JPH0884238A - Facsimile equipment - Google Patents

Abstract

PURPOSE: To allow a facsimile equipment to cope with image data sent at random with respect to the re-transmission request of image data corresponding to a data error. CONSTITUTION: A temporary buffer 1 stores received image data by one block and a storage buffer 2 stores the received image data transferred from the buffer 1 by a transfer means for each block corresponding to address data. A management data storage section 3 stores the address data of the received image data stored in the buffer 2, a page number and a block number added to a post message command. A retrieval means searches the address data and retrieves whether or not the data corresponding to the received image data are stored in the buffer 1. Through the constitution above, the image data sent at random are received in matching with the image data received normally.

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 corrects a data error during data transmission by retransmitting correct data in facsimile communication.

[0002]

2. Description of the Related Art In recent years, ITU-T Recommendation T. 30 ANN
A new communication protocol (hereinafter referred to as G3C protocol) is recommended by EXC. The G3C protocol is proposed as a combination of the ideas of the G3 protocol and the G4 protocol. As a prior art, an error control method of full-duplex communication is disclosed in Japanese Patent Publication No. 5-48.
No. 013 is proposed. In this publication, when a receiving side detects an error frame, a tone signal requesting retransmission is transmitted to the transmitting side by full-duplex communication. Also,
The transmitting side, which has received the tone signal requesting retransmission, measures which frame has an error from the time until the receiving side transmits the tone signal and receives the tone signal, and then the frame in which the error occurred I am trying to retransmit after that immediately.

[0003]

[Problems to be Solved by the Invention] However, the G3C
A facsimile machine to which the protocol is applied cannot know which block is transmitted in response to a partial page request (hereinafter referred to as PPR) command in response to an error. That is, even if the receiving side sends the PPR command, it does not necessarily mean that the sending side immediately retransmits the corresponding block, and the sending side has already started to send the next block. There is.

The technique disclosed in Japanese Patent Publication No. 48013/1993 has nothing to do with the G3C protocol.
This was devised on the assumption that the transmitting side immediately retransmits the block in response to the retransmission request from the receiving side. Therefore, as described above, if the sender does not know which block is to be retransmitted, there is a problem in that it cannot respond at all.

Further, in the above-mentioned conventional facsimile apparatus, when the error for one block is eliminated, the process proceeds to the next page. Therefore, it was possible to control if the receive buffer was one block (64 Kbytes).
In a facsimile machine to which the G3C protocol is applied,
Even if there is an error, there is a possibility of moving to the next block or page, and the conventional facsimile apparatus does not consider such an operation at all, and cannot cope with it.

Further, in the above-mentioned conventional facsimile apparatus, when a resending request is made for a block having an error,
It is sent back to the block in error. So if the next block has already been sent,
This block is also transmitted, and there is a problem that wasteful transmission is performed. An object of the present invention is to eliminate the above-mentioned problems of the prior art, and to respond to a data resend request for a data error, in whatever order and in what data is sent. It is to provide a facsimile machine.

[0007]

In order to achieve the above object, the present invention receives a plurality of received image data and a first storage means for storing received image data for one block or one frame. Second storage means for storing in the area corresponding to each block or frame in the order described, address data relating to the received image data stored in the second storage means, and page added to the post message command Management data storing means for storing a number and a block or frame number and the management data storing means are searched to determine whether or not data corresponding to the received image data stored in the first storing means is stored. A search means for searching whether or not, and an area of the second storage means corresponding to the page number and block or frame number of the post message command, Received image data stored in the serial first storage means is characterized in that comprising a transfer means for transferring.

[0008]

According to the present invention, the received image data is stored in the first storage means once for each block or frame, and after the management data storage means is searched, the received image data is returned for one block or one frame. Each time, the data is sequentially transferred to and stored in the area in the second storage means. As a result of the search, when the page number of the post message command of the received image data and the block or frame number do not exist in the management data storage means, these are stored in association with the area number of the second storage means. To do. As a result,
Even if the retransmitted image data is sent out of order, the received image data can be accurately stored in the area in the second storage unit by referring to the management data stored in the management data storage unit. It will be possible.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the facsimile apparatus of the present invention will be described in detail below with reference to the drawings. FIG. 2 is a block diagram showing a schematic configuration of a facsimile apparatus to which the present invention is applied. In the figure, 11 is a CPU for controlling the entire facsimile machine, 12 is a RAM as a work area used by a control program, 13 is an operation display device for an operator to operate the facsimile machine, and 14 is a transmission document or a copy document. And the like, 15 is a printing device for recording the copy original, received images, etc., 16 is an image processing device for encoding, decoding, or expanding and contracting image signals, and 17 is storage of image information. An image storage device 18, a system control unit 18 in which the CPU 11 controls the entire system of the facsimile device, and a program for controlling the facsimile device are stored. A digital control unit 19 controls communication suitable for a digital network. Communication control device, 20
Is an analog communication control device that controls communication suitable for an analog network, and has an automatic call originating / receiving function. Reference numeral 21 is a digital network interface for connecting a facsimile machine and a digital network, 22 is a modulator / demodulator having a function of switching between a low speed mode function and a high speed mode function, 23 is an analog network interface for connecting the facsimile machine and an analog network, 24 Is a system bus for exchanging data with each other, and 25 is a line switching control device for connecting an external line interface such as the digital network interface 21 and the analog network interface 23 to a plurality of internal communication circuits.

FIG. 1 is an explanatory diagram showing an outline of the function of one embodiment of the present invention. In the figure, 1 is a temporary buffer for storing one block of received image data, and 2 is a storage buffer N for each block of received image data of a plurality of blocks.
o. A storage buffer 3 for storing the data corresponding to the area n (however, n = 1, 2, 3, ...) Is the storage buffer 2
Address data related to the received image data stored in
This is a management data storage unit that stores the page number and block number or frame number added to the post message command as needed. The temporary buffer 1 corresponds to the RAM 12, the storage buffer 2 corresponds to the image storage device 17, and the management data storage unit 3 corresponds to the system control unit 18, for example.

Next, the operation of data reception control of this embodiment will be described with reference to the drawings. FIG. 3 is a diagram showing an example of transmission / reception of commands, image information and the like between the facsimile apparatuses of the present invention. In addition, “3 ×” at the head of each command in FIG. 3 means that the command is transmitted three times. 4 and 5 are flowcharts showing the operation of the data reception control of this embodiment. First, in step S1, it is determined whether or not there is an incoming call from another facsimile device. In step S2, it is determined whether or not an exchange identification procedure (hereinafter, referred to as XID) command is received. If the determination is affirmative, the process proceeds to step S3, and the XID command, the non-standard A multi-frame command {XID, (NSF), (CSI), D in which a function signal (hereinafter, NSF) command, a called terminal identification signal (hereinafter, CSI) command, and a digital identification signal (hereinafter, DIS) command are combined.
IS} is transmitted.

In step S4, it is determined whether or not a digital command signal (hereinafter, DCS) has been transmitted. When this determination is affirmative, the process proceeds to step S5, while when it is negative, the multi-frame command is transmitted again. Here, in FIG. 3, since the DCS command is not transmitted from the transmitting side with respect to the first multi-frame command, the determination in step S4 is negative, and the multi-frame command is transmitted again. The DCS command is transmitted from the transmitting side in response to the second multi-frame command, and the receiving side receives this, so the determination in step S4 is affirmative and the process proceeds to the next step.

In step S5, the received image data, that is, facsimile encoded data (hereinafter, referred to as FCD) is stored in the temporary buffer 1. In step S6, it is determined whether one block of received image data has been received. If this determination is affirmative, the process proceeds to step S7, and the post message command (hereinafter, P
It is determined whether a PS-Q command) is received. A page number, a block number, and a frame number are added to the PPS-Q command, and a null signal of a partial page signal (hereinafter referred to as PPS-NULL) and a multi-page signal of a partial page signal (hereinafter referred to as PPS-MP).
S), the procedure end signal of the partial page signal (hereinafter P
PS-EOP) and a message end signal of the partial page signal (hereinafter referred to as PPS-EOM).
In step S7, as shown in FIG.
Since UL (1, 1, z) has been transmitted, this determination is affirmative, and the process proceeds to step S10 in FIG. here,
Returning to step S6, if the determination is negative,
In step S8, it is determined whether a command has been received. If the determination is affirmative, the process proceeds to step S9. In step S9, it is determined whether or not a PPS-Q command has been received. If this determination is affirmative, step S10
Go to. On the other hand, if step S8 or S9 is negative, the process returns to step S5, and the operation of storing the received image data in the temporary buffer 9 is continued.

Next, in step S10, the received PP
Whether or not the information corresponding to the page number and the block number of the SQ command is already stored in the management data storage unit 3 is searched by the search means provided in the system control unit 18. In step S11, the information is stored in the management data storage unit 3 based on the search result.
Is stored in. If this determination is negative, the process proceeds to step S12 and the accumulation buffer 2
The received image data stored in the temporary buffer 1 is transferred to the unused area and the uppermost area of the system control section 18, for example, by the transfer means. Succeedingly, in a step S13, the accumulation buffer No. of the accumulation buffer 2 to which the received image data is transferred. , The PP
The page number and block number of the SQ command are
It is stored in the management data storage unit 3.

Here, returning to step S11, if the determination is affirmative, the process proceeds to step S15, and the corresponding storage buffer No. In the area of
The normal received image data stored in the temporary buffer 1 is transferred. In this case, the fact that the information is stored in the management data storage unit 3 means that some kind of received image data, for example, errored received image data has already been stored in the accumulation buffer 2. For this reason,
The new normal received image data will be overwritten.
In step S14, for the received image data stored in the accumulation buffer 2, a frame check sequence (FC
S) A check is made to determine if a resend is necessary. If this determination is affirmative, that is, if the received image data has an error, the process proceeds to step S16 and the PPR command is transmitted. On the other hand, when the result is negative, that is, when normal received image data is obtained, the process proceeds to step S17, and a message confirmation (hereinafter, MCF) command is transmitted.

Now, the operation of transmitting and receiving commands and image data of the facsimile machine to which the present invention is applied will be described with reference to FIGS. First, PPS-NULL (1, 1,
z), the FCD frame of the storage buffer No. 1 is stored in the storage buffer, and the page number = 1, the block number = 1, and the storage buffer No. 1 are stored. =
1 is stored in the management data storage unit 3. Then, PPS
Similarly, for the FCD frame of MPS (1, 2, y), the accumulation buffer No. of the accumulation buffer 2 is the same. 2 is stored in the storage buffer, and the page number = 1, the block number = 2, and the storage buffer No. = 2 is stored in the management data storage unit 3. Here, the PPS-NULL
As a result of the FCS check of the FCD frames of (1,1, z) and PPS-MPS (1,2, y), there was a data error. Therefore, PPR (1,2, y) and PPR were detected.
Send (1,1, z).

Next, F of PPS-MPS (2,1, x)
Similarly to the frame described above, the CD frame also stores the accumulation buffer No. of the accumulation buffer 2. 3 and store the data, and page number = 2, block number = 1 and storage buffer No. = 3 is stored in the management data storage unit 3. As a result of the FCS check, there is no data error in this FCD frame, so MCF (2, 1) is transmitted. Then, similarly for the FCD frame of PPS-EOP (3, 1, w), the storage buffer No. of the storage buffer 2 is similarly set. 4 and store the same, and also page number = 3, block number = 1 and accumulation buffer No. =
4 is stored in the management data storage unit 3. As a result of the FCS check, there was a data error, so PPR (3,1,
a) is transmitted.

Next, in accordance with the PPR, PPS-E
When the FCD error frame of OP (3, 1, a) is retransmitted, the search means searches the management data in the management data storage unit 3 and the search data corresponding to page number = 3 and block number = 1. The storage buffer No. of the storage buffer 2 Take out 4. As a result, this accumulation buffer No. Area 4 is rewritten with the retransmitted frame. As a result of the FCS check, no data error was detected, so MCF (3, 1) is transmitted. Then PPS-MPS (1,2, v) and PPS-MPS
As for the FCD error frame of (1,1, z), similarly to the FCD error frame of PPS-EOP (3,1, a), the accumulation buffer No. 2 and No. Area 1 is rewritten with the retransmitted frame, and MCF
(1,2) and MCF (1,1) are transmitted. Note that the PPS-MPS (1, 1, z) command is transmitted twice, but the MCF for the first command
Since (1,1) was not transmitted, PPS-MP is performed again.
It is just sending S (1,1, z).

As described above, in the G3C protocol, the transmitting side retransmits the FCD frame in random order with respect to the PPR transmitted from the receiving side, but according to the present embodiment, it is added to the post message command. Storage buffer N based on the page number and block number
o. And the received FCD frame is searched for the corresponding storage buffer No. Since it is overwritten, the receiving side can obtain the image information in the correct order. As a result, if this is displayed on a display device or printed by a printing device, a beautiful image or a printed document can be obtained.

Further, by preparing one temporary buffer capable of storing data for one block,
Since normal received image data can be obtained in the correct order, there is an effect that it can be realized by preparing a small memory area. Further, since it is possible to avoid the normal retransmission of the image data, it is possible to solve the problem of wasteful transmission and efficiently retransmit the normal data in response to a data error. In this embodiment, the data is stored for each block, but the present invention is not limited to this, and the data may be stored for each frame. In this case, if the data is accumulated for each frame, the error can be corrected more finely, the useless data transmission is less than the case of performing the error correction for each block, and the normal data retransmission for the data error is performed. Can be performed efficiently.

[0021]

As is apparent from the above description, according to the present invention, the image data which can be normally received is converted into the second image data.
Can be properly stored in the area of the storage means of
Also, the received image data retransmitted out of order with respect to the PPR command can be received in alignment with the image data for normal reception. As a result, it is possible to provide a receiver suitable for image data received according to the G3C protocol.

Further, it can be realized by preparing only one small-capacity first storage means capable of storing data for one block or one frame. Further, the problem of wasteful transmission of image data can be solved, and normal data can be retransmitted efficiently in response to a data error.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of functions of one embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a facsimile apparatus to which the present invention is applied.

FIG. 3 is an explanatory diagram showing an example of transmission / reception of commands, image information and the like between the facsimile apparatuses of the present invention.

FIG. 4 is a flowchart showing an operation of data reception control according to the present embodiment.

FIG. 5 is a flowchart showing a continuation of the operation of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Temporary buffer, 2 ... Accumulation buffer, 3 ... Management data storage part, 11 ... CPU, 12 ... RAM, 13 ... Operation display device, 14 ... Reading device, 15 ... Printing device, 16 ...
Image processing device, 17 ... Image storage device, 18 ... System control unit, 19 ... Digital communication control device, 20 ... Analog communication control device, 21 ... Digital network interface, 22
… Modulator / demodulator, 23… Analog network interface, 2
4 ... System bus, 25 ... Line switching control device.

Claims (1)

[Claims] 1. A first storage means for storing one block or one frame of received image data in a facsimile apparatus that corrects a data error by retransmitting correct data in response to a data error during data transmission. And second storage means for storing a plurality of received image data in an area corresponding to each block or frame in the order of reception, and address data relating to the received image data stored in the second storage means. , Management data storage means for storing the page number and block or frame number added to the post message command, and search the management data storage means to obtain the received image data stored in the first storage means. The corresponding data is
Search means for searching whether or not it is stored, and received image data stored in the first storage means in the area of the second storage means corresponding to the page number and block or frame number of the post message command. And a transfer means for transferring the received image data, when it is determined by the search by the search means that the received image data is already stored in the first storage means,
The received image data stored in the first storage means is transferred to the corresponding area of the second storage means, and when it is determined that it is not stored, the page number and block or frame number A facsimile apparatus, wherein the received image data stored in the first storage means is transferred to a corresponding area of the second storage means while being stored in the management data storage means.