JPH09130497A - Modem with error correction function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discontinue the negotiation for the setting of an error correction function in the case when an opposite modem is not provided with an error correction function. SOLUTION: A second address control part an 24-2 receives the result information of the negotiation executed at the time of the previous abbreviated dial transmission by the same abbreviated number from an error correction function corresponding part 27 and stores the information in a second error correction function setting storage part 26. An abbreviated dial time command corresponding part 22 reads the result information of the negotiation from the second error correction function setting storage part 26 via the second address control part 24-2, sets the information to the error correction function corresponding part 27, reads the terminal number of a terminal to be called from a dial number storage part 25 via a first address control part 24-1 and instructs an NCU part 29 to perform a dial transmission. When an opposite modem is not provided with an error correction function, the execution of the negotiation of the error correction function is discontinued because the negotiation result is an error correction function 'null'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modem with an error correction function, and more particularly, when the opposite modem does not have an error correction function, the modem accommodating the calling terminal LINKs for negotiating the error correction function setting. R
The present invention relates to a method for preventing an erroneous signal from being sent from a remote modem to a called terminal by stopping sending an EQUEST signal.

[0002]

2. Description of the Related Art A conventional modem having an error correction function will be described with reference to the drawings. FIG. 6 is a block diagram of the conventional modem with error correction function of FIG. 5. The conventional modem 60 with an error correction function shown in FIG.
1, a command handling unit 62, an error correction function setting storage unit 63, an address control unit 64, a dial number storage unit 65, an error correction function handling unit 67, and a modulation / demodulation unit 68.
And an NCU unit 69.

The terminal interface corresponding part 61 is V.2
It has a 4 / V.28 interface function, and converts various commands received from the calling terminal into a predetermined digital signal level handled in the own modem. Command correspondence section 62
Verifies various commands received from the terminal interface corresponding unit 61 and sends a control signal corresponding to the command.

The error correction function setting storage unit 63 receives the error correction function setting command for initial setting sent from the calling terminal via the command corresponding unit 62, and stores the error correction function setting information at the time of initial setting. Command corresponding part 6
The error correction function setting information at the time of initialization stored in response to the request of No. 2 is transmitted.

The address control unit 64 stores the terminal number of the called terminal included in the speed dial registration request command sent from the calling terminal in correspondence with the speed code, and the dial number storage unit 65.
In addition to registering with, and receiving a speed dial call notification from the command handling unit 62, the terminal number of the called terminal for speed dialing is read from the dial number storage unit 65,
It is sent to the command handling unit 62.

The dial number storage unit 65 stores the terminal number of the called terminal for the speed dial registration notified from the address control unit 64 in a register (not shown) corresponding to the speed code, and the address control unit In response to the request from 64, the terminal number of the called terminal is transmitted from the register. Since this register corresponds to each abbreviated code, the terminal number of the called terminal included in the abbreviated dial registration request command notified from the address control unit 64 is overwritten. In addition,
Since the register has a battery backup, the terminal number of the called terminal is retained even while the modem is powered off.

[0007] The error correction function corresponding section 67 executes a negotiation regarding the setting of the error correction function with the modem accommodating the called terminal (hereinafter called the called modem), and performs all the control related to the communication using the error correction function. Run.

The modem unit 68 performs a handshake (connection training with a called-side modem) after the line is connected and V.22 / V.22bis / V.32 / V.32b.
The communication data conversion (A / D and D / A conversion) processing is performed in accordance with criteria such as is.

The NCU 69 has a function of monitoring and controlling various information for dial transmission and reception and has an automatic transmission / reception control function.

In a conventional modem with an error correction function,
In the case of initially setting the presence or absence of the error correction function, FIG. 5 shows an error correction function setting command from an external terminal (not shown) such as a personal computer or a data terminal through an interface determined by V / 24 / V28. The terminal interface corresponding unit 61 sends it to the terminal interface corresponding unit 61, and the terminal interface corresponding unit 61 converts the received error correction function setting command into a predetermined signal level handled by itself and sends it to the command corresponding unit 62.

The command corresponding section 62 stores the error correction function setting information in the error correction function setting storage section 63 and sets the error correction function setting information in the error correction function corresponding section 67. The error correction function setting storage unit 63 has one register (not shown) for storing error correction function setting information. The error correction function setting information set in this register is backed up by a battery. It is held until the next setting change command is notified from the command corresponding unit 62. When the modem is installed, the initial setting information is normally set to the error correction function “Yes”.

When communicating with a personal computer (not shown) or a composite terminal device (not shown) to which the initially set modem with an error correction function is connected via a telephone network, speed dial registration is first performed. The terminal interface corresponding unit 61 of the modem with error correction function on the calling terminal side (hereinafter called the calling side modem) receives the speed dial registration request command including the abbreviated code transmitted from the calling terminal and the terminal number of the called terminal. .

The terminal interface support unit 61 converts the level of the received speed dial registration request command into a predetermined signal level, and then sends it to the command support unit 62. The command handling unit 62 analyzes the received speed dial registration request command and identifies that the request is a speed dial registration request, and the dial number storage unit 6 is sent via the address control unit 64.
The terminal number of the called terminal is stored in 5 in correspondence with the shortened code. This operation is performed for each abbreviated code to complete the registration of the abbreviated dial.

When making a speed dial call after registering the speed dial, the terminal interface corresponding unit 61 converts the speed dial call request command received from the calling terminal into a predetermined signal level and then sends it to the command corresponding unit 62. The command handling unit 62 analyzes the received speed dial call request command, identifies that it is a speed dial transmission request, and responds to the speed code received from the dial number storage unit 65 via the address control unit 64. The stored terminal number of the called terminal is read out, the terminal number of the called terminal is sent to the NCU section 69 to instruct dialing, and the NCU section 69 sends a dial signal to an exchange (not shown). Send out.

The dial number storage unit 65 has a register (not shown) for storing the terminal number of the called terminal corresponding to each abbreviated code, and the abbreviated code included in the abbreviated dial registration request command. The terminal number of the called terminal is stored corresponding to. Therefore, when the speed dial registration request command is received, the terminal number of the called terminal stored in the register corresponding to the speed code included in the speed dial registration request command receives the speed dial registration request command. Overwritten each time. In addition, since the register is battery-backed up, the terminal number of the called terminal is held even while the power of the modem is cut off.

As described above, when a call is made to a called terminal that has already been registered as a speed dial, a speed dial calling request command including a speed code is automatically sent to a called terminal corresponding to the speed code. Further, the terminal number of the called terminal is stored in the dial number storage unit 65 as the shortened dial number corresponding to the shortened code by the speed dial registration request command including the shortened code and the terminal number of the called terminal.

Further, when a speed dial transmission request is made using a speed code not registered in the speed dial, a registration flag indicating that the register corresponding to the speed code is empty is stored in the dial number storage section 65 via the command processing section 64. And automatically cancel the call to the called terminal. The registration flag is provided for each register corresponding to the abbreviated code, and when there is a speed dial registration request command, it is held until only the part corresponding to the designated abbreviated code is reset.

When the called modem receives a dial signal, the modem unit 68 of the calling modem executes a handshake with the called modem, and when the handshake ends, the error correction function corresponding unit 67 initializes. The error correction function setting “present” is sometimes identified from the error correction function setting information set by the command handling unit 62, and the LINK R
An EQUEST signal (hereinafter, an LR signal) is transmitted to start negotiation with the called modem, and when the negotiation is completed, a transition is made to a communication state.

In such a situation of handshake or negotiation between modems, if a connection failure occurs due to some reason, the calling modem notifies the calling terminal of communication failure information indicating that the connection is not possible.

In order for the calling terminal which has received the notification of the communication failure to call again by using the speed dial function of the calling modem, for example, the corresponding speed code button (not shown) is operated to speed dial. Send a call request command.

Upon receiving the speed dial call request command, the terminal interface corresponding section 61 of the calling modem performs a predetermined level conversion, sends the speed dial call request command to the command corresponding section 62, and the command corresponding section 62. Is
The terminal number of the called terminal that was stored at the beginning of communication (when the speed dial call request command was received) was analyzed by analyzing the received speed dial call request command to identify that it is a speed dial call request. Is read from the dial number storage section 65 via the address control section 64 and sent to the NCU section 69 as a dial number.

NCU unit 69 that received the speed dial number
Sends a dial signal for abbreviated dialing to the exchange, and when the called modem receives this dial signal, the modem unit 68 of the calling modem calls the called party via the exchange as at the start of communication. Perform a handshake with the local modem.

When the handshake is completed, the error correction function setting information is set to "present" in the error correction function support unit 67 at the time of initial setting.
Start negotiation on error correction function,
The R signal is sent to the exchange via the modem 68 and the NCU 69. When the negotiation ends, the communication state is established.

If the called modem does not have an error correction function, that is, if the error correction function is "absent", the LR signal sent from the calling modem for negotiation regarding the error correction function is the same as that of the called modem. The received data demodulated by the modulator / demodulator is sent to the called terminal, and the called terminal handles the received LR signal as erroneous data.

[0025]

A conventional modem with an error correction function performs negotiation with the opposite modem based on the error correction function setting information at the time of initial setting. However, there is a disadvantage that the LR signal for the negotiation regarding the error correction function setting is transmitted to the called terminal as erroneous data.

As a workaround, a method may be considered in which the setting of the presence or absence of the error correction function is repeated in the calling modem every time it is connected to the opposite modem, but this method is troublesome in the operation at the time of calling. Not only that, but it also has the drawback of increasing the communication preparation time.

An object of the present invention is to provide a modem with an error correction function which does not erroneously send an LR signal as received data from the opposed modem to the called terminal even when the opposed modem does not have an error correction function. There is something to do.

[0028]

A modem with an error correction function according to the present invention is a caller-side modem that accommodates a caller-side terminal device when the terminal device is accommodated and communication is performed between the terminals via a telephone network. A modem with an error correction function that forms a communication line by performing a handshake with the modem connection training sequence between the caller and the called modem that accommodates the called terminal device, and then performing a negotiation with the error correction function connection sequence. , Has speed dial transmission function,
When the speed dial transmission request is received from the terminal device on the calling side, the modem with an error correction function that accommodates the terminal device on the calling side receives the result of the negotiation performed at the time of the last speed dial transmission with the same abbreviated code. When the information is referred to and it is identified that the modem accommodating the called terminal device does not have an error correction function, the negotiation is stopped.

Further, the first error correction function setting storage means for storing the error correction function setting information at the time of initial setting, and the received information which is the result information of the negotiation executed at the time of the previous speed dial transmission with the same shortening code. A second error correction function setting storage means for storing error correction function setting information of the calling modem, and the result of the negotiation stored in the second error correction function setting storage means at the time of speed dial transmission. Refer to the error correction function setting information of the called modem, which is the information, and if the error correction function setting is “Yes”, execute the negotiation,
In the case of "absent", the negotiation is stopped.

Further, a terminal interface corresponding unit which receives various commands from the accommodated terminal device and performs a predetermined level conversion, and various commands received from the terminal interface corresponding unit are verified, and control corresponding to the received command is performed. When the command corresponding unit for transmitting information and the command corresponding unit receives an error correction function setting command including at least information on presence / absence of the error correction function for initial setting through the terminal interface corresponding unit, the error correction function A first error correction function setting storage unit for storing presence / absence information, and the command corresponding unit receives a speed dial registration request command including at least a short code and a terminal number of a called terminal via the terminal interface corresponding unit. The speed dial registration request command via the first address control unit. A dial number storage unit that stores the terminal number of the called terminal included in the command corresponding to the abbreviated code, and the called side that is the result information of the negotiation executed at the time of the previous abbreviated dial transmission using the same abbreviated code A second error correction function setting storage unit that stores the error correction function setting information of the modem corresponding to the shortened code via the second address control unit, a modulation / demodulation unit that executes handshaking, and an automatic call control function. When the NCU section and the command corresponding section receive the speed dial registration request command via the terminal interface corresponding section,
The terminal number of the called terminal included in the speed dial registration request command is stored in the dial number storage unit in association with the speed code, and the command corresponding unit is at least the short code via the terminal interface corresponding unit. When the abbreviated dial call request command including the received abbreviated code is received, the first address control unit for reading the terminal number of the called terminal device corresponding to the received abbreviated code from the dial number storage unit and the same abbreviated code are used. The error correction function setting information of the modem accommodating the terminal device on the called side, which is the result information of the negotiation executed at the time of dialing the speed dial, corresponds to the shortened code in the second error correction function setting storage unit at the end of the negotiation. And the command corresponding part is stored in the shortened timetable via the terminal interface corresponding part. When receiving a call request command,
The second address control unit for reading the error correction function setting information corresponding to the received abbreviated code from the second error correction function setting storage unit, and the speed dial transmission by the speed dial call request command, The error correction function setting information, which is the result information of the negotiation executed at the time of the previous speed dial transmission using the same abbreviation code read from the second error correction function setting storage unit via the second address control unit, performs error correction. When the function setting is “present”, the negotiation is executed, and when the error correction function setting is “absent”, the negotiation is stopped, and an error correction function corresponding unit is provided.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a modem with an error correction function showing an example of the present invention. FIG. 2 is a system diagram in which a modem with an error correction function of the present invention is connected via a public telephone network. FIG. 3 is a diagram showing an example of a memory configuration of the second error correction function setting storage unit. FIG. 4 is a diagram showing an example of a memory configuration of the dial number storage unit.

In FIG. 2, a modem 2 with an error correction function is provided.
0-1 accommodates the terminal 10-1 and is connected to the exchange 40,
The modems 20-2 and 20-3 with the error correction function accommodate the terminals 10-2 and 10-3, respectively, and are connected to the exchange 41. The modem 30 without the error correction function accommodates the terminal 10-4. It is connected to the exchange 41. The exchanges 40 and 41 are connected to terminal devices 50 and 51, respectively.

Modem 20 with error correction function shown in FIG.
Is a terminal interface corresponding unit 21, a command corresponding unit 22, a first error correction function setting storage unit 23,
Address control unit 24-1 and second address control unit 2
4-2, a dial number storage unit 25, a second error correction function setting storage unit 26, and an error correction function correspondence unit 27.
And a modulation / demodulation unit 28 and an NCU unit 29.

The terminal interface corresponding unit 21 is V.2
A terminal 10-1 equipped with a 4 / V.28 interface function
From the various commands received from the modem to a predetermined digital signal level handled in the own modem.

The command handling unit 22 verifies various commands received from the terminal interface handling unit 21, and sends a control signal corresponding to the command.

The first error correction function setting storage section 23 is
The error correction function setting information is received and stored from the command corresponding unit 22 that has received the error correction function setting command sent by the terminal 10-1 for initial setting, and is also stored according to the request of the command corresponding unit 22. Sends error correction function setting information.

The first address controller 24-1 is connected to the terminal 1
0-1 receives the abbreviated code included in the abbreviated dial registration request command transmitted at the time of abbreviated dial registration and the terminal number of the called terminal from the command corresponding unit 22 and stores it in the dial number storage unit 25 corresponding to the abbreviated code. Store. Also,
The first address control unit 24-1 includes the command handling unit 22.
Receives a speed dial call request command including a speed code from the terminal 10-1, reads the terminal number of the called terminal corresponding to the speed code from the dial number storage unit 25,
It is sent to the command handling unit 22.

The second address control section 24-2 corrects the error of the called modem, which is the negotiation result information executed when the speed dial call request command sent from the error correction function supporting section 27 at the end of the negotiation is received. The function setting information is stored in the register corresponding to the shortened code of the second error correction function setting storage unit 26, and when the command corresponding unit 22 receives the speed dial call request command, the second error correction function setting storage The error correction function setting information, which is the result of the negotiation executed at the time of the previous speed dial transmission using the same speed code, is read from the unit 26 and sent to the command handling unit 22.

The dial number storage unit 25 has a large number of registers corresponding to the battery-backed abbreviated codes, and the first address control unit 24-1 when the command corresponding unit 22 receives the abbreviated dial registration request command. The terminal number of the called terminal notified from is overwritten and stored as a speed dial number.

The second error correction function setting storage unit 26
It has a large number of registers corresponding to the battery-backed abbreviated codes, and the previous abbreviated dial transmission using the same abbreviated number notified from the error correction function corresponding unit 27 via the second address control unit 24-2 at the end of negotiation. The error correction function setting information of the called modem, which is the result information of the negotiation executed at some time, is overwritten and the error correction function setting information is stored, and the second address control unit 2
The error correction function setting information is sent from the register in response to the request from 4-2.

The error correction function support unit 27 carries out a negotiation regarding the setting of the error correction function with the called modem, and executes all controls related to communication using the error correction function.

The modulation / demodulation unit 28 performs handshake and V.22 / V.22bis / V.3 after the line is connected.
The communication data conversion (A / D and D / A conversion) processing is performed according to a standard such as 2 / V · 32bis. NCU unit 29
Has an automatic transmission / reception control function, and monitors various information for dial transmission and reception.

Next, referring to FIGS. 1 and 2, the terminal 10-1
The operation when a call is made from the terminal to the terminal 10-2 will be described. Initialization of the error correction function has already been completed by a method similar to the conventional method, and the error correction function “present” of the terminal 10-2 is stored in the first error correction function setting storage unit 23 as shown in FIG. Is stored. Further, as shown in FIG. 4, the abbreviated code registered in the abbreviated dial of the called terminal 10-2 in the calling terminal 10-1 is, for example, "0".
1 "and the terminal number is" 9-1234-5678 ".

The terminal 10-1 shown in FIG. 2 is the terminal 10-2.
In order to make a call to, the shortened dialing call request command is sent to the modem 20-1 in accordance with the V.24 / V.28 standard by designating the shortened code "01" by a predetermined method.

Upon receiving the speed dial call request command, the terminal interface corresponding unit 21 of the modem 20-1 converts it to a predetermined signal level handled by the modem 20-1 and sends it to the command corresponding unit 22.

The command handling unit 22 analyzes the received speed dial call request command, identifies that it is a speed dial transmission request from the terminal 10-1 to the terminal 10-2, and responds to the speed code "01". The terminal number "9-1234-5678" of the terminal 10-2 to be read is read from the dial number storage unit 25 via the first address control unit 24-1, and the NCU unit 29 is instructed to make a call to the terminal 10-2. Then, the NCU unit 29 sends the dial signal corresponding to the terminal number "9-1234-5678" of the terminal 10-2 to the exchange 40.

When the modem 20-2 accommodating the terminal 10-2 responds, the modulation / demodulation unit 28 switches the exchange 40 to the terminal device 5.
0 through terminal equipment 51 through exchange 41, V.22 / V.
The handshake by the connection sequence according to 22bis / V · 32 / V · 32bis or the like is started.

When the handshake ends, the error correction function support unit 27 starts negotiation of the error correction function with the modem 20-2, and when the negotiation such as mutual confirmation of the protocol between the modems ends, the error correction function support unit 27 enters the communication state. Along with the transfer, the error correction function setting information of the terminal 10-2, which is the result information of the negotiation, is stored in the corresponding register of the second error correction function setting storage unit 26 via the second address control unit 24-2. (See Figure 3).

If the connection process between the modems fails due to some reason during the handshake or negotiation, the modem 20-1 notifies the terminal 10-1 that communication is impossible. The terminal 10-1 which has received the notification of the communication failure disconnects the line and cancels the speed dial transmission. In order to speed dial again to the terminal 10-2 which has already ended the call by the speed dial transmission once, a predetermined method, for example, a speed code button (not shown) is operated to issue a speed dial call request command. Modem 20-1
Send to

Upon receiving the speed dial calling request command, the terminal interface corresponding unit 21 of the modem 20-1 sends the speed dial request command converted to a predetermined level to the command corresponding unit 22.

The command handling unit 22 identifies the abbreviated code "01" included in the speed dial calling request command, identifies that it is a speed dial calling request, and controls the second address control unit 24-2. Via the second error correction function setting storage unit 26, the error setting function information of the terminal 10-2 stored at the end of the negotiation carried out at the time of the first call is read out, and the error correction function corresponding to the error correction function supporting unit 27 Is set, and the terminal number “9-1 of the terminal 10-2 stored at the time of the first call from the dial number storage 25 via the first address controller 24-1.
"234-5678" is read out and sent to the NCU section 29 as a shortened dial number to instruct re-calling to the terminal 10-2, and the NCU section 29 sends a dial signal to the exchange 40.

When the dial signal arrives at the modem 20-2 via the exchange 41 and responds, the modem unit 28 of the modem 20-1 responds to the exchange 40 to the terminal device 50 to the terminal station in the same manner as at the time of calling. V / 22 / V via the device 51 to the exchange 41
Execute handshake by a connection sequence according to 22bis / V32 / V32bis or the like.

Upon completion of the handshake, the error correction function corresponding unit 27 instructs the second address control unit 24-2 to shorten the previous time from the second error correction function setting storage unit 26 via the command corresponding unit 22. Error correction function setting information read at the time of dialing, the error correction function “existence” of the terminal 10-2 is identified, the negotiation regarding the error correction function is started as in the case of the last call, and the communication state is reached when the negotiation ends. become.

Next, a case will be described in which a call is made from the terminal 10-1 to the terminal 10-4 accommodated in the modem 30 having no error correction function. The abbreviated code "0" for registering the abbreviated dial number of the terminal 10-4 in the terminal 10-1.
2 "and the terminal number is" 9-0123-4567 ".

The modem 20-1 receives the speed dial call request command from the terminal 10-1 and calls the terminal 10-2 accommodated in the modem 20-2 with an error correction function, similarly to the case where the terminal 10 is called. A terminal number of -4 is transmitted, and handshake and negotiation are executed.

In this negotiation, if there is no response from the called modem 30 within a predetermined time, the error correction function support unit 27 determines that the called modem 30 has no error correction function, The error correction function setting information “absent” is stored in the corresponding register of the second error correction function setting storage unit 26 via the second address control unit 24-2 (see FIG. 3), and the line is disconnected.

After that, when the speed dial call request command is received again from the terminal 10-1, the command handling unit 22 of the modem 20-1 identifies that it is a speed dial call request, and the second address control unit. Second through 24-2
From the error correction function setting storage unit 26, the error correction function setting information, which is the negotiation result information stored at the time of the negotiation at the time of receiving the previous speed dial call request command, is read to identify the error correction function setting "none", and the modem The transmission of the LR signal to 30 is stopped.

As described above, in the modem with error correction function of the present invention, the second address control unit 24-2 and the second error correction function setting storage unit 26 are newly provided, and the second address control unit 24 is provided. -2 receives from the error correction function correspondence unit 27 the result information of the negotiation regarding the error correction function executed by the error correction function correspondence unit 27 at the time of the last call, and makes the second error correction function setting storage unit 26 correspond to the shortened code. The calling terminal is stored in order to store the last call to the other party, the callee is absent, the call is reissued, or the callee terminal that has made a call by speed dialing last time is speed dialed again. When the speed dial call request command sent from 10-1 is received, the command handling unit 22
Reads the result information of the negotiation regarding the error correction function executed at the time of the previous speed dial transmission using the same speed code from the second error correction function setting storage unit 26 via the second address control unit 24-2, and corrects the error. The error correction function setting information is set in the function corresponding unit 27, and the terminal number of the called terminal stored at the time of the last call is read from the dial number storage unit 25 via the first address control unit 24-1 to speed dial. NCU part 2 as a number
9 and sends an instruction to dial.

At this time, if the called modem does not have an error correction function, the negotiation result information relating to the error correction function executed at the time of the previous speed dial transmission using the same abbreviated code is the error correction function setting "none". Therefore, the negotiation of the error correction function is not executed at the time of speed dialing, and the called terminal 10-4 accommodated in the called modem does not receive the LR signal sent from the calling modem at the time of negotiation.

Although the case where the called modem has the error correction function and the case where the called modem does not have the error correction function have been described above, the effect of the present invention does not change even if the called modem is used.

[0061]

As described above, the modem with error correction function of the present invention is the same as the first error correction function setting storage section for storing the error correction function setting information of the opposite modem at the time of initial setting. A second error correction function setting storage unit for storing the negotiation result information executed at the time of the previous speed dial transmission using the abbreviated code, and a control for storing and reading this negotiation result information in the second error correction function setting storage unit. The second address control unit is provided with two address control units, and the second address control unit uses the same shortened code read from the second error correction function storage unit at the time of speed dial to perform the error correction function which is the negotiation result information executed at the time of the previous speed dial transmission. Based on the setting information, the error correction function support unit performs negotiation for speed dial. If the error correction function is set to "No", the negotiation for speed dial transmission is stopped. Therefore, as if the LR signal was received from the called modem to the called terminal device as in the past. It is possible to avoid erroneous transmission as described above.

[Brief description of the drawings]

FIG. 1 is a block diagram of a modem with an error correction function according to an embodiment of the present invention.

FIG. 2 is a system diagram using a modem with an error correction function according to the present invention.

FIG. 3 is a diagram showing an example of a memory configuration of a second error correction function setting storage unit.

FIG. 4 is a diagram showing an example of a memory configuration of a dial number storage unit.

FIG. 5 is a block diagram of a conventional modem with an error correction function.

[Explanation of Codes] 10-1 to 10-4 Terminals 20-1 to 20-3 Modem with Error Correction Function 30 Modem without Error Correction Function 60 Conventional Modem with Error Correction Function 21,61 Terminal Interface Corresponding Section 22 , 62 command corresponding unit 23 first error correction function setting storage unit 63 error correction function setting storage unit 24-1 first address control unit 24-2 second address control unit 64 address control unit 25, 65 dial number storage Unit 26 Second error correction function setting storage unit 27,67 Error correction function corresponding unit 28,68 Modulation / demodulation unit 29,69 NCU unit

Claims (3)

[Claims] 1. A calling-side modem accommodating a calling-side terminal and a called-side modem accommodating a called-side terminal when accommodating a terminal and communicating between terminals via a telephone network. A modem with an error correction function that forms a communication line by performing a handshake with a modem connection training sequence and then performing a negotiation with an error correction function connection sequence. When a speed dial transmission request is received from the device, the modem with an error correction function that accommodates the terminal device on the calling side refers to the result information of the negotiation executed at the time of the previous speed dial transmission with the same speed code, If the modem accommodating the called terminal device does not have an error correction function, the negotiation is performed. Error correction function with a modem which is characterized in that. 2. A first error correction function setting storage means for storing error correction function setting information at the time of initial setting, and the received information which is the result information of the negotiation executed at the time of the previous speed dial transmission with the same shortening code. A second error correction function setting storage means for storing error correction function setting information of the calling modem, and the result of the negotiation stored in the second error correction function setting storage means at the time of speed dial transmission. Refer to the error correction function setting information of the called modem, which is the information, and if the error correction function setting is "Yes", execute the negotiation and "No".
The modem with an error correction function according to claim 1, wherein in the case of the above, the negotiation is stopped. 3. A terminal interface corresponding unit that receives various commands from the accommodated terminal device and performs a predetermined level conversion, and a control corresponding to the received command by verifying the various commands received from the terminal interface corresponding unit. A command corresponding unit for transmitting information, and the error correcting function when the command corresponding unit receives an error correction function setting command including at least information on presence / absence of an error correction function for initial setting via the terminal interface corresponding unit. A first error correction function setting storage unit for storing presence / absence information, and the command corresponding unit receives a speed dial registration request command including at least a short code and a terminal number of a called terminal via the terminal interface corresponding unit. When you do the first
A dial number storage unit for storing the terminal number of the called terminal included in the speed dial registration request command corresponding to the speed code via the address control unit of A second error correction function setting storage unit for storing the error correction function setting information of the called modem, which is the result information of the executed negotiation, in correspondence with the shortened code via the second address control unit, and a handshake. A modem unit to be executed, an NCU unit having an automatic transmission / reception control function, and when the command corresponding unit receives the speed dial registration request command via the terminal interface corresponding unit, it is included in the speed dial registration request command. Storing the terminal number of the called terminal corresponding to the abbreviated code in the dial number storage unit, and When the terminal corresponding unit receives the speed dial call request command including at least the shortened code via the terminal interface corresponding unit, the terminal number of the called terminal device corresponding to the received shortened code is received from the dial number storage unit. At the end of the negotiation, the first address control unit to read out and error correction function setting information of the modem accommodating the called terminal device, which is the result information of the negotiation executed at the time of the speed dial transmission with the same abbreviated code, The shortened code received when stored in the second error correction function setting storage unit in correspondence with the shortened code and when the command handling unit receives the shortened dial call request command via the terminal interface handling unit. From the second error correction function setting storage unit corresponding to the error correction function setting information The second address control unit to be read, and the same abbreviated code read from the second error correction function setting storage unit via the second address control unit at the time of speed dial transmission by the speed dial call request command. When the error correction function setting information, which is the result information of the negotiation executed at the time of the previous speed dial transmission by the, is the error correction function setting “Yes”, the negotiation is executed, and when the error correction function setting is “No”, the negotiation is performed. The modem with an error correction function according to claim 1 or 2, further comprising: