JPH04307838A - Data transmission/reception method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transmitting and receiving data in communication systems such as computer systems and data terminals.

0002

Conventionally, in this type of data transmission/reception method, in order to identify the end of one data on the receiving side, the length of the data to be sent and received is fixed in advance by agreement between the sending and receiving sides, or the length of the data is fixed. The method is to add a specific character or string of characters to the end.

0003

[Problems to be Solved by the Invention] However, among the conventional methods described above, in the method of fixing the data length to be transmitted and received, it is necessary to fix the data length to the maximum length of data required by the communication system. It is not efficient in terms of resource and line usage. On the other hand, the method of adding a specific character or character string to the end of data complicates control when performing transparent communication.

SUMMARY OF THE INVENTION The present invention is intended to solve these conventional problems, and an object of the present invention is to provide a data transmission/reception method that can realize efficient communication using variable length data with easy control. That is.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention monitors a data line on the receiving side of a communication system, and terminates received data when no data exists on the data line for a certain period of time. The transmitting side and the receiving side agree in advance that one piece of data ends when no data exists on the data line for a certain period of time, and when transmission/reception starts, the data ends. The data line is monitored by the detection means, and reception processing is performed by detecting the end of received data.

[0006]

[Operation] Therefore, according to the present invention, when communication is started, the data end detection means on the receiving side monitors the data line, and when the transmitting side finishes transmitting the data, it waits for a certain period of time to start the next data. Stop sending. Since the data end detection means performs reception processing by detecting that no data exists on the data line for a certain period of time, variable length data can be can be sent and received.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram of a receiving side embodying a data transmitting/receiving method in an embodiment of the present invention.
In the figure, solid line arrows indicate the flow of received data, and dotted line arrows indicate control or notification).

In FIG. 1, reference numeral 1 denotes a microcomputer, which controls the operation of the entire receiving function. 2 is a serial interface that serially sends received data; 3 is a receiving section that receives received data through the serial interface 2; 4 is a transfer section that transfers the received data received by the receiving section 3; 5 is a transfer section that transfers the received data from the transfer section 4. A receive buffer 6 is a mark hold detector which temporarily stores the received data, and when the receive data line of the serial interface 2 continues to be in a mark state, that is, a state in which no receive data exists, a signal is sent to the microcomputer 1. Give notice. The value of N is determined in advance between communication systems that transmit and receive data.

Next, a data transmission/reception method will be explained with reference to the flowchart shown in FIG.

[0011] The transmitting side and the receiving side agree in advance that when transmitting one piece of data, one piece of data will end if no data exists on the data line for a certain period of time (N seconds). First, the microcomputer 1 instructs the transfer section 4 to transfer the received data, and also instructs the reception section 3 to receive the data (steps 11 and 12). After receiving the command to receive data, the receiving section 3 receives the first character of the received data through the serial interface 2 (step 13) and notifies the microcomputer 1. Accordingly, the microcomputer 1 instructs the mark hold detection section 6 to start monitoring the duration of the mark state of the received data line of the serial interface 2 (step 14). The reception data received by the reception section 3 is transferred to the reception buffer 5 by the transfer section 4. When the sending side finishes sending the data, it stops sending the next data for N seconds, so when the receiving end of the data ends, the receive data line of the serial interface 2 enters the marked state. When the mark hold detection unit 6 detects that the received data line continues to be marked for N seconds (step 15), it notifies the microcomputer 1. Along with this, the microcomputer 1
, the transfer unit 4, and the mark hold detection unit 6 are instructed to stop their operations (steps 16 and 17). In this way, the reception processing of one received data is completed.

As described above, according to the above-mentioned embodiment, the mark-hold detection section 6 is provided which monitors the data line and detects the end of received data when no data exists on the data line for a certain period of time. Since the end of the data is detected, variable length data can be transmitted and received without using a method of indicating the end with a specific character or character string. Therefore, efficient communication can be achieved. Further, when performing transparent communication, there is no need to perform complicated control.

[0013]

As explained above, according to the present invention, when communication is started, the data end detection means on the receiving side monitors the data line, and on the sending side, when data transmission is finished, the data line is monitored for a certain period of time. , stop sending the next data. Since the data end detection means performs reception processing by detecting that no data exists on the data line for a certain period of time, variable length data can be can be sent and received. Therefore, communication using variable length data that is efficient in terms of communication system resources and line usage can be realized with easy control.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of a receiving side embodying a data transmission/reception method in an embodiment of the present invention.

FIG. 2: A reception process flowchart for explaining a data transmission and reception method in an embodiment of the present invention.

[Explanation of symbols]

1 Microcomputer 2 Serial interface 3 Receiving section 4 Transfer section 5 Receive buffer 6 Mark hold detection section

Claims (1)

[Claims] Claim 1: The receiving side is equipped with data end detection means for monitoring the data line and detecting the end of the received data when no data exists on the data line for a certain period of time. It is agreed that one piece of data ends when no data exists on the line for a certain period of time, and when transmission and reception start, the data line is monitored by the data end detection means, and the data is received by detecting the end of the received data. Data transmission/reception method for processing.