JP2003219133A - Facsimile apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a facsimile apparatus which decides whether a short frame is suitable or not in response to a decided result of whether the short frame is final data frame or not at a reception time of the short frame. <P>SOLUTION: The facsimile apparatus decides whether the received data frame is suitable or not, processes to regenerate data of the data frame when normal data frame is decided, and transmits a re-transmission request signal when an error frame is decided. In this apparatus, when the number of bytes of the received data frame does not satisfy the specified number of the bytes to be the short frame, the apparatus searches for the contents of the frame received next to the short time, decides the short frame as the error frame of the searched frame is the data frame, transmits the re-transmission request signal, decides the short frame as the final data frame if the frame is an RCP frame, and processes to regenerate the data of the short frame. <P>COPYRIGHT: (C)2003,JPO

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 having an error correction mode (ECM) communication function.

[0002]

2. Description of the Related Art Generally, a facsimile machine is an international telecommunications union (ITU).
ITU-T Recommendation (formerly CCITT Recommendation) T.T. By 30,
When a facsimile message to be transmitted / received is divided into a plurality of high level data link control (HDLC) frames, a frame number is assigned to each divided frame, and when there is an error frame in which a transmission error occurs in the receiving side facsimile device, An error correction mode (ECM) communication method is specified in which a retransmission request signal is transmitted from a reception side facsimile apparatus to a transmission side facsimile apparatus to retransmit an error frame.

Conventionally, the error correction mode communication method used in a facsimile machine divides transmitted / received data into respective data frames for each predetermined data amount, and a frame check sequence (FCS) is applied to each obtained data frame. A frame check sequence (FCS) is added when an error frame is detected.
It was done by checking the contents of.

[0004]

In the known error correction mode communication method used in a facsimile machine, even if a transmitted data frame is an error frame, a frame check sequence () added to the data frame is used. If the FCS) is normal, the error frame may be erroneously recognized as a normal data frame.

Originally, a normal data frame has a header of 4 bytes for one data frame and 64 bytes or 256 bytes.
Although it is 260-byte data composed of byte (hereinafter, data size is described as 256 bytes) data, when the data frame is transmitted from the transmitting side facsimile apparatus, noise or the like is superimposed during transmission, When the receiving facsimile machine receives a plurality of data frames of less than 260 bytes, the error frames may be erroneously recognized as normal data frames.

When the receiving facsimile machine erroneously recognizes that the error frame is a normal data frame, a decoding error occurs or the number of received data frames is notified by the partial page signal. If the number of transmission data frames does not match the number of transmission data frames, a retransmission request signal may be repeatedly transmitted to the transmitting side facsimile device.

Here, FIG. 4 is a frame configuration diagram showing an example of a transmission / reception frame used in a facsimile apparatus.

As shown in FIG. 4, the transmit and receive frames used in a facsimile machine are first a sync signal, then a coded data (FCD) frame, and then a final (RC
P) The frame is arranged to come. And FCD
The frames are FCD frame 0 to FCD frame m-.
The RCP frame is also composed of a plurality of continuous data frames up to 1. The RCP frame is also composed of a plurality of continuous RCP frames.

Further, FIGS. 5A, 5B and 5C are frame configuration diagrams showing an example of an FCD frame and an RCP frame used in a facsimile machine.
(A) is a configuration example of a normal data frame, (b) is a configuration example of a short frame, and (c) is a configuration example of an RCP frame.

As shown in FIG. 5A, a normal data frame has "FF", "03", "0" in the header portion.
6 ", a frame number, and then a data part, and the total number of bytes of the header part and the data part is 260, which is the specified number of bytes. In addition, as shown in FIG. 5B, the short frame has “F
Although there is F ”,“ 03 ”,“ 06 ”, a frame number, and a data portion after that, the total number of bytes of the header portion and the data portion is less than the prescribed number of bytes 260. 260
It is less than. Furthermore, the RCP frame has "FF", "03", and "86" in the header part, and then has a frame check sequence (FCS) part.

When frames are detected, all the data frames obtained by dividing the data are 260 bytes except the final data frame, and the 260-byte data frames are all normal data. It is determined to be a frame. On the other hand, since the data amount of the last data frame of the divided data frames, that is, the final data frame is not always 260 bytes, it may be a short frame of less than 260 bytes. When a method of detecting an error frame by the number of bytes of the data frame is used, the final data frame may be a short frame. Therefore, although the error frame is actually a normal data frame, It may be determined that there is.

The present invention has been made in view of the above technical background, and an object thereof is to, when a short frame is received, determine whether or not the short frame is a final data frame, and make the determination. It is an object of the present invention to provide a facsimile apparatus that determines the suitability of a short frame according to the result.

[0013]

To achieve the above object, the present invention determines whether a received data frame is a normal data frame or an error frame, and determines whether the received data frame is a normal data frame. When it is determined that there is a data frame, the data reproduction processing of the data frame is performed, and when it is determined that the data frame is an error frame, the number of bytes of the received data frame is If the short frame does not satisfy the specified number of bytes, if the frame received next to the short frame is a data frame, the short frame is determined to be an error frame, and the facsimile machine on the other end recognizes the short frame. Request to resend and receive after short frame Frame is determined to be the last data frame short frame when was RCP frame comprises means for performing data reproduction processing of the short frame.

According to the above means, when a short frame is received, it is not immediately judged whether this short frame is an error frame or a final data frame, but the content of the next frame to be received is a data frame. If so, it is determined that the short frame received immediately before is an error frame, and a request to retransmit the short frame is made to the facsimile device on the other side. On the other hand, if the next received frame is an RCP frame. For example, it is determined that the short frame received immediately before is the final data frame, and the data reproduction processing of the short frame is performed. Therefore, when the short frame is received, is the short frame an error frame? Or to make sure that it is the final data frame. It becomes possible.

Further, in the above-mentioned means, when a short frame is received, the data and frame number of the short frame are stored in the storage unit without setting the frame reception end state, and the short frame reception flag is set. After that, when a normal data frame is received, the short frame reception flag is reset, the saved short frame data is discarded, and when an RCP frame is received,
It is preferable to confirm that the short frame reception flag is in the set state, send the stored short frame data to the data reproducing process, and set the short frame to the frame reception end state.

According to the above configuration, when the above-mentioned means is executed, it is possible to perform the operation in the most rational operation mode without adding new structural requirements to the known facsimile apparatus of this type.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows one embodiment of a facsimile apparatus according to the present invention, and is a block diagram showing the main configuration of the facsimile apparatus, which constitutes a G3 standard facsimile apparatus.

As shown in FIG. 1, the facsimile apparatus according to this embodiment reads a document to be transmitted,
A scanner 1 that forms transmission data, a printing unit 2 that prints received data and forms printing information, an input unit 3 that has various operation keys, and that sets the function of the facsimile apparatus according to the operation keys. Display unit 4 for displaying various information contents
And R that stores encoded data and other digital information
A network that has a storage unit 5 such as an AM, a frame determination unit 6 that determines the content of a received frame and the suitability of a data frame, and an automatic transmission / reception function, and connects this facsimile device to a communication line 15 such as a public telephone line. Control unit (NCU) 7
A facsimile (FAX) modem 8 that implements a G3 standard facsimile modem function; an encoding unit 9 that encodes and compresses transmission data to form transmission encoded data; It controls the communication state between the decoding unit 10 which decodes and reproduces data and the facsimile device and the facsimile device on the other side, and manages transmission and reception of various codes used when transmitting and receiving encoded data.
A communication control unit 11 that controls transfer of various types of information in the facsimile apparatus, and a ROM 12 that stores operation programs used for various control processes executed by the communication control unit 11.
And a system control unit 13 that controls the facsimile apparatus as a whole, and a system bus 14 that interconnects these components 1 to 13.

In this case, the transfer of various information carried out between these constituent elements 1 to 13 is carried out via the system bus 14, but the encoded data between the network control device 7 and the facsimile modem 8 is transferred. Only transfer is system bus 1
Directly without going through 4.

FIG. 2 is an operation explanatory diagram showing a state of transmission and reception of various kinds of information when transmitting the encoded data from the transmitting side facsimile apparatus to the receiving side facsimile apparatus.

In FIG. 2, the left side portion of the drawing shows the transmitting side facsimile apparatus, and the right side portion of the drawing shows the receiving side facsimile apparatus.

With reference to the operation explanatory diagram shown in FIG. 2, a description will be given of a state of transmitting and receiving various kinds of information when transmitting the encoded data from the transmitting side facsimile apparatus to the receiving side facsimile apparatus.

First, at time T0, the communication control unit 1
Reference numeral 1 communicatively connects the transmitting side facsimile apparatus and the receiving side facsimile apparatus through the network control apparatus 7 and the communication line 15.

Next, at time T1, the communication control unit 11
Sends a calling tone (CN
G) is transmitted.

Next, at time T2, when the receiving side facsimile device receives a calling tone (CNG), it transmits a called terminal identification signal (CED) to the transmitting side facsimile device in response.

Subsequently, at time T3, the receiving side facsimile apparatus 11 sends the transmitting side facsimile apparatus a non-standard function signal (NSF) and a calling terminal identification signal (CS).
I) and the digital identification signal (DIS) are transmitted.

Next, at time T4, the communication control unit 11
Is a called terminal identification signal (CED), a non-standard function signal (N
SF), the calling terminal identification signal (CSI), and the digital identification signal (DIS), respectively, in response to the non-standard function setting signal (NS)
S), the transmission terminal identification signal (TSI), and the digital command signal (DCS).

Subsequently, at time T5, the communication control section 11 sends a training check signal (TCF) to the receiving facsimile machine.

Note that the non-standard function signal (NSF) sent by the sending facsimile machine at time T3 and the non-standard function setting signal (NSS) sent by the receiving facsimile machine at time T4 are omitted. Sometimes.

The digital identification signal (DIS) transmitted by the receiving side facsimile device at time T3 is a signal indicating the capability of the receiving side facsimile device, and at time T4.
The digital command signal (DCS) transmitted by the transmitting side facsimile device selects the common capability of the transmitting side facsimile device and the receiving side facsimile device based on the digital identification signal (DIS) transmitted from the receiving side facsimile device. It was created by That is,
Digital identification signal (DIS) and digital command signal (DC
The purpose of exchanging with S) is to compare the capabilities of the receiving side facsimile device and the transmitting side facsimile device, and to set the encoding method, communication speed (data speed), etc. used for this transmission. The speed is the digital identification signal (DI
By comparing the capabilities of S) and the digital command signal (DCS), the highest communication speed is set among the communication speeds that both the transmitting side facsimile apparatus and the receiving side facsimile apparatus have in common.

Further, the training check signal (TCF) transmitted by the transmitting facsimile machine at time T5 is
When the training is unsuccessful, the communication control unit 11 sequentially reduces the communication speed and continues the training until it succeeds, because the training is performed using the set communication speed.

Next, at time T6, the reception side facsimile apparatus transmits a reception preparation confirmation signal (CFR) to the transmission side facsimile apparatus due to the successful training. Upon receiving the reception preparation confirmation signal (CFR), the transmission side facsimile device sets the communication speed used for successful training to the communication speed in the current transmission.

Subsequently, at time T7, in the transmitting side facsimile apparatus, the scanner 1 starts the reading of the transmission original to form the transmission data, and the encoding unit 9 encodes the transmission data to form the encoded data. . At this time, the communication control unit 11 transmits the encoded data (PIX) to the receiving side facsimile device via the network control device 7.

Subsequently, at time T8, the communication control unit 11 transmits the page signal (PPS-MPS) together with the coded data (PIX) to the receiving side facsimile device.

Next, at time T9, when the receiving side facsimile device receives the encoded data (PIX) of the first page, in response to this, it transmits a message confirmation signal (MCF) to the transmitting side facsimile device. Page (second
Encourage the transmission of encoded data (page).

Next, at time T10, the communication control section 11 transmits the coded data (PIX) of the next page (second page) to the receiving side facsimile apparatus.

After that, at time T11, when the transmission of all the encoded data is completed, the communication control section 11 sends a procedure end signal (PPS-EOP) to the receiving facsimile machine.
To send.

Next, at time T12, when the receiving side facsimile device receives the procedure end signal (PPS-EOP), it transmits a message confirmation signal (MCF) to the transmitting side facsimile device in response thereto.

Next, at time T13, the communication control unit 11 transmits a disconnection command signal (DCN) to the receiving facsimile machine in response to the reception of the message confirmation signal (MCF). After that, the communication control unit 11 disconnects the communication connection with the facsimile apparatus on the receiving side through the network control device 7, and the exchange of this series of various information ends.

Next, FIG. 3 is a flow chart showing a procedure of receiving a data frame and the like which is executed by the facsimile apparatus according to this embodiment shown in FIG.

Using the flow chart shown in FIG.
A procedure for receiving a data frame or the like executed by the facsimile apparatus according to this embodiment will be described.

In the operation process of steps S1 to S10 in this flowchart, the operation process executed in steps S1 to S6 is the same as the operation process executed in times T1 to T6 shown in FIG. The operation processing is the same, and the operation processing executed in steps S8 to S10 is the same as the operation processing executed in times T11 to T13 shown in FIG. For this reason,
The description of the operation processing executed in steps S1 to S6 and steps S8 to S10 will be omitted.

First, in step S7, the communication control unit 11 determines whether or not reception of all coded data (PIX) has been completed. When it is determined that the reception of all the encoded data (PIX) is completed (Y), the process proceeds to the next step S8, while the reception of all the encoded data (PIX) is not yet completed. When the determination is (N), the process proceeds to another step S11.

In step S11, the communication control unit 11 cooperates with the frame determination unit 6 to determine whether the received frame is a data frame. And
If the received frame determines that the received frame is a data frame (Y), the process proceeds to the next step S12, while if the received frame determines that the received frame is not a data frame (N), another step is performed. S1
Move to 3.

Next, in step S12, the communication control unit 11 determines that the frame received in step S11 is a data frame, and therefore the data frame received in cooperation with the frame determination unit 6 is a short frame. Or not. Then, it is determined that the received data frame is a short frame (Y).
If it is determined that the received data frame is not a short frame (N), the process proceeds to another step S20.

Next, in step S13, the communication control unit 11 determines that the frame received in step S11 is not a data frame, and therefore the frame received in cooperation with the frame determination unit 6 is an RCP frame. Determine whether or not. When it is determined that the received frame is the RCP frame (Y), the process proceeds to the next step S14, while the received frame is the RCP frame.
If it is determined that the frame is not a frame (N), the process returns to the previous step S7, and the operations after step S7 are repeatedly executed. In this case, it is determined whether the received frame is a data frame or an RCP frame if the information of the frame control frame (FCF) in the header part of the frame is "06", it is a data frame. If it is "86", it can be determined that the frame is an RCP frame.

Subsequently, in step S14, the communication control section 11 determines whether or not the short frame reception flag is set (set). When it is determined that the short frame reception flag is set (Y), the process proceeds to the next step S15, while when it is determined that the short frame reception flag is not set (N), the previous step is performed. Returning to S7, the operations after step S7 are repeatedly executed again.

Next, in step S15, the communication control unit 11 determines that the frame received in step S13 is RCP.
Since the frame is a frame, and it is determined that the short frame reception flag is set at this time, the short frame reception flag is not set (reset state).

Next, in step S16, the communication control unit 11 receives the RCP frame, and performs a frame data reception end process. After this processing is performed, the process returns to the previous step S7, and the operations after step S7 are repeatedly executed again.

Further, in step S17, the communication control section 11 sets (sets) the short frame reception flag because it has determined that the short frame has been received in step S12.

Next, in step S18, the communication control section 11 transfers the frame information of the received short frame to the storage section 5 and stores it therein.

Next, in step S19, the communication control unit 11 stores the received short frame itself in the storage unit 5.
And save it there. After this processing is performed, the process returns to the previous step S7, and the operations after step S7 are repeatedly executed again.

Further, in step S20, the communication control unit 11 determines that the short frame is not received in step S12. Therefore, if the short frame reception flag is set, the short frame reception flag is not set ( Reset state).

Next, in step S21, the communication control unit 11 determines that the normal data frame is received in step S12, and thus transfers the normal data frame to the storage unit 5 and stores it therein.

Next, in step S22, the communication control unit 11 carries out a frame data reception end process when a normal data frame is received. After this processing is performed, the process returns to the previous step S7, and the operations after step S7 are repeatedly executed again.

It should be noted that there is a rare case where the RCP frame itself has an error while it is judged in step S13 that the received frame is not the RCP frame. In this case, return to the previous step S7,
The operations after step S7 are repeatedly executed again.

Thus, after returning to step S7, the processing procedure of this flowchart is repeatedly executed until there are no more frames to be received.

If the reception of an error frame is detected when the reception operation is completed through the above processing procedure, a request for resending the error frame is issued to the facsimile apparatus on the other side, and the reception of the error frame is detected. If not, data reproduction processing such as decoding of the received data frame is performed.

Further, in this facsimile apparatus,
Similar to a known facsimile apparatus having an error correction mode (ECM) communication function, error frame determination by a frame check sequence (FCS) may be used together.

[0061]

As described above, according to the present invention, when a short frame is received, it is not immediately determined whether the short frame is an error frame or a final data frame, but the short frame is received next. If the content of the frame is a data frame, it is determined that the short frame received immediately before is an error frame, and a retransmission request signal for that short frame is transmitted to the facsimile machine on the other side. If the received frame is an RCP frame, it is determined that the short frame received immediately before is the final data frame, and the data reproduction processing of the short frame is performed. Therefore, when the short frame is received, The short frame is the error frame or the final data frame. There is an effect that it is possible to reliably distinguish whether.

[Brief description of drawings]

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

FIG. 2 is an operation explanatory diagram showing a transmission / reception state of various information when transmitting encoded data from a transmission side facsimile apparatus to a reception side facsimile apparatus.

FIG. 3 is a flowchart showing a procedure of receiving a data frame and the like executed by the facsimile apparatus according to this embodiment shown in FIG.

FIG. 4 is a frame configuration diagram showing an example of a transmission / reception frame used in a facsimile apparatus.

FIG. 5 is a frame configuration diagram showing an example of a data frame used in a facsimile apparatus.

[Explanation of symbols]

1 scanner 2 printing section 3 input section 4 Display 5 memory 6 frame determination section 7 Network control unit (NCU) 8 fax (fax) modem 9 Encoding section 10 Decoding section 11 Communication control unit 12 ROM 13 System control unit 13 14 system bus 15 communication lines

Claims (2)

[Claims] 1. A data reproduction process of the data frame is performed when it is determined whether the received data frame is a normal data frame or an error frame, and the data frame is determined to be a normal data frame. In a facsimile device that transmits a retransmission request signal to a partner facsimile device when the data frame is determined to be an error frame, if the number of bytes of the received data frame is a short frame that does not satisfy the specified number of bytes, The contents of the frame received next to the short frame are examined, and when the next received frame is a data frame, it is determined that the short frame is an error frame, and the facsimile machine of the other side is notified of the short frame. Send a resend request signal and then receive A facsimile machine, wherein the short frame is determined to be the final data frame when the frame is an RCP frame, and the data reproduction process of the short frame is performed. 2. When a short frame is received, the data and frame number of the short frame are stored in the storage unit without setting the reception end state, and the short frame reception flag is set to the normal state, When the data frame is received, the short frame reception flag is reset without setting the reception end state, the stored data of the short frame is discarded, and when the RCP frame is received, the short frame is received. 2. The facsimile apparatus according to claim 1, wherein it is confirmed that the frame reception flag is in a set state, the stored data of the short frame is sent to a data reproduction process, and a reception end state is set.