JPH01251937A - Data transmission system - Google Patents

Abstract

PURPOSE:To certainly transmit data in a simple algorithm by sending an answer to a signal sent from an opposite side specific times. CONSTITUTION:Transmission side equipment 2 is connected with reception side equipment 6 through a transmission line 4 and the equipments 2 and 6 are respectively constituted of, for example, computers, terminal equipment, etc. The transmission line 4 is constituted of a directly managed transmission line, transmission line of a telecommunication company, etc. When a signal sent from an opposite side is received, an answer is made to the opposite side, but the answer is outputted several times. Therefore, even if the answer is changed by the influence of noises, etc., in the transmission line 4, the answer can be decided and the communication can be continued, if one of the plural answer outputs is received by the opposite side. Thus communication can be carried out certainly in the simple algorithm.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a data transmission method that transmits data in a procedural manner, and in particular, to a data transmission method that transmits data reliably even in an environment with disturbances even without an error correction function. This relates to a data transmission method that allows for

[Conventional technology]

In this type of conventional data transmission method, when transmitting data between a sending device and a receiving device, ■ the sending device sends an ENQ (with communication data) to the receiving device;
■When the receiving device that received this is able to receive data, it sends an ACK (transmission permission) acknowledgment to the transmitting device, and ■The sending device that received this transmits data D7 and other data (ETX ( ETB)) is sent to the receiving device, and by repeating ■~■, multiple pieces of data D1 are transmitted.Finally, the transmitting device sends EOT(
The data transmission is ended by sending a message (transfer complete) to the receiving device. In addition, in this data transmission method, when transmitting data between a sending device and a receiving device,
The sending device sends an ENQ (communication data available) to the receiving device, and if the receiving device that receives this is unable to receive data for some reason (such as a device failure), it sends a NAK (unable to send). ) by sending a negative response to the sending device, thereby terminating the communication. In this way, the data transmission method transmits data in a sequential manner.

[Problems to be Solved by the Invention] By the way, in conventional data transmission systems, data transmission systems that are equipped with an error correction function cannot be used even if the environment of the data transmission path is bad, or if the transmission path or the device concerned is Although it has the advantage of being able to reliably transmit data because it can correct errors even if there is a flaw in the circuitry, on the other hand, the algorithm becomes complex and it is not possible to easily transmit data. There is a big drawback.

On the other hand, according to the data transmission method using a simple algorithm,
Although the algorithm is simpler, it has the disadvantage that if the environment such as the data transmission path is poor and disturbances are introduced, communication will not be possible.

The present invention has been made to solve the problems of the prior art described above, and an object of the present invention is to provide a data transmission method that uses a simple algorithm to reliably transmit data.

(Means for Solving the Problems) In order to achieve the above object, a data transmission system according to the present invention transmits a response to a signal sent from the other party in a data transmission system that transmits data in a procedural manner. It is sent a predetermined number of times.

Further, another data transmission method according to the present invention is a data transmission method that transmits data in a procedural manner, and continues to send a response to a signal sent from the other party until the next signal is sent from the other party. It is something.

[Effect]

In the data transmission system of the present invention, when a signal transmitted from the other party is received, a response is made to the signal, and the response is output multiple times. Thereby, even if the response changes due to the influence of noise or the like on the transmission path, if even one of the plurality of responses is received, the response can be determined and communication can be continued. According to the present invention, communication can be reliably performed using a simple algorithm.

Furthermore, in another data transmission method of the present invention, a response to a signal sent from the other party continues to be sent until the next signal is sent from the other party, so if even one of the multiple responses is received, , it becomes possible to judge the response and continue communication. According to the present invention, communication can be reliably performed using a simple algorithm.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a time chart showing an embodiment of the data transmission system according to the present invention, and FIG. 2 is a flow chart showing the operation of the embodiment. FIG. 3 is a block diagram showing the configuration of an apparatus to which an embodiment of the present invention is applied.

In FIG. 3, 2 is a transmitting device, and this transmitting device 2 is connected to a receiving device 6 via a transmission path 4. In FIG. The transmitting side device 2 and the receiving side device 6 are composed of, for example, a computer, a terminal device, or the like. Further, the transmission line 4 is configured of a directly managed transmission line, a transmission line provided by a telecommunications carrier, or the like. When connecting the transmitting side device 2 and the receiving side device 6 to the line, a communication device such as a modem is used as necessary. Further, the data transmission method of the present invention is realized by processing means built into the transmitting side device 2 and the receiving side device 6.

The operation of the embodiment configured in this way will be explained.

<Normal Case> In the case of normal operation, the time chart will be as shown in FIG. 1 (H).

That is, the sending device 2 and the receiving device 6 start. Each sending device 2 and receiving device 6 first performs a ready check (step 1OO1200), and then, after the sending device 2 processes step 100, ■ ENQ (with communication data) is sent from the sending device 2 to the receiving device. Send to device 6.

■The receiving device 6 that has received this ENQ (communication data available) determines whether or not data can be received in step 201, and if it is able to receive data, it sends an ACK (transmission permission) acknowledgment in 5 (mS), for example. The data is sent to the receiving device 6 three times each time (steps 1202 to 205) and waits for data reception (steps 206 and 207).

(2) On the other hand, if any one of the acknowledgments is received, the transmitting device 2 sends the transmission data D and other control data (ETB) to the receiving device 6 (steps 102 to 104).

(2) After that, by repeating (2) to (4), a plurality of data D is transmitted (the transmitting device 2 processes steps 102 to 104, and the receiving device 6 processes steps 207 to 213).

(2) After sending all the data D, the sending device 2 sends the control data ETX (step 105).

(2) Upon receiving the control data ETX, the receiving device 6 outputs an affirmative response (steps 214 to 219).

■Finally, the sending device 2 sends the EOT (end of transfer) in step 105), the receiving device 6 receives the EOT (end of transfer) in step 220), and steps 225, and then end the processing. .

<In the case of abnormality> In the case of this abnormal operation, the time chart will be as shown in FIG. 1(n).

That is, after each sending device 2 and receiving device 6 performs a ready check (steps 100 and 200), and after the sending device 2 processes step 100, ■receives ENQ (communication data available) from the sending device 2. It is sent to the side device 6.

■The receiving device 6 that has received this ENQ (communication data available) determines whether or not it is possible to receive data in step 201, and if it is not possible to receive data due to some reason (for example, a device failure), it sends a NAK. A negative response (transmission not possible) is sent to the receiving device 6 three times, for example, every 5 (mS) (steps 221 to 224), and the process ends.

In addition, in the above example, the number of responses was set to N=3, but
Not only this, but it is necessary to select an appropriate value for N based on the balance between transmission speed and reliability in the system. In addition, in the above example, the time interval was set to 5 (ms), but
This interval is not limited to this and may be selected as appropriate for the system.

According to this embodiment, data transmission can be reliably performed using a simple algorithm.

FIG. 4 is a time chart shown to explain another embodiment of the present invention, and FIG. 5 is a flow chart of the same embodiment.

This embodiment is also realized by processing means built into the transmitting side device 2 and the receiving side device 6 shown in FIG.

This embodiment differs from the embodiments shown in FIGS. 1 and 2 above in that steps 208 to 212 are performed as follows. That is, after data D is received (step 300), responses are continued to be sent at fixed time intervals (here, 10 (mS)) until the next data D is sent from the sending device 2. This is what was operated (steps 301 to 303).

In this way, for example, as shown in FIG. 4, after the receiving device 6 receives the data D (times 1 to t2), it continues to send responses (tz to t,), and the response is sent for the third time. Since the data D2 from the side device 2 has been received (ti, stop sending the response. Once again, the reception of the data D has been completed, so (ti)
t3), the receiving device 6 sends a response (tn~ts)
. However, the receiving device 6, at the time,
Since data D3 is received, the response transmission is immediately terminated at this time.

In this embodiment, the receiving device 6 continues to send responses at fixed time intervals, and when the receiving device 6 receives the data D, the response transmission ends.

In the above embodiment, the time interval is set to 10 (mS), but this interval is not limited to this and may be selected as appropriate for the system.

According to this embodiment, data transmission can be reliably performed using a simple algorithm.

[Effects of the Invention] As described above, according to the present invention, there is an effect that communication can be reliably performed using a simple algorithm.

[Brief explanation of the drawing]

FIG. 1 is a time chart shown to explain the present invention in detail, FIG. 2 is a flowchart to explain the embodiment, and FIG. 3 is a block diagram showing an example of the configuration of a device to which the embodiment is applied. , FIG. 4 is a time chart shown to explain the embodiment at the same place, and FIG. 5 is a flowchart to explain the embodiment at the same place. 2... Sending side device, 4... Transmission line, 6... Receiving side installation agent Patent attorney Tomo Murakami - E SS N TQnT Q )

Claims (2)

[Claims] (1) A data transmission method in which data is transmitted in a controlled manner, and the data transmission method is characterized in that a response to a signal sent from the other party is sent a predetermined number of times. (2) A data transmission system that transmits data in a sequential manner, and is characterized in that a response to a signal sent from the other party continues to be sent until the next signal is sent from the other party.