JPH0787479B2 - Communication method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a communication system, and more particularly to a communication method for transmitting and receiving a procedure signal.

[Conventional example]

A conventional facsimile machine may receive an echo sent by itself after transmitting an initial identification signal, and the facsimile transmission may not be possible because the pre-procedure is not established.
It was a drawback.

A specific example in which facsimile transmission is disabled due to the above echo reception and the pre-procedure is not established is shown in FIGS. 4 (a) and 4 (b).

In FIG. 4 (a), the echo of the NSF / CSI / DIS signal sent from the device itself is received, and the 9th bit of the FIF (Facsimile information field) of this DIS signal is 0 (no document).
Immediately sends a DCN signal and opens the line.

Similarly to FIG. 4 (a), FIG. 4 (b) receives the echo of the NSF / CSI / DIS signal sent by itself and detects the CCITT recommendation V21 signal, but detects a significant signal. Since it is not, it immediately goes to sending NSF / CSI / DIS signals again. After that, this is repeated, and when the initial identification timer (30 to 40 seconds) times out, the DCN signal is transmitted and the line is opened.

〔Purpose〕

An object of the present invention is to eliminate the above-mentioned drawbacks of the conventional example and to provide a communication method in which an echo signal of a signal sent by a partner machine is not mistakenly recognized as a procedure signal from the partner machine and does not malfunction. In detail, in order to destroy the echo in the facsimile procedure, at the time of colliding with the digital identification signal included in the initial identification signal, a predetermined tonal signal is transmitted, the digital identification signal is detected, and the digital identification signal is detected. It is an object of the present invention to provide a communication method characterized by stopping the transmission of the tonal signal before the end of the signal.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings.

First, the outline of this embodiment will be described. In the following embodiments, a facsimile machine will be described as an example. In the present embodiment, when the first command is received in the transmitting state, the received signals are sequentially analyzed, and when the FCF (Facsimile control field) of the DIS signal is detected, a predetermined signal (for example, 160 ms) is only once for 160 ms. 1100Hz signal). Where 160ms
Is the time required to transmit 6 bytes = 48 bits of data at 300 b / s. Considering that the FIF (Facsimile information field) that composes DIS is 3 bytes or 4 bytes, the FCS is 2 bytes, and the flag is 1 byte, the predetermined signal of 6 bytes (1100 Hz signal, for example) DI by colliding
It is possible to destroy the echo signal of the S signal.

In this example, it is the time when the main part of DIS is received 1
Since the echo signal of DIS is destroyed by sending the predetermined signal for 60 ms, the partner machine does not detect the 1100 Hz signal and malfunction.

Hereinafter, the present embodiment will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the facsimile machine of this embodiment.

In FIG. 1, numeral 2 is used for data communication and the like. Therefore, by connecting to the terminal of that line, connection control of the telephone switching network, switching to the data communication path, loop maintenance, etc. Network control unit NCU (Network Co
ntrol Unit). The signal line 2a is a telephone line. The NCU 2 operates based on the signal output from the control circuit 28 via the signal line 28a. Signal line 28 from control circuit 28
When the "0" level signal is output to a, the NCU 2 connects the telephone line to the telephone side, that is, the signal line 2a to the signal line 2b. When the control circuit 28 outputs a "1" level signal to the signal line 28a, the NCU 2 connects the telephone line to the facsimile machine side, that is, the signal line 2a to the signal line 2c. In the normal state, the telephone line is connected to the telephone side.

Reference numeral 4 is a telephone.

Reference numeral 6 is a hybrid circuit that separates a transmission system signal and a reception system signal. The hybrid circuit 6 includes a signal line 18a
The transmission signal from the telephone line 2a via the signal line 2c and NCU2
The signal sent from the other party via the telephone line 2a, NCU2, and signal line 2c is output to the signal line 6a.

Reference numeral 8 denotes a reading unit, which sequentially reads the original and outputs it to the encoding circuit 10 via a signal line 8a as a signal string representing binary values of white and black. The reading unit 8 is composed of an image pickup device such as a CCD (charge coupled device) and an optical system.

10 is output from the reading unit 8 via the signal line 8a 2
A coding circuit for coding the read data of the binarized document, and a coding method by the coding circuit 10 is, for example,
The MH method (modifid Huffman method), the MR method (modifid read method), etc., the data encoded by the circuit is output to the modulator 12 via the signal line 10a.

Reference numeral 12 is a modulator that performs modulation based on the well-known CCITT recommendation V27ter (differential phase modulation) or V29 (quadrature modulation). The modulator 12 is a line encoded by the encoding circuit 10.
The original data signal of 10a is input, modulated, and output to the addition circuit 18 via the signal line 12a.

Reference numeral 14 is a circuit for transmitting a 1100 Hz signal for 160 ms. The 1
The 100Hz signal sending circuit 14 sends a signal of 1100Hz based on the signal (pulse signal) output from the control circuit 28 via the signal line 28b, and when the sending of the 1100Hz signal of 160ms ends, a pulse is sent to the signal line 14b. Is output to notify the control circuit 28 of the end of signal transmission.

Reference numeral 16 is a modulator that performs modulation based on the well-known CCITT recommendation V21. The modulator 16 modulates the facsimile procedure signal output from the control circuit 28 via the signal line 28c to generate a signal line.
It outputs to addition circuit 18 via 16a.

Reference numeral 18 adds the signals from the modulator 16, the 1100 Hz signal sending circuit 14 and the modulator 12, and the added data is sent to the telephone line 2a via the signal line 18a, the hybrid circuit 6 and the NCU2. Normal modulator
Any one of 12, 16 image data, procedure signal and 1100 Hz signal is transmitted.

Reference numeral 20 is a demodulator that performs demodulation based on the well-known CCITT recommendation V21. The demodulator 20 includes an NCU 2, a hybrid circuit 6, and a signal line 6
The facsimile procedure signal from the telephone line 2a input via a is demodulated and input to the control circuit 28 via the signal line 20a.

Reference numeral 22 is a demodulator that performs demodulation based on the well-known CCITT recommendation V27ter (differential phase modulation) or V29 (quadrature modulation). The demodulator 22 demodulates the image data (original data) from the telephone line 2a and outputs it to the decoding circuit 24 via the signal line 22a.

Reference numeral 24 is a decoding circuit that decodes the image data output from the demodulator 22 via the signal line 22a and outputs the decoded image data to the recording circuit 26. The decoding method by the decoding circuit 24 is, for example, MH method, MR method or the like.

Reference numeral 26 is a known recording unit that sequentially records the decoded image data line by line.

Reference numeral 28 is a control circuit for controlling the entire facsimile machine and controlling facsimile communication. The control circuit 28 includes a micro computer and a read only memory (ROM) storing a control program for the micro computer, a random access memory for temporarily storing data, an input / output port and the like.

Based on the above configuration, this embodiment performs the operation shown in the flow chart of FIG. 2 below.

FIG. 2 is a flow chart showing the control operation of the control circuit 28 shown in FIG. A program for performing the operation according to the flow chart is stored in the ROM (not shown) of the control circuit 28.

In FIG. 2, step S30 represents the beginning of control. When the control is started, in step S32, the control circuit 28 outputs a "0" level signal to the NCU2 via the signal line 28a, turns off the CML relay of the NCU2, and connects the telephone line 2a to the telephone 4 side.

Then, in step S34, in the initial identification procedure, D
When the FCF of the IS signal is detected, the flag F110TR (provided on the control circuit 28 as a sost) indicating whether or not the signal of 1100 Hz (160 ms) which is the signal to be transmitted is transmitted only once. To set.

In step S36, it is determined whether or not it is in the transmission state. The determination as to whether or not this is transmission is made by determining whether or not the transmission button provided on the operation unit (not shown) is turned on. If it is not in the transmission state, the process proceeds to step S38 to perform the other processing specified, and if it is in the transmission state, the step is performed.
Go to S40.

In step S40, the control circuit 28 outputs a "1" level signal to the NCU2 via the signal line 28a to turn on the CML relay of the NCU2 and connect the telephone line 2a to the facsimile machine side.

Next, in step S42, the timer T1 (which is the soft timer of the control circuit 28) is set for 35 seconds, and the process proceeds to step 44.

In step S44, the facsimile procedure signal demodulated by the demodulator 20 is sequentially analyzed to determine whether or not the FCF of the DIS signal is detected. The FCF of the DIS signal here is detected.
The FCF detection of the DIS signal is performed when all the FCF patterns of the signal are detected. Then, the procedure signal is sequentially analyzed and the FCF of the DIS signal is analyzed.
If the FCF of the DIS signal is not detected by sequentially analyzing the procedure signal, the procedure proceeds to step S52.
Then, it is judged whether the 35-second timer T1 has timed out, and if the 35-second timer T1 has not timed up, the procedure returns to step S44.

When it is determined that the FCF is detected in step S44 and the process proceeds to step S46, it is determined whether the flag F110TR is 0, that is, whether the signal of 1100 Hz has already been transmitted once, and the flag F110TR is 0.
And when not sending out the 1100Hz signal yet,
Proceed to step S48 and send the 1100 Hz circuit via signal line 28b.
A pulse signal is output to 14 and a 1100 Hz signal is sent for 160 ms. Also, in step S46, the flag F110TR is already 1 instead of 0.
If the signal of 100 Hz is being transmitted, the process proceeds to step S54.

In step S48, if a 1100 Hz signal is sent for 160 ms, the other device sends it using this 1100 Hz signal.
The V21 signal (specifically, the DIS signal) is destroyed and the echo signal of the DIS signal is destroyed, but since the DIS signal has already been detected, there is no problem in the facsimile procedure.
When the control circuit 28 inputs a signal indicating that the 1100 Hz signal has been transmitted from the 1100 Hz transmission circuit 14 via the signal line 14b, the control circuit 28 proceeds to step S50, and at step S50,
Since the transmission of the 1100Hz signal has ended, set 1 in the flag F110TR.
After setting, proceed to step S52.

In step S52, it is determined whether the timer T1 has timed out. When the timer T1 has not timed out, the process proceeds to step S44. When the timer T1 times out, the process proceeds to step S62 to open the line 2a.

If it is determined in step S46 that the 1100 Hz signal has already been transmitted, and if the process proceeds to step S54, the facsimile procedure (pre-procedure) is performed in step S54, the communication mode is determined, and then image data is transmitted in step S56. . When the transmission of the image data for one page is completed, the facsimile procedure (post-procedure) is performed in step S58 to receive the presence / absence of the next page data, the presence / absence of the change of the communication mode, and the information of the completion of the communication, and the data of the next page is transmitted. Yes If the communication mode is not changed, the process proceeds from step S60 to step S56 and the previous procedure is performed again.If there is data on the next page and the communication mode is changed, the process proceeds from step S60 to step S42 and the previous procedure is performed again. If there is no next page data, the flow advances from step S60 to step 62 to end the transmission.

FIG. 3 shows a section of a signal in which a part of the initial identification signal (a part of the DIS signal) sent from the partner device is collided with a signal of 1100 Hz from this device. That is, when the FIF of the DIS signal is 3 bytes, the 1100 Hz signal is collided from the first FIF to the end flag, and when the FIF of the DIS signal is 4 bytes, from the first FIF to the second FCS. You're smashed.

In this embodiment, the FCF of the DIS signal is detected and then the 1100 Hz signal is transmitted to destroy the DIS signal, so that the echo signal of the DIS signal can prevent the receiving side from malfunctioning. Then, as the echo signal of the DIS signal, only the part that malfunctions the receiving side is destroyed by sending out the 1100 Hz signal for 160 ms, so the receiving side receives the 1100 Hz signal and erroneously recognizes this as a procedure signal. Can also be prevented.

Further, in this embodiment, the signal of 1100 Hz is transmitted to prevent the malfunction due to the echo signal, but the signal is not limited to the signal of 1100 Hz, and another signal may be used.

Further, although the facsimile apparatus has been described as an example in the above embodiments, the present invention is not limited to the facsimile apparatus, but can be implemented in any communication apparatus for exchanging communication procedure signals such as tele-axes.

〔effect〕

As described above, according to the present invention, in order to destroy the echo in the facsimile procedure, the predetermined tonal signal is transmitted at the time of colliding with the digital identification signal included in the initial identification signal, and the digital identification signal is transmitted. Is detected and the transmission of the tonal signal is stopped before the end of the digital identification signal, preventing the partner machine from erroneously recognizing the echo signal of the signal sent by the partner machine as a procedure signal from the partner machine and malfunctioning. At the same time, it is possible to prevent the other device from erroneously recognizing the tonal signal transmitted by the own device as a significant signal and causing a malfunction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration of a facsimile machine of this embodiment, FIG. 2 is a flow chart showing the control operation of this embodiment, and FIG. FIG. 4 is a diagram showing the transmission of a procedure signal according to the embodiment, and FIGS. 4 (a) and 4 (b) are diagrams showing the exchange of the procedure signal of the conventional facsimile machine. 2 is an NCU, 4 is a telephone, 6 is a hybrid circuit, 8 is a reading circuit, 10 is an encoding circuit, 12 is a V27ter or V29 modulator, 14 is a 1100 Hz signal sending circuit, 16 is a V21 modulator, and 18 is an adding circuit. , 20 is a V21 demodulator, 22 is a V27ter or V29 demodulator, 24 is a decoding circuit, 26 is a recording circuit, 28 is a control circuit.

Claims (1)

[Claims] 1. An echo generating line is used to connect a calling side and a called side to each other, an initial identification signal is transmitted from the called side device, and the initial identification signal is sent from the calling side. In a communication method in which a signal similar to the above may be sent, in order to destroy the echo of the digital identification signal at the time when the echo of the digital identification signal included in the initial identification signal occurs, from the calling side. A communication method comprising transmitting a predetermined tonal signal on a line, detecting the digital identification signal, and stopping transmission of the tonal signal before the end of the digital identification signal.