JPS61173579A - Resending system with automatic resending interrupting function for facsimile communication - Google Patents

Abstract

PURPOSE:To prevent the operating rate of a device and the efficiency of a communication circuit from decreasing by receiving the function identification signal of an opposite receiving device and inhibiting a signal from being resent when a call is disconnected owing to a no-communication state. CONSTITUTION:A CPU7 receives a called station identification (CED) signal from the opposite device and further receives a digital identification signal (DIS) signal to judge whether communication is required or not from the contents of the received signals. When it is judged that the communication is not necessary, the CPU7 instructs a communication protocol control part 13 to disconnect a circuit, and adds a code showing no communication to the cause code of communication abnormality and sends the answer of the end of phase A including said codes to the CPU1 of a resending control part through a shared memory 6. The CPU1 receives it to print a scanned original and also print the number of originals sent to the opposite device and an original nonreach message including the cause code of no communication.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a facsimile communication system, and in particular has a function of storing image information of a document, and is capable of facsimile communication when an abnormality occurs during communication.
The present invention relates to a retransmission method for a facsimile machine having a function of automatically retransmitting when the call is restored or disconnected.

(Prior art) In a facsimile machine 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, that is, the waiting time for receiving a control signal while the facsimile procedure is in progress. When the call is restored due to a timeout, an alarm call, a telephone call, etc., or when the call is interrupted by a procedure interrupt signal, the operator has to start scanning again from the document where the communication error occurred.

On the other hand, with a facsimile machine that has the function of storing image information of a document and then transmitting it, if a communication error occurs and the call is restored or disconnected, there is no need to scan the document again, and the call is disconnected or disconnected. Retransmission can be performed automatically after a certain period of time after recovery. This type of facsimile device is effective against line disconnections due to a busy state of the other party's device or line disconnections due to a 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 not possible, that is, if there is no communication, or if communication is not possible even after a period of time due to line quality deterioration, etc. In some cases, retransmission becomes meaningless, resulting in a problem of lowering the actual operating rate of the device and lowering the efficiency of the communication line.

(Objective of the Invention) The present invention solves the above-mentioned 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 other device. It is.

(Means for Achieving the Object of the Invention) The present invention provides a facsimile IJ that has a function of automatically retransmitting when a call is restored or disconnected due to communication abnormality during transmission.
The above-mentioned drawbacks are solved by adopting a retransmission method in which the device receives the function identification signal of the other receiving device and does not perform retransmission when the call is disconnected due to lack of communication.

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

FIG. 1 is a block diagram of a communication control section and a retransmission control section of a facsimile apparatus according to the CCITT Recommendation G standard to which the retransmission method of the present invention is applied.

In the figure, 1 is a general-purpose 8-bit CPU that controls the retransmission control unit, 2 is a read-only memory (ROM) in which a control program for the CPUI is stored, and 3 is a random access memory (RAM) for working storage of the CPUI. 4 is a time LSI having three channels of timers per chip.

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 unit is CPU1.
．． ROM2. RAM3, time 4 and parallel input/output L
Contains SI5.

The communication control unit includes a general-purpose 8-bit CPU 7, a ROM 8 in which a control program for the CPU 7 is stored, a RAM 9 for working storage of the CPU 7, and a general-purpose unit that controls the shared memory 6 and performs handshake communication with the CPU 7 of the communication control unit. This includes a parallel input/output LSI (PIO).

6 is a memory shared by both the CPUI of the retransmission control section and the CPUUT of the communication control section. Information is exchanged between the retransmission control section and the communication control section via this shared memory. This shared memory is connected to the internal data bus of either the CPU I or the CPU 7 by a shared memory control signal from the parallel input/output LSIs 5 and 10. Also, information on the completion of writing and completion of reading is sent to the other CPU by handshake signals of the parallel input/output LSIs 5 and 10. For example, when transferring commands from CPU1 to CPU7, CPU
After confirming that U7 has finished reading, connect the shared memory to the internal data bus of the CPUI using the shared memory control signal on the CPU1 side, write the data, and then notify the CPU that the writing has finished.
Send to 7. In response to this, the CPU 7 uses the shared memory control signal on the CPU 7 side to connect the shared memory to the internal data bus of the CPU 7, reads the data, and then indicates the end of the reading to the CP.
Send to UI.

In this way, commands are transferred from the CPU 7 to the CPU 7. Transfer of response from CPU7 to CPUUI is also done by CPUUI.
It is sent in the same way as the transfer from n 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 exchanging of image signal data is performed by direct memory access (DMA) transfer in units of bytes.

The DMA transfer and DMA transfer of image signal data between the communication protocol control unit 13 and the transmitting/receiving puff 7a 11 is performed by the DM.
This is performed by the A transfer control LS 112.

The communication protocol control unit 13 performs seven framing and frame check sequence (Fe2) operations of binary instructions specified in CCITT Recommendation T30. -f) Performs detection, modem control, image signal data transmission and reception, etc.

14 is the same 3-channel time as time 4, and is mainly used for transmission of called station identification/calling (CED/CNG) signals and as a timer in the T30 binary procedure. The disk control unit and the disk device 15 store image information of the scanned and transmitted document.

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. Initially, transmission start state (16)
Then, all the originals to be transmitted to the destination receiving device are scanned and stored in the disk device 15. When the retransmission 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 uses the communication protocol control unit 13 and the timer 14 to transmit a ringer (CNG) signal (17
)do. Receives the called station identification (CED) signal from the other party's receiving device (19), and further receives the digital identification signal (DIS).
Upon receiving the signal (20), the CPU 7 determines whether there is interchangeability based on its contents (21).

If there is communication, the CP of the retransmission control unit is sent via the shared memory 6.
A response indicating the completion of phase A (call setting phase) including information indicating the presence of communication is returned to the UI in response to the call request command (22). When the CPUI of the retransmission control unit receives the response indicating that communication is possible, it sends a disk read request command to the CPU 7 via the shared memory 6 (23). Communication control unit C
PU7 sends a training check (TCP) signal (
24) Ready to receive (CFR) from the other device
When the signal is received (25), a response to the disk read request is returned via the shared memory 6 (26). CPU1
Upon receiving this response, the disk controller 15 sends a read signal to the disk controller 15, and the disk controller 15 writes 10 bytes of image signal data to the transmitting/receiving puffer 11 by DMA transfer.

The CPU 7 receives this image signal data and converts the DMA control LS
Under the control of I, the image signal is sent to the communication protocol control unit 13 and sent to the partner device (27). As described above, the image signal is transmitted after the CPU 1 issues a disk read request to the CPU 7 and the CPU 7 responds to the CPU I. 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 the process (21) A code indicating no communication is added to the cause code, and a response indicating the end of 7A's A including the cause code indicating no communication is sent to the CPUI of the retransmission control unit via the shared memory 6 (31). In response to this, the CPUI of the retransmission control unit prints all the scanned originals, and also prints a document undelivered message with the number of originals sent to the other party's facsimile machine and the cause code of no communication (
32). When the transmission end state (28) is reached, the transmission start state (
At step 16), the transmission of the scanned original is completed.

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

Communication abnormalities occur during the progress of each binary control procedure, and if the control signal is not received within a specified time,
Alternatively, there may be a case where a malfunction in the procedure is detected in the partner device and a procedure interruption signal is received.

When such a communication abnormality is recognized, the CPU 7 sends a communication end response including a code indicating that the communication has ended due to the communication abnormality to the CPUI via the shared memory 6. C.P.U.I.
detects the number of responses (34), and when the number of responses is the third time, that is, the communication error occurs for the third time, the document enters the document/document undelivered message print state (32), and the transmission starts state. In step (16), all scanned originals are printed, and a document undelivered message with the number of originals sent to the other party's facsimile machine and other cause codes is also printed. Finally, the transmission end state (2
In step 8), the transmission of the document scanned in step (16) is completed.

If the communication abnormality is determined to have occurred twice or less (34), the process waits for the two-minute timer to complete (35).

That is, the timer 402 is activated and waits for the timer to count up. When timer 4 counts up, CP
Send an interrupt signal to the UI.

The CPU receives this interrupt signal and sends a command to request a call via the shared memory 6 to the CPU 7 of the communication control unit 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 accumulated on the disk will not be retransmitted if one page has been sent, but will be retransmitted from the first page that was not transmitted due to the previous communication error. do.

(Effects of the Invention) As explained above, the present invention receives a function identification signal,
By stopping retransmission at the point when no communication is detected, there is an effect of preventing unnecessary automatic retransmission.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the communication control unit and retransmission control unit of the CCITT Recommendation Gl [standard facsimile machine] according to an embodiment of the present invention, and FIG. 2 is a binary control block diagram of the communication control unit and retransmission control unit shown in FIG. It is a flowchart showing a procedure. 1...Retransmission control unit control CPU, 2.8...
...ROM for program storage, 3,9...RAM for working storage, 4.14...
Timer LSI, 5.10...L for parallel input/output
SI, 6... Shared memory, 7... CPU for controlling communication control unit, 11... Transmission/reception buffer, 12... LSI for DMA transfer control, 13・・・
. . . Communication protocol control section, 15 . . . Disk control section and disk device. Cloudy: 5J Old Figure 2 Procedural Amendment (Author) 60.5.31 Showa Year Month Day 1, Incident Display 1985 Patent Application No. 1475
4 No. 3, Relationship with the case of the person making the amendment Applicant: 5-33-1-4, Shiba 5-chome, Minato-ku, Tokyo, Agent: Sumitomo Sanda Building, 37-8 Shiba, 5-chome, Minato-ku, Tokyo, 108 NEC Co., Ltd. Uchi,'-1 (6591) Patent attorney Susumu Uchihara Telephone Tokyo (
03) 456-3111 (main representative) (Contact information: NEC Corporation Patent Department) i Column 6 of “Detailed Description of the Invention” of the specification to which the amendment is made Contents of the amendment (1) Specification, page 2, no. In the 16th line, after "this type", delete "If communication is not possible even after a certain period of time". (3) Same, page 4, line 9, "time" is corrected to "timer". (4) Same, page 4, line 14, "time" is replaced by "timer"
Correct. (5) Same, page 5, first line, rLsI (PIO)J is corrected to rLsIxO(PIO)J. (6) Same, page 6, line 14, "time" and "channel time" are corrected to "timer" and "channel timer", respectively. (7) Ibid., page 7, line 14, “exchangeability” is replaced by “communicability”
Correct. (8) Same, l! Page 8, line 6, "Read" is corrected to "Read". e) Same, I! Page 8, I! Line 13, 1 [included trm included] is corrected.

Claims (1)

[Claims] If the call is restored or disconnected due to a communication error during transmission,
An automatic retransmission method characterized in that a facsimile machine having an automatic retransmission function receives a function identification signal of a receiving device of the other party, and does not perform retransmission if a call is disconnected due to lack of communication.