JPH08163272A - Data communication device - Google Patents

Abstract

(57) [Summary] [Purpose] Shortening the communication time when performing full duplex communication,
The purpose is to enable proper full-duplex communication during transmission / reception changes. [Structure] At the time of an incoming call, the control circuit 20 sends an ANSam signal for disabling the echo suppressor function, and thereafter, the calling side sends a procedure signal and an image signal so as not to cause a signal interruption of 50 msec or more. However, at the time of transmission / reception change due to the end of the image signal from the calling side, the called side
The Sam signal is transmitted and the procedure signal is transmitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication device capable of data communication by full-duplex communication.

[0002]

2. Description of the Related Art Conventionally, as this type of apparatus, for example, a facsimile apparatus has been known. When performing full-duplex communication using a general public line, it is necessary to stop the function of an echo suppressor (or echo canceller) provided in the public line network. The echo suppressor function of the public line network has a predetermined time (500 msec to 1 sec) of 2
It is stopped (disenabled) by sending a 100Hz signal to the line, and the signal on the line is 100m.
Returned by disconnecting for more than sec (enable)
To be done.

In a conventional facsimile apparatus capable of full-duplex communication, procedure signals are transmitted in half-duplex and image signals are transmitted in full-duplex. Then, in the communication of the procedure signal by the half-duplex communication, a signal disconnection of 100 msec or more may occur. Therefore, the signal of 2100 Hz for disabling the echo suppressor is transmitted for a predetermined time immediately before the communication of the image signal. After that, image signal communication was performed by full-duplex communication.

[0004]

However, a 2100 for disabling the echo suppressor described above.
The Hz signal needs to be transmitted for 500 msec to 1 sec. Then, for each page image signal communication, the above 2
When a 100 Hz signal is sent, when sending image signals of a plurality of pages, the communication time becomes longer by the sending of the 2100 Hz signal.

In particular, in recent years, due to the progress of modem technology, the transmission speed has been increased, but as described above, the echo enable signal of the echo suppressor is transmitted for each image signal communication of each page. Then, there is a problem that the reduction of the communication time cannot be realized efficiently.

[0006]

According to the present invention, the sending means sends the first signal for enabling full-duplex communication at the time of call connection, and the data communication means sends the first signal. After that, the procedure signal and the data are communicated so that the signal disconnection does not occur for a predetermined time or longer. Then, following the end of the data communication, when the transmission / reception means switches the transmission / reception of the data to / from the other party to continue the data communication, the transmission means transmits the first signal, whereby the first signal is transmitted. The number of times of sending one signal is minimized, and moreover, full duplex communication can be appropriately performed.

Further, according to the present invention, when the data transmission / reception with the other party is switched after the end of one data communication,
By performing the procedure signal communication and continuing the data communication so that the signal disconnection does not occur for a predetermined time or more, the number of times the first signal is transmitted can be reduced as much as possible, and the total number of the two signals can be appropriately reduced.
It is designed to enable heavy communication.

[0008]

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

In the following embodiments, a facsimile apparatus will be described as an example, but the present invention can be applied to any data communication apparatus capable of full-duplex communication for communication of procedure signals and data communication. .

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

In the figure, 2 is an NCU (network control unit),
A CML relay for selectively connecting the telephone line 2a of the public line network to the telephone 4 or the hybrid circuit 6, a loop forming circuit for forming a line loop of the telephone line 2a, and a call signal (CI signal) from the telephone line 2a. ) Is detected by a CI detection circuit or the like.

The hybrid circuit 6 is a circuit for separating a transmission system signal and a reception system signal.

Reference numeral 8 denotes a modulator / demodulator (modem) which demodulates the signal of the receiving system from the hybrid circuit 6 and outputs it as digital data to the control circuit 20 or modulates the digital data from the control circuit 20 to add it. Is output to the hybrid circuit 6 as a transmission system signal. The modem 8 is a V.V. recommended by the V series for modulation and demodulation of procedure signals. 8, V.I. 21, V.I. 34, or V. 27 ter, V.I. 29, V.I. 17, V.I.
It has 34 functions. These modulation / demodulation method and transmission speed are switched by a control signal from the control circuit 20.

Reference numeral 10 is a disenable signal (2100 Hz signal or 2100 Hz signal) for disenabling the echo suppressor or echo canceller function of the public line network.
A signal obtained by modulating the signal of (1) is transmitted to the line 2a via the adder circuit 12, the hybrid circuit 6, and the NCU 2. The disenable signal transmission circuit 10 transmits the disenable signal according to the control signal from the control circuit 20.

Reference numeral 14 is a reading unit for reading a document, and 16 is a recording unit for recording an image signal as an image.

Reference numeral 18 is an image memory for storing read image data and received image data.

Reference numeral 20 is a control circuit, which is composed of a microcomputer, ROM, RAM and the like. The control circuit 20 controls the reading unit 14, the recording unit 16, the input control of various key signals from the operation unit 22, and the operation unit 22.
Display control of the display unit provided in, image data encoding / decoding (encoding of MH, MR, MMR, etc.,
(Decoding process), switching control of modulation / demodulation system of modem 8, switching control of transmission speed, signal transmission control by disenable signal transmission circuit 10, transmission / reception of procedure signal described later, control of communication sequence of image data communication, etc. .

Next, the outline of this embodiment will be described.

In this embodiment, first, the procedure signal is transmitted and received by full duplex communication. FIG. 2 is a diagram showing a communication sequence of this embodiment.

In response to the incoming call, the called side receives the ANSam signal (2100H) from the disable signal sending circuit 10.
z modulated at 15Hz) or 2100H for 1 second
A z monotone signal (a disenable signal for enabling full-duplex communication) is transmitted. The ANSam signal or the 2100 Hz monotone signal disables the echo suppressor function or the echo canceller function of the public network to enable full-duplex communication. When the calling side receives the ANSam signal from the called side, 8
A modulated CM signal is sent out, and the CM signal notifies the called side of a transmission mode that can be executed in image signal transmission. When the called side receives the CM signal, it stops sending the ANSam signal and the V. The JM signal by 8 modulation is transmitted. With this JM signal, the called side notifies the calling side of the transmission modes that can be executed by the called side among the executable transmission modes notified by the CM signal. When the calling side receives the JM signal, it stops sending the CM signal, 8 modulation C
Send the J signal. The calling side receives the JM signal from this CJ signal.
The callee is notified of the transmission mode determined based on the signal. When the called side receives the CJ signal, it stops sending the JM signal and proceeds to the process of receiving the line proving signal from the calling side.

On the other hand, the calling side sends a line probing signal (a signal modulated by V.34) for checking the status of the line 2a, 50 msec after the sending of the CJ signal is stopped. Signal loss during this period is 50 ms
ec, the echo suppressor or echo canceller function of the public network remains disabled.
On the other hand, when the called side receives the line proving signal, it sends a response signal (V.34 modulated signal) to the line proving signal, and the response signal corrects the sending level and amplitude level of subsequent signals. The transmission baud rate is notified to the calling side, and the process proceeds to the process of receiving the long training signal from the calling side.

When the calling side receives the response signal, it stops the transmission of the line probing signal, and 5 seconds after the transmission is stopped.
After 0 msec, V. A 34-modulation long training signal is transmitted. The called side executes processing such as adjustment of the equalizer of the modem 8 and timing detection by this long training signal.

After the long training signal is transmitted, the calling side receives V.50 after elapse of 50 msec. A 34-modulation parameter exchange signal is transmitted. When the callee receives the parameter conversion signal, A 34-modulation parameter conversion response signal is sent, and the link correction and pit rate thereafter are notified to the calling side by this response signal. Then, the called party follows the T. 30 recommended CSI, DIS
Signal is V. The signal is transmitted by the T.34 modulation, and the T.
The flag (dummy signal) is transmitted until the 30 recommended TSI and DCS are received.

When the calling side receives the CSI and DIS signals, it stops sending the parameter exchange signal, After transmitting TSI and DCS by the 34 modulation, the flag is transmitted until the CFR signal is received from the called side. On the other hand, the called party
When the TSI and DCS signals are received from the calling side, flag transmission is stopped, and V. The CFR signal is transmitted by the 34 modulation.
In transmitting and receiving the DIS and DCS signals, the called side
The calling side is notified that the document image to be transmitted after receiving is set. Then, the calling side recognizes that the image is transmitted from the called side after the transmission is completed.

When the calling side receives the CFR signal, it stops sending the flag and, after 50 msec has passed, sends the image signal in the transmission mode set in the previous procedure.
Image signals are received according to the set transmission mode. The transmission / reception of the image signal here may be error resending communication by full-duplex communication or error resending communication by half-duplex communication (ECM communication).

The calling side, after transmitting the image signal of one page,
When sending the image signal of the next page in the same transmission mode, P is set 50 msec after the end of the image signal transmission.
After sending the PS-MPS signal (in the case of T.30 recommended ECM), the flag is sent until the MCF signal is received from the called side. When the transmission mode is changed to transmit the next page, the calling side sends a PPS-EOM signal instead of the PPS-MPS signal.

The called side receives the PPS-MPS after the image signal.
When the signal is received, if the image signal is well received, M
After transmitting the CF signal, the process proceeds to the image signal receiving process of the next page.

When the calling side receives the MCF signal, it stops sending the flag and, after 50 msec has elapsed, sends the image signal of the next page. If the page is the last page, 50 mse after the transmission of the image signal of the page is completed.
After the lapse of c, the PPS-EOP signal is sent out, and the called side receives M
The flag is transmitted until the CF signal is received. In the above communication processing, a signal interruption of 50 msec or longer does not occur, so the echo suppressor or echo canceller function remains in the disabled state.

When the calling side receives the MCF signal from the called side, it stops sending the flag and shifts to the receiving procedure by the exchange of transmission and reception. On the other hand, when the called side detects the stop of the flag from the calling side, it judges that the MCF signal is correctly received by the calling side, and proceeds to the procedure for transmitting the image signal by the transmission / reception change. If the line delay is 0.6 sec one way at the time of detection of the flag stop on the receiving side, 1.25 as shown in FIG.
A signal break of sec may occur, and the echo suppressor function may be enabled. Therefore, in this embodiment,
At the time of transmission / reception change, the called side detects 50 when the flag stop is detected.
After msec, the ANSam signal is transmitted again, and the echo suppressor or echo canceller function is disabled. Then, after transmitting the ANSam signal, 50
A line probing signal is sent after msec,
A communication sequence similar to the procedure described above is performed.

By the above processing, when full duplex communication is performed, a signal disconnection of 100 msec or more is prevented from occurring as much as possible, and a disenable signal for disabling the echo suppressor function is reduced. It was done.

4 to 8 are flowcharts showing the control operation of the control circuit 20 for executing the above-mentioned processing.

First, in step S1 (FIG. 4), the control circuit 20 initializes each unit and enters a standby state.

Then, in steps S2 and S3, the presence or absence of incoming call detection (CI detection) and the presence or absence of a transmission instruction are determined,
If neither is detected, another process is executed in step S4, and the process returns to step S2. When an incoming call is detected, the process proceeds from step S2 to step S5 to perform the receiving process, and when a transmission instruction is detected, the process proceeds to step S35 (FIG. 7) to perform the transmitting process.

At step S5, the CML of NCU2
The relay is turned on and the line 2a is connected to the hybrid circuit 6 side to form a line loop. Then, in step S6, it waits for the line condition to stabilize (waiting for 0.5 sec). The ANSam signal is transmitted until the CM signal is received in the 8 mode. When the CM signal is received, steps S9 and S10
At, the JM signal is transmitted until the CJ signal is received. When the CJ signal is received, the modem 8 is switched to the V.V. 34 mode, steps S11-S
At 14 (FIG. 5), the modem 8 is made to receive a line proving signal, send a line proving response signal, and receive a long training signal.

When the end of reception of the long training signal is detected in step S15, the parameter exchange signal is received in step S16, and when the parameter exchange signal is received, the parameter exchange response signal is sent and NSF is sent in steps S17 and S18.・ Send CSI / DIS signals. Then, in steps S19 and S20, NS
The flag is transmitted until the S / TSI / DCS signal is received. At this time, if a document for transmission is set in the reading unit 14 or image data for transmission is set in the image memory 18, bit 9 of the DIS signal is set to "1" and the caller side is notified. Notice.

In step S20, NSS / TSI / DC
When the S signal is received, in step S21, the CFR signal is transmitted if the communication in the transmission mode set by the procedure signal transmitted and received until then is good, and the process proceeds to the image signal reception in step S22.

In step S22, the image signal is received, the received image data is decoded, and the received image is recorded. And steps S23, S24, S25
At PPS-MPS, PPS-EOM, PPS-EOP
(In the case of ECM mode) Whether or not a signal is received is determined, and if neither signal is received, image signal reception is continued.

When the PPS-MPS signal is received in step S23, if the image received in step S26 is good, the MCF signal is transmitted and then the image signal of the next page is received. Proceed to S22.

Further, in step S24, the PPS-EOM
When the signal is received, the process proceeds to step S14 to change the transmission mode.

Further, in step S25, PPS-EOP
If a signal is received, it will progress to step S27 (FIG. 6).

In step S27, it is determined whether or not an image for transmission is set in the reading unit 14 or the image memory 18, and if the image for transmission is not set, the DCN signal is output in steps S28 and S29. Until received
The MCF signal is sent out periodically. When the DCN signal is received, the line is opened and the line 2 is opened in step S30.
After switching a to the telephone 4 side, the process returns to the standby state of step S2.

When the transmission image is set in step S27, the MCF signal is periodically transmitted until it is determined in steps S31 and S32 that the reception of the flag is completed. Then, if it is determined in step S32 that the flag reception has ended, after waiting for 50 msec in step S33, the ANSam signal is retransmitted in step S34 to disable the echo suppressor or echo canceller function of the public network. , Step S4
1 (FIG. 7).

In step S3, the transmission instruction is detected,
In step S35 (FIG. 7), the CML relay of the NCU 2 is turned on and the line 2a is switched to the hybrid circuit 6 side to form a line loop.
Then, after calling (dialing) the other party input through the operation unit 22, the ANSam signal is received in step S36.

When the ANSam signal is received in step S36, the modem 8 is connected to the V.V. The 8 mode is set, and in steps S37 and S38, the CM signal is transmitted until the JM signal is received.

When the JM signal is received in step S38, the CJ signal is transmitted in step S39. Then, when the transmission of the CJ signal is completed, after waiting for 50 msec in step S40, the modem 8 is set to V.5 in step S41. The mode 8 is set to allow the modem 8 to send a line proving signal and receive a response signal to the line proving signal. When the transmission of the line probing signal is completed, in step S42, 50 m
After waiting for sec, in step S43, the modem 8
To send a long training signal. Then, when the transmission of the long training signal is completed, step S4
After waiting 50 msec at step 4, step S45,
In S46 (FIG. 8), the parameter exchange response signal, NSF
-The parameter exchange signal is transmitted until the CSI / DIS signal is received.

When the parameter exchange response signal and the NSF / CSI / DIS signal are received in step S46, the NSS / TSI / DCS signal is transmitted in step S47. Then, in steps S48 and S49, the flag is transmitted until the CFR signal is received.

When the CFR signal is received in step S49, after waiting for 50 msec in step S50, the image signal of one page is transmitted in step S51 in the transmission mode set by the above procedure. And 1
When the transmission of the image signal of the page is completed, the presence or absence of the next page is determined in step S52. If there is the next page, it is determined in step S53 whether or not the mode change operation has been performed. If the mode change operation has not been performed, after waiting for 50 msec in step S54, the PPS in step S55. -Send the MPS signal. Then, in steps S56 and S57, the flag is transmitted until the MCF signal is received, and when the MCF signal is received, the image signal of the next page is transmitted in step S5.
Proceed to 1.

If there is a mode change in step S53, after waiting for 50 msec in step S58, a PPS-EOM signal is transmitted in step S59. Then, in steps S60 and S61, the flag is transmitted until the MCF signal is received, and when the MCF signal is received, the process proceeds to step S42 (FIG. 7) to change the transmission mode.

If there is no next page in step S52, after waiting for 50 msec in step S62, a PPS-EOP signal is sent out in step S63. Then, in steps S64 and S65, the flag is transmitted until the MCF signal is received, and when the MCF signal is received, in step S66, the ninth fax information field of the DIS signal received in step S46 is received.
It is determined whether the th bit is "1", and if bit 9 of the DIS signal is not "1", in step S68, DC
The N signal is transmitted, the line is opened in step S69, and the process returns to the standby state of step S2 in FIG.

If bit 9 of the DIS signal is "1" in step S66, the process proceeds to the receiving process, and step S66 is executed.
After receiving the ANSam signal at 67, the process proceeds to step S11 of FIG. 4 to perform the receiving process.

With the above processing, the communication sequence shown in FIG. 2 is executed.

When there is an error in the received image data, the receiving side sends a resend request signal (PPR) designating the frame data to be resent instead of the MCF signal, and when the sending side receives the PPR signal, Stop sending flags, 5
The frame data indicated by the PPR signal received after 0 msec is retransmitted.

Further, in the above-described embodiment, the called-side ANSam signal is transmitted at the time of transmission / reception change.
You may make it transmit a Sam signal. In this case, the called side detects the reception of the ANSam signal instead of performing the processing of steps S33 and S34 of FIG. 6, and when it determines that the ANSam signal is received, it sends a flag until the ANSam signal ends, and the ANSam signal is transmitted. After this, the flag transmission is stopped and the process proceeds to step S41 in FIG. On the other hand, the calling side sends the ANSam signal for 1 second instead of the process of step S67 of FIG. 8, and then proceeds to step S11 of FIG. FIG. 9 is a diagram showing a communication sequence when the calling side sends an ANS signal at the time of transmission / reception change.

Further, in the above-mentioned embodiment, the called side sends the ANSam signal when a call is received, but the calling side sends ANSa.
The m signal may be transmitted. In this case, the calling side waits for 0.5 seconds after turning on the CML relay instead of the process of step S36 of FIG. 7, and then sets the ANSam signal to 1
It is sent for a second and the process proceeds to step S37. On the other hand, the called party
After omitting the processes of steps S6 and S7 in FIG. 4 and turning on the CML relay, the CM signal is received in step S8. In FIG. 10, when the call is made (when the call is received)
It is a figure showing the communication sequence at the time of sending a Sam signal.

Further, in the above-mentioned embodiment, at the time of transmission / reception change,
The ANSam signal is sent to disable the echo suppressor or echo canceller function of the public network. However, instead of sending the ANSam signal, a flag is sent so that a signal interruption of 50 msec or more does not occur. Good. In this case, as shown in FIG. 11, the called side sends the flag until the calling side determines that the flag from the calling side has ended after the MCF signal, and determines that the flag from the calling side has ended. Then, the flag transmission is stopped and 50m
A line probing signal is transmitted after sec. As the control performed by the control circuit 20, the called side sends a flag in step S31 of FIG. 6 following the sending of the MCF signal, and if it is determined in step S32 that the calling side has finished the flag, step S33. After waiting 50 msec at, the process proceeds to step S41 in FIG. On the other hand, the calling side omits the process of step S67 of FIG. 8 and proceeds from step S66 to step S11 of FIG.

According to the above processing, it is possible to minimize the number of times a signal for disabling the echo suppressor or echo canceller function of the public network (a signal for enabling full duplex communication) is transmitted. The communication time when performing full-duplex communication can be shortened as a whole.

Further, the present invention is not limited to the above-mentioned embodiment, but various modifications can be made.

[0058]

As described above, according to the present invention, for example, even when data is transmitted from the calling side to the called side, and subsequently the data is transmitted from the called side to the calling side, transmission / reception can be properly performed. Dual communication can be performed. Moreover, according to the present invention,
It is possible to reduce the number of times of signal transmission for enabling full-duplex communication as much as possible, and to shorten the communication time.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a communication sequence according to the present embodiment.

FIG. 3 is a diagram showing occurrence of signal disconnection during transmission / reception change.

FIG. 4 is a flowchart showing the control operation of this embodiment.

FIG. 5 is a flowchart showing a control operation of this embodiment.

FIG. 6 is a flowchart showing the control operation of this embodiment.

FIG. 7 is a flowchart showing the control operation of this embodiment.

FIG. 8 is a flowchart showing the control operation of this embodiment.

FIG. 9 is a diagram showing a communication sequence of another embodiment.

FIG. 10 is a diagram showing a communication sequence of another embodiment.

FIG. 11 is a diagram showing a communication sequence of another embodiment.

[Explanation of symbols]

 2 NCU 4 Telephone 6 Hybrid circuit 8 Modem 10 Disenable signal sending circuit 12 Adder circuit 14 Reading unit 16 Recording unit 18 Image memory 20 Control circuit 22 Operation unit

Claims (15)

[Claims] 1. A data communication device for communicating by full-duplex communication, transmitting means for transmitting a first signal for enabling full-duplex communication, and a predetermined time after the transmission of the first signal. Data communication means for performing data communication by full-duplex communication without generating the above-mentioned signal interruption, and transmission / reception alternation means for switching data transmission / reception with the other party to continue data communication after the end of the data communication. And a means for causing the transmitting means to transmit the first signal when the transmission / reception altering means performs the transmission / reception alternation. 2. The data communication apparatus according to claim 1, wherein the transmission / reception altering means continues the data communication without generating a signal interruption for a predetermined time or more after the transmission of the first signal. 3. The data communication means according to claim 1, wherein data communication is performed according to transmission and reception of a procedure signal,
A data communication device, wherein the transmission and reception of the procedure signal is performed by full-duplex communication, and the data communication is performed by half-duplex communication. 4. The data communication means according to claim 1, wherein data communication is performed according to transmission and reception of a procedure signal,
A data communication device, wherein communication of the procedure signal and the data is performed by full-duplex communication. 5. A data communication device for communicating by full-duplex communication, transmitting means for transmitting a first signal for enabling full-duplex communication, and a predetermined time or more after transmitting the first signal. Data communication means for performing data communication by full-duplex communication without generating signal disconnection, and transmission / reception exchanging means for continuing data communication by switching data transmission / reception with a partner after the end of the data communication. The data communication device, wherein the transmission / reception altering means continues the data communication by performing communication of a procedure signal without generating a signal interruption for a predetermined time or more at the time of the transmission / reception alternation. 6. The method according to claim 5, wherein at the time of the transmission / reception change,
A data communication device, characterized in that a predetermined signal is sent out after a procedure signal to prevent the occurrence of signal disconnection for a predetermined time or more. 7. The data communication according to claim 1, wherein the data communication means prevents the occurrence of signal disconnection for the predetermined time or longer by transmitting a predetermined signal after the procedure signal. apparatus. 8. The data communication device according to claim 6, wherein the predetermined signal is a dummy signal. 9. A data communication method for performing full-duplex communication, wherein a first signal for enabling full-duplex communication is transmitted at the time of call connection, and a predetermined signal is transmitted after the first signal is transmitted. Procedure signals and data are communicated so as not to cause signal interruption for longer than time, and after the end of the data communication, the data transmission / reception with the other party is switched to continue the data communication, and when the transmission / reception is switched. And transmitting the first signal to the data communication method. 10. The data communication method according to claim 9, wherein transmission / reception of the procedure signal is performed by full-duplex communication, and communication of the data is performed by half-duplex communication. 11. The data communication method according to claim 9, wherein the communication of the procedure signal and the communication of the data are performed by full-duplex communication. 12. A data communication method for performing communication by full-duplex communication, transmitting a first signal for enabling full-duplex communication at the time of call connection, and after transmitting the first signal, a predetermined signal is transmitted. Procedure signals and data are communicated so as not to cause signal interruption for longer than time, and after the end of the data communication, the data transmission / reception with the other party is switched to continue the data communication, and when the transmission / reception is switched. In addition, the data communication method is characterized in that the procedure signal is communicated so that the signal interruption does not occur for the predetermined time or longer. 13. The method according to claim 12, wherein when the transmission / reception switching is performed, a predetermined signal is transmitted after the procedure signal so that a signal interruption for the predetermined time or more does not occur. Data communication method. 14. The method according to claim 9 or 12,
A data communication method, characterized in that after the signal is transmitted, a predetermined signal is transmitted after the procedure signal so that the signal disconnection for the predetermined time or longer does not occur. 15. The data communication method according to claim 13, wherein the predetermined signal is a dummy signal.