JP3482269B2 - Modem device for data communication and facsimile communication - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modem device for performing data communication and facsimile communication.

[0002]

2. Description of the Related Art Data communication such as personal computer (personal computer) communication is carried out using a public telephone network. Facsimile communication also uses the public telephone network,
Both of these are handled by the same modem device. ITU-
T (International Telecommunication Union, Telecommunication Standards Division) has issued a recommendation called V series for data communication by public telephone network, and V. A 22bis modem is often used. V. 22bis is a public telephone network or a 2-wire point-to-point leased line
It is a regulation regarding a modem for performing 400 bps full-duplex communication. The procedure for establishing a line for facsimile communication is V. A 300 bps modem for 21 public telephone networks is used. V. Reference numeral 21 is a recommendation for a modem that enables full-duplex communication at 300 bps using a public telephone network or a two-wire dedicated line.

In a modem device that handles data communication and facsimile communication, since the mode is different between data communication and facsimile communication, the called terminal does not operate until it is determined whether the calling terminal is the data communication terminal or the facsimile communication terminal. The data communication mode and the facsimile communication mode are alternately switched to send a signal to obtain a response from the calling side terminal.

FIG. It is a figure which shows the communication procedure in 2400pbs of a calling side and a called side by a 22bis modem. Here, the calling side is a connection modem and the called side is a response modem. When there is an incoming signal from the switch, the answering modem sends a CED (Called Terminal Identification Signal) of 2100 Hz and then sends a US1 signal, that is, an unscrambled binary "1", that is, a continuous signal of 1 at 1200 bps. On the other hand, the connection modem is V. S1 signal indicating that it is a 22bis modem is transmitted, followed by SC1 signal,
That is, a scrambled binary "1" at 1200 bps
The signal of is transmitted. When the response modem detects the S1 signal on the connection modem side, it responds to V. The S1 signal indicating that the modem is a 22bis modem is transmitted, and subsequently, the SC1 signal is transmitted. Thus, V. If you confirm that it is a 22bis modem, the data communication speed will be 2400bp
After outputting the scrambled binary "1" signal SC2 of s, the data communication is started. Thus, when the called side sends out the US1 signal and the calling side responds with the SC1 signal, V. Data communication is performed by a 22bis modem.

FIG. 10 shows a connection procedure by a modem device which handles conventional data communication and facsimile communication. When the called side receives the ringing tone of 16 Hz, it sends out a CED signal. The US1 signal is transmitted in the 22bis incoming call mode, and the response of the SC1 signal is awaited. In addition, V. Since data communication by the 22bis modem is performed by full-duplex communication, it is performed in the same transmission / reception mode. The call is made from the callee side, so the callee mode is set. US1 is transmitted for a predetermined time, and there is no response of the SC1 signal during that time. The transmission mode of 21,300 bps is set and the DIS (digital identification signal) is transmitted, and the response signal D
To receive CS (digital command signal), V. 21, 3
The reception mode is changed to 00 bps and the DCS waits for a predetermined time. DCS is a command signal indicating a function set from the standard functions indicated by the DIS signal. Facsimile communication uses half-duplex communication and cannot send and receive at the same time.
Two modes are used, a transmission mode and a reception mode. In this way, for sending US1 or DIS signal,
If there is an SC1 signal response, the data communication connection procedure is entered, and if there is a DCS signal response, the facsimile communication connection procedure is entered. Is done. Figure 11 is CED
Then, DIS is transmitted, and if this response signal DCS is not present, the procedure of transmitting US1 is performed as shown in FIG. 10 and DIS and US1.
The transmission order of is reversed.

[0006]

As described above, in order to confirm from the called side whether the calling side is the data communication terminal or the facsimile communication terminal in any of the procedures, the US1 signal, DIS
It outputs a signal and waits for this response. 22bis incoming call mode, V.I. 21,300 bps transmission mode, V. Two
It was necessary to alternately switch the three modes of the 1,300 bps reception mode. Alternately switching the modes in this manner causes a problem that the processing load of the modem device increases.

The present invention has been made in view of the above problems, and an object thereof is to provide a modem device capable of performing a connection procedure in the same mode regardless of whether the calling terminal is a data communication terminal or a facsimile communication terminal. And

[0008]

In order to achieve the above object, according to the invention of claim 1, a common mode for setting the data communication mode and the facsimile communication setting mode in the same mode is set, and a common command for setting the common mode is set. Set the common mode with the register to hold and the common command when receiving a call. If the calling side is a data communication terminal, perform the data communication connection procedure in the common mode, and if it is a facsimile terminal, perform the facsimile communication connection procedure in the common mode. And a communication control means for performing.

According to a second aspect of the present invention, the first signal indicating that the common mode is data communication is transmitted for a predetermined time,
If there is no response during that time, the second signal indicating the facsimile communication is subsequently transmitted.

[0010]

According to the invention of claim 1, a common mode is provided in which the data communication mode and the facsimile communication setting mode are set in the same mode, and the common mode is set by a common command so that the calling side is a data communication terminal. The connection procedure is performed in the common mode, and the connection procedure is also performed in the common mode for the facsimile terminal. As a result, it is not necessary to switch to the data communication mode, the transmission mode of facsimile communication, or the reception mode of facsimile communication, so the load on the modem device is reduced.

According to the second aspect of the present invention, in the common mode, the first signal indicating that the communication is data communication is first sent for a predetermined time, and if there is no response during that time, the second signal indicating that the communication is facsimile communication. Is sent and the response is waited for a predetermined time. Since data communication is full-duplex communication and transmission and response can be performed at the same time, if there is a response, the data communication can be started according to the connection procedure. Since the facsimile communication is a half-duplex communication, no response is received in the transmission state, and after the transmission is completed, the response is received. For this reason, the waiting time is reduced by first sending the first signal indicating the data communication for which a response is obtained during transmission and then sending the second signal indicating the facsimile communication.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a communication system provided with a modem device for data communication and facsimile communication of this embodiment. The terminals 1 are connected to each other via a telephone line switch 2. The terminal 1 is a main body 3 including a personal computer and a facsimile,
It consists of a data modem 4 and a fax modem 5. In addition,
One of the terminals 1 may be a personal computer equipped with a data modem 4 or a facsimile equipped with a fax modem 5.

FIG. 2 is a block diagram showing the configuration of the data modem and the fax modem device shown in FIG. The analog front processor 6 converts analog data and digital data. The digital signal processor 7 is a central function of a modem operation for performing modulation / demodulation. The reception register 8 stores the reception data, and the transmission register 9 stores the transmission data. The command register A stores general commands, and the command register B stores communication mode commands. The status register A shows the status of the data handshake, and the status register B shows the status of the line side. Interrupt control register A is status register A
The interrupt control register B controls the interrupt when the status register B changes. The buffer 10 is a bus for temporarily storing the data of the above-mentioned registers, and the FAX control unit bus 11 is a bus for transmitting a signal of the fax control unit.

FIG. 3 shows a mode table stored in the command register B. Each communication mode is b0, b1, b2, b3
Is represented by 4 bits. V. 21,300 bps is 30
It is used to set the communication conditions of the facsimile at 0 bps, and since it is facsimile communication, half-duplex communication is performed.
It is divided into transmission mode and reception mode. V. 29, 9
600 bps is used for communication of facsimile image signals at 9600 bps, and since half-duplex communication is performed, it is divided into a transmission mode and a reception mode. V. The 22 modem is a 1200 bps full-duplex modem in a public switched telephone network and a two-wire leased line, and is used for data communication. Since transmission and reception are performed at the same time, there is no distinction between the transmission mode and the reception mode. V. The 22 bis modem is a 2400 bps full-duplex modem for public telephone networks and 2-wire leased lines. Can communicate with 22 modems, then 1200
Communicate at bps. Since it is used for data communication and performs transmission and reception at the same time, V. Similar to the 22 modem, a distinction is made between the calling side mode and the called side mode.

V. 22 + 300 bps, V.I. 22bis
+300 bps is a mode used in the present invention, and V. Two
At 2 + 300 bps, data communication is 1200 bps full-duplex communication, and facsimile communication condition setting is 300 b.
This is a mode for performing half-duplex communication at ps. This mode is only used by the called party. V. 22 bis + 300 bps
For data communication, the caller is With a 22 bis modem, full-duplex communication at 2400 bps is performed, and V. With 22 modems, 1200 bps full-duplex communication is performed, and facsimile communication condition setting is a mode in which 300 bps half-duplex communication is performed.

V. The 32 modem is a two-wire line of a public telephone network or a dedicated two-wire line, and is a modem that performs full-duplex communication at a communication speed of 9600 bps. Since it is used for data communication and performs transmission and reception at the same time, there is no distinction between transmission and reception modes, and a distinction is made between the calling side and the called side. V. The 32-bis modem is a two-wire line of a public telephone network or a dedicated two-wire line, and is a modem that performs full-duplex communication at a communication speed of 14400 bps. In addition, V.
It is possible to communicate with 32 modems at 9600 bps. V.
As with the 32 modem, a distinction is made between the calling side and the called side.

FIG. 4 shows a connection procedure of the embodiment. Exchanger 2
When an incoming signal of 16 Hz is sent to the called side and a DC loop is formed with the called side, the called side sends a CED signal. Then, V. The mode is set to 22 bis + 300 bps mode and the US1 signal is transmitted. As described with reference to FIG. 9, the US1 signal continuously outputs a scrambled binary "1" signal of 1200 bps, and the hatched portion represents the period of continuous transmission. For the US1 signal, the calling side is When the SC1 signal indicating that the modem is a 22 bis modem is transmitted, both the calling side and the called side are V.2 Since it was found to be a 22-bis modem, data communication is started at a communication speed of 2400 bps. When the SC1 signal is not received, the DIS (digital identification signal) for facsimile communication is sent at a speed of 300 bps, and the response signal DCS (digital command signal) is waited for a predetermined time. When there is no response signal DCS, the US1 and DIS signals are transmitted for the second time. In this way, the US1 and DIS signals are repeated three times without a response, and then the line is disconnected. During this time, the called party is 22bis +
There is no mode conversion in the 300 mode.

In FIG. 5, the calling side is V. The connection procedure when the response of the SC1 signal is immediately transmitted by the 22-bis modem is shown. If the SC1 signal is immediately returned as a response signal when the US1 is transmitted, V.V. 22bis + 300
The mode is V. 22bis mode is automatically continued,
V. 22 bis data mode is entered and data communication is started. This is the procedure described earlier in FIG. 9, where the called party is US1.
When the S1 signal is detected during signal transmission, SC1 and SC2 are transmitted and data communication is started.

In FIG. 6, the called side is V. The connection procedure when the calling side is a facsimile machine using a 22-bis modem is shown below. The connection modem indicates the facsimile modem of the calling side, and the answering modem is the V.V. of the called side. 22 bis modem is shown. CE from the called side
If the US1 signal is sent out after the D signal for the period shown by the diagonal lines in FIG. 4 and the response signal SC1 does not come, the facsimile D
Send an IS signal. On the other hand, a DCS signal is sent from the calling side. As a result, the called side knows that the calling side is the facsimile end. Following the DCS signal from the calling side, a training check signal TCF indicating whether the called side can receive a facsimile message, that is, an image signal, is transmitted. The facsimile connection procedure is performed thereafter.

The above is the V. V.22 based on a 22bis modem. The case where the 22 bis + 300 mode is used has been described. 22 based on V.22 modem. 22 + 300
Similarly, the mode allows connection with a data terminal and a facsimile terminal in one mode. FIG. 22 shows the connection procedure between two modems. The calling mode modem indicates the calling party and the answer mode modem indicates the called party. CE from the called side
A D signal is sent, followed by a signal A representing an unscrambled binary "1" and a 1800 Hz signal. On the other hand, when the calling side detects the signal A, it sends out the signal B representing the scrambled binary "1". When the called side detects the signal B, it sends out a signal C representing a scrambled binary "1" and a signal of 1800 Hz, enters the data communication, and the calling side detects the signal C and then shifts to the data communication. .

FIG. This is a connection procedure when the 22 + 300 mode is used, and is basically the same as the case of FIG. When an incoming signal of 16 Hz is sent from the exchange 2 to the called side, the called side sends out a CED signal, and then the V.V. 22
The mode is set to +300 bps, and the signal A is transmitted for a predetermined period indicated by the diagonal lines. When the response signal B is sent from the calling side, FIG.
When the data communication is started according to the procedure described in 1 above but there is no response signal, the DIS signal for facsimile communication is transmitted and the response signal DCS is waited for a predetermined time. If there is no DCS signal, the signals A and DIS are sent for the second time, and if there is no response, the communication is interrupted after sending up to the third time. These procedures are described in V. It is performed in 22 + 300 mode.

[0023]

As is apparent from the above description, the present invention sets the common mode in which the data communication mode and the facsimile communication setting mode are set in the same mode, and when the calling side is the data communication terminal, the common mode is set. Data communication is performed, and in the case of a facsimile terminal, facsimile communication conditions can be set. In this way, since one mode can be used for the data communication terminal and the facsimile terminal, the load on the called modem can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a communication system for performing data communication and facsimile communication.

FIG. 2 is a diagram showing a configuration of a modem device according to the present embodiment.

FIG. 3 is a diagram showing names of communication modes stored in a command register.

FIG. 4 is a diagram showing a connection procedure of the embodiment.

FIG. 5 is a connection procedure diagram when a data terminal on the calling side responds to a US1 signal on the called side.

FIG. 6 is a connection procedure diagram when a facsimile terminal on the calling side responds to a DIS signal on the called side.

FIG. 7: V. 22 Connection procedure diagram between modems

FIG. 8 is a connection procedure diagram of another embodiment.

FIG. 9: V. 22bis modem connection diagram

FIG. 10 shows that the called party is a V. Conventional connection procedure diagram for 22bis modem

FIG. 11 shows that the called party is a V. Other conventional connection procedure diagram for 22bis modem

[Explanation of symbols]

1 terminal 2 exchanger 3 PC and / or facsimile 4 data modem 5 fax modem

─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-6-62148 (JP, A) JP-A-3-237863 (JP, A) JP-A-62-181569 (JP, A) JP-A-4-62 156172 (JP, A) JP 59-34765 (JP, A) JP 7-46339 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/32-1 / 36 H04N 1/42-1/44 H04M 11/00-11/10 H04L 13/00-13/00 309 H04L 13/00 317-13/18

Claims (2)

(57) [Claims] 1. A common mode in which a data communication mode and a facsimile communication setting mode are set in the same mode is set, and a register holding a common command for setting the common mode and a common mode is set by the common command when an incoming call is received. If the calling side is a data communication terminal, the data communication connection procedure is carried out in the common mode, and if the calling side is a facsimile terminal, the facsimile communication connection procedure is carried out in the common mode. 2. The common mode sends a first signal indicating data communication for a predetermined period of time, and if there is no response during that time, second indicating that it is facsimile communication subsequently.
2. The modem device for data communication and facsimile communication according to claim 1, which transmits a signal.