JPH0774910A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To prevent the generation of communication disablement due to a communication error by providing an opposite facsimile equipment with a full duplex communication function so as to execute duplex communication based upon setting, and when a receiver does not have this resending function and inhibition is set up, executing inhibition control. CONSTITUTION:When a transmission side does not select a continuous error resending or a receiver does not have the resending function, a signal level '0' is outputted to a signal line 26a to execute normal transmission. In this case, an echo suppressor function stopping tone generating circuit 16 does not send a stop tone to the signal line 16a. When the receiver has this function and the transmitting side does not select the function, the circuit 26 outputs a signal level '1' to the line 26a and transmits a signal in a continuous error resending mode. Immediately before sending a picture signal, the circuit 16 sends a stop tone, and when the sending ends, generates a pulse to a line 16b. At the time of executing reproducing also, the tone is sent immediately before sending the picture signal. Consequently full duplex operation can be executed also in an international line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile machine having a full-duplex communication function.

[0002]

2. Description of the Related Art Conventionally, a facsimile apparatus having a full-duplex communication function has always been configured to execute a full-duplex communication if a partner apparatus has the full-duplex communication function.

[0003]

However, in the conventional facsimile apparatus, when the echo is intense on an international line, the signal from the other party is drowned out by the echo of the signal that the other party has sent, and the communication is not successful. was there.

It is an object of the present invention to provide a facsimile machine which does not cause a communication error in the above case.

[0005]

According to the present invention, in a facsimile apparatus capable of full-duplex communication, a discriminating means for discriminating whether or not a partner apparatus has a function capable of executing full-duplex communication, and an operator's operation. In the setting means for setting whether to permit or prohibit full-duplex communication, the other device has a function capable of executing full-duplex communication based on the determination result of the determination means and the setting of the setting means, and If the setting means is set to allow full-duplex communication, full-duplex communication is performed and the partner device does not have a function of executing full-duplex communication, or
If the setting means is set to prohibit full-duplex communication, the setting means has a control means for performing control to prohibit full-duplex communication.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the output timing of the output signals of the transmitting side and the receiving side in the facsimile transmission system of this embodiment.

First, when receiving the calling signal CI from the transmitting side, the receiving side outputs the called station identification signal CED. Then, thereafter, the initial identification signal NSF indicating the non-standard function is used to notify the transmitter side of whether or not there is a function of performing continuous error retransmission. This has the error resending function when one of the bit strings of the facsimile information field FIF of NSF, for example, the 50th bit is set to 1, and does not have it when it is 0. The receiving side also has a called station identification binary signal CS.
I and digital identification signal DIS.

On the other hand, the transmitter side determines whether the operator has selected the error resending function and whether the receiving side has the function. Here, the operator selects the function, and when the receiving side has the function, the 50th bit of the FIF of the non-standard device setting signal NSS is set to 1 and transmitted. In addition, the transmitter station identification signal TSI and the digital command signal D
Send CS. The receiving side can determine whether to use the function by NSS.

Upon receiving the reception preparation confirmation signal CFR from the receiving side, the transmitting side sends a 2100 Hz tonal signal for 1 second as the echo suppressor function stopping tone EST when performing the error resending function, and then 100
A training signal and a message signal (image signal) are transmitted without a signal interruption of mS or less or without a signal interruption. Therefore, it becomes possible to use the line in full-duplex mode while sending a message, continuous error resending is performed, and if some image signals cannot be received at the receiving side during message communication, the error part Can be transmitted to the sender.

When the communication for one page is completed and there is a next page, the NSS signal is sent again, and in this case also, the EST is sent immediately before sending the training, which leads to the sending of the message.
Is sent. When the transmission of all pages is completed, the transmission side transmits the line open signal DCN and ends the communication.

FIG. 2 is a block diagram of an embodiment of the transmitter side of the facsimile apparatus which executes the procedure shown in FIG.

In FIG. 2, reference numeral 2 denotes a telephone network used for data communication, so that the terminal of the line is connected to control connection of the telephone switching network, switch to a data communication path, and loop. Network control unit NCU (Net
work control unit). Signal line 2
a is a telephone line. The NCU 2 inputs the signal on the signal line 28a, and if the signal level is "0", connects the telephone line to the telephone side, that is, the signal line 2a to the signal line 2b. When the signal on the signal line 28a is input and the signal level is "1", the telephone line is connected to the facsimile machine side, that is, the signal line 2a is connected to the signal line 2c. In a normal state, the telephone line is connected to the telephone side.

Reference numeral 4 is a telephone.

Reference numeral 6 is a hybrid circuit for separating a transmission system signal and a reception system signal. That is, the signal line 18a
The transmission signal of passes through the signal line 2c and the NCU2,
It is sent to the telephone line. Further, the signal sent from the other party is output to the signal line 6a after passing through the NCU 2 and then the signal line 2c.

Reference numeral 8 denotes a reading circuit, which sequentially reads image signals for one line in the main scanning direction from a transmission document, and outputs two lines of white and black.
Create a signal string that represents a value. CCD (charge coupled device)
And the like, and an optical system. The binarized signal sequence of white and black is output to the signal line 8a.

Reference numeral 10 is a circuit for inputting the binarized data output to the signal line 8a and encoding it. The encoding circuit 10 has a memory that only performs retransmission. When the signal level of the signal line 28d is "0", normal transmission encoding is performed. When the signal line 28d is at the signal level "1", the coding is performed by the continuous error retransmission. When the Countdown error retransmission mode is selected, the following control is performed. When the signal level of the signal line 28b becomes "1", the image transmission is interrupted. When the signal line 28b becomes the signal level "0", the signal line 28b
The retransmission start line output to c is input, and retransmission is performed from this line. Encoding (MH (Modified
The data that has been Huffman coded or MR (Modified Read) coded is output to the signal line 10a.

Reference numeral 12 is a known CCITT recommendation V27te.
It is a modulator that performs modulation based on r (differential phase modulation) or V29 (quadrature modulation). The modulator 12 receives the signal on the signal line 10a, modulates the signal, and outputs the modulated data to the signal line 12a.

Reference numeral 14 is a modulator for performing modulation based on the well-known CCITT recommendation V21. The modulator 14 receives the procedure signal on the signal line 28e, performs modulation, and outputs the modulated data to the signal line 14a. In addition, the signal line 28f has an N
The 50th bit information of the FIF of the SS signal is output.

Reference numeral 16 is a circuit for generating an echo suppressor function stopping tone on the signal line 16a when a pulse is generated on the signal line 28g. In this embodiment, 2100 Hz is used as the tone for stopping the echo suppressor function.
I am thinking of a signal for 1 second. 16 is a signal line 16 when transmission of the tone for stopping the echo suppressor function is completed.
Generate a pulse on b.

Reference numeral 18 denotes an adder circuit which inputs the signals of the signal lines 12a, 14a and 16a and outputs the addition result to the signal line 18a.

A demodulator 20 performs demodulation based on the well-known CCITT recommendation V21. The demodulator 20 receives the signal on the signal line 6a, performs V21 demodulation, and outputs the demodulated data to the signal line 20b. Further, the demodulator 20 uses the NSF
The 50th bit information of the FIF of the signal is output to the signal line 20a.

When the receiving side detects a reception error during data communication, the receiving side facsimile machine sends a NACK signal. When 22 detects this NACK signal, the signal line 22a
It is a circuit that generates a pulse.

Reference numeral 24 is a circuit for detecting the retransmission start line number transmitted subsequently to the NACK signal and outputting the line number to the signal line 24a.

At 26, the operator is Continuou
s It is a circuit that detects whether or not the error retransmission mode is selected. When the operator does not select the continuous error retransmission mode, the signal 26 outputs a signal of signal level "0" to the signal line 26a. Further, 26 outputs a signal of signal level "1" to the signal line 26a when the operator selects the continuous error retransmission mode.

Reference numeral 28 is a control circuit for performing the control described below. Operator on the transmitter side is Continuous
Error retransmit is not selected, or the receiver is Con
If it does not have the function of retransmitting a tinous error, normal transmission is performed. At this time, the echo suppressor function stop tone is not sent immediately before sending the image signal. The receiver has the function to perform continuous error retransmission, and the operator on the transmitter side does not
Cont.
Transmission is performed in the inous error retransmission mode. At this time, the tone for stopping the echo suppressor function is transmitted immediately before the image signal is transmitted. This tone is sent immediately before the image signal even when retransmitting. This allows full-duplex operation even on international lines.

FIG. 3 shows a control flow chart of the control circuit 28 shown in FIG.

In FIG. 3, in step S50, the telephone line is connected to the telephone side and the calling signal CI is transmitted. Then, CED is detected in S52, and when the start button is pressed, the telephone line is connected to the hybrid circuit side in S54.

Then, in S56, the other party's NSF is received,
It is determined in S58 whether the receiving side has the continuous error resending function. If there is a function, it is determined in S60 whether the operator has selected the error resending function. S5
If either one of S8 and S60 is "none", the normal mode is selected in S61, and the signal level "0" is output to the signal lines 28b, 28d, and 28f.

On the other hand, if both are present, the error retransmission mode is selected in S62, and the signal level "1" is output to the signal lines 28d and 28f.

Therefore, in the pre-procedure of S64, the FIF 5
An NSS signal whose 0th bit is "1" is transmitted. S
If the CFR is detected during the pre-procedure of 64, the echo suppressor function stop tone EST is transmitted in S66, and then the training signal message (image signal) is transmitted without a signal interruption of 100 mS or less (S6).
8, S70).

Therefore, the line is always used in full-duplex during message transmission in error resend mode. If a NACK signal is received from the receiver during message transmission, NACK
The line number signal for starting the retransmission following the signal is detected in S74, and when the preparation for retransmission is completed in S76, the process returns to S66 again, and the EST, the training, and the message are sequentially transmitted.

When the end of the message of one page is detected in S78, the presence or absence of the next page is determined in S80. If the next page is present, the process returns to S58 to repeat the above operation. If there is no next page, DCN is sent and the operation is completed.

On the other hand, when the normal mode is selected in step S61, the NSS signal in which the 50th bit of the FIF is set to "0" is transmitted in the pre-procedure of S82, and the EST is not transmitted thereafter in the normal mode. Is sent.

[0035]

As described above, according to the present invention, based on the discrimination result of the discrimination means and the setting of the setting means, the partner device has a function of executing full-duplex communication, and the setting is made. If the setting allows full-duplex communication, the other device does not have the function of performing full-duplex communication, or the setting means prohibits full-duplex communication. In this case, the control for prohibiting the full-duplex communication is performed. Therefore, when the communication fails on the international line or the like, the full-duplex communication can be prohibited, and it is possible to prevent the communication error from occurring and the communication being disabled.

[Brief description of drawings]

FIG. 1 is a signal output timing chart of a transmission side and a reception side in a communication system of this embodiment.

FIG. 2 is a circuit block diagram of a facsimile transmission apparatus according to the present exemplary embodiment.

FIG. 3 is a control flow chart of the control circuit of FIG.

[Explanation of symbols]

 2 NCU 4 Telephone 6 Hybrid circuit 8 Reading circuit 10 Encoding circuit 12 V27ter or V29 modulator 14 V21 modulator 16 Echo suppressor function stop tone generation circuit 18 Addition circuit 20 V21 demodulator 22 NACK signal detection circuit 24 Retransmission start line detection Circuit 26 Continuous error retransmission selection detection circuit 28 Control circuit

Claims (1)

[Claims] 1. In a facsimile apparatus capable of full-duplex communication, a determination means for determining whether or not a partner apparatus has a function capable of executing full-duplex communication, and an operator's operation to permit full-duplex communication. Setting means for setting whether to prohibit or not, and the other device has a function capable of executing full-duplex communication based on the determination result of the determination means and the setting of the setting means, and the setting means performs full-duplex communication. If it is set to permit communication, full-duplex communication is performed and the partner device does not have the function to execute full-duplex communication, or if it is set to prohibit full-duplex communication by the setting means, full-duplex communication is set. A facsimile apparatus comprising: a control unit that performs control for prohibiting double communication.