CONNECT 37333 EC 105 Connection at 37333 bps V 90 mode CONNECT 38666 EC 106 Connection at 38666 bps V 90 mode CONNECT 41333 EC 107 Connection at 41333 bps V 90 mode CONNECT 42666 EC 108 Connection at 42666 bps V 90 mode Command Set Result Codes Table Continued Result Code Numeric Description EC appears only when the Extended Result Codes configuration option is enabled EC is replaced by one of ...

Page 69: ...e CONNECT 54666 EC 114 Connection at 54666 bps V 90 mode Command Set Result Codes Table Continued Result Code Numeric Description EC appears only when the Extended Result Codes configuration option is enabled EC is replaced by one of the following symbols depending upon the error control method used V 42bis V 42 error control and V 42bis data compression V 42 V 42 error control only MNP 5 MNP clas...

Page 70: ...Chapter 5 Error correction overview 52 Operation modes 53 Flow control 54 Data compression 57 ...

Page 71: ...s in data communication Noise is especially a problem at high speeds of 14 400 bps or greater The MNP and V 42 protocols were developed to ensure reliable data communications despite the high probability of error generation from line noise MNP error correction MNP was developed by Microcom MNP class 4 enables data correction of full duplex communications and also provides asynchronous synchronous ...

Page 72: ...classes 2 3 and 4 This protocol first tries to establish a link to the remote modem with LAP M If it is unsuccessful it tries to connect with MNP Although this modem uses class 4 correction it can connect in class 5 to remote modems that support class 5 Operation modes The operation mode depends on whether an error correction protocol is being used Normal mode Errors are not corrected even if comm...

Page 73: ...l port or between modems modem port If there is a speed difference between the serial port and modem port the buffers in the modem will become full periodically Therefore the communication activity is controlled so that data transmission or reception is temporarily halted before the data exceeds buffer capacity and transmission is resumed when the receiving buffers have room This is the flow contr...

Page 74: ...his control function sends a transmission halt request to the personal computer before the buffers in the modem are about to become full When the buffers have room to receive data again the transmission halt request is canceled and data transmission from the personal computer is resumed The internal modem provides three kinds of serial port flow control one determined by software and two determine...

Page 75: ...the modem and the computer A transmission halt or restart request is made from the modem to the computer using the CTS signal A transmission halt or restart request is made from the personal computer to the modem using the RTS signal Commands Qn Kn Select flow control between the modem and computer serial port as follows When CTS RTS flow control is supported by the communication software Q3 K3 Co...

Page 76: ... compress data received from the computer The receiving modem decompresses the received data and sends it to its own computer This data compression function increases actual transmission speed up to twofold in communications using MNP5 or up to three or fourfold in communications using V 42bis The compression ratio varies depending on the data Actual speed will not always be raised close to the ma...

Page 77: ...Chapter 6 Test description 59 Testing procedure 60 ...

Page 78: ...loopback test function that identifies the cause of a malfunction You can use the test to check errors in data communications or to check operation following modem connection When conducting a test use the T command to select test mode and control For details on the T command refer to Tn Self test commands on page 28 In this test data is transmitted from the computer is looped back analog loopback...

Page 79: ...cedure 60 Local analog loopback test Testing procedure To conduct the loopback test 1 Enter the following AT commands to set the modem to normal mode AT F N0 Receive OK Computer Modem Transmitter Receiver Transmission Reception ...

Page 80: ... T1 You are now in the online state 3 Enter characters from the keyboard as desired The characters you enter should be displayed on the screen 4 Enter the escape code as follows to return to the command state from the online state Receive OK 5 Enter the following AT commands to terminate the test AT T0 Receive OK ...

Page 81: ...Appendix A ...

Page 82: ...zes the Toshiba internal modem s technical specifications Network control unit NCU Type of NCU AA Type of line General telephone line Type of dialing Pulse Tone Control command AT commands EIA 578 commands Monitor function Computer s speaker ...

Page 83: ...bis V 32 V 32bis V 34 56K V 90 Bell 103 212A Fax ITU T Rec V 17 V 29 V 27ter Former CCITT V 21 ch2 Communication speed Data 300 1200 2400 4800 7200 9600 12000 14400 16800 19200 21600 24000 26400 28800 29333 30666 33333 34666 37333 38666 41333 42666 45333 46666 49333 50666 53333 54666 bps Fax 2400 4800 7200 9600 12000 14400 bps Transmitting level 10 dBm ...

Page 84: ...Appendix B ...

Page 85: ...ons Communication parameters Select communication parameters from the table below Start bit Data length bit Parity bit Stop bit 1 8 None 1 or more 1 7 0 1 or more 1 7 1 1 or more 1 7 Odd 1 or more 1 7 Even 1 or more 1 7 None 2 ...

Page 86: ... home telephones that are connected to a key service unit or a PBX WARNING These are digital lines that can damage the modem Lines that require pressing the Line button for example 0 before dialing Dial modes There are two types of dial modes pulse dial and tone dial Generally pulse dial lines are associated with rotary phones but there may be cases where a push button phone is connected to a puls...

Page 87: ...Communication Conditions 68 If you connect to the dialed number the line is tone dial type If you do not get a connection it is pulse dial type The command ATDP will connect a pulse line ...

Page 88: ...ort 2 serial port CPU Central Processing Unit FCC Federal Communications Commission FTP File Transfer Protocol GND Ground HDD Hard Disk Drive HTML HyperText Markup Language I O Input Output IRQ Interrupt Request ISA Industry Standard Architecture KB Kilobyte LAN Local Area Network LBA Logical Block Addressing ...

Page 89: ...erial Bus VCR Video Cassette Recorder VESA Video Electronics Standards Association WSS Windows Sound System WWW World Wide Web A Auto reliable mode This mode connects to a remote station by MNP or V 42 if the remote modem accepts either of these protocols Otherwise it connects in normal mode address A number that identifies a location in the computer s memory or on disk It tells the computer where...

Page 90: ...its See also synchronous B baud baud rate The speed at which communications devices such as printers terminals and modems transmit information Information travels as a series of electronic signals The baud rate measures the rate of change in these signals This is not necessarily the same as bits per second although the two are related It is named for Emil Baudot a pioneer in printing telegraphy Se...

Page 91: ...F in hexadecimal or a character such as a letter numeral or other symbol See also binary bit gigabyte hexadecimal kilobyte megabyte C carrier A modem converts the digital signals of the personal computer into analog signals to send them through the telephone line The analog signals are carrier because they transport the data The analog frequency is determined by the individual communication specif...

Page 92: ...orm for storage or transmission In computer terms files are compressed by removing repetitive and blank characters Depending on the type of file this can result in a size reduction of over 90 Modems use compression to reduce the amount of time needed to send or receive a file Configuration 1 The set of components in a computer system such as memory printers and disk drives 2 How parts of the syste...

Page 93: ...ed party download 1 To receive a file from another computer through a modem 2 To transmit font data from the computer to a printer See also upload DSP A digital signal processor is a chip designed for real time applications DSP techniques are used in PC processors as well as media engines For example some high end notebooks use a DSP chip to provide Sound Blaster emulation for the internal modem a...

Page 94: ...mmunication If operating speed differs between the personal computer and modem or between your modem and a remote modem and if the remote station runs short of buffer capacity a transmission halt request is sent from the receiver to the transmitter When the receiver has enough buffer capacity to resume receiving data a transmission restart request is sent There are two ways of flow control XON and...

Page 95: ...rs output A disk drive is both an input and an output device since it can both provide information to the computer and receive information from the computer ITU T Standard A series of communication procedures for telephone lines and analog data transmission standardized by ITU International Telecommunications Union formerly CCITT K keyboard The device you use to type information into the computer ...

Page 96: ...refer to information on the hard disk such as online documentation or online help or a connection through a modem to another computer or the Internet On hook Off hook On hook means the handset is on the telephone and off hook means it is off The line is disconnected from the internal modem when the handset is on hook and connected to the internal modem when it is off hook P parity A method in seri...

Page 97: ...aracters or numeric values RJ11 A modular telephone connector used on most telephone networks and direct connect modems RTS signal A Request to Send signal is an RS 232C standard that indicates the modem is ready to receive data RS 232 C The standard defining control data and status signals for cables allowing asynchronous communication with computers printers and other peripheral devices S serial...

Page 98: ... they are normal Tone dialing A dialing method that uses tones instead of pulses to generate atelephone number Generally associated with push button phones although some push button phones can be connected to pulse lines U upload To send a file to another computer through a modem See also download UART Universal Asychronous Receiver Transmitter is the circuit interface between the modem and comput...

Page 99: ...esult codes 24 format 13 guard tone control 27 hook control 16 load factory settings 26 local flow control selection 27 32 monitor speaker mode 20 monitor speaker volume 20 MS command 34 N modulation handshake 21 protocol result code 32 recall stored profile 25 repeat last command string 14 request ID information 17 result code control 22 result code option 23 result code selection 23 return to on...

Page 100: ...gnostics 2 dial a telephone number 15 dial tone detect 24 disconnecting the internal modem 7 display result codes 23 downsteam rate 45 E echo command 16 error control mode selection 31 escape sequence 14 extended result codes 24 F fax communication 11 features internal modem xiii flow control 54 computer to modem 54 modem port 55 56 modem to modem 54 serial port 55 computer to modem 55 software 55...

Page 101: ...lect pulse dial make break ratio 27 select pulse dialing 22 select tone dialing 22 self test commands 28 serial port flow control 55 set protocol and connection speed parameters 34 speaker on off 20 speaker volume 20 specifications Toshiba s internal modem 63 S register values AT escape character 41 Automatic disconnect delay 43 Comma pause time 43 Command line editing character 41 Command line te...

Page 102: ...Index 83 test function loopback test 60 transfer on transfer off 10 V V 42 protocol 53 V 90 enable disable 33 view active configuration and stored profile 28 X XON XOFF control 10 ...

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