JP3437402B2 - Communication device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to, for example, ITU-T.
Recommendation V. 8, V.I. 34 relates to a communication device such as a facsimile device having a communication function.

[0002]

2. Description of the Related Art Conventional ITU-T Recommendations 8, V.I. 34
In a facsimile device having a communication function, various momentary interruptions may occur, resulting in a communication error.

(1) For example, if a momentary interruption for a predetermined time or more occurs during reception of primary channel information, the process immediately shifts to reception of the control channel. In this case, even if waiting for 3 seconds, Sh, Sh _* Signal or PP
Since the h and ALT signals cannot be received, the control channel shifts to the retrain sequence and Sh, Sh _*
A signal or an AC signal for the PPh and ALT signals is transmitted. Note that Sh _* is a phase inversion signal of Sh,
In the drawings described below, Sh is shown with an overline.

However, since it is recommended that the retrain on the control channel be executed after entering the control channel data, the transmitter cannot properly receive the AC signal, resulting in a procedure error and communication. I can't continue.

(2) Further, the conventional ITU-T Recommendation V. Two
1, V.I. 27 ter, V.I. 29, V.I. Since it is half-duplex communication in all of 17, it was not necessary to disable the echo suppressor. 8, V.I. In 34 communications,
Since the procedure is full-duplex communication and image transmission is half-duplex communication, it is necessary to execute full-duplex communication.
An NSam signal (a signal obtained by modulating 2100 Hz at 15 Hz) is transmitted, the echo suppressor is disabled, and full-duplex communication is executed.

However, when the international communication is performed and the image signal is transmitted through the primary channel, the echo suppressor is enabled when a momentary interruption of 100 mS or more occurs because of half-duplex communication, and the procedure after the primary channel is performed. Will result in an error.

(3) Further, the conventional ITU-T Recommendation V.
27 ter, V.I. In the communication by 29, the training signal immediately before the TCF signal and the training signal immediately before the image information are the same, and it is determined by the TCF signal that follows the training signal whether communication at a predetermined speed is possible. Since the determination was made, if a momentary interruption or the like occurs in the training signal immediately before the TCF signal, the TCF signal is not correctly demodulated, and it is possible for the host device to recognize this and reliably reduce the communication speed. .

However, the ITU-T Recommendation V. 8, V.I. 34
In the communication means, by the line probing signal,
Check the usable bandwidth of the line, S / N, etc., and
The long training signal was used to adjust the equalizer etc. for receiving the primary channel.

Here, immediately before the primary channel,
I was only doing resync (short training). Further, once the transmission of the primary channel is started, the long training signal is not transmitted unless the call is disconnected. Further, after the long training, there is no means for the demodulated data on the host device side to judge the success or failure of the training, and the modem automatically determines.

If there is a momentary interruption during reception of the training signal, the modem will function to match the line characteristics in which the momentary interruption has occurred, and this information will be stored for the next parameter exchange. It will shift to the sequence of.

Then, the resync transmitted immediately before the primary channel information after the parameter exchange makes a fine adjustment of the equalizer or the like based on the information received by the previous training signal, but this fine adjustment always fails. Ends with 1
The transmission of the page primary channel information and the transmission of the PPR signal in which all the frames are in error are repeated to fall back the transmission rate. When the transmission speed can be further reduced, the EOR-Q signal and the ERR signal are transmitted and received, and the line is disconnected.

In the ECM communication, the communication can be continued even when all the frames are in error. Therefore, when the information of one partial page is close to 256 frames, if the above operation is repeated, the fallback control is also performed. According to
Since it takes several tens of minutes and communication becomes impossible after this, enormous waste occurs.

[0013]

As described above, the ITU
-T Recommendation V. 8, V.I. 34 communication results in a communication error, and V.34 communication is performed. 8, V.I. There is a problem that the function of speeding up, which is the purpose of communication, is rather hindered.

Therefore, an object of the present invention is to provide a communication device capable of avoiding a communication error state with respect to various types of instantaneous interruptions as described above.

[0015]

SUMMARY OF THE INVENTION The present invention is directed to the presence of received signals.
Means to detect nothing and primer based on ITU-T recommendation
At the time of shifting to re-channel reception, a timer for the first predetermined time is set.
The means to set and the absence of signal for the second predetermined time or more
Means for outputting and a second predetermined time or more by the detecting means.
If the above no signal is detected, the timer will
Until it is over, control based on ITU-T recommendation
Communication control means for continuing to receive the specific information of the channel
And the specific information of the control channel is S
h, Sh _* group or PPh, ALT group
Is a communication device.

The present invention is also based on the ITU-T recommendation.
At the time of transition to reception on the primary channel,
Set the timer and send a signal for the second predetermined time or longer.
If no signal is detected, the timer will expire.
Until the control chart based on ITU-T recommendation
The reception of the specific information of the
The roll channel specific information is Sh, Sh _* group,
Or, it is the information of PPh and ALT group.
This is the communication method to be adopted.

Furthermore, the present invention detects the presence or absence of a received signal.
Means, a means for transmitting a first tone signal, and an IT
Reception of S, S _* , PP, TRN signals based on UT recommendations
At times, when a no signal condition is detected for more than a predetermined time,
The first tone signal is transmitted and then the second tone signal is transmitted.
When a signal is detected, INFOh is transmitted,
Again, shift to receiving S, S _* , PP, TRN signals,
If there is no signal for more than the fixed time, then the PPh
Communication control means for shifting to signal reception
Is a communication device.

The present invention is based on the ITU-T recommendation.
When receiving S, S _* , PP, TRN signals,
The first tone upon detecting the above no signal condition
If a signal is transmitted and then a second tone signal is detected,
In that case, INFOh is transmitted and S, S _* , and
Transition to reception of PP and TRN signals, and signals for a predetermined time or longer
If there is no non-existing state, the process proceeds to the reception of the PPh signal.
The communication method is characterized in that

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a first embodiment of the present invention will be described.
Examples will be described.

As described above, according to the conventional ITU-T Recommendation V.26.
8, V.I. In the facsimile machine having the 34 communication function,
If a momentary interruption occurs for more than a predetermined time during the reception of the primary channel information, the control channel immediately shifts to reception of the control channel.
Since the Sh _* signal or the PPh / ALT signal cannot be received, the control channel shifts to the retrain sequence and the AC signal corresponding to the Sh, Sh _* signal or the PPh / ALT signal is transmitted.

However, since it is recommended that the retrain on the control channel be executed after entering the control channel data, the transmitter cannot properly receive the AC signal, resulting in a procedure error and communication. I can't continue.

Therefore, in the first embodiment of the present invention, when a momentary interruption of, for example, 40 mS or more occurs during reception of the primary channel information, the control channel of the Sh, Sh _* group, or PPh, ALT group is surely set. The present invention provides a facsimile machine capable of continuing communication in response to a signal.

FIG. 1 is a block diagram showing the structure of a facsimile apparatus according to the first and second embodiments of the present invention.

The NCU (network control unit) 2 is connected to the terminal of the line in order to use the telephone network for data communication and the like,
It controls the connection of the telephone switching network, switches to the data communication path, and holds the loop. Further, the NCU 2 connects the telephone line 2a to the telephone 4 side if the signal level (signal line 20a) from the control circuit 20 is "0", and connects the telephone line 2a if the signal level is "1". It is connected to the facsimile machine side.
In the normal state, the telephone line 2a is connected to the telephone 4 side.

The hybrid circuit 6 separates the transmission system signal and the reception system signal, sends the transmission signal from the addition circuit 12 to the telephone line 2a via the NCU2, and sends the signal from the partner side via the NCU2. The signal is received and sent to the modulator / demodulator 8 via the signal line 6a.

The modulator / demodulator 8 complies with ITU-T Recommendation V.6. 8,
V. 21, V.I. 27 ter, V.I. 29, V.I. 17, V.I.
Which performs modulation and demodulation based on 34,
Each transmission mode is designated by the signal line 20c. The modulator / demodulator 8 inputs the signal output to the signal line 20b, outputs the modulated data to the signal line 8a, inputs the received signal output to the signal line 6a, and inputs the demodulated data to the signal line 8b. Output.

The ANSam transmission circuit 10 is a circuit for transmitting an ANSam signal. When an ANSam signal is output to the signal line 20d, the ANSam signal is transmitted to the signal line 10a and then to the signal line 20d. When the signal of the signal level "0" is being output, no signal is output to the signal line 10a.

The adder circuit 12 inputs the information on the signal line 8a and the information on the signal line 10a, and adds the result of addition.
It is output to a. The reading circuit 14 reads an image of a document and outputs the read image data to the signal line 14a. The recording circuit 16 sequentially records the information output to the signal line 20e line by line.

The memory circuit 18 is used for storing raw information of read data or coded information, and for storing received information, decoded information or the like.

The signal presence / absence detection circuit 22 is used to detect an instantaneous interruption during reception of the primary channel information. When the signal presence / absence detection circuit 22 detects a signal of -43 dBm or more, it outputs a signal of the signal level "1" to the signal line 22a, and when it detects a signal of -48 dBm or less, the signal line 22a. The signal of the signal level "0" is output to.

The control circuit 20 uses the ITU-T Recommendation V.50. 8,
V. In the first embodiment of the present invention, a timer capable of receiving one partial page of 256 frames is set for a predetermined time (for example, 40 mS) or more in the first embodiment of the present invention. When no signal is detected, the Sh, Sh _* group, or PPh, A is detected until the timer times out.
The control is performed so as to concentrate on the reception of information on the control channel of the LT group.

2 to 4 are flow charts showing the control flow of the control circuit 20 in the first embodiment.

First, when the operation is started in S0, a signal of a signal level "0" is output to the signal line 20a in S2 to output CM.
Turn off L. In S4, the signal of the signal level "0" is output to the signal line 20d, and the ANSam signal is not transmitted.

In S6, it is determined whether or not the incoming call is selected. When the incoming call is selected, the process proceeds to S10, and when the incoming call is not selected, the process proceeds to S8 and other processes are performed.

In S10, a signal of signal level "1" is output to the signal line 20a to turn on the CML. S12 sends the ANSam signal, S14 receives the CM signal, S
16 sends JM signal, S18 receives CJ signal,
In S20, a line probing signal is received, in S22, a long training signal is received, and in S24, parameter exchange is performed.

At S26, one frame includes 256 bytes of data and FLAG, A, C, FCF, and FrameN.
o. , FCS, FCF, and FLAG, a margin of 5 bytes is further added, the number of bits is calculated considering that this advances 256 frames, and the value divided by the transmission speed to be executed is set in the timer. This value is S when there is a momentary interruption of 40 mS or more during reception of the primary channel.
This is the time devoted to reception of this control channel when receiving signals of h, Sh _* group, or PPh, ALT group.

In S28, 40 mS is set to the instantaneous interruption timer for detecting the instantaneous interruption of 40 mS. In S30, the primary channel information is received. In S32, it is determined whether or not the RCP signal is detected. When the RCP signal is detected, the process proceeds to S40, a timer (control timer) for executing control channel reception is set to 12 seconds, and the process proceeds to S42. If the RCP signal is not detected, the process proceeds to S34.

In S34, the information of the signal line 22a is input, and it is determined whether or not there is a signal. If there is a signal, the process proceeds to S28, and if there is no signal, the process proceeds to S36.

In S36, it is determined whether or not the momentary interruption timer has timed out. When the momentary interruption timer has timed out, the process proceeds to S38, and if there is an instantaneous interruption at the start of reception of the primary channel, Sh, Sh _* , or P of the control channel.
A timer dedicated to the reception of Ph and ALT is started, but if the value of this timer (the value of this timer is shorter than the time set in S26) is set in the control timer and the time has not expired. Proceed to S30.

In S42, the V. 34 control channels are received, and in S44 and S46, Sh, Sh _* ,
Alternatively, it is determined whether or not PPh and ALT are detected, and S
When h and Sh _* are detected, the process proceeds to S50, and PPh and ALT
When is detected, the process proceeds to S52. If neither signal is detected, the process proceeds to S48.

In S48, it is determined whether or not the control timer has timed out. If the time is over, the process proceeds to S2, and if not, the process proceeds to S42.

Further, in S50, Sh, Sh _* , AL
T, E are received, Sh, Sh _* , ALT, E are transmitted, and the process proceeds to S54.

Further, in S52, PPh, ALT, MP
h and E are received, PPh, ALT, MPh, and E are transmitted, and the process proceeds to S54.

In S54, the V. 34 control channel data is transmitted and received. In S56, it is determined whether or not there is a next page. If there is a next page, the process proceeds to S30, and if there is no next page, the process proceeds to S2.

Next, a second embodiment of the present invention will be described.

In the second embodiment, the transmission speed is the predetermined speed (for example, 12 kb / s) in the first embodiment described above.
In the following cases, control is performed so that the time devoted to receiving information on the control channel due to a momentary interruption of 40 mS or more after the transition to reception on the above-mentioned primary channel is the same as the case of the predetermined transmission rate.

FIG. 5 is a flow chart showing a part of the operation of the second embodiment which is different from the operation of the first embodiment (FIGS. 2 to 4) described above.

First, S60 represents S24 described above. Then, in S62, the transmission rate determined by receiving the long training signal and exchanging parameters is 12.0k.
It is determined whether or not it is b / s or more, and if it is 12.0 kb / s or more, the process proceeds to S66 (S26) and 12.0 kb / s.
If it is less than, the process proceeds to S64. In S64, 12.0 kb / s is set as the transmission rate, and based on this value,
The calculation of S26 described above is executed.

Next, a third embodiment of the present invention will be described.

As described above, according to the conventional ITU-T Recommendation V.26.
21, V.I. 27 ter, V.I. 29, V.I. Since it is half-duplex communication in all of 17, it was not necessary to disable the echo suppressor. 8, V.I. In the 34 communication, since the procedure is full-duplex communication and the image transmission is half-duplex communication, full-duplex communication needs to be performed. Therefore, the ANSam signal (a signal obtained by modulating 2100 Hz at 15 Hz at the called terminal) is used. ) Was sent, the echo suppressor was disabled, and full-duplex communication was being performed.

However, when the international communication is performed and the image signal is transmitted through the primary channel, since the half-duplex communication causes a momentary interruption of 100 mS or more, the echo suppressor is enabled and the procedure after the primary channel is performed. Will result in an error.

Therefore, in the third embodiment of the present invention, V. 8,
V. In international communication of 34, even if a momentary interruption of 100 mS or more occurs while receiving the primary channel information, the echo suppressor can be immediately disabled, and the full-duplex procedure after that can be performed. The present invention provides a facsimile device that can reliably transmit.

FIG. 6 is a block diagram showing the structure of the facsimile apparatus according to the third embodiment.

An NCU (network control unit) 102 connects the telephone network to a terminal of the line, uses the telephone network for data communication, controls connection of the telephone switching network, and switches to a data communication path. Or, it holds the loop. Further, the NCU 102 connects the telephone line 102a to the telephone 104 side when the signal level (signal line 120a) from the control circuit 120 is "0", and connects the telephone line 102a when the signal level is "1". It is connected to the facsimile machine side. In the normal state, the telephone line 102a is connected to the telephone 104 side.

The hybrid circuit 106 separates the transmission system signal and the reception system signal, and sends the transmission signal from the addition circuit 12 to the telephone line 102a via the NCU 102.
It receives a signal from the other party via the NCU 102 and sends it to the modulator / demodulator 108 via the signal line 106a.

The modulator / demodulator 108 complies with ITU-T Recommendation V.70.
8, V.I. 21, V.I. 27 ter, V.I. 29, V.I. 17,
V. Modulation and demodulation based on 34 are performed, and each transmission mode is designated by the signal line 120c. The modulator / demodulator 108 inputs the signal output to the signal line 120b, outputs the modulated data to the signal line 108a, inputs the received signal output to the signal line 106a, and inputs the demodulated data to the signal line 108b. Output.

The ANSam transmission circuit 110 uses the ANSam
It is a circuit for transmitting a signal, and when the signal of the signal level "1" is output to the signal line 120d, the signal line 110
When the ANSam signal is transmitted to a and the signal of the signal level "0" is output to the signal line 120d, the signal line 11
No signal is output to 0a.

The adder circuit 112 inputs the information of the signal line 108a, the information of the signal line 110a, and the information of the signal line 124a, and outputs the addition result to the signal line 112a. The reading circuit 114 reads an image of a document and outputs the read image data to the signal line 114a. The recording circuit 116 sequentially records the information output to the signal line 120e line by line.

The memory circuit 118 is used to store raw information of read data or coded information, or to store received information, decoded information, or the like.

The signal presence / absence detection circuit 122 includes the signal line 106.
When the information of "a" is input and a signal of -43 dBm or more is detected, a signal of a signal level "1" is output to the signal line 122a, and when a signal of -48 dBm or less is detected, the signal line 122a is detected. A signal of signal level "0" is output.

The tonal signal transmitting circuit 124 is 2100.
It is a circuit that sends out a tonal signal of Hz, and the signal line 12
If a signal of signal level "1" is output to 0f,
When the 2100 Hz tonal signal is transmitted to the signal line 124a and the signal of the signal level "0" is output to the signal line 120f, the 2100 Hz tonal signal is not transmitted to the signal line 124a.

The control circuit 120, especially in this embodiment, has a V.V. 8, V.I. 34 Control to send a 2100 Hz tonal signal for a predetermined time (for example, 1 second) when a signal-less state for a predetermined time or longer (for example, 100 mS or more) is continuously detected in the receiver state during execution of communication Is.

7 to 9 are flow charts showing the control flow of the control circuit 120 in the third embodiment. Note that FIG. 9 shows an interrupt process every 5 mS.

First, the operation is started in S100 and then S102.
Then, the signal of the signal level "0" is output to the signal line 120a to turn off the CML.

In S104, the signal of the signal level "0" is output to the signal line 120d and the ANSam signal is not transmitted. In S106, the signal of the signal level "0" is output to the signal line 120f, and the 2100 Hz tonal signal is output. The signal is not sent.

In S108, the instantaneous interruption control flag is set to 0, and in the interrupt processing every 5 ms, the instantaneous interruption detection is not controlled.

In S110, it is determined whether or not the reception is selected. If the reception is selected, the process proceeds to S114, and if the reception is not selected, the process proceeds to S112 and other processes are performed.

In S114, a signal of signal level "1" is output to the signal line 20a to turn on the CML, and in S116, a wait of 2 seconds is performed. Then, in S118,
The ANSam signal is transmitted.

Next, in S120, the timer 1 is set to 20. That is, since this timer 1 processes with an interrupt every 5 mS, it corresponds to 100 mS.

Next, in S122, the counter 2100CT used for 2100 Hz transmission is set to 0. Further, in S124, the instantaneous interruption control flag is set to 1 and the instantaneous interruption detection is controlled in the interrupt processing every 5 ms.

In S126, the CM signal is received, in S128, the JM signal is transmitted, and in S130, the CJ signal is received.

Further, in S132, the line probing signal is received, in S134, the long training signal is received, and in S136, the parameters are exchanged. Also, S
At 138, primary channel information is received.

In S140, it is determined whether or not the reception of the primary channel information is completed. The intermediate procedure of 34 is executed and the process proceeds to S44. If not finished, the process proceeds to S138.

In S144, it is determined whether or not there is a next page. If there is a next page, the process proceeds to S138, and if there is no next page, the process proceeds to S146, where V. 34 post-procedure to execute S
Proceed to 102.

Further, in FIG. 9, when an interrupt is applied every 5 mS (S150), it is determined in S152 whether the instantaneous interruption control flag is 0, and if it is 0, S154.
And proceeds to other processing and returns to the main routine (S
56).

If it is 1, the process proceeds to S158, it is determined whether the counter 2100CT exceeds 0, and if it exceeds 0, 2100 Hz is being transmitted.
If it is 0 or less, the process proceeds to S160.

In S160, the information of the signal line 122a is input, it is determined whether or not there is a signal, and if there is a signal, S16.
Go to 2 and set 20 to timer 1 which counts 100 mS without signal (20 × 5 mS = 100 mS),
If there is no signal, the process proceeds to S164, and the value of timer 1 is decremented by one.

In S166, it is determined whether or not the timer 1 is less than 0, that is, it is determined whether or not there is no signal for 100 mS continuously, and if it is 0 or more, the process proceeds to S154 and is less than 0. That is, if there is no signal continuously for 100 mS, the process proceeds to S168, the signal of the signal level "1" is output to the signal line 120f, and the 2100 Hz tonal signal is transmitted. Here, after the transmission of 2100 Hz is completed (S176), the process returns to the process that has been executed so far. This 2100 Hz transmission again disables the echo suppressor.

Next, in S170, the counter 2100C
T is set to 200, and 2100 Hz is set to be transmitted for 1 second (200 × 5 mS = 1S), and the process proceeds to S154.

Further, in S172, the counter 2100C
Decrement the value of T by one. Then, in S174, it is determined whether or not the value of the counter 2100CT is 0. If it is not 0, the process proceeds to S154, and if it is 0, the process proceeds to S176, where the signal of the signal level “0” is output to the signal line 120f, Stop sending 2100 Hz tonal signals. After this, the immediately preceding operation is continuously executed.

Next, a fourth embodiment of the present invention will be described.

In the fourth embodiment, the control of the third embodiment described above is executed only when the line delay time is determined by the pre-procedure in the above-described third embodiment and it is determined that the communication is international communication. However, if it is determined that the communication is not international communication, control is performed so that transmission of the 2100 Hz tonal signal due to detection of no signal is not executed. In addition, C after transmitting the JM signal
Whether or not it is an international communication is determined by the time until the J signal is received.

FIG. 10 is a flowchart showing a part of the operation of the fourth embodiment which is different from the operation of the third embodiment (FIGS. 7 to 9) described above.

In FIG. 10, S180 represents S122. Then, in step S182, the CM signal is received, and in step S184, the JM signal is transmitted.

In S186, it is determined whether or not the transmission of one JM signal is completed. If it is not completed, the process proceeds to S184, and if it is completed, the process proceeds to S188.

At S188, the timer A is started. In S190, the JM signal is transmitted. In S192, it is determined whether or not the CJ signal is received. If the CJ signal is received, the process proceeds to S194, and if the CJ signal is not received, the process proceeds to S190.

In S194, it is determined whether or not the timer A is 600 mS or more. If it is 600 mS or more, it is determined to be international communication, the process proceeds to S196, 1 is set in the momentary interruption control flag, and the process goes to S198 (S132). move on. In addition, 600m
If it is less than S, the process directly proceeds to S198 (S132).

Next, a fifth embodiment of the present invention will be described.

In the fifth embodiment, in the above-mentioned third and fourth embodiments, when the no signal state for a predetermined time or longer is detected, if the own device is in the signal transmission state, the 2100 Hz tonal signal is not transmitted. That's what I did.

In order to realize this, as shown in FIG. 11, the interrupt processing for every 5 mS in FIG. 9 may be changed.

In FIG. 11, S200 represents Y in S166.
It represents ES. Then, in S202, the device determines whether or not it is transmitting a signal. If the device is transmitting a signal, the process proceeds to S204 (S162). If the device is not transmitting a signal, S206 (S168). ).

Next, a sixth embodiment of the present invention will be described.

As described above, according to the conventional ITU-T Recommendation V.26. 27 ter, V.I. In the communication by 29, the training signal immediately before the TCF signal and the training signal immediately before the image information are the same, and it is determined by the TCF signal that follows the training signal whether communication at a predetermined speed is possible. Since the determination was made, if a momentary interruption or the like occurs in the training signal immediately before the TCF signal, the TCF signal is not correctly demodulated, and it is possible for the host device to recognize this and reliably reduce the communication speed. .

However, the ITU-T recommendation V. 8, V.I. 34
In the communication means, by the line probing signal,
Check the usable bandwidth of the line, S / N, etc., and
The long training signal was used to adjust the equalizer etc. for receiving the primary channel.

Here, immediately before the primary channel,
I was only doing resync (short training). Further, once the transmission of the primary channel is started, the long training signal is not transmitted unless the call is disconnected. Further, after the long training, there is no means for the demodulated data on the host device side to judge the success or failure of the training, and the modem automatically determines.

Then, if there is a momentary interruption or the like during reception of the training signal, the modem will function to match the line characteristics in which the momentary interruption has occurred, and this information will be stored for the next parameter exchange. It will shift to the sequence of.

Then, the resync transmitted immediately before the primary channel information after the parameter exchange makes a fine adjustment of the equalizer or the like based on the information received by the previous training signal, but this fine adjustment always fails. Ends with 1
The transmission of the page primary channel information and the transmission of the PPR signal in which all the frames are in error are repeated to fall back the transmission rate. When the transmission speed can be further reduced, the EOR-Q signal and the ERR signal are transmitted and received, and the line is disconnected.

In the ECM communication, the communication can be continued even when all the frames are in error. Therefore, when the information of one partial page is close to 256 frames, if the above operation is repeated, the fallback control can be performed. According to
Since it takes several tens of minutes and communication becomes impossible after this, enormous waste occurs.

Therefore, the sixth embodiment of the present invention is the ITU-T
Recommendation V. 8, V.I. In 34 communication, if an instantaneous interruption occurs during transmission of a long training signal, the host apparatus detects this and repeats transmission of the long training signal in the setting of the host apparatus to send it immediately before the next primary channel. The present invention provides a facsimile device which enables reception of primary channel information by the resync.

Although the structure of the facsimile apparatus according to the sixth embodiment is common to that shown in FIG. 1, the control circuit 20 of this embodiment performs the following control. .

That is, in the control circuit 20, S, S _* ,
When the PP / TRN signal is received and no signal is detected for a predetermined time or longer, tone A (first tone signal) is transmitted,
After detecting tone B (second tone signal), INFO
After sending h, the process moves to the reception of S, S _* , PP, and TRN signals again, and if there is no interruption for a predetermined time or more, then PP
The control for shifting to the reception of the h signal is performed. Also, S, S _* ,
Transmission of PP and TRN is performed only in the pre-procedure, and immediately before the primary channel, S, S _* ,
Transmission of PP and B1 is executed. In addition, S, S _* , PP,
By receiving the TRN signal, training for the line characteristic is executed, and resync is executed by S, S _* , PP, and B1.

12 to 14 are flow charts showing the control flow of the control circuit 20 in the sixth embodiment.

First, the operation is started in S300 and then S302.
Then, the signal of the signal level "0" is output to the signal line 20a to turn off the CML. In S304, the signal of the signal level "0" is output to the signal line 20d, and the ANSam signal is not transmitted.

In S306, it is determined whether or not reception is selected. If it is selected, the process proceeds to S310, and if it is not selected, the process proceeds to S308 to perform other processing, and then S302.
Proceed to.

In S310, a signal of signal level "1" is output to the signal line 20a to turn on the CML, and in S312, the timer 1 is set to 60 seconds. This V. 8 procedures, V. In the pre-procedure 34, when the timer 1 times out, the line is disconnected.

In step S314, the ANSam signal is transmitted, and in step S3
In step 16, the CM signal is received, in step S318, the JM signal is transmitted, and in step S320, the CJ signal is received.

Then, the V. At the timing when the procedure of 8 is completed, the timer 1 is reset to 35 seconds in S322. Next, in step S324, line probing is received, and in step S326, INFOh is transmitted.

At S328, 100 mS is set to the off timer which is a timer for detecting no signal on the line.
That is, the time from the B signal at the rear end of the line probing signal to the S signal at the front end of the training signal is 70 ms.
Since it is ± 5 mS, the initial value is 100 mS.

In S330, the S, S _* , PP, and TRN signals are received and the training corresponding to the line characteristic is executed. In S332, the information of the signal line 22a is input and it is determined whether or not there is a signal. If there is a signal, the process proceeds to S42, and if there is no signal, the process proceeds to S334. In S334, it is determined whether or not the off-timer has timed out, and when the time-out has occurred, it is determined that a momentary interruption of 20 mS or more has occurred. Send the tone A signal from
If the time has not expired, the process proceeds to S330.

In S338, it is determined whether or not the tone B signal is detected. When the tone B signal is detected, the process proceeds to S326, INFOh is repeatedly transmitted again, the training signal is received again, and the tone B signal is detected. If not, the process proceeds to S340. In S340, it is determined whether or not the timer 1 has timed out.
If the time has not expired, the process proceeds to step S336.

In S342, the off timer is set to 20 mS. In S344, it is determined whether or not the reception of the TRN signal is completed. If the reception is completed, the process proceeds to S348, and if the reception is not completed, the process proceeds to S46.

In S346, it is determined whether or not the timer 1 has timed out. If the timer has timed out, the process proceeds to S302. If not, the process proceeds to S330.

In S348, the PPh signal is received, and then the parameter exchange is executed. Then, in S350, by receiving S, S _* , PP, and B1, resync is performed and primary channel information is received.

In S352, the V. Then, in S354, it is determined whether or not there is an error in the received information of the primary channel. If there is an error, the process proceeds to S356, and V.34. In the control channel of 34, the PPR signal is transmitted, and the process proceeds to S350.

If there is no error, the process proceeds to S358,
V. Out of 34 control channel transmissions, MCF
Send a signal. Then, in S360, it is determined whether or not there is a next partial page, and if there is a next partial page, the process proceeds to S350, and if there is no next partial page, S36.
Proceed to V.2. In the transmission of 34 control channels, a DCN signal is transmitted. Then, the process proceeds to S302.

[0134]

According to the inventions of claims 1 to 5,
Even if a momentary interruption of 40 mS or more occurs during reception of the primary channel information according to the ITU-T recommendation, S
It is possible to reliably respond to the control channel signal of the h, Sh * group, or the PPh or ALT group to continue the communication, and to provide a convenient device with few communication errors.

According to the invention described in claim 4, for example, 3
Vs from 3.6 kb / s to 12 kb / s. 8, V.I. Three
In 4 communication, communication can be continued even when a momentary interruption occurs,
V. of 9.6 kb / s or less. 8, V.I. In 34 communication, if one partial page is long after the occurrence of a momentary interruption, a communication error is tolerated, and the invalidity of the line from the receiver side is not captured, so that a convenient device can be provided.

According to the inventions of claims 6 to 9, the ITU
-If a short interruption occurs during the long training signal transmission according to the T recommendation, this is detected by the host device side, and the long training signal is repeatedly transmitted by the setting of the host device side, so that it is sent immediately before the next primary channel. The resync performed enables reception of the primary channel information.

[0137]

[0138]

[0139]

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a facsimile apparatus according to first, second and sixth embodiments of the present invention.

FIG. 2 is a flowchart showing a control operation of a control circuit in the first embodiment.

FIG. 3 is a flowchart showing a control operation of a control circuit in the first embodiment.

FIG. 4 is a flowchart showing a control operation of the control circuit in the first embodiment.

FIG. 5 is a flowchart showing a control operation of a control circuit in the second embodiment.

FIG. 6 is a block diagram showing a configuration of a facsimile apparatus according to third, fourth and fifth embodiments of the present invention.

FIG. 7 is a flowchart showing a control operation of a control circuit in the third embodiment.

FIG. 8 is a flowchart showing a control operation of a control circuit in the third embodiment.

FIG. 9 is a flowchart showing the control operation of the control circuit in the third embodiment.

FIG. 10 is a flowchart showing the control operation of the control circuit in the fourth embodiment.

FIG. 11 is a flowchart showing the control operation of the control circuit in the fifth embodiment.

FIG. 12 is a flowchart showing the control operation of the control circuit in the sixth embodiment.

FIG. 13 is a flowchart showing the control operation of the control circuit in the sixth embodiment.

FIG. 14 is a flowchart showing the control operation of the control circuit in the sixth embodiment.

[Explanation of symbols]

2, 102 ... NCU, 4, 104 ... telephone, 6, 106 ... Hybrid circuit, 8, 108 ... Modem, 10, 110 ... ANSam sending circuit, 12, 112 ... Adder circuit, 14, 114 ... Reading circuit, 16, 116 ... Recording circuit, 18, 118 ... Memory circuit, 20, 120 ... Control circuit, 122 ... Signal presence / absence detection circuit, 124 ... Tonal signal sending circuit.

Claims (10)

(57) [Claims] 1. A means for detecting the presence or absence of a received signal; a means for setting a timer for a first predetermined time at the time of reception transition to a primary channel based on the ITU-T recommendation; no signal for a second predetermined time or longer Communication for continuing the reception of the specific information of the control channel based on the ITU-T recommendation until the timer times out when the detection unit detects that there is no signal for a second predetermined time or more. And control means; and the specific information of the control channel is S
h, Sh _* group or PPh, ALT group
A communication device characterized by being information of . 2. The communication device according to claim 1 , wherein the timer for the first predetermined time is a timer capable of receiving one partial page of 256 frames. 3. An apparatus according to claim 1 or 2, wherein the second predetermined time, the communication apparatus characterized by a 40 mS. 4. A any one of claims 1 to 3 transmission rate, if less than a predetermined transmission rate setting means sets the first predetermined time the same as in the case of the predetermined transmission rate Communication device. 5. A timer for a first predetermined time is set at the time of shifting to reception on a primary channel based on the ITU-T recommendation, and when the absence of a signal for a second predetermined time or more is detected, the timer expires. Until I
So as to continue the reception of the specific information in the control channel based on the TU-T Recommendation, the control channel
Specific information of Sh, Sh _* group, or PP
h, a communication method characterized by being information of an ALT group . 6. A means for detecting the presence or absence of a received signal; a means for transmitting a first tone signal; a signal for a predetermined time or more when receiving S, S _* , PP, TRN signals based on ITU-T recommendation When the absence state is detected, the first tone signal is transmitted. After that, when the second tone signal is detected, INFOh is transmitted and S, S _* , PP, TRN are transmitted again. If there is no signal for a predetermined time or longer, move to signal reception, then P
A communication control means for shifting to reception of a Ph signal; 7. The transmission of the S, S _* , PP, and TRN signals is performed in a pre-procedure according to claim 6 , and the S, S _* , PP, and B1 signals are transmitted for each page immediately before the primary channel. A communication device characterized by performing transmission. 8. The method of claim 6, wherein the S, S _*, PP, by the reception of the TRN signal, and executes a training corresponding to the line characteristics, S, S _*, PP,
A communication device characterized by executing resync by a B1 signal. 9. S, S _* , P based on ITU-T recommendation
At the time of receiving the P and TRN signals, when the absence of a signal for a predetermined time or more is detected, the first tone signal is transmitted,
After that, if the second tone signal is detected, the INF
It is characterized in that after transmitting Oh, it shifts to reception of S, S _* , PP and TRN signals again, and if there is no signal for a predetermined time or longer, it shifts to reception of PPh signal subsequently. And communication method. 10. The ITU-T Recommendation V.5 according to any one of claims 6 to 8 . 8, V.I. 34. A communication device, which is a facsimile device having a communication function.