JPS6319938A - Data communication equipment - Google Patents

Abstract

PURPOSE:To improve the communicating efficiency by informing the release of a busy state to a data communication equipment set at the originating side after other communications are over in case an incoming call is rejected since a data communication equipment set at the inclong side is busy. CONSTITUTION:When a facsimile equipment 21 receives an originating request from a facsimile equipment 24 while the equipment 21 is kept under a communication state with a facsimile equipment 22, the equipment 21 informs its busy mode to the equipment 24. When the communication is through with the equipment 22, the equipment 21 has an originating request to inform the release of its busy mode to the equipment 24. Thus the equipment 24 sends back an answer of confirmation to the equipment 21. Then the equipment 21 issues the end of receiving preparation after release of its busy mode and the equipment 24 starts its transmission. Then the equipment 21 informs the end of reception and cuts off the connection with a network 22.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a data communication device, and particularly to a data communication device that has a function on the receiving side to issue a transmission request to the transmitting side by canceling “busy”. .

[Prior Art] Conventionally, in this German device, as a means for the calling side to know when the called side has cleared the "busy" state, the calling side retries the transmission request. In this case, there is a drawback that the calling side does not know when the called side will be able to transmit depending on the circumstances of the called side.

[Problems to be Solved by the Invention] The present invention eliminates the drawbacks of the conventional example described above, and solves the problem of "busy".
It is an object of the present invention to provide a data communication device equipped with an efficient communication system that starts transmission in response to a command from a receiving side to a communication side when canceling the release.

[Means for solving the problem] In order to achieve this purpose, a single physical interface connected to the network has multiple logical paths, and one logical bus is connected to other first devices. During communication, when receiving communication from another second device via another logical bus, it notifies the second device of the message, terminates communication with the second device, and terminates communication with the first device. The present invention is characterized in that it includes means for issuing a transmission request to the second device immediately after the end of communication.

[Function] According to the present invention, when the called data communication device rejects an incoming call because it is "busy" due to communication with another party, the calling party data communication device cancels the busy state after communication with the other party is completed. The communication method that informs the device eliminates the need for retries on the calling side.
In addition, it is possible to know in real time whether the called side is released from a busy state, thereby improving communication efficiency.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an embodiment showing a block configuration of a facsimile machine according to the present embodiment. In the figure, 1 is a microprocessor (hereinafter referred to as MPtJ), 2 is an MPU bus, and 3 is a read-only memory that stores programs (hereinafter referred to as RO).
4 is a read/write memory (hereinafter referred to as RAM) into which necessary information is written and read, 5 is an input circuit, 6 is a reader, 7 is an output circuit, 8 is a printer, and 9 is image data. 10 is an encoding circuit for compression, 10 is a communication circuit, and 11 is a physical line such as a public telephone line.

FIG. 2 is an example showing the configuration of a plurality of facsimile machines of this example. In the figure, 21 is a receiving side of a facsimile machine, 22 is a network that is an exchange and relay device, 23 is a sending side of a facsimile machine that is connected to the facsimile machine 21 and is currently communicating, and 24 is a facsimile machine that wants to make a new call to the facsimile machine 21. be.

FIG. 3 shows the format structure of a transmission control procedure exchanged between facsimile machines. In the figure, F1 is a logical channel number field, F2 is a command field, and F3 is a parameter field. The logical channel number F1 is
A plurality of logical channels multiplexed onto a single physical line, and corresponds to, for example, the logical channels in CCITT Recommendation x, 25.

In the above configuration, the MPU 1 creates a communication protocol signal using the ROM 3 and RAM 4 that store a program, and sends it to the line 11 via the communication circuit 10.

FIG. 4 shows the facsimile device 24 and the facsimile device 2.
1 shows the sequence of facsimile control communication protocol performed between

While the facsimile machine 21 is communicating image information with the facsimile machine 23 on the logical channel number A, the facsimile machine 24 requests a call on the logical channel number B (Sl
), a rejection response is returned in Sl.

The parameter field F3 in the rejection response stores the printer "busy" due to another communication in progress as the reason for rejection, and informs the facsimile machine 24 that the printer is busy.

Next, when communication with the facsimile device 23 using the logical channel number A is completed, the process advances to S3.

In S3, a call request is made to the facsimile machine 24 to notify the cancellation of the "busy" status, the facsimile machine 24 returns a confirmation response in S4, and the facsimile machine 21 issues a notification that reception preparation is completed due to the cancellation of the "busy" status in 35; The facsimile device 24 starts transmission (S6), transmits image information in S7, and notifies the end of transmission in S8.

The facsimile machine 21 notifies the completion of reception in S9 and disconnects from the network 22 (510). These series of controls are performed by the MPU 1. The network 22 disconnects from the facsimile machine 24 (311).

Although this embodiment has been described using a facsimile machine as an example of a data communication device, the present invention is of course applicable to other communication devices such as a telex device that communicates document information by hand.

[Effects of the Invention] As explained above, 1. When the called side facsimile machine rejects the call because it is "busy" due to communication with another party, the calling side facsimile machine can cancel the busy state after the communication with the other party is completed. This communication method eliminates the need for a retry on the calling side, allows the callee to clear the busy state in real time, and has the advantage of good communication efficiency.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of a facsimile device according to the present embodiment, FIG. 2 is a configuration diagram showing an example of the configuration of multiple facsimile devices, FIG. 3 is a format configuration diagram of a transmission control procedure, and FIG. FIG. 3 is a diagram illustrating an example of a sequence of a facsimile control communication protocol. 1...MPU. 2...Bus, 3...ROM. 4...RAM. 5... Input circuit, 6... Reader, 7... Output circuit, 8... Printer, 9... Encoding circuit, IO... Communication circuit, 11... Line, 21, 23 .24...Facsimile machine, 22...
Rope. Figure 1 Figure 2 Figure 3 Kushimiri fold 124 Ichimoku 7? Kushimi) En'll 2/Figure 4

Claims (1)

[Claims] A plurality of logical paths are provided on a single physical interface connected to a network, and while communicating with another first device on one logical path, communication with another second device is performed by another logical path. When receiving communication from the second device, notify the second device that it is busy, terminate the communication with the second device, and immediately send the message to the second device after the communication with the first device ends. A data communication device characterized by comprising means for issuing a request.