JP2000050034A - Facsimile equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide facsimile equipment capable of effectively preventing the collision of signals in various communication environments. SOLUTION: When a post message command is received, a communication control part 4 starts a monitoring timer. Then, the printing processing is completed at a print part 8 and the output of the next page print preparation complete signal are waited. When the next page print preparation complete signal is outputted, the communication control part 4 confirms whether the monitoring timer takes time out or not. When it does not take time out, a multiple-page(MPS) signal is applied to a modem part 6 and its modulation wave is outputted to the side of a line. Afterwards, the processing is returned to a phase B. When the monitoring timer takes time out, the processing is returned to the phase B without outputting any response signal. When the processing is returned to the phase B without sending a message confirming(MCF) signal, in the receiving processing of the phase B, a retransmitted MPS signal is received.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to the ITU-T Recommendation T. The present invention relates to a facsimile apparatus conforming to No. 30

[0002]

2. Description of the Related Art ITU-T Recommendation T. When a facsimile apparatus conforming to No. 30 transmits a command signal in a facsimile procedure at the time of transmission, it monitors a response signal by a T4 timer. When the T4 timer times out without receiving a response signal, the command signal is retransmitted. Since the T4 timer is specified as 3.0 seconds ± 15%, generally 3.0 seconds is used. That is, if 3.0 seconds have elapsed without receiving a response signal, the command signal is retransmitted.

A transmission path of a facsimile signal generally has a propagation delay. In particular, when overseas communication is performed using satellite communication or the like, the propagation delay becomes a large value. Then, despite the fact that the facsimile apparatus on the receiving side has transmitted a response signal to the transmitting side, due to the propagation delay, T4
The transmitting side may not be able to receive the response signal within the timer set time. In that case, the command signal is retransmitted from the transmitting side, and the retransmitted signal may collide with a delayed response signal from the receiving side. As a result, the facsimile communication procedure cannot be continued, and the communication may be interrupted.

FIG. 8 is a sequence diagram showing an example of phases C and D of a facsimile communication procedure recommended by T30.
In the example shown in FIG. 8, when the partner terminal (transmitting side) transmits a plurality of page signals (MPS signals) and the printing process of the own terminal (receiving side) ends, a message confirmation signal (MCF signal) corresponding to the MPS signal Is transmitted.

[0005] In this case, if the printing process takes time and the propagation delay of the transmission path is large, the arrival of the MCF signal at the destination terminal is delayed, and the timeout time of the T4 timer and M
The arrival times of the CF signals may overlap. If the timeout time of the T4 timer and the arrival time of the MCF signal overlap, the retransmitted MPS signal and the MCF signal will collide. Then, the T4 timeout occurs again on the transmitting side, and the MPS signal is retransmitted again.
Generally, the command signal is retransmitted twice, but in such a case, it takes time until the correct MPS signal is transmitted to the receiving side. Further, although the MPS signal can be transmitted three times in total, the MPS signal which can be substantially detected on the receiving side is obtained.
Since the S signal is only for the third time, the reliability of signal transmission and reception is reduced.

As a method for avoiding such a problem, for example, there is a method disclosed in Japanese Patent No. 2599543. In the image information communication device that cannot immediately send a response signal in response to a command signal from the transmission side,
Time measurement is started when a command signal is received, and when a response signal becomes available for transmission, a response signal is sent if the elapsed time does not conflict with the retransmission of the command signal from the transmitting side. For example, it is a method of waiting for a response signal to be sent.

[0007]

However, Patent No. 259
The device disclosed in Japanese Patent No. 9543 is not a facsimile terminal device but an image information communication device including an information processing device and a plurality of FAX boards. In such an apparatus, a plurality of communications can be performed simultaneously using a plurality of FAX boards, and the information processing apparatus stores received data in a file. Then, the problem described in Japanese Patent No. 2599543 is a problem peculiar to a device that manages received data in a file, and is unsuitable to be directly applied to a general facsimile device.

In the apparatus disclosed in Japanese Patent No. 2599543, a table is stored in the apparatus in advance, and the table includes, for example, each time of every 100 ms and a flag indicating whether a response signal can be transmitted. Is set. Then, the elapsed time from the reception of the command signal is compared with each time in the table, and it is determined whether or not a response signal can be transmitted according to the value of the flag corresponding to the matched time.
However, there are various communication environments in which facsimile communication is performed. The propagation delay time of the transmission path also varies, and there is a problem that various communication environments cannot be accommodated if it is determined whether or not a response signal can be transmitted based on the contents of a uniquely set table. In other words, there is a problem that even if a specific communication environment can be handled, signal collision still occurs in other various communication environments.

Accordingly, an object of the present invention is to provide a facsimile apparatus that can effectively prevent signal collision under various communication environments.

[0010]

A facsimile apparatus according to the present invention has a rewritable timer value storage means in which a timeout value of a monitoring timer is set, a monitoring timer activated upon receipt of an instruction signal, and a next processing in its own terminal. The communication control means checks whether or not the monitoring timer has timed out when it is ready, sends a response signal if it has not timed out, and does not send a response signal if it has timed out.

The facsimile apparatus may include timer value changing means for rewriting the timeout value of the monitoring timer in the timer value storage means according to a communication environment. Also,
The timer value changing means may be configured to perform control for changing the timeout value of the monitoring timer according to the cumulative value of the number of retransmissions of the command signal.

The facsimile apparatus is provided with a specific party storage means for storing a specific communication party, and the communication control means is configured not to send a response command when receiving a first command signal during communication with the specific communication party. It may be.

The specific communication partner in the specific partner storage means is
It may be configured to be set via the user interface means, or may be configured to be set according to the communication result.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of a facsimile apparatus according to the present invention. FIG.
, The control unit 1 takes in information input by the user via the user interface control unit 2 and controls the entire facsimile apparatus. Further, the control unit 1 gives the communication control unit 4 a transmission / reception instruction of a facsimile communication procedure. The communication control unit 4 exchanges a facsimile communication procedure with the partner terminal via the modem unit 6 and the line control unit 5 according to the instruction. The line control unit 5 accommodates a communication line.
Further, the modem unit 6 also performs modulation / demodulation processing of image data.

The image processing unit 7 encodes an image signal read by the scanner unit 9 in accordance with an instruction from the control unit 1 and decodes the encoded data from the modem unit 6 into an image signal. Output to The print unit 8 performs print output based on the input image signal. Also,
As shown in FIG. 2, the storage unit 3 includes a counterpart terminal storage area 31 for storing information indicating each specific counterpart terminal and a monitoring timer value setting area 3 in which a timeout value of a monitoring timer is set.
There are two.

Next, the operation will be described with reference to the flowchart of FIG. When the facsimile machine is installed, a user or a maintenance person sets predetermined values in the counterpart terminal storage area 31 and the monitoring timer value setting area 32. For example,
The telephone number (including the country code) of the overseas partner terminal having a high communication frequency is set as the specific partner in the partner terminal storage area 31. Further, 2.5 seconds are set in the monitoring timer value setting area 32. The monitoring timer determines whether a response signal can be transmitted. Propagation delay (one hop 250m of satellite link)
s: 500 ms round-trip), if the response signal is transmitted for more than 2.5 seconds, the retransmission command signal and the response signal may collide with each other. However, any value can be set in the monitoring timer value setting area 32 according to the communication environment of the device. Remote terminal storage area 31 and monitoring timer value setting area 32
When communication starts, the information in the communication control unit 4
Will be notified.

After the start of communication, when the reception of one page of image information from the partner terminal (transmission side) is completed, the facsimile communication procedure enters phase D. FIG. 3 shows a process of the communication control unit 4 in the phase D after receiving the MPS signal which is one of the post message commands. The communication control unit 4 first confirms whether the reception of the post message command has been performed for the first time (step S1). If it is the first time,
It is confirmed whether or not the partner terminal is one of the specific partners set in the partner terminal storage area 31 (step S).
2). The partner terminal is recognized, for example, by the telephone number included in the TSI signal (calling terminal identification signal) received in phase B of the facsimile communication procedure.

If the partner terminal is a specific partner, the process returns to phase B without sending a response signal. Since the other terminal monitors the reception of the response signal by the T4 timer, if the response signal is not received, the terminal retransmits the MPS signal due to the timeout of the T4 timer.

If the partner terminal is not a specific partner, a monitoring timer is started (step S3). Then, it waits until the printing process of the printing unit 8 is completed and the next page printing preparation completion signal is output (step S4). The next page print preparation completion signal is notified to the communication control unit 4 via the control unit 1. When the next page printing preparation completion signal is output, the communication control unit 4 checks whether the monitoring timer has timed out (step S5). If the timeout has not occurred, the MPS signal is supplied to the modem unit 6 to output the modulated wave to the line side (step S6). Then, the process returns to the phase B. If the monitoring timer has timed out, the process returns to phase B without sending a response signal. MCF
When returning to phase B without transmitting a signal, a retransmitted MPS signal is received in the phase B receiving process.

With the above control, as shown in FIG. 4, if the monitor timer times out before the print section 8 outputs the next page print preparation completion signal, the next page print preparation completion signal is output. Even if output, MCF
No signal is sent. As described above, the timeout value of the monitoring timer is 2.5 seconds, and 2.
Within 5 seconds, the possibility that the MCF signal will collide with the retransmitted MPS signal is low. Then, since the transmitting side retransmits the MPS signal due to T4 timeout, the facsimile apparatus on the receiving side receives the MPS signal again. Then, since the second and subsequent receptions are performed according to the determination in step S1,
Waiting for the next page printing preparation completion signal (step S8),
Send MCF signal. As shown in FIG. 4, generally,
Since the next page print preparation completion signal has been output before this timing, the MCF signal is transmitted immediately upon receiving the second MPS signal.

FIG. 5 shows an example of a case in which it is recognized as a specific partner in the judgment in step S2. In that case, the MCF signal is transmitted in response to the second MPS signal without responding to the first MPS signal. Therefore, when the partner terminal is the specific partner, the second MPS signal does not collide with the MCF signal.

Although the timeout value of the monitoring timer is 2.5 seconds in this example, this value can be changed. For example, the control unit 1 accumulatively adds the number of retransmissions of the post message command in all communications, and when the frequency of retransmission is high, prompts the user to change the monitoring timer value via the user interface control unit 2. The user or the maintenance staff can reset a new, for example, a shorter time in the monitoring timer value setting area 32 of the storage unit 3 according to the notification. The control unit 1 may automatically change the contents of the monitoring timer value setting area 32 when the frequency of retransmission is high.

FIG. 6 shows a communication control unit 4 according to the second embodiment.
6 is a flowchart showing the operation of the first embodiment. In this embodiment, the specific partner stored in the partner terminal storage area 31 is set according to the communication result. The communication control unit 4 first confirms whether the reception of the post message command has been performed for the first time (step S11). If it is the first time, it is confirmed whether the partner terminal is one of the specific partners set in the partner terminal storage area 31 (step S1).
2).

If the partner terminal is a specific partner, the process returns to phase B without sending a response signal. If the partner terminal is not a specific partner, a monitoring timer is started (step S1).
3). Then, it waits until the printing process of the printing unit 8 is completed and the next page printing preparation completion signal is output (step S14). When the next page print ready signal is output,
The communication control unit 4 checks whether the monitoring timer has timed out (step S15). If the timeout has not occurred, the MPS signal is supplied to the modem unit 6 to output the modulated wave to the line side (step S16). afterwards,
Return to phase B. If the monitoring timer has timed out, the process returns to phase B without sending a response signal.

If it is determined in step S1 that the reception is the second or subsequent reception, the communication control unit 4 increments the value of the counter set corresponding to the communication partner by one (step S1).
7). Then, it waits for a next page printing preparation completion signal (step S18). If the next page print preparation completion signal has been output, it is checked here whether the counter value has exceeded a predetermined threshold value n (step S19). If it exceeds
The control unit 1 is requested to store this communication partner in the partner terminal storage area 31 as a specific partner (step S2).
0). Thereafter, an MCF signal is transmitted.

When a counter area corresponding to each partner terminal is formed in the storage unit 3, the communication control unit 4 updates the counter value via the control unit 1. Further, the counter value is not cleared even when the communication ends, but is cleared, for example, when retransmission is not executed.

As described above, according to this embodiment,
Even if the MCF transmission timing is adjusted by the monitoring timer, in the case where the retransmission of the post message command is continuously performed in any communication, the partner terminal is determined as the specific partner. This is because when the retransmission of the post message command is performed continuously, there is a high possibility that the retransmission of the MPS signal and the MCF signal collide.

FIG. 7 is a flowchart showing the operation of the communication control unit 7 in the third embodiment. In this example, the monitoring timer is not used for the normal communication partner,
Use the monitoring timer only for a specific partner. The communication control unit 4 first confirms whether the reception of the post message command is the first time (step S21). If it is the first time, it is checked whether the partner terminal is one of the specific partners set in the partner terminal storage area 31 (step S22).

If the partner terminal is a specific partner, a monitoring timer is started (step S23). Then, it waits until the printing process of the printing unit 8 is completed and the next page printing preparation completion signal is output (step S24). When the next page print preparation completion signal is output, the communication control unit 4 confirms that the monitoring timer has not timed out or that the monitoring timer has not been set (step S2).
5). If the timeout has not occurred or the monitoring timer has not been set, the MPS signal is given to the modem unit 6 to output the modulated wave to the line side (step S
26). Then, the process returns to the phase B. If the monitoring timer has timed out, the process returns to phase B without sending a response signal.

If it is the second or later reception in the determination in step S1, the communication control unit 4 increments the value of the counter set corresponding to the communication partner by one (step S2).
7). Then, it waits for the next page printing preparation completion signal (step S28). If the next page print preparation completion signal has been output, it is checked here whether the counter value has exceeded a predetermined threshold value n (step S29). If it exceeds
This communication partner is stored in the partner terminal storage area 31 as a specific partner (step S30). Thereafter, an MCF signal is transmitted.

In this embodiment, if the communication partner is not the specific partner, the MCF signal is transmitted immediately when the next page printing preparation completion signal is output from the printer unit 8. When such control is performed, the retransmission MP
If it is determined that there is a high possibility that the collision between the S signal and the MCF signal has occurred, the communication partner is registered as a specific partner. In this embodiment, the MCF signal is
In communication with a partner terminal connected via a transmission path that does not collide with the S signal, the MCF signal is sent immediately when the next page print ready signal is output, so that the communication time does not increase. is there.

[0032]

As described above, according to the present invention, the facsimile apparatus activates the monitoring timer when receiving the command signal,
The monitoring timer times out according to the timeout value set in the rewritable storage means, and is configured not to send a response signal if the monitoring timer has timed out even if the own terminal is ready for the next process. So
In various communication environments, it is possible to effectively prevent the collision between the command signal and the response signal from the transmission side.

In the case where the first command signal is received and the response command is not sent out when communicating with a specific communication partner, it is determined that signal collisions occur particularly frequently in normal communication control. At the time of communication with a specific partner, signal collision can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a facsimile apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing contents stored in a storage unit.

FIG. 3 is a flowchart illustrating an operation of a communication control unit according to the first embodiment.

FIG. 4 is a sequence diagram illustrating an operation when a monitoring timer times out before a next page print preparation completion signal is output.

FIG. 5 is a sequence diagram showing an operation in the case where a specific partner is recognized.

FIG. 6 is a flowchart illustrating an operation of a communication control unit according to the second embodiment.

FIG. 7 is a flowchart illustrating an operation of a communication control unit according to the third embodiment.

FIG. 8 is a sequence diagram showing operations in conventional phases C and D.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control part 2 User interface part 3 Storage part 4 Communication control part 5 Line control part 6 Modem part 7 Image processing part 8 Printing part 9 Scanner part

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiko Iida 1-403 Kosugi-cho, Nakahara-ku, Kawasaki-shi, Kanagawa F-term in NEC Telecom System Corporation (reference) 5C075 BB05 CA01 CD02 CD07 CD09 CF01

Claims (7)

[Claims] 1. A facsimile apparatus which, when receiving a command signal from a transmitting side, sends a response signal to the transmitting side when the terminal itself is ready for the next processing, wherein a timeout value of a monitoring timer is set. Rewritable timer value storage means, and a communication control means for activating a monitoring timer upon receiving a command signal and not sending a response signal if the monitoring timer has timed out even if the terminal is ready for the next processing. A facsimile machine comprising: 2. The facsimile apparatus according to claim 1, further comprising timer value changing means for rewriting a timeout value of the monitoring timer in the timer value storage means according to a communication environment. 3. The facsimile apparatus according to claim 2, wherein the timer value changing means performs control for changing a timeout value of the monitoring timer according to an accumulated value of the number of retransmissions of the command signal. 4. A communication device according to claim 1, further comprising: a specific communication device storing means for storing a specific communication device, wherein the communication control device does not send a response command when receiving a first command signal during communication with the specific communication device. 4. The facsimile apparatus according to 2 or 3. 5. A facsimile apparatus which, when receiving a command signal from a transmitting side, sends a response signal to the transmitting side when the terminal is ready for the next processing, and stores a specific communication partner. With the other party storage means, when the command signal is received from the specific communication partner, the monitoring timer is started, and even if the terminal is ready for the next processing,
A facsimile apparatus comprising: a communication control unit that does not transmit a response signal when the monitoring timer has timed out. 6. The facsimile apparatus according to claim 4, wherein the specific communication partner in the specific partner storage means is set via the user interface means. 7. The facsimile apparatus according to claim 4, wherein a specific communication partner in the specific partner storage means is set according to a communication result.