JPH08163105A - Transmitting method and device for asynchronous transmission data - Google Patents

Abstract

PURPOSE: To provide a transmitting method which can confirm whether the data transmitted from a transmitting station have been surely received at a receiving station without changing much the constitution of a transmission frame. CONSTITUTION: A transmitting station A is connected to a receiving station B via a 1:1 transmission line, and the frame constitution of the transmission data consists of an information field 3 including the transfer information data, the transmission identifiers 2 and 4 which are arranged before and after the field 3 and a reception identifier 1. In a transmission mode, the station A sets the same identification data (bb) at both identifiers 2 and 4 and also sets the identification data (aa) different from the data (bb) at the identifier 1. The station B compares the identifiers 2 and 4 with each other. When the coincidence is confirmed between both identifiers 2 and 4, the station B receives the transfer information data from the field 3 and rewrites the data (aa) of the identifier 1 into the data (bb) of the identifier 2 to return it to the station A. The station A compares the identifier 1 of the returned data with the data (bb) of the identifier 2 and recognizes that the transmission data have been surely received at the station B when the coincidence is confirmed between the identifier 1 and the data (bb).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an asynchronous transmission data communication method, and more particularly to an asynchronous transmission data transmission method and a transmission device for a remote monitoring and control device.

[0002]

2. Description of the Related Art In a distant monitoring control device, a master station and a plurality of slave stations are connected by a 1: 1 transmission line, and in a transmission path forming a star coupling, the master station is a star coupling transmission line. By selecting, it is possible to perform 1: 1 communication. In order to efficiently transmit a large amount of data at high speed through the transmission path having such a configuration, the frame configuration of transmission data is often very simplified.

For example, a frame of transmission data is constituted by an information field into which data to be transferred such as control information required by the user and actual transfer information is inserted, and a transmission identifier arranged before and after this information field. . When the transmitting station transmits data, as described above, the transmitting station transmits by a transmission data frame in which transmission identifiers having the same identification data are arranged before and after the information field in which the data to be transferred is inserted, and the receiving station transmits this data. Only when the identification data of the transmission identifiers arranged before and after the transmitted transmission data frame match, the data of the information field transmitted in this transmission data frame is received as valid data.

An identifier is a name given to identify data, statements, etc., and is predetermined as a convention in the device / system to which it is applied, and is usually a division between data and label, and a flag in data. The labels such as buffers and address pointers, and the labels such as branch destinations and subroutines are labeled with easy-to-identify symbols. The transmission identifier used in this transmission data frame is, for example, a transmission identifier including a transmission number and a label code of transmission data transmitted by the transmission station to the reception station, or an address, a transmission number and a label code of the reception station. Identification data is used.

[0005]

However, in the prior art, the transmission data frame is transmitted only when the identification data of the transmission identifiers arranged before and after the information field of the transmitted transmission data frame match. Since the transfer information in the information field was validated and received by the receiving station, it could not be confirmed even when it was desired to check whether the transfer information transmitted by the transmitting station could be reliably received by the receiving station. .

The present invention has been made in consideration of the above points, and an object thereof is to solve the above-mentioned problems and to transfer the transfer information transmitted by the transmitting station without significantly changing the frame structure of the transmission data. An object of the present invention is to provide a method and apparatus for transmitting asynchronous transmission data, which can confirm whether or not the receiving station has surely received the data.

[0007]

In order to achieve the above object, according to the present invention, at least a transmitting station and a receiving station are connected by a 1: 1 transmission line, and a frame structure of transmission data is transmitted to a receiving station at the other end. It consists of an information field consisting of transfer information to be transferred, a transmission identifier placed before and after this information field, and a reception identifier.The transmitting station sets the same identification data in both transmission identifiers and the transmission identifier in the reception identifier. The receiving station includes an identifier setting unit for setting different identification data and a transmission / reception identifier comparing unit for comparing the identification data of the transmission identifier and the identification data of the reception identifier, and the receiving station compares both transmission identifiers of the received transmission data. Transmission identifier comparison means, reception means for receiving transfer information in the information field when both transmission identifiers match, transmission data for receiving return data to the transmission station. An identifier rewriting means for rewriting the identification data transmission identifiers received identification data received identifier when replying to, shall comprise.

[0008]

With the above structure, when the transmitting station transmits the transmission data, the transmitting station sets the same identification data in both transmission identifiers, sets the identification data different from the transmission identifier in the reception identifier, and the receiving station receives the received transmission. Both transmission identifiers of the data are compared, and when both transmission identifiers match, the transfer information in the information field is received, the identification data of the reception identifier is rewritten to the identification data of the received transmission identifier, and the data is returned to the transmitting station as reply data. , The transmitting station compares the identification data of the reception identifier of the reply data with the identification data of the transmission identifier, and it can be known that the transmission data transmitted can be surely received by the receiving station from the fact that the identification data match. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram for explaining the structure of a transmission data frame and the reception and reception confirmation operation according to an embodiment of the present invention. According to the present invention, a master station and a plurality of slave stations are connected by a 1: 1 transmission line, and a master station selects a star-coupled transmission line in a transmission path forming a star coupling. 1: 1 communication is performed between them. In FIG.
The frame structure of transmission data includes an information field 3 including transfer information (data), transmission identifiers (in the illustrated example, the identifier is simply indicated as ID) 2 and 4 arranged before and after the information field 3, and a reception identifier. 1 and.

In step S1, the transmitting station A uses the identifier setting means (not shown) to assign the same identification data bb to the transmission identifiers 2 and 4 arranged before and after the information field 3.
And the identification data aa different from the identification data bb of the transmission identifiers 2 and 4 is set in the reception identifier 1. The identification data bb of the transmission identifiers 2 and 4 is, for example, the transmission number and label code of the transmission data transmitted by the transmitting station A to the receiving station B, or the address of the receiving station B, as described in the prior art. Identification data of a transmission identifier including a transmission number and a label code is used. Further, as the identification data aa of the reception identifier 1, for example, data meaning invalid data is used.

In step S2, the transmission data transmitted by the transmission station A is matched with the identification data of the transmission identifiers 2 and 4 of the transmission data in the reception station B by the transmission identifier comparison means (in the illustrated example, the identification data is bb Match)
Assuming that the transfer information (data) in the information field 3 has been correctly transmitted, the transfer information (d) is received by the receiving means of the receiving station B.
ata) is received.

Then, in step S3, the receiving station B
When the transfer information (data) is correctly received, the identifier rewriting means rewrites the identification data aa of the reception identifier 1 into the identification data bb of the received transmission identifier 2 described above.
Reply to transmitting station A. If the received data cannot be received correctly, the above rewriting operation is not performed. Therefore, at this time, the identification data aa of the reception identifier 1 remains unchanged, and the identification data aa of the reception identifier 1 and the transmission identifier 2
Is different from the identification data bb of.

Next, in step S4, the transmitting station A
The reply data from the receiving station B is received, and the sending / receiving identifier comparison means included in the sending station A causes the sending identifier identification data.
bb is compared with the identification data bb of the reception identifier (for normal reception) and aa (for abnormal reception). The transmission station A that has transmitted the transmission data transmits the transmission data from the transmission station A because the transmission / reception identifier comparison means causes the reception identifier 1 of the reply data returned from the reception station B and the identification data bb of the transmission identifier 2 to match. It is possible to know that the data can be reliably received by the receiving station B.

The transfer information (data) in the information field 3 in steps S3 and S4 is not always necessary. When the transfer information (data) in the information field 3 is described and sent back, the transmitting station A checks the returned data as necessary, and the receiving station B receives the transfer information (data) really correctly. You can verify whether it was possible. Further, when there is no transfer information (data) in the information field 3, the return data frame is shortened accordingly, so that the deterioration of the transmission efficiency can be prevented.

[0015]

According to the present invention, by providing a simple code called a reception identifier in a transmission frame, in the method of transmitting asynchronous transmission data, whether or not the transmitted data can be correctly received by the receiving station at the transmitting station side. That is, it is possible to improve the reliability of data transmission.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a transmission data frame and reception and a reception confirmation operation according to an embodiment of the present invention.

[Explanation of symbols]

 1 reception identifier 2, 4 transmission identifier 3 information field aa reception identification data bb transmission identification data A transmission station B reception station

Claims (2)

[Claims] 1. At least a transmitting station and a receiving station are connected by a 1: 1 transmission line, and a frame structure of transmission data is arranged with an information field consisting of transfer information to be transferred to a counterpart receiving station and before and after this information field. When the transmitting station transmits the transmission data, the transmitting station sets the same identification data in both of the transmitting identifiers and the receiving identifier is set to the identification data different from the transmitting identifier. The receiving station compares the two transmission identifiers of the received transmission data, and when both transmission identifiers match, receives the transfer information of the information field and transmits the identification data of the reception identifier to the received transmission. The identification data of the identifier is rewritten and returned to the transmitting station as reply data. The transmitting station identifies the receiving identifier of the reply data and the transmitting identifier. Comparing the identification data, from the identification data match, it knows that the transmission data the transmission is reliably be received in the receiving station, a method of transmitting asynchronous transmission data, characterized in that. 2. At least a transmitting station and a receiving station are connected by a 1: 1 transmission line, and a frame structure of transmission data is arranged with an information field consisting of transfer information to be transferred to a counterpart receiving station and before and after this information field. In the transmission device comprising a transmission identifier and a reception identifier, the transmission station sets the same identification data in both the transmission identifiers, and an identifier setting unit that sets the reception identifier different identification data from the transmission identifier, Transmission / reception identifier comparison means for comparing identification data of the transmission identifier with identification data of the reception identifier, wherein the receiving station has transmission identifier comparison means for comparing the both transmission identifiers of the received transmission data; Receiving means for receiving the transfer information of the information field when the transmission identifiers match, and receiving the transmission data and returning the reply data to the transmitting station. And an identifier rewriting means for rewriting the identification data of the reception identifier to the identification data of the received transmission identifier when the transmission station that has transmitted the transmission data is returned by the transmission / reception identifier comparison means from the reception station. The asynchronous transmission data transmission device is characterized by knowing that the transmission data transmitted can be reliably received by the receiving station by the identification data of the reception identifier and the identification data of the transmission identifier being matched.