JPH08195865A - Communication controller - Google Patents

Abstract

PURPOSE: To evade the collision of signals on a communication channel by stopping the response when the response to control signals from a facsimile equipment is delayed owing to the circumstances of a computer and the response is made possible near retransmission signal termination. CONSTITUTION: CNG signals are transmitted from a FAX 3 through a FAX modem 1 to a host 4 and a reception start instruction is sent out as the response. Subsequently, an operation is advanced corresponding to a communication procedure and training signals and training check signals TCF are transmitted from the FAX 3. When the reception of the TCF is ended, the operation of a timer provided in a main control part is immediately started. The time-up time of the timer is set slightly shorter than the time when the FAX 3 retransmits facsimile control signals. Then, whether or not the timer is timed out after the lapse of prescribed time is checked and CFR signals are sent out to the FAX 3 when it is not timed out, however, the send-out of the CFR signals is stopped when it is timed out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control device for controlling communication between a facsimile machine and a computer.

[0002]

2. Description of the Related Art When a G3 facsimile machine connected to a public line and a computer communicate with each other, a communication controller is provided between them so that the facsimile machine and the communication controller communicate with each other according to a facsimile communication procedure. And the communication control device communicate with each other by a data communication procedure.

[0003]

In the case of a facsimile machine, since it is exclusively used for facsimile communication, it devotes itself to transmission and response of facsimile control signals and image signals. However, in a computer, when multitasking is operating, it responds to the other party. Often there is a delay. When the response is delayed, the facsimile side retransmits the signal. However, when the retransmitted signal and the response collide on the line, the signal does not reach any side, and the facsimile side repeats the transmission after a predetermined time. Therefore, the communication time by the facsimile control signal becomes long.

FIG. 7 is a communication procedure diagram showing such an example. The host is a computer, and the FAX modem is a communication control device. FAX indicates a facsimile machine. Communication is shown from the middle, and CNG (calling tone) on the FAX side
In response to the signal, the host sends out an ATA (reception start command), and the FAX modem transmits it to CED (callee terminal identification signal).
And the reception function of the called end is indicated by DIS (digital identification signal), and CSI (called terminal identification signal) and NSF (non-standard function command signal) are transmitted. On the other hand, the FAX indicates the communication function by DCS (digital command signal), transmits TSI (transmission terminal identification function), and transmits training and TCF (training check) signals. Upon receiving these, the FAX modem sends an AT + FCO (facsimile connect) signal and a training OK signal to the host. On the other hand, the host sends AT + FDR (reception command) with some delay. The FAX modem receives this and transmits a CFR (reception preparation confirmation signal), but on the FAX side TSI / DCS
If the response signals to the above are not transmitted even after the lapse of the specified time after transmitting these, TSI / DCS is transmitted again.
As a result, the CFR and TSI / DCS may collide on the line, and when they collide, these signals do not reach either side. Therefore, in the FAX, the TSI / DCS signal is transmitted again after the specified time, and the communication time by the facsimile control signal is extended.

The present invention has been made in view of the above problems, and an object of the present invention is to avoid collision of signals on a communication line and prevent extension of communication time of a facsimile control signal.

[0006]

In order to achieve the above object, in the invention of claim 1, first input / output means for performing facsimile communication with a facsimile terminal, second input / output means for performing data communication with a data terminal, and When a facsimile control signal is input from the facsimile terminal, a corresponding command corresponding to this is transmitted to the data terminal, and when this response command is input, a response facsimile control signal corresponding to this is transmitted to the facsimile terminal. When the facsimile control signal is input from the facsimile terminal, the control means transmits the corresponding command to the data terminal, and when the response command is input after a predetermined time has elapsed from the input of the facsimile control signal, the facsimile terminal To stop sending the response facsimile control signal to

According to the second aspect of the present invention, the first input / output means for performing facsimile communication with the facsimile terminal, the second input / output means for performing data communication with the data terminal, and the facsimile control signal input from the facsimile terminal And a control means for transmitting a corresponding corresponding command to the data terminal and, when the response command is input, transmitting a response facsimile control signal corresponding to the response command to the facsimile terminal, the control means comprising the facsimile control signal from the facsimile terminal. Is input, the corresponding command is transmitted to the data terminal, and when the response command is input after a lapse of a predetermined time from the input of the facsimile control signal, the sending of the response facsimile control signal to the facsimile terminal is temporarily stopped. , The facsimile control signal from the facsimile terminal When that has been sent in response to releasing the stop of the response facsimile control signal.

According to the third aspect of the invention, the predetermined time period is shorter than a prescribed time period in which the facsimile control signal from the facsimile terminal is retransmitted and is close to the prescribed time period.

In the invention of claim 4, the facsimile control signal is a signal including a DCS signal and a training signal, and the response facsimile control signal is a CFR signal.

According to the fifth aspect of the present invention, the facsimile control signal or the EOP signal is used, and the response facsimile control signal is the MCF signal.

[0011]

According to the invention of claim 1, when the facsimile control signal is inputted from the facsimile terminal, the control means converts the signal into a signal on the data terminal side, transmits the corresponding command to the data terminal, and inputs the response command. Then, the response facsimile control signal obtained by converting this into a facsimile control signal is sent to the facsimile terminal by the first input / output unit,
Transmission and reception is performed through the second input / output means. The facsimile terminal retransmits the facsimile control signal if it does not receive a response signal after a certain period of time has passed since the transmission. Therefore, the control means measures the time after the facsimile control signal is input from the facsimile terminal, and when a response command is input from the data terminal after a predetermined time has elapsed, converts the response command into a facsimile control signal. Stop sending the response facsimile control signal to the facsimile terminal. As a result, it is possible to prevent the retransmission signal from the facsimile terminal from colliding on the line and both signals from not reaching the transmission destination.

According to the second aspect of the invention, after receiving the response facsimile control signal stopped in the first aspect, the facsimile control signal retransmitted from the facsimile terminal, the response facsimile control signal is transmitted to the facsimile terminal in response thereto. This allows the facsimile terminal to proceed to the next step.

In the invention of claim 3, the predetermined time in claims 1 and 2 is shorter than the specified time for the facsimile terminal to retransmit the facsimile control signal and is close to the specified time. If the response command is input from the data terminal before this time and the response facsimile control signal is sent to the facsimile terminal, it will not collide with the retransmission signal from the facsimile terminal on the line, but after this predetermined time and close to this. If the response command is sent to the facsimile terminal in time, there is a high possibility of collision on the line. Therefore, the predetermined time is set to a time with a high possibility of collision, and the response signal can be processed while avoiding this time.

According to another aspect of the present invention, when a signal including a DCS signal and a training signal for defining and instructing a communication function is used as the facsimile control signal, the response signal is the communication speed or the like performed by the training signal. The CFR signal that responds that the preparation for the communication using the communication function is completed is used.

In the fifth aspect of the invention, the facsimile control signal is the EOP signal indicating the end of the procedure, and the response signal from the data terminal side to this is the MCF signal indicating the message confirmation by the positive response to the EOP.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a communication system including a facsimile modem of the present invention. A facsimile modem (hereinafter referred to as FAX modem) 1 of the present invention is connected to a public line 2 and communicates with a facsimile device (hereinafter referred to as FAX) 3. FAX modem 1 is computer 4 and RS-
232C standard connection, computer 4 and FAX
It mediates the communication with 3. That is, the FAX 3 and the FAX modem 1 communicate with each other by the facsimile communication protocol, and the FAX modem 1 and the computer 4 communicate with each other by the data communication protocol. Therefore, both protocols are converted, and when the respective protocols are input, they are converted. Then, when the response signal comes back, it is converted and transmitted to the other party. Computer 4
A hard disk 5 and a display device 6 are provided for storing and displaying data to be transmitted and received.

FIG. 2 is a diagram showing the configuration of the FAX modem of the embodiment. The network control unit 11 is called an NCU and controls the connection of the public line 2 such as a connected telephone line. The modulation / demodulation unit 12 modulates and outputs the data to be transmitted, and demodulates the data received from the public line 2. The encoding / decoding unit 12 encodes and compresses the data to be transmitted, and decodes the received encoded data into the original data. MH, MR, MMR or the like is used as the encoding method. The parallel / serial converter 14 converts the data output to the computer 4 from serial data into parallel data, and converts the parasol data input from the computer 4 into serial data. The main controller 15 controls the whole.

Next, the operation of this embodiment will be described. Figure 3 is F
A procedure for transmitting an image from the AX 3 to the computer (hereinafter referred to as a host) 4 is shown, and FIGS. 4 to 6 are flowcharts of FIG. First, a CNG (calling tone) signal from the FAX 3 is transmitted via the FAX modem 1 to the host 4
And an ATA (reception start command) is sent as a response. The flow charts of FIGS.
The communication procedure performed by the modem 1 is described. In response to the ATA signal, the called terminal identification signal CED is sent to the FAX 3 (S1), the digital identification signal DIS indicates the receiving function of the called end, and the called terminal identification signal CSI and the non-standard function command NSF are sent. (S2). Then, F3 is transmitted from the FAX 3 by the digital command signal DCS together with the transmission terminal identification function TSI.
Since the communication function of AX3 is notified (S3), FAX
Host 4 sends an AT + FCO signal indicating that it is connected to
(S4). Subsequently, the training signal and the training check signal TCF are transmitted from the FAX 3 (S5). Immediately after receiving the TCF, the main controller 1
The operation of the timer provided in 5 is started (S6). The timer may be provided as hardware or software. The time-up time of the timer is FAX
3 is set to be slightly shorter than the time for retransmitting the facsimile control signal. After the timer is started, an OK signal indicating that the training is normally completed is transmitted to the host 4 (S7). The host 4 receives a reception command AT + FDR indicating that preparation for receiving the image signal is completed (S8). When this reception is performed, it is checked whether or not the timer has timed out after a predetermined time has passed (S9), and if not, a reception preparation confirmation signal CFR is sent to the FAX 3 (S12). If it has timed out, the transmission of the CFR signal is stopped. As a result, the CFR signal and the retransmitted TSI, DCS signal from the FAX 3, the training signal, the T
It is possible to avoid collision with the CF signal.

SI / DCS at (S3) on the FAX3 side
Although the signal, the training signal and the TCF signal in (S5) were sent, there was no response even after the stipulated 3 seconds,
The TSI / DCS signal, the training signal and the TCF signal are transmitted again, and the FAX modem 1 receives them (S1
0, S11). After receiving this, AT + from host 4
FAX3 for the reception preparation confirmation signal CFR based on the FDR signal
(S12). When the FAX3 side receives the CFR, it sends the image information along with the training signal.
When the FAX modem 1 receives the training signal (S1
3), CO indicating whether or not the image information is ready to be received
The NECT signal is transmitted (S14), and the <DC2> signal indicating that the acceptance preparation is good is received (S15). When this signal is received, the image information currently being received from FAX 3
(S16).

When the fax 3 has finished sending the image information, it sends an EOP signal indicating the end of the procedure (S17).
When this is received, the operation of the timer is started (S1
8). The set time of the timer is the same as the time explained for the training signal. At the same time, a <DLE><ETX> signal indicating the end of image information is sent (S19),
An AT + FPS: 1 signal indicating that the image information has been normally received is transmitted (S20). AT + F indicating that EOP has been received
The ET: 2 signal is transmitted (S21), and finally OK is transmitted (S22) to the host 4. On the other hand, AT + FDR indicating that image information and these signals are received from the host 4
The signal is received (S23). When this AT + FDR signal is received, check whether the timer has timed out (S
24) If not timed out, fax the MCF signal indicating affirmation of the end of the procedure based on the AT + FDR signal.
3 (S26). When the timer has timed out (S24), the transmission of MCF is stopped.
On the other hand, on the FAX side, if the response to the EOP has not exceeded the specified time of 3 seconds, the EOP signal is sent again. F
MC that stopped when receiving EOP in AX modem 1
The F signal is transmitted (S26). E retransmitted by this
It is possible to avoid the line collision between the OP signal and the MCF signal.
When the FAX 3 receives the MCF signal, the disconnection command signal DCN
Is transmitted (S27), the AT + FHS: 0 signal indicating the end of information is transmitted (S28) and the OK signal is transmitted (S29).

As described above, from FAX3 to DCS, TC
Even when the response signal AT + FDR from the host 4 is delayed after receiving the F signal, and when the response signal AT + FDR from the host 4 is delayed after receiving the EOP, the arrival of the retransmission signal from the FAX 3 side can be known by the timer. Therefore, it is possible to avoid the collision on the line by transmitting the CFR which is the response signal to the FAX 3 while avoiding the retransmission time.

[0022]

As is apparent from the above description, according to the present invention, the response to the control signal from the facsimile machine is delayed due to the processing of the computer, and it becomes possible to respond near the arrival of the retransmission signal from the facsimile machine. In this case, this response can be stopped to avoid collision with the retransmission signal on the line. By avoiding this, it is possible to prevent the retransmission signal from being sent again, so that it is possible to prevent the communication time from increasing.

[Brief description of drawings]

FIG. 1 is a diagram showing a communication system including a facsimile modem of the present invention.

FIG. 2 is a configuration diagram of a facsimile modem according to an embodiment.

FIG. 3 is a diagram showing a communication procedure of the embodiment.

FIG. 4 is a flowchart of the communication procedure of the embodiment.

FIG. 5 is a communication procedure flow chart of the embodiment following FIG.

FIG. 6 is a communication procedure flow chart of the embodiment following FIG.

FIG. 7 is a procedure diagram showing an example in which a retransmission signal and a response signal collide on the line due to a response delay on the computer side.

[Explanation of symbols]

 1 Facsimile modem 2 Public line 3 Facsimile device 4 Computer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Matsumoto 2-3-8 Shimomeguro, Meguro-ku, Tokyo Matsushita Dentsu Co., Ltd.

Claims (5)

[Claims] 1. A first input / output unit for performing facsimile communication with a facsimile terminal, and a second for performing data communication with a data terminal.
When a facsimile control signal is input from the input / output means and the facsimile terminal, a corresponding command corresponding thereto is transmitted to the data terminal, and when this response command is input, a response facsimile control signal corresponding thereto is transmitted to the facsimile terminal. The control means for transmitting the corresponding command to the data terminal when the facsimile control signal is input from the facsimile terminal,
A communication control device, wherein when the response command is input after a lapse of a predetermined time from the input of the facsimile control signal, the transmission of the response facsimile control signal to the facsimile terminal is stopped. 2. A first input / output unit for performing facsimile communication with a facsimile terminal, and a second for performing data communication with a data terminal.
When a facsimile control signal is input from the input / output means and the facsimile terminal, a corresponding command corresponding thereto is transmitted to the data terminal, and when this response command is input, a response facsimile control signal corresponding thereto is transmitted to the facsimile terminal. The control means for transmitting the corresponding command to the data terminal when the facsimile control signal is input from the facsimile terminal,
When the response command is input after a predetermined time has elapsed from the input of the facsimile control signal, the transmission of the response facsimile control signal to the facsimile terminal is temporarily stopped, and when the facsimile control signal is retransmitted from the facsimile terminal. The communication control device releasing the stop of the response facsimile control signal in response to the response. 3. The predetermined time is shorter than a prescribed time when the facsimile control signal is retransmitted from the facsimile terminal and is close to the prescribed time. The communication control device described. 4. The communication control device according to claim 1, wherein the facsimile control signal is a signal including a DCS signal and a training signal, and the response facsimile control signal is a CFR signal. . 5. The communication control device according to claim 1, wherein the facsimile control signal is an EOP signal, and the response facsimile control signal is an MCF signal.