JP2802271B2 - Facsimile machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile apparatus, and more particularly to a facsimile apparatus having a modem for efficiently performing HDLC processing on transmission / reception data.

[0002]

2. Description of the Related Art In recent years, in a communication system such as a facsimile, communication is performed in the format of communication data HDLC (high-level data link control) in order to detect a communication data error due to a line quality or the like. There are many methods. In order to perform HDLC framing or deframing, conventionally, an HDLC framing / deframing processing unit is provided in a modem control device. FIG. 6 shows a conventional example of such a modem device. This modem device has a modem control line 1
And HDLC framing for transmission data and HDL for reception data.
A modem controller 3 having an HDLC circuit 2 for performing C deframing; an I / O circuit 5 arranged between the modem controller and the line for inputting / outputting data;
And a modem 8 having a control digital signal processor 6 for controlling digital signals and an analog circuit 7 for performing analog communication with the line 4. Then, the modem control device 3 sends and receives control signals and data to and from the modem 2 through the control lines 1A and 1B and the data lines 2A and 2B. In the modem controller 3, the control circuit 1 and the HDLC circuit 2
A and 3B are connected to exchange data.

For example, at the time of data transmission, the control circuit 1 in the modem control device 3 puts the modem 8 into a receiving state using the control lines 1A and 1B. Next, the control circuit 1 controls the HDLC circuit 2 inside the modem control device 1 through the signal lines 3A and 3B and writes transmission data. The data subjected to HDLC framing by the HDLC circuit 2 is sent to the modem 8 through the signal line 2A. The modem 8 modulates the data and sends out the data to the line 4. At the time of reception, a signal input from the line 4 is demodulated by the modem 8, and the demodulated data is
The signal is input to the HDLC circuit 2 inside the modem control device 3 through the signal line 2B. Then, the control circuit 1 controls the signal line 3B
Through which the deframed data is received.

[0004]

However, in the above-described conventional facsimile apparatus, since the HDLC circuit 2 is incorporated in the modem control device 3, the modem control device 3 has its original role. In this case, the HDLC circuit 2 must be controlled in addition to the control of the modem 8, which is a heavy burden on hardware and software.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a facsimile control unit for controlling an entire facsimile apparatus, an HDLC framing process for data to be transmitted, and modulating or transmitting the data. And a modem unit for HDLC deframing processing of the data, and the modem unit notifies the facsimile control unit of the progress of processing in the modem.

[0006] With this configuration, in the modem section, H
By performing processing such as DLC framing processing and HDLC deframing processing, and notifying the progress of this processing to the facsimile control unit, the facsimile control unit can control the facsimile and recognize the processing of the modem unit. Even if the facsimile control unit does not perform the control for the HDLC framing process or the HDLC deframing process, the process can be recognized, and the load on the hardware and software of the facsimile control unit is reduced, and smooth and efficient Data transmission and reception can be performed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing one embodiment of the periphery of a modem unit in a facsimile apparatus according to the present invention. A facsimile apparatus according to this embodiment is a modem control apparatus 10 having a control circuit 9 for performing general control such as reading control and code decoding control of a facsimile apparatus and the like.
And a modem 11 controlled by the modem control device 10 to modulate and demodulate transmission / reception data. The modem 11 includes an I / O circuit 12 for interfacing with a modem control device and a control D for performing digital signal processing.
An SP 13 and an analog circuit 15 connected to the line 14 are provided. Further, the control DSP 13 controls the I / O circuit 12
, An HDLC framing unit 17 connected by a signal line 16, a memory 18 for storing data after HDLC framing, and a modulation unit 19 for modulating transmission data.
And a demodulation unit 20 for demodulating received data, a memory 21 for storing demodulated data, and an HD for receiving data.
An HDLC deframing unit 23 for performing LC deframing and outputting to an I / O circuit through a signal line 22;
And a control unit 25 connected to each functional unit via the control unit 4 for controlling these functional units. In the control DSP 13, the modulation unit 19 and the demodulation unit 20 are connected to the analog circuit 15 by a bus 26 and a signal line 27, and a signal line 29 is connected from the signal line 16 to the memory bus 28. While extending from the memory bus 30 to the signal line 2
2, a branch signal line 31 extends. The transmission and reception of signals between the modem control device 10 and the modem 11 are performed on the control signal line 3.
2. Performed by the data signal line 33. The HDLC framing unit 17 has a function of adding an HDLC format flag pattern and an error determination FCS in a frame to data transmitted from the modem control device 10 through the I / O circuit 12. The HDLC deframing unit 23 has a function of detecting a flag pattern in the HDLC format from data input from the partner terminal device through the line 14, performing an error check by the FCS, and notifying the modem control device 10 of the result. Have. In order to notify the modem control device of the detection result of the HDLC format flag pattern and the like, the control circuit 9 and I
A flag detection signal line 34 is provided between the / O circuit 12 and the signal lines 32 and 33.

The operation of the facsimile apparatus having such a configuration will be described below. First, the operation in the data transmission mode will be described with reference to FIGS. In this mode, the mode control device 10 sends an HDLC flag transmission command to the modem 11 via the control line 32, and at the same time, the HDLC format flag pattern "7"
E "(hex) through the data signal line 33 to the modem 11
Send to The modem 11 receives the HDLC flag transmission command and the HDLC flag in a processing step (hereinafter simply referred to as a step) ST1. Then modem 11
In step ST2, the number of flags transmitted via the data signal line 33 is transmitted on the line 14, and the process proceeds to step ST3 to check whether there is a data transmission command. During this time, the modem controller 10 sends an HDLC data transmission command to the modem 11 via the control line 32, and sends transmission data D1, D2,... Dn via the data signal line 33. Modem 11 is HD
When the LC data transmission command is received, in step ST4, the transmission data D1, D2... Dn are output to the line 14 while performing a "0" insertion, and the data is transmitted. On the other hand, simultaneously with the output of the transmission data, the modem 11 calculates an FCS (frame check sequence), and checks in step ST5 whether or not there is a flag transmission command. Then, while there is no flag transmission command, data transmission is continued, while if there is a flag transmission command, the process proceeds to step ST6 to transmit 2 bytes of FCS, and then transmits the HDLC flag to the line 14 (ST2). . And steps ST2 to ST6
The data transmission is performed by repeating the above operation.

Next, the operation in the data receiving mode is shown in FIG.
A description will be given based on FIG. In this mode, the modem controller sends an HDLC reception mode command to the modem 11 via the control line 32. As a result, the modem 11
It goes into the DLC reception mode, demodulates the signal on the line 14,
In step ST11, the HDLC flag pattern ("
7E "). In this processing step, when the modem 11 detects the HDLC flag pattern in the demodulated data, the modem 11 turns on the flag detection signal line 34 in step ST12, and the modem controller 10 detects the flag. Then, the modem 11 proceeds to step ST1.
In step 3, the device waits for an HDLC flag pattern to be received. When the HDLC flag pattern is received, three bytes of data (D1, D2, D3) are continuously detected, and the flag detection signal line 34 is connected in step ST14. Off, and then proceeds to step ST15, where the data signal line 3
The received data is transmitted to the modem control device 10 via the communication device 3. After that, the modem 11 enters a state of waiting for detection of an end flag in step 16 while outputting the received data. When the end flag is detected in this processing step, the flag detection signal is turned on in step ST17. Of the received data, the last two bytes are FCSs and are not sent to the modem control device 10.
S is checked, and the result is coded and sent to the modem controller 10 via the data signal line 33 as a 1-byte code. Upon receiving the result, the modem control device 10 performs a process according to the result. For example, if the FCS indicates an error, control is performed to retransmit the data of the frame again. With the above operation, the receiving operation of one frame subjected to HDLC framing is completed, and the processing operation of steps ST13 to ST18 is started to continuously receive the next frame.

[0010]

As described above, in the facsimile apparatus of the present invention, the modem unit performs processing such as HDLC framing processing and HDLC deframing processing.
By notifying the processing progress to the facsimile control unit,
Since the facsimile control unit can recognize the processing of the modem unit while controlling the facsimile, the facsimile control unit performs the HDLC framing processing or the H
Even if control for the DLC deframing process is not performed, the process can be recognized, the load on the hardware and software of the facsimile control unit can be reduced, and smooth and efficient data transmission and reception can be performed.

[Brief description of the drawings]

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

FIG. 2 is a time sequence diagram in a transmission mode of the embodiment.

FIG. 3 is a flowchart showing the operation of the modem in the transmission mode of the embodiment.

FIG. 4 is a time sequence diagram in a reception mode of the embodiment.

FIG. 5 is a flowchart showing the operation of the modem in the reception mode of the embodiment.

FIG. 6 is a block diagram showing an example of a conventional facsimile machine.

[Explanation of symbols]

 Reference Signs List 10 modem control device 11 modem 13 control DSP 14 line 17 HDLC framing unit 19 modulation unit 20 demodulation unit 23 HDLC deframing unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04L 29/08 H04L 29/10 H04N 1/00 H04N 1/32

Claims (2)

(57) [Claims] 1. A facsimile control unit for controlling an entire facsimile apparatus, and a modem unit for performing HDLC framing processing on data to be transmitted and modulating the processed data, wherein the modem unit monitors the progress of the HDLC framing processing. A facsimile apparatus for notifying the facsimile control unit. 2. A facsimile control unit for controlling the entire facsimile apparatus, and a modem unit for demodulating received data and HDLC deframing the processed data, wherein the modem unit performs HDLC deframing processing. A facsimile apparatus for notifying the progress to the facsimile control unit.