JPH08111761A - Facsimile equipment - Google Patents

Abstract

PURPOSE: To provide facsimile equipment provided with communication controller capable of operating normally even by using a partial page buffer of prescribed capacity. CONSTITUTION: When an incoming call is received, a G3C protocol control part 21 requests plural sheets of areas which become the partial page buffers to the memory managing device 23 of an image accumulation device. A partial page buffer managing part 24 secures the area of an available partial page buffer at that time, and reports the number of secured sheets of areas to the memory managing part 23. The memory managing part 23 reports the number of sheets of areas of available partial page buffer to the G3C protocol control part 21. The G3C protocol control part 21 selects a half-duplex operation when the number of sheets of areas of the available partial page buffer is one, and selects a full-duplex operation when it is two or more. Consequently, the facsimile equipment can be operated normally even by using the partial page buffer of prescribed capacity.

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, it achieves high-speed communication by appropriately switching between full-duplex operation and half-duplex operation, and at the same time, stores image information in a memory having a predetermined capacity. The present invention relates to a facsimile device capable of receiving a message without overflow.

[0002]

2. Description of the Related Art Conventionally, the transmission and reception of data in the G3 and G4 protocols of a facsimile machine is controlled by the ITU.
-Developed according to the T recommendation. As is well known, G
Currently, the maximum speed of the three protocols is 1
Since it is 4.4 Kbps, the communication speed is slower than that of the G4 protocol, but since data transmission and reception can be performed by software control, an 8-bit CPU
It can be used in the system. Therefore, the G3 facsimile apparatus can be realized with the minimum necessary hardware configuration and can be manufactured at low cost.

On the other hand, the G4 protocol is characterized by high-speed communication, and it is necessary to realize a communication speed of 64 Kbps. For this reason, sending and receiving of data cannot be done by software control alone, and requires a DMA and a buffer for accumulating data. Also, CPU
Also, if it is not a 16-bit system, the communication speed cannot be satisfied. Therefore, although the production cost of the G4 facsimile apparatus is higher than that of the G3 facsimile apparatus, it can be said that the communication speed has an overwhelming advantage.

Protocols having the above characteristics are well known to those skilled in the art, but in recent years, ITU-T T.264 has been known. At 30, a new communication protocol (hereinafter referred to as G3C protocol) was recommended. The features of this G3C protocol are:
It looks like this: That is, (1) the protocol procedure is based on the G3 protocol. (2) The communication speed is 64 Kbps, which is equivalent to the G4 protocol.
(3) Communication can be controlled in full duplex. It is also possible to control with half-duplex.

An example of the error collect mode (ECM) in the conventional G3 protocol will be described with reference to FIG. In the figure, when the transmitter performs calling (CNG) on the receiver, as is well known, the receiver receives CED,
It sends back a command such as DIS and notifies its own capability, identification number, etc. When the transmitter receives these commands, D
The CS notifies the transmission conditions, the identification number of the transmission side, etc., and performs a training check (TCF). On the other hand, when there is a reception preparation confirmation response (CFR) from the receiving side, the transmitter starts transmitting image information. The image information is sent by FC
D (facsimile coded data) frame. Usually, when 256 frames are transmitted, partial page signal-null (PPS-NULL) is transmitted. Note that the 256 frames are called partial pages, and
It consists of K bytes of data.

In the G3 protocol ECM, as shown in the figure, a response confirmation signal (MC) for PPS-NULL that all frames have been correctly received.
When F) is received by the transmitter, the transmission of the image information of the next partial page can be started. On the other hand, when a partial page request signal (PPR) is received instead of this MCF, the requested frame is retransmitted, and after receiving the MCF, the next partial page is transmitted. In addition,
In the illustrated example, the image information of the second partial page is sent following PPS-NULL (0,0), and by sending this image information, all the image information has been sent, so the transmitter After outputting PPS-EOP from MCF, MCF is received and a disconnection command (DCN) is transmitted.

Next, an example of full-duplex operation of the G3C protocol will be described with reference to FIG. In the G3C protocol, there is a rule that the same command is output three times in succession, so each command is marked with “3 ×”. The feature of this full-duplex operation is that the transmitter does not send PP after sending partial pages.
When S-NULL (for example, arrow A) is transmitted, the image information of the next partial page can be output without receiving the response confirmation signal from the receiver. In the example shown, MCF
It is indicated that the FCD frame of the next partial page is transmitted before the (arrow B) is received.

Next, an example of half-duplex operation of the G3C protocol will be described with reference to FIG. The feature of this half-duplex operation is that the transmitter can send PPS-NULL after sending partial pages.
This means that the FCD frame of the next partial page cannot be sent unless the response confirmation signal MCF (view C) from the receiver is received when (for example, arrow A) is sent. In the G3C protocol, the selection of full-duplex operation and half-duplex operation is not specified in the above recommendation, and is left to the designer of the device.

[0009]

As described above, in the conventional ECM of the G3 protocol, the transmitting side cannot send the next partial page until after receiving the MCF signal. Therefore, the partial page buffer is used. Is one side, ie 6
If there was a 4 Kbyte partial page buffer, communication could be controlled. However, in the G3C protocol, the image information of the next partial page can be transmitted between partial pages without any confirmation response. Also, if there is a response such as MCF or PPR between pages,
It becomes possible to send the image information of the next page. Therefore, there is a problem that the receiving side needs a large capacity partial page buffer.

An object of the present invention is to eliminate the above-mentioned problems of the prior art and to provide a facsimile apparatus having a communication control device which can operate normally even if a partial page buffer having a predetermined capacity is used. It is in.

[0011]

In order to achieve the above-mentioned object, the invention of claim 1 is capable of transmitting and receiving data by appropriately switching between full-duplex operation and half-duplex operation. In a facsimile apparatus, a means for setting a partial page buffer for temporarily storing received data when starting a receiving operation, a means for detecting the capacity of the set partial page buffer, and a means for detecting the detected partial page buffer It is characterized in that it has means for activating a half-duplex operation when the capacity is equal to or less than a predetermined predetermined capacity, and activating a full-duplex operation when the capacity is larger than the predetermined capacity.

According to the second aspect of the present invention, it is determined whether or not a signal indicating that reception is impossible is received from the receiver side when transmitting in full-duplex operation, and when it is determined that a signal indicating reception is impossible is received. , Means to activate the mode change procedure, and when receiving,
When the mode change procedure is received, the mode change means for changing the mode of the signal indicating the capability of the receiver from the full-duplex operation to the half-duplex operation is provided.

[0013]

According to the invention of claim 1, when the capacity of the partial page buffer of the receiver is equal to or smaller than a predetermined size, the half-duplex operation is selected, and when the capacity is larger than the predetermined size, the half-duplex operation is selected.
Full-duplex operation is selected. Therefore, it is possible to prevent a failure from occurring in the full-duplex operation due to the small capacity of the partial page buffer.

According to the second aspect of the invention, when unreceivable data is generated due to a line abnormality or the like, a large amount of unreceivable data may be generated if the full-duplex operation is continued. By switching to the half-duplex operation as in the present invention, it is possible to prevent a large amount of unreceivable data from being generated and reduce the load of protocol processing on the transmitter side.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 2 is a block diagram showing a hardware configuration of a facsimile machine to which the present invention is applied. In the figure, reference numeral 1 denotes a CPU for performing control processing of the entire facsimile apparatus and facsimile transmission control procedure processing, 2 denotes a work area used by a control program described later, or RAM for providing a memory for temporarily storing data, 3 Is an operation display device used by the user to operate the facsimile apparatus. Further, 4 is a reading device for reading a transmission document, 5 is a printing device for printing out a received image, etc., 6 is an image processing device for encoding transmission data and decoding reception data,
An image storage device 7 stores transmission or reception image information.

Further, 8 is a system control section which is the control program for controlling the entire facsimile apparatus,
A communication control unit 9 is a program for controlling facsimile communication, that is, G3C communication. The system control unit 8 and the communication control unit 9 are composed of ROM.
Reference numeral 10 is a network control device connected to the ISDN line network and has an automatic call originating / receiving function. Reference numeral 11 is a system bus for exchanging data with each other among the above-mentioned components.

Next, the configuration of an embodiment of the present invention will be described with reference to the functional block diagram of FIG. This functional block diagram shows the functions of the communication control unit 9 and the image storage device 7. When there is an incoming call, the G3C protocol control unit 21 causes the memory management unit 23 of the image storage device 7 to
Request multiple areas for the partial page buffer. When the memory management unit 23 receives this request, it instructs the partial page buffer management unit 24 to prepare partial page buffers for multiple planes. Here, the partial page buffer management unit 24 secures a usable area of the partial page buffer in the state at that time and notifies the memory management unit 23 of the secured number of pages. The memory management unit 23 notifies the G3C protocol control unit 21 of the number of usable partial page buffers.

Next, the operation of the first embodiment of the present invention will be described with reference to FIG.
This will be described with reference to the flowchart in FIG. FIG. 3 represents the operation of the receiver. In step S1, it is determined whether or not there is an incoming call, and if there is an incoming call, the process proceeds to step S2 and line connection processing is performed. When it is determined that the connection is completed in step S3, the process proceeds to step S4, and the G3C protocol control unit 21 requests the memory management unit 23 for N (for example, 3) partial pages. In step S5, it is determined whether or not there are two or more set partial pages. If the determination is affirmative, the process proceeds to step S7, and full-duplex operation is activated. On the other hand, if the number is one or less, the process proceeds to step S6 to activate the half-duplex operation.

In step S8, it is determined whether or not a signal is received from the transmitter, and if received, the process proceeds to step S9, in which it is determined whether or not the received signal is an XID signal (exchange identification procedure signal). It If this determination is affirmative, the process proceeds to step S10, the XID signal is processed,
In step S11, a DIS signal in which an operation mode including the mode activated in step S6 or S7 is set is created. For example, in half-duplex operation, the G3C protocol control unit 21 sets the full-duplex / half-duplex display bit of DIS to “0”, and in full-duplex operation, full-duplex / half-duplex of DIS. The double display bit is set to "1". Step S1
In 2, the XID (NSF) (CSI) DIS signal is transmitted.

When the determination in step S8 is negative, the process proceeds to step S13, it is determined whether a time-out has occurred, and if a signal is not received within a predetermined time, the process proceeds to step S14 to disconnect the line. To do. Also,
When the determination in step S9 is negative, step S1
In step S16, other signal processing is performed, a signal corresponding to the signal processing is transmitted to the transmitter in step S16, and finally the line disconnection processing is performed in step S17 to finish the processing.

As described above, according to this embodiment, if the number of partial page buffers first notified from the memory management unit 23 is one, the half-duplex operation is selected, and if it is two or more. For example, full-duplex operation is selected so that the operation appropriate to the current state of the receiver can be performed.
Further, when the number of partial page buffers set is one, full-duplex operation is not selected, so the possibility that received data will overflow the partial page buffer is reduced, and a reliable facsimile device is provided. You will be able to.

Next, a second embodiment of the present invention will be described with reference to the flow charts of FIGS. In this embodiment, when the receiving side returns an unreceivable signal (RNR signal) to the image information sent by the transmitting side, the full-duplex operation is switched to the half-duplex operation.

When a call is made in step S21 of FIG. 4, the process proceeds to step S22, and line connection processing is performed. In step S23, it is determined whether or not the connection is completed. When the connection is completed, the process proceeds to step S24, where X
ID signal transmission processing is executed. In step S25, it is determined whether or not any signal is received from the receiver side. If the determination is negative, the process proceeds to step S26, and it is determined whether or not a predetermined time has elapsed. When the time-out has occurred, the process proceeds to step S27, and it is determined whether or not the retry-out has occurred. If the determination is affirmative, the process proceeds to step S28 and the line disconnection process is performed.

On the other hand, if the determination in step S25 is affirmative, it is determined in step S29 whether the DIS signal has been received. If this judgment is affirmative, step S
In step 30, the DIS signal is processed. At this time, it is detected whether the receiver has the capability of half-duplex operation or full-duplex operation. In step S31, the DCS in which the operation mode is set according to the capability of the receiver is created, and this is transmitted to the receiver in step S32. When the DIS signal indicates that the receiver is capable of full duplex operation, the transmitter instructs the DCS signal to transmit in full duplex operation.

Next, when the protocol advances and step S29 becomes negative, the process proceeds to step S33, it is judged whether or not the reception disable signal (RNR signal) is received, and this judgment is negative. At times, the process proceeds to step S34, other signal processing is performed, the signal of the processing result is transmitted in step S35, and the line disconnection process is performed in step S36.

When it is determined that the page cannot be received in step S33, the process proceeds to step S37, and it is determined whether there is a page to be further transmitted. If the determination is affirmative, the process proceeds to step S38 and the mode is set. The change procedure is activated. Specifically, the PPS-EOM signal is transmitted. When step S37 is negative, step S37
Proceed to 39 to activate the termination procedure (PPS-EOP).

After the procedure of step S38, step S25
Then, the operation is restarted from the phase B. When the transmitter transmits the PPS-EOM signal, the receiver determines whether or not it is in the RNR state, as apparent from steps S59 to S63 (see FIG. 5) of the receiver, which will be described later. If it is in the state, since the DIS signal indicating the half-duplex operation capability is transmitted, it is detected in step S30 in FIG. 4 that the receiver has displayed the half-duplex operation capability, and in step S31, half-duplex operation is detected. Create a DCS that directs the operation,
Send to receiver. As a result, the subsequent image information transmission operation will be performed in half-duplex operation, and the image information of the next partial page or page will be transmitted only after receiving a response signal from the receiver that the image has been normally received. Is no longer performed, and the operation of transmitting image information can be ensured.

Next, the operation of the receiver will be described with reference to FIG. In the figure, steps S41 to S54 and S
56 to S58 are steps S1 to S14 and S of FIG.
The description is omitted because it is the same as 15 to S17. If it is determined that the PPS-EOM is received in step S55,
In step S59, it is determined whether or not the reception is impossible (RNR). If this determination is affirmative, the flow proceeds to step S60, and half-duplex operation is activated. On the other hand, if the reception is not disabled, the full-duplex operation is activated. Assuming that the reception is disabled, in step S62, a DIS with half-duplex operation is created,
In step S63, XID (NSF) (CSI) DIS
Send a signal. Then, the process returns to step S48 again to continue the operation.

Generally, receiving the RNR signal from the receiver is expected to cause a situation in which the state of the line or the like is unstable and reception is impossible in future communication. According to the present embodiment, in the above case, since the full-duplex operation is switched to the half-duplex operation, the reliability of communication can be increased and the load of the protocol processing on the transmitter side can be reduced. Will be able to.

FIG. 6 shows the operation of the second embodiment in a concrete sequence diagram. For the RNR signal (arrow D) sent from the receiver side in the figure, the transmitter
When the PS-EOM signal (view E) is output, the receiver outputs the DIS signal (view F) indicating the half-duplex operation capability. This causes the transmitter to instruct the DCS to perform half-duplex operation, and the subsequent operation is switched to half-duplex operation.

[0031]

According to the first aspect of the present invention, the half-duplex operation is selected when the partial page buffer of the receiver has a predetermined amount or less, and the full-duplex operation is selected when the partial page buffer is larger than the predetermined amount. Therefore, full-duplex operation is not selected when the capacity of the partial page buffer is less than or equal to a predetermined amount, the possibility that received data overflows the partial page buffer is reduced, and a reliable facsimile device is provided. be able to.

According to the second aspect of the present invention, when the state of unreceivability occurs, the full-duplex operation is switched to the half-duplex operation, so that the unreceivable reception occurs when the full-duplex operation is continued. It is possible to prevent a large amount of data from being generated. Also, the load of protocol processing on the transmitter side can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing functions of essential parts of the present invention.

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

FIG. 3 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of the transmitter according to the second exemplary embodiment of the present invention.

FIG. 5 is a flowchart showing an operation of the receiver of the second embodiment.

FIG. 6 is a diagram showing an example of a protocol according to the present invention.

FIG. 7 is a diagram showing an example of a conventional G3 protocol.

FIG. 8 is a diagram showing full-duplex operation in the G3C protocol.

FIG. 9 is a diagram showing half-duplex operation in the G3C protocol.

[Explanation of symbols]

10 ... Network control device, 21 ... G3C protocol control unit, 2
2 ... HDLC frame sending / receiving unit, 23 ... Memory management unit, 24 ... Partial page buffer management unit, 25-27 ... Partial page buffer.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H04L 29/08 13/08 9371-5K

Claims (2)

[Claims] 1. A facsimile device capable of transmitting and receiving data by appropriately switching between full-duplex operation and half-duplex operation, and a portion for temporarily storing received data when starting the receiving operation. Means for setting the page buffer, means for detecting the set capacity of the partial page buffer, and activating half-duplex operation when the detected capacity of the partial page buffer is equal to or less than a predetermined capacity. And a means for activating full-duplex operation when the capacity is larger than the predetermined capacity. 2. A facsimile apparatus capable of transmitting and receiving data by appropriately switching between full-duplex operation and half-duplex operation, and from the receiver side when transmitting in full-duplex operation. A means for activating a mode change procedure when it judges that it has received a non-receivable signal and judging that it has received a non-receivable signal, and a signal indicating the capability of the receiver when the mode change procedure is received during reception. And a mode changing means for changing the mode from full-duplex operation to half-duplex operation.