JPH06233104A - Transmitting method for facsimile or the like - Google Patents

Abstract

PURPOSE:To provide the transmitting method for facsimile so as to enable communication without decelerating communication speed even when training is failed on the reception side. CONSTITUTION:A reception side B transmits DIS corresponding to call origination from a transmission side A. The transmission side receiving this DIS transmits DCS and TCF signals. On the reception side, the training is performed corresponding to the TCF signal by performing setting instructed by the DCS. When the training is failed, the reception side requests retraining by sending an FTT signal to the transmission side. On the transmission side, a signal sending level is increased for 1dBm and the TCF signal is transmitted again without decelerating the communication speed. The reception side performs the training again, when it is made successful, a CFR signal is sent to the transmission side, and the transmission of image signals is performed from the transmission side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission / reception method in data communication by a protocol such as facsimile, and more particularly,
The present invention relates to a transmission / reception method for poor communication during training.

[0002]

2. Description of the Related Art Conventionally, in data communication such as facsimile, data exchange is started after exchanging signals based on a protocol (communication protocol). Explaining the binary code signal system in the facsimile communication, as shown in the explanatory diagram of the signal sequence in FIG. 3A, a calling tone (CNG) is transmitted from the transmitting side. This signal is a signal in which a 1100 Hz tone for 0.5 seconds is interrupted with a rest period of 3 seconds. In response to this, the receiving side, after being connected to the line, 2100Hz
The called terminal identification (CED) signal which is a tone signal lasting 2.6 to 4.0 seconds is transmitted. The receiving side sends a digital identification signal (DIS) after the CED signal,
This indicates that the receiving side has the CCITT standard receiving function, and the content is a digital signal formed into a frame with all the functions of the receiving side, that is, a facsimile group number, a transmitting / receiving function, a terminal constant, and the like. When the transmitting side receives the DIS, the digital command signal (DCS)
To specify the selected function to the receiving side, and then
Send a Training Check (TCF) signal. When the adjustment by training is completed, the reception side transmits a reception preparation confirmation (CFR) signal, notifies the transmission side of the completion of reception preparation, and prompts transmission of an image signal (DOCUMENT DATA). The transmitting side which has received the CFR signal transmits the image signal, and upon completion thereof, transmits the procedure end (EOP) signal, receives the message confirmation (MCF) signal from the receiving side, and then the disconnect command (DCN) signal. To end the communication.

When the receiving side which receives the TCF signal fails the training, the receiving side requests the retraining as shown in FIG. 3B, and the training fails (FT).
T) Send the signal to the sender. The transmitting side that has received the FTT signal reduces the communication speed and transmits the TCF signal again. In response to this, if the training is successful on the receiving side, the TCF signal is sent to the transmitting side, and the image signal is transmitted. Therefore, if the training fails, there is a problem that the communication speed is lowered, the transmission time is increased, and the communication cost is increased.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and a facsimile machine or the like which can communicate without lowering the communication speed even if the receiving side fails in training. The purpose is to provide a transmission method.

[0005]

According to the present invention, in a transmission method for a facsimile or the like, when a signal requesting retraining is received from the receiving side after transmitting a training signal during handshake, the communication speed is not reduced. The feature is that the training signal is transmitted again by raising the signal transmission level.

The transmission level can be increased stepwise. The communication speed may be reduced if the training is not successful even after reaching the predetermined number of times or the predetermined level.

[0007]

[Function] When communicating with a remote place such as overseas communication, particularly when communicating through a satellite, the signal reaching the receiving side is attenuated, and the SN against the transmitted signal is
It is well known that the ratio also increases. Then, if the training fails,
Training may be successful by increasing the signal transmission level on the transmission side.

According to the present invention, after the training signal is transmitted during the handshake, when the signal requesting retraining is received from the receiving side, the signal transmission level is increased without lowering the communication speed and the training signal is retransmitted. By transmitting, it becomes possible to make training successful.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic block diagram for explaining an embodiment in which the present invention is applied to a facsimile machine.
In the figure, 1 is a line, 2 is a line control unit, 3 is a transmission control unit, 4
Is a ROM for storing programs and fixed information, and 5 is an RA
M and 6 are transmission level setting units, 7 is a document reading unit, 8 is a recording unit, 9 is an operating unit, and 10 is a main control unit (CPU) in charge of overall control of these. The transmission level setting unit 6 can set the signal transmission level within the range of 0 to -15 dBm, and the initial state is set to, for example, -10 dBm.
It can be increased by Bm. However, the amount of increase in the signal transmission level does not have to be constant, and may take a value at a preset stage, or
The amount of increase may increase as the signal transmission level increases.

FIG. 2 is a diagram for explaining an embodiment of a transmission method applied to the facsimile apparatus in FIG. 1 by a signal sequence. As described in FIG. 3, the receiving side transmits DIS in response to the call from the transmitting side.
Upon receiving this, the transmitting side transmits DCS and TCF signals, and the transmission level thereof is -10 dBm which is the initial setting value. On the receiving side that receives the DCS and TCF signals, the DC
The setting instructed by S is performed, and the training with the TCF signal is performed. If the training fails, the receiver sends an FTT signal to the sender to request retraining. On the transmitting side, the signal transmission level is set to 1
The CPU commands the transmission level setting unit to raise the dBm. It does not reduce the communication speed. The signal transmission level is raised, the TCF signal is transmitted, and the receiving side performs training again. If the training is successful, from the receiving side,
The CFR signal is sent to the transmission side, and in response to this, the transmission side transmits the image signal.

Even when the TCF signal whose transmission signal level has been raised is retransmitted, the reception side fails the training and F
When the TT signal is transmitted, the transmission side can increase the possibility of successful training by increasing the transmission signal level as described above each time the TCF signal is transmitted. .

If the training is not successful even if the signal transmission level is increased to the predetermined level or increased to the predetermined level and retransmitted, the signal transmission level is returned to the initial value to reduce the communication speed to reduce the TCF signal. It is better to send it.

[0013]

As is apparent from the above description, according to the present invention, in the data communication for exchanging signals based on the protocol (communication protocol) of the facsimile apparatus, if the training fails, the communication is performed. There is an effect that training can be performed again and communication can be performed without reducing the speed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining an embodiment in which the present invention is applied to a facsimile device.

2 is an explanatory diagram of a signal sequence of a transmission method in the embodiment of FIG.

FIG. 3 is an explanatory diagram of a signal sequence in a conventional communication method.

[Explanation of symbols]

 1 line 2 line control unit 3 transmission control unit 4 ROM 5 RAM 6 transmission level setting unit 7 document reading unit 8 recording unit 9 operation unit 10 main control unit (CPU)

Claims (1)

[Claims] 1. When a signal requesting retraining is received from the receiving side after the training signal is transmitted during the handshake, the training signal is transmitted again by increasing the signal transmission level without lowering the communication speed. Characteristic facsimile transmission method.