JPH06133131A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To provide the facsimile equipment avoiding a defect of communication caused when picture information is sent in succession to an echo protector tone(EPT) signal. CONSTITUTION:When an EPT signal is outputted in compliance with the recommendations CCITT V.29, a frequency of 1700Hz has been used for the signal in a conventional equipment. Then the frequency signal is mis-detected from a preamble (1650Hz) of a DCS command and a communication fault may take place. In this case, plural EPT frequencies are stored in an EPT frequency storage section 21. An EPT frequency setting section 22 sets the frequency of 1850Hz not mis-detected as 1650Hz, an EPT transmission section 23 outputs the EPT of the frequency. As example of other embodiment, the EPT transmission time is optionally set, or the ERT signal whose frequency or transmission time is revised is sent when a called station is made up of equipments of its own company.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile machine, and more particularly to a facsimile machine which can reduce failure in transmitting / receiving image information.

[0002]

2. Description of the Related Art A conventional G3 communication protocol procedure is performed as shown in FIG. As is apparent from the figure, when the calling station receives a CFR (reception preparation confirmation) signal from the called station, it shifts to sending out a training signal, and subsequently transmits image information to the called station.

When the called station sends out the CFR signal, it prepares for receiving image information such as switching the operating speed of the modem. For example, V2 recommended by CCITT T30
1 (300BPS) modem to V29 (9600B
PS, 7200BPS) or V27ter (420
The operation of switching to the 0 BPS, 2400 BPS) modem is performed.

At this time, depending on the model of the facsimile machine at the called station, it takes time to prepare for receiving the image information, and the beginning or all of the training signal cannot be received, so that the training signal reception may fail.

Also, an echo processor function is provided in a switch that is interposed in the middle of a public line or the like.
This function is to prevent a signal transmitted via the exchange from wrapping around and returning to the side that transmitted the signal, and preventing the side transmitting the signal from erroneously recognizing this as a normal reception signal. In addition, it is a function to prevent the return of the sneak signal.

For example, as shown in FIG. 13, the exchange 31 is provided with echo processor functions 32 and 33. Now, for example, if the CFR is transmitted from the called station facsimile machine to the calling station facsimile machine, the echo processor function 33 is effective in the exchange 31 so that the CFR sneak signal 34 does not return to the called station. become. As a result, the roundabout signal 34 of the CFR is blocked and does not return to the called station.

When the CFR transmission is completed, the echo processor function 33 is released and the echo processor function 32 is enabled at an appropriate timing. Therefore, the training signal sent from the calling station is sent to the called station,
On the other hand, the wraparound signal 35 of the training signal is blocked by the echo processor function 32 and is not returned to the calling station.

The echo processor functions 32 and 33 are
The timing of the switching is important. For example, if the switching timing is too late, the beginning portion of the training signal is cut off by the echo processor function 33,
In some cases, the beginning of the training signal did not reach the called station and the transmission of image information failed.

In particular, in the case of overseas communication, since a large number of exchanges are used, there is a high rate of communication failure.

In view of the above problems, Japanese Patent Laid-Open No. 1-1306
Japanese Patent Laid-Open No. 67 and Japanese Patent Laid-Open No. 1-276964 disclose measures for the called station when the training signal fails to be received when the image information is received and the image information cannot be received.

That is, in JP-A-1-130667 (first prior art), the receiving side determines the success or failure of the training after training the high-speed modem, and if the training fails, it is predetermined. If a control signal following the image signal sent from the transmission side is detected by standing by in the reception mode, a predetermined transmission control procedure is performed after transmitting a signal requesting retransmission of the training signal and the image signal to the transmission side. It is intended to continue.

Further, in JP-A-1-276964 (second prior art), when a receiving side detects a training error, a training error tone is immediately sent back to the transmitting side, and the transmitting side detects the training error tone. Then, a technique is disclosed in which transmission of image information is stopped to prevent useless transmission of image information.

In addition, Japanese Patent Laid-Open No. 4-61470 (3rd
Prior art), H of 300 BPS before sending the image information.
A technique is disclosed in which an OM (Head Of Message) signal is transmitted and the signal to be transmitted next is a high-speed signal so that the other device is prompted to receive image information.

In addition, conventionally, CCITT V. 27te
r, V. 33 and V.I. In 17 it is recommended to send an EPT (echo protector tone) signal after receiving the CFR and before sending the training signal.

FIG. 14 shows that the calling station is
The protocol when the EPT signal is sent before sending the training signal is shown.

[0016]

As is well known, the calling station of the facsimile machine waits for the CFR to be sent from the receiver side after sending the TCF signal, and when the CFR is confirmed, the training signal is sent. Then, the image information is transmitted.
On the other hand, if the CFR cannot be confirmed, the calling station transmits DCS.

On the other hand, the called station stands by in a state where it can receive both the image information reception and the DCS reception, and the DCS
When it receives, the process moves to the TCF (training check) reception operation again.

At the present time, V. 29 for EPT
Signal transmission is not recommended, but V. Also in 29, before transmitting the training signal after receiving the CFR,
When an EPT signal is transmitted, the V. Since the carrier frequency of 29 is 1700 Hz, the frequency of the EPT signal is also expected to be 1700 Hz.

In this case, since the DCS is composed of the 1650 Hz preamble and the 300 Hz command, as described above, when the calling station transmits the 1700 Hz EPT signal, it reaches the called station. However, it is expected that it may be confused with 1650 Hz for some reason (for example, the deterioration of the line condition). Then, the called station erroneously recognizes the EPT signal as the DCS preamble, and enters the TCF reception state again. As a result, EP
There is a fear that the image information sent after the T signal cannot be normally received.

Further, since the switching timing of the echo processor function of the above-mentioned exchange is not constant or the partner machine is a model that takes a long time to prepare to receive the image information, the EPT signal is transmitted before the image information is transmitted. Even if it is provided, there is a problem that transmission of image information may fail.

The object of the present invention is to eliminate the above-mentioned problems of the prior art, eliminate the communication problems that occur when image information is sent subsequently to an EPT signal, and improve the rate of successful image information transmission. To provide a facsimile machine.

[0022]

In order to achieve the above-mentioned object, the invention of claim 1 uses an EP before transmitting image information.
In a facsimile machine that sends T, E
An EPT frequency setting unit for setting the PT frequency, and the EP
It is characterized in that it is provided with an EPT transmission unit for transmitting the EPT of the frequency set by the T frequency setting unit.

Further, the invention of claim 2 is that the EPT sending time setting unit for setting the sending time of the EPT, and the EPT sending the EPT at the time set by the EPT sending time setting unit.
It is characterized in that it has a sending unit.

Further, the invention of claim 3 is provided with means for judging whether or not the called station is its own machine. The invention of claim 4 is, when the called station is its own machine, the called station. Is equipped with a judging means for judging whether or not it is capable of receiving an EPT signal whose frequency or transmission time is changed.

[0025]

According to the invention of claim 1, the frequency of the EPT is set to 1
Can be set to a frequency away from 650 Hz, and the called station
There is no risk of erroneously recognizing the PT signal as the DCS preamble.

According to the second aspect of the invention, the EPT sending time can be set arbitrarily. Therefore, it is possible to reduce the probability of transmission failure of the image information due to the fact that the switching timing of the echo processor function of the exchanger is not constant.

According to the invention of claim 3, the frequency or the transmission time is changed only when the called station is the own machine.
Since the PT signal is sent out, there is no possibility of causing a communication error even if the communication is different from that according to the CCITT recommendation.

Further, according to the invention of claim 4, the called station is the own machine, and the frequency or the transmission time is changed.
Since the EPT signal whose frequency or transmission time is changed is transmitted only when it has the ability to receive the PT signal, communication abnormality does not occur even if the communication conforms to the CCITT recommendation.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. First, a hardware configuration diagram of a facsimile apparatus to which the present invention is applied will be described with reference to FIG.

In the figure, reference numeral 1 denotes a CPU, which performs control processing of the entire facsimile apparatus and facsimile transmission control procedure processing. A RAM 2 provides a work area used by the control program. An operation display device 3 is an operation unit and a display unit for operating the facsimile apparatus. A reading device 4 has a function of reading a transmission document. Reference numeral 5 denotes a printing device, which has a function of recording received image information.

Reference numeral 6 denotes an image processing device, which performs encoding and decoding processing. An image storage device 7 serves to store image information. A system control unit 8 is a program for controlling the entire facsimile apparatus. Reference numeral 9 is a program for controlling facsimile communication. These programs are stored in the ROM.

A modem (modulator / demodulator) 10 has a low speed mode (for transmission procedure signal: V.21) and a high speed mode (for transmitting / receiving image information: V.27ter, V.29).
V. 33, V.I. 17) It has a function. A network control device 11 has a function of connecting to a public network and an automatic call originating / receiving function. A system bus 12 is a bus for exchanging data with each other.

Next, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the functions of the essential parts of this embodiment. In the figure, 21 is an EPT frequency storage unit, 22 is an EPT frequency setting unit, and 23 is an EPT transmission unit 2.
Reference numeral 4 is a control unit, and these functions are functions that the communication control unit 9 has.

In the EPT frequency storage section 21, for example, ten frequency values can be set as shown in FIG. Specifically, values 0 to 9 can be set in the storage unit 21, and each value 0 to 9 is 0 Hz, 462 Hz, 1004 Hz, 130 as shown in the drawing.
0 Hz, ... The values of 0 to 9 can be arbitrarily selected like the system data.
The PT frequency can be arbitrarily selected.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. When a call is made in step S1, the process proceeds to step S2, and NSF or DIS is received. If the control unit 24 determines that these signals have been received, the process proceeds to step S3 and the NSS or DCS
Is sent. Then, in step S4, the TCF is transmitted.

In steps S5 and S6, CFR or F
It is determined whether TT (training failure) is received, and if CFR is received, the process proceeds to step S7.
On the other hand, if the FTT is received, the process returns to step S3.

In step S7, the EPT frequency setting section 22 reads a frequency away from 1650 Hz, for example, 1850 Hz, from the EPT frequency storage section 21, and sets the read frequency as the EPT frequency. Then, the EPT transmission unit 23 transmits the EPT signal of this frequency.

In step S8, a training signal is transmitted, and subsequently, in step S9, image information is transmitted.
After step S10, the normal protocol procedure is executed. As described above, according to the present embodiment, the EPT signal having a frequency apart from 1650 Hz from the calling station, for example, 1
Since the 850 Hz EPT signal is output, the called station does not have the possibility of mistakenly recognizing this as the DCS preamble. As a result, the called station can normally receive the training signal and the image information sent after the EPT signal, and can prevent the communication failure.

Next, a second embodiment of the present invention will be described. FIG. 4 is a functional block diagram of the essential parts of this embodiment, where 25 is E.
The PT transmission time storage unit 26 is an EPT transmission time setting unit, and these functions are included in the communication control unit 9. Reference numerals other than these indicate the same or equivalent parts as in FIG. The EPT delivery time storage unit 25 has a storage capacity of, for example, 1 byte of data, and stores an EPT delivery time of 0 to 255 msec, for example. The EPT sending time setting unit 26 can set an arbitrary time in the EPT sending time of 0 to 255 msec.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. In the figure, step S1
~ S6 and steps S8 to S10 are the same as those in Fig. 3, and thus the description thereof will be omitted and only step S11 will be described.

In step S11, the EPT sending time setting unit 26 reads the EPT sending time from the EPT sending time storage unit 25 and sets an arbitrary time within 0 to 255 msec. Then, by a timer (not shown) or the like, C
Measure the time after receiving the FR, and if the time-out occurs, E
Send the PT signal.

In the present embodiment, for example, in ECM (error collect mode) communication, when there is a request for retransmission of all frames or when RTN (retraining negative) is received, the echo of the exchange is received. It is considered that there is a high possibility that the transmission of the image information may have failed due to a delay in the switching timing of the processor functions or a model in which the other device takes a long time to prepare for receiving the image information. Set a long time.

Therefore, according to this embodiment, it is possible to reduce the probability of image information transmission failure due to the non-uniform switching timing of the echo processor function of the exchange.

Next, a third embodiment of the present invention will be described. FIG. 6 is a functional block diagram of a main part of the present embodiment, 28 is a partner device storage part, 29 is an EPT transmission determination part, and other symbols are the same as or equivalent to those in FIG. The other party storage unit 2
For example, 1 bit is assigned to 8, and when it is 1, it is determined to be a company machine, and when it is 0, it is determined to be a machine of another company.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. The present embodiment differs from the first embodiment (FIG. 3) only in steps S12, S13, S14 and S15, so only these steps will be described.

In step S12, step S2
In the NSF, the supply code (see Fig. 10) in the NSF is used to determine whether the partner machine is an own machine or another company's machine. And
The determination result is stored in the partner storage unit 28.

In step S13, after receiving the CFR, it is determined whether the partner machine is the company machine. This decision is
The EPT transmission determination unit 29 performs this.

In the case of own machine, step S1
4, the EPT frequency storage unit 21 is used to determine a frequency value that is predetermined between the machines, for example, 1850H.
z is read and the EPT signal of that frequency is transmitted.

Alternatively, although not shown, in step S14, as in the second embodiment, the sending time is read from the EPT sending time storage section, and after the sending time elapses, E
Send the PT signal. Alternatively, both the frequency and the sending time are read from the EPT frequency storage unit and the EPT sending time storage unit, and the EPT signal of that frequency is sent during the sending time.

On the other hand, when the partner's machine is another company's machine (No at step S13), the process proceeds to step S15 and CCIT
An EPT signal having a frequency conforming to T's recommendation is transmitted.

In general, when the partner machine is another company's machine, EP
If the T frequency is changed or the EPT transmission time is changed, the communication does not comply with the CCITT recommendation, so there is no guarantee that the other device will execute the communication normally. In this case, the communication conforming to the CCITT recommendation is performed, and thus the probability of causing a communication abnormality can be reduced.

On the other hand, in the case of own machines, it is known that even if the communication conforms to the CCITT recommendation, it is designed to accept it beforehand, so there is no communication abnormality and the EPT signal is not generated. You can increase the effect of using.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. In FIG. 8, 30 is EPT
It is a reception capacity storage unit, and other reference numerals indicate the same or equivalent parts as those in FIG.

In the case of own machines, since the original mode communication can be performed by NSF (non-standard function), the partner machine can change the frequency or the EPT signal or the transmission time.
It knows if it is capable of receiving PT signals. The E
The PT reception capability storage unit 30 stores, for example, 1 when the partner machine has the capability and 0 when it does not.

Next, referring to the flowchart of FIG.
The operation of this embodiment will be described. 9 differs from FIG. 7 in that
Since only steps S16 and S17 are described, only this step will be described.

In step S16, NSF and DIS
Thus, it is determined whether the partner machine is the own machine or another company's machine, and the partner machine storage unit 28 stores it. Further, when the partner machine is the own machine, it is determined whether or not the frequency change EPT reception capability and the transmission time change EPT reception capability are present, and the determination result is stored in the EPT reception capability storage unit 30.

In step S17, it is determined from the stored contents of the EPT receiving capacity storage section 30 whether or not the partner has the frequency changing EPT receiving capacity and the sending time changing EPT receiving capacity. Then, if there is reception capability, the process proceeds to step S14, and if not, the process proceeds to step S15.

In step S14, as in the third embodiment, if the partner device has the frequency change EPT reception capability, EP
If the frequency is set by the T frequency setting unit 22 and the partner device has the transmission time change EPT receiving capability, the EPT transmission time setting unit 26 (not shown) sets the transmission time and transmits the EPT signal. In step S15, CC
Communication based on ITT recommendations is performed.

FIG. 10 shows the structure of one frame of the NSF command. As shown, the NSF command is composed of a preamble, a flag F, an address field A, a control field C, an NSF command code FCF, a facsimile information field FIF, a frame checking sequence FCS and a flag F.

The country code (00H in Japan) is written in the first byte of the facsimile information field FIF, and the code for each company is assigned in the second and third bytes. In addition, the second bit of the 6th byte is a flag indicating whether or not the EPT reception capability with the changed transmission time is available (no capability = 0, capability =
1) is present, and the EPT with the frequency changed in the first bit
A flag indicating whether or not there is reception capability (no capability = 0, capability = 1) is written.

In step S16, it is possible to judge whether or not the called station has the frequency change EPT reception capability and the transmission time change EPT reception capability based on the flag.

FIF of NSS command in step S3
Also has the same configuration as the NSF command, and F
The flag of the EPT reception instruction that changed the transmission time (not instructed = 0, instructed = 1) is set in the second bit of the 6th byte of the IF, and the flag of the EPT reception instruction changed in the frequency is set in the first bit ( Not instructed = 0 and instructed = 1) are described.

Therefore, the called station transmits N transmitted from the calling station.
By analyzing the SS, it can be known that there is an instruction to receive the EPT signal whose transmission time or frequency is changed.

As described above, according to this embodiment, the EPT
Since the frequency or the transmission time is changed and transmitted only to the receiver that is permitted to change the frequency or the transmission time of the signal, the communication error may occur by transmitting the changed EPT signal. It has the effect of disappearing.

[0065]

As is apparent from the above description, according to the first aspect of the invention, since the EPT signal of the frequency away from 1650 Hz is output from the calling station, the called station sends the EPT signal to the DCS preamble. There is no fear of making a mistake. As a result, it is possible to prevent the communication failure of the image information.

According to the second aspect of the present invention, since the EPT transmission time can be arbitrarily set, it is possible to reduce the probability of image information transmission failure due to non-uniform switching timing of the echo processor function of the exchange. .

According to the third aspect of the present invention, the EPT in which the frequency or the transmission time is changed only when the called station is the own machine.
Since the signal is transmitted, it can be accepted even if the communication is different from that according to the CCITT recommendation. As a result, communication abnormality does not occur, and the effect of using the EPT signal can be improved.

According to the fourth aspect of the invention, the EPT signal with the changed frequency or the transmission time is transmitted only when the called station is the own machine and has the ability to receive the EPT signal with the changed frequency or the transmission time. I tried to send it out. Therefore, even if the communication conforms to the CCITT recommendation, no communication abnormality occurs and the effect of using the EPT signal can be enhanced.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a main part of a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of data stored in an EPT frequency storage unit.

FIG. 3 is a flowchart for explaining the operation of the first embodiment.

FIG. 4 is a functional block diagram of a main part of a second embodiment of the present invention.

FIG. 5 is a flowchart for explaining the operation of the second embodiment.

FIG. 6 is a functional block diagram of an essential part of a third embodiment of the present invention.

FIG. 7 is a flowchart for explaining the operation of the third embodiment.

FIG. 8 is a functional block diagram of an essential part of a fourth embodiment of the present invention.

FIG. 9 is a flowchart for explaining the operation of the fourth embodiment.

FIG. 10 is a diagram showing a configuration example of an NSF command.

FIG. 11 is a block diagram showing a hardware configuration of a facsimile apparatus to which the present invention is applied.

FIG. 12 is an explanatory diagram of a G3 communication protocol procedure.

FIG. 13 is an explanatory diagram of an echo processor function of the exchange.

FIG. 14 is an explanatory diagram of a G3 communication protocol procedure using an EPT signal.

[Explanation of symbols]

9 ... Communication control unit, 21 ... EPT frequency storage unit, 22 ... E
PT frequency setting unit, 23 ... EPT sending unit, 24 ... control unit, 25 ... EPT sending time storage unit, 26 ... EPT sending time setting unit, 28 ... partner device storage unit, 29 ... EPT sending determination unit, 30 ... EPT reception Capacity memory

Claims (4)

[Claims] 1. A facsimile apparatus in which an echo protector tone (hereinafter abbreviated as "EPT") is transmitted before transmitting image information, and an EPT frequency setting unit for setting an EPT frequency, and the EPT frequency setting unit. And an EPT transmission unit for transmitting the EPT having the frequency set in step 1. 2. A facsimile apparatus adapted to transmit an EPT before transmitting image information, wherein an EPT transmission time setting section for setting an EPT transmission time and a time set by the EPT transmission time setting section are set. , An EPT sending unit for sending the EPT. 3. The facsimile apparatus according to claim 1, further comprising means for determining whether or not the called station is the own machine, and when the called station is the own machine, it is set by the EPT frequency setting unit. A facsimile apparatus, wherein an EPT having a different frequency is transmitted, or the EPT is transmitted at a time set by the EPT transmission time setting unit. 4. The facsimile apparatus according to claim 3, wherein when the called station is its own machine, it is judged whether or not the called station is capable of receiving an EPT signal having a changed frequency or transmission time. Means for transmitting the EPT having the frequency set by the EPT frequency setting unit or the EPT at the time set by the EPT sending time setting unit when the judging unit judges that the receiving capability is available. A facsimile machine characterized by the above.