JPH0449829B2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a facsimile communication method, and in particular has a function of storing image information of a document, and in case an abnormality occurs during communication and the call is restored or disconnected. The present invention relates to a facsimile device having a function of automatically retransmitting data in case of a facsimile machine.

(Prior Art) In a facsimile device that does not have a function to store image information of a document, if a communication error occurs for some reason and the call is restored or disconnected, in other words, the waiting time for receiving a control signal while the facsimile procedure is in progress. When the call is restored due to a timeout, alarm call, telephone call, etc., or when the call is interrupted by a procedure interrupt signal, the operator has to scan again from the document where the communication error occurred. On the other hand, with a facsimile device that has the function of storing the image information of the original and then transmitting it, if a communication error occurs and the call is restored or disconnected, there is no need to scan the original again, and the call is disconnected or disconnected. It is possible to automatically retransmit after a certain period of time. This type of facsimile device is effective against line disconnections due to the other party's busy state or line disconnections due to short-term deterioration in line quality. However, if the communication functions of the retransmitting device and the destination receiving device are different, and communication between the two devices is impossible, that is, if there is no communicability,
Retransmissions become meaningless, and there are problems in that they reduce the actual operating rate of the equipment and the efficiency of the communication line.

(Objective of the Invention) The present invention solves the above drawbacks by adopting an automatic retransmission method that prevents automatic retransmission when communication is restored due to lack of communication during the capability identification phase with the partner device. It is.

(Means for Achieving the Object of the Invention) The present invention provides a facsimile device having a function of automatically retransmitting when a call is restored or disconnected due to communication abnormality during transmission, receiving a function identification signal of a receiving device of the other party. This problem is solved by adopting a retransmission method in which retransmission is not performed when a call is disconnected due to lack of communication.

(Example) Next, an example of the present invention will be described with reference to the drawings.

Figure 1 shows a CCITT using the retransmission method of the present invention.
FIG. 2 is a block diagram of a communication control section and a retransmission control section of a recommended G standard facsimile device.

In the figure, 1 is a general-purpose 8-bit CPU that controls the retransmission control section, 2 is a read-only memory (ROM) in which the control program for CPC1 is stored, and 3 is a general-purpose 8-bit CPU that controls the retransmission control section.
This is random access memory (RAM) for working storage of the CPU1. 4 is LSI for timer
Each chip has three channel timers. A general-purpose parallel input/output LSI (PIO) 5 is used for controlling the shared memory 6 and for handshake communication with the CPU 7 of the communication control section. The retransmission control section includes these CPU 1, ROM 2, RAM 3, timer 4, and parallel input/output LSI 5.

The communication control unit consists of a general-purpose 8-bit CPU7 and a CPU
ROM 8 in which control programs of 7 are stored;
RAM9 for working storage of CPU7,
CPU 7 for controlling shared memory 6 and communication control unit
It includes a general-purpose parallel input/output LSI 10 (P10) that performs handshake communication with.

6 is CPU1 of the retransmission control section and CPU of the communication control section
7. This is shared memory between both parties. Information is exchanged between the retransmission control section and the communication control section via this shared memory. This shared memory is for parallel input/output
It is connected to the internal data bus of either CPU 1 or CPU 7 by shared memory control signals from LSIs 5 and 10. Also, parallel input/output LSI5,1
Writing ends with a handshake signal of 0.
Sends information on completion of reading to the other party's CPU. For example, when transferring commands from CRU1 to CPU7,
After confirming that the CPU 7 has finished reading, the shared memory is connected to the internal data bust of the CPU 1 using the shared memory control signal on the CPU 1 side, data is written, and then the completion of writing is sent to the CPU 7. In response to this, the CPU 7 connects the shared memory to the internal data bus of the CPU 7 using a shared memory control signal on the CPU 7 side, reads the data, and then sends a read end notification to the CPU 1. In this way, commands are transferred from CPU1 to CPU7. The response is transferred from the CPU 7 to the CPU 1 in the same manner as the transfer from the CPU 1 to the CPU 7.

Reference numeral 11 denotes a transmitting/receiving buffer used for exchanging image signal data with the magnetic disk device 15. The image signal data is exchanged by direct memory access (DMA) transfer in units of 10 Kbytes. Image signal data between the DMA transfer and communication protocol control unit 13 and the transmission/reception buffer 11
DMA transfer is performed by the DMA transfer control LSI 12. The communication protocol control unit 13 performs framing of binary commands specified in CCITT Recommendation T30, detection of frame check sequence (FCS) errors, control of the modem, transmission and reception of image signal data, and the like. 14 is a 3-channel timer, which is the same as timer 4, and is mainly used as a timer in the transmission of called station identification/calling (CED/CNG) signals and in the T30 binary procedure. The disk control unit and the disk device 15 store image information of the scanned and transmitted original.

Next, the operation of each part during document transmission will be explained in conjunction with FIG. 2.

FIG. 2 is a flowchart showing the facsimile call operation of the apparatus shown in FIG. When the rephase control unit receives a call request command from the outside, the CPU 1 transfers the call request command to the communication control unit via the shared memory 6 (17). In response to this, the CPU 7 issues a ringer using the communication protocol control unit 13 and timer 14 and transmits 17 a calling (CNG) signal. When a called station identification (CED) signal is received 19 from the other party's receiving device and a digital identification signal (DIS) signal is received 20, the CPU 7 determines the presence or absence of communication based on the contents thereof (21).

If there is communication, a response indicating the completion of phase A (call setup phase) including information indicating that communication is available is returned to the CPU 1 of the retransmission control unit in response to the call request and command (22). . When the retransmission control CPU 1 receives a response indicating that communication is possible, it sends a disk read request command via the shared memory 6.
Send to CPU 7 (23). The CPU 7 of the communication control section is
When the receiving ready (CFR) signal is received 25 from the partner device in response to the training check (TCF) signal transmission 24, a response to the disk read request is returned via the shared memory 6 (26). CPU
1 receives this response and sends a read signal to the disk control section 15, and the disk control section 15 writes 10 Kbytes of image signal data to the transmission/reception buffer 11 by DMA transfer. The CPU 7 receives this image signal data, and sends it to the communication protocol control section 13 under the control of the DMA control LSI, and sends the image signal to the partner device (27). As mentioned above, the image signal is transmitted by the command from the CPU to the CPU7 to request a disk read.
This is done after the response from CPU7 to CPU1. When all image signals are transmitted and communication is completed normally,
The CPU 7 sends a communication end response to the CPU 1 via the shared memory 6 (28).

In process 21, when it is determined that there is no communication, the CPU 7 instructs the communication protocol control unit 13 to send a line disconnection command (DCN) signal 30 to the line, and also sets the communication error cause code to indicate no communication. A response indicating the end of phase A including a cause code for no communication is sent to the CPU 1 of the retransmission control unit via the shared memory 6 (31). In response to this, the CPU 1 of the retransmission control unit prints all the scanned originals, and also prints an original undelivered message with the number of originals sent to the other party's facsimile machine and the cause code for no communication (32 ). When the transmission end state 28 is reached, the transmission of the document scanned in the transmission start state 16 is ended.

Next, a case will be described in which a communication error occurs even though there is communication.

Communication errors occur during the progress of each binary control procedure, such as when a control signal is not received within a specified time, or when a procedure abort signal is received that indicates a procedure malfunction in the other device. be. If such a communication abnormality is recognized,
The CPU 7 sends a communication termination response to the CPU 1 via the shared memory 6, including a code indicating that the communication has terminated due to an abnormality. The CPU 1 detects the number of responses 34, and when the number of responses is the third time, that is, when the communication error occurs for the third time, the document enters the document undelivered message print state 32, and is scanned in the transmission start state 16. Prints all originals and also prints an original undelivered message with the number of originals sent and other cause codes to the other party's facsimile machine. Finally, in a transmission end state 28, the transmission of the document scanned in step 16 is ended.

If the communication abnormality determination 34 indicates that the communication abnormality has occurred twice or less, the two-minute timer completes 35. That is, it waits for the 2-minute timer of timer 4 to start and count up. When timer 4 counts up, it sends an interrupt signal to CPU1. CPU
1 receives this interrupt signal and sends a call request command to the CPU 7 of the communication control unit via the shared memory 6 in the same manner as described above, and communication is executed again in the same manner as described above. When transmitting image data, the data stored in the disk is not retransmitted for one page that has been sent, but is retransmitted from the first page that could not be sent for one page due to a previous communication error.

(Effects of the Invention) As described above, the present invention has the effect of preventing unnecessary automatic retransmission by stopping retransmission when a function identification signal is received and a lack of communication is detected.

[Brief explanation of the drawing]

Figure 1 shows an embodiment of the present invention in CCITT Recommendation G.
FIG. 2 is a block diagram of the communication control section and retransmission control section of the standard facsimile apparatus, and is a flowchart showing the binary control procedure of the communication control section and retransmission control section shown in FIG. 1... CPU for controlling the retransmission control unit, 2, 8... ROM for storing programs, 3, 9... Working...
ROM for storage, 4, 14... LSI for timer,
5, 10... LSI for parallel input/output, 6... Shared memory, 7... CPU for controlling communication control unit, 11... Transmission/reception buffer, 12... LSI for DMA transfer control,
13...Communication protocol control unit, 15...Disk control unit and disk device.

Claims (1)

[Scope of Claims] 1. A communication control unit that controls the transmission of image data, and a communication control unit that controls retransmission of the image data when the call is restored or disconnected due to communication abnormality after the start of transmission. In a facsimile device with a retransmission function, the communication control unit determines communication from the contents of the DIS signal when the communication control unit receives a standard function identification signal (DIS signal) from the other party's receiving device after starting transmission. A facsimile apparatus with a retransmission function, characterized in that the retransmission control unit stops retransmission when it is determined by the means that there is no communication.