JP2560758B2 - Communication control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a communication control device, and more particularly to a standard G III FAX.
The present invention relates to a communication control device (hereinafter, referred to as “communication adapter”) having a communication procedure having an error resending function that can be used for data communication in addition to the procedure.

2. Description of the Related Art A conventional communication adapter of this type has only a standard G III FAX procedure, and does not have an error resending function usable for data communication.

However, it is possible to connect a terminal such as a personal computer or a word processor to a facsimile terminal through a network control device, a modulation / demodulation device, and the like. It goes without saying that it is desirable to have

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide, in addition to the standard G III FAX procedure, a communication adapter having a communication procedure having an error resending function that can also be used for data communication. To provide.

Structure The above object of the present invention is a communication adapter for connecting a terminal, such as a personal computer or a word processor, which is connected via serial data transmission control means, to a facsimile terminal via a network controller or a modulator / demodulator. A plurality of block memories for accumulating image signals transmitted or received via a modulator / demodulator, and a block memory for controlling transmission of image signals on the block memory or controlling writing of the received image signal to the block memory The present invention is achieved by a communication adapter characterized in that it is configured to have a control section and a communication procedure control section which performs a standard facsimile procedure of G III and a facsimile procedure having error resending means.

Hereinafter, the configuration of the present invention will be described in more detail based on examples. In the following description, the case where the present invention is applied to a communication adapter for using a personal computer (PC) as a facsimile terminal will be described as an example.

FIG. 1 is a block diagram of a communication adapter showing an embodiment of the present invention. In the figure, 1 is connected to the PC through the RS-232-C built in the PC, and RS-232-
The C driver, receiver, serial data transmission / reception unit that performs serial / parallel conversion, and 2 exchange CFU (control function element) by exchanging ENQ and ACK according to the control procedure between the PC and this communication adapter. It shows a serial data procedure control unit for performing.

At the time of transmission, the serial data procedure control unit 2 sends the transmission data to the PC by CFU which is CDT (data transmission request).
And writes it in order to the block memory, which will be described later, in an empty state. In addition, at the time of reception, the contents of the block memory, which has been written, is RDR (data reception notification).
The CFU has a function of transmitting data to the PC through the serial data transmitting / receiving unit 1.

Returning to FIG. 1, 3a and 3b are block memories having a function of accumulating transmission data or reception data. The block memories 3a and 3b are, for example,
It is sequentially divided into 56-byte block unit memory. 4 is a block memory control unit,
In the standard G III communication, the data is simply read from the block memory 3a or 3b at the time of transmission and passed to the communication procedure control unit 5 described later, and at the time of reception, the data received from the communication procedure control unit 5 is blocked. Write to the memory 3a or 3b. The block memories 3a or 3b are used in a normal number order, and in some cases cyclically.

The communication procedure control unit 5 has two communication procedures. The first procedure follows the standard procedure of CCITT T.30, and the second procedure follows the following procedure. As described above, the block memory 3a or 3b is divided into block unit memories (BUM) as shown in FIG. Image information is accumulated in the block memory, and the contents of the block memory are transmitted / received in block unit memory units in HDLC frames.

On the other hand, on the data reception side, the reception result of the contents of the block unit memory is transmitted to the transmission side in the format of data shown in FIG. The transmitting side checks this data, and retransmits the contents of the block unit memory which was not received. This is repeated until all block unit memory contents are ready for reception. When the transmission of a certain block memory is completed, the process proceeds to the transmission of the next block memory. The reception result storage unit is provided in the block memory control unit 4.

6 is a modem (MODEM), 7 is a network controller (N
CU) is shown.

The error retransmission function mode in transmission and reception will be described in detail below.

(1) Error resending function mode transmission: When transmitting the contents of a certain block memory, it is passed to the communication procedure control unit 5 in units of 256 bytes. Communication procedure controller 5
HDLC with it the number of block unit memory
Frame and send. When the data of the reception result is received, only the contents of the block unit memory in error are passed to the communication procedure controller 5 (see FIG. 4).

At this time, the above-mentioned serial data procedure control unit 2 receives and stores the data from the PC in another vacant block memory according to the procedure. For this purpose, the efficiency is low unless there are at least two block memories. In other words, if you do not finish sending all of a certain block memory,
You will not be able to receive data from.

(2) Error retransmission function mode reception: When receiving data of a certain block, the contents of the block unit memory in which there is no error is received from the communication procedure control unit 5 together with the block unit memory number, and according to the block unit memory number. , Is stored in an area of a predetermined block memory. All (0 to 255)
Upon receipt of the contents of the block unit memory, the serial data procedure controller 2 starts transmitting the data to the PC. Also in this case, the efficiency is low unless at least two block memories are provided.

Regarding the mutual function confirmation procedure of whether or not the receiving side has such a function of error correction,
Exchanged by DCS or DIS signal of G III FAX.

As described above, according to the present invention, communication for connecting a terminal such as a personal computer or a word processor connected via the serial data transmission control means to a facsimile terminal via the network controller or the modulator / demodulator. In the adapter, a plurality of block memories for accumulating image signals transmitted or received via the modulator / demodulator,
A block memory control unit that controls transmission of image signals on the block memory or writing of received image signals to the block memory, and a standard G III facsimile procedure and a facsimile procedure having error resending means. Since it is configured to have a communication procedure control unit,
In addition to the G III FAX procedure, it is possible to realize a communication adapter having a communication procedure having an error resending function that can be used for data communication.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a communication adapter showing an embodiment of the present invention, FIG. 2 is a diagram showing a detailed configuration of a block memory, and FIG. 3 is an example of a format showing a reception result of contents of a block unit memory. FIG. 4 is a diagram showing a sequence of a communication procedure. 1: Serial data transceiver, 2: Serial data procedure controller, 3a, 3b: Block memory, 4: Block memory controller,
5: Communication procedure controller, 6: MODEM, 7: NCU.

Claims (1)

(57) [Claims] 1. A communication control device for connecting a terminal such as a personal computer or a word processor connected via a serial data transmission control means to a facsimile terminal via a network control device or a modulation / demodulation device. A plurality of block memories for accumulating image signals transmitted or received through the block memory, and a block memory control unit for controlling transmission of image signals on the block memory or controlling writing of the received image signal to the block memory And a communication procedure control unit for performing a standard facsimile procedure of G III and a facsimile procedure having an error resending means.