JPH0336851A - Data link communication control system - Google Patents

Abstract

PURPOSE:To transmit the data of the same content in a short time and to improve the immediate response by sending transmission data from a primary station, receiving the response to a secondary station whose address is designated and confirming the transmission. CONSTITUTION:A primary station 1 sends the data of the same content in a command UI frame in a broadcast format and secondary stations 2a-2d receive the frame. The secondary stations 2a-2d reference to its information part and receive only a data whose UI frame is subjected to its own station address designation and process the frame. Then only the secondary stations 2a-2d receiving the data return a reply to the primary station 1. Then the secondary stations 2a-2d receive the frame simultaneously and discriminate whether or not the frame is to be received at the address set in the information part. Since the primary station 1 confirms the transmission, the data is sent in a short time, the line efficiency is improved and the transmission with high immediate response is attained.

Description

[Detailed description of the invention] [Industrial application field]

This invention allows data with the same content to be sent to multiple i! The present invention relates to a data link communication control method that can efficiently transmit data to a single communication control device.

[Conventional technology]

Figure 4 shows, for example, the Japanese Industrial Standard (JIS)
1 is a configuration diagram of a communication system that executes a high-level data link control procedure shown in ``Procedure class of high-level data link control procedure'', in which 1 is a primary station that executes a high-level data link control procedure; 2a, 2b,
2c and 2d are secondary stations, and 3 is a transmission line. Next, the operation will be explained. Generally, when transmitting the same data from the primary station 1 to multiple secondary stations 2a to 2d via data links, the command adds (specifies) an address to each secondary station and sends an information I frame. are sent individually. Each secondary station 2a to 2d adds its own station address and sends an RR frame to the primary station 1 indicating that each secondary station can now accept the next information I frame. I've confirmed it. FIG. 5 shows the communication control procedure in this case. The function of the primary station 1 is to control the data link, have full responsibility for error control and recovery at the link level, and send commands and receive responses. Also 2
The next stations 2a to 2d execute data link control functions in response to instructions from the primary station 1, and in the asynchronous response mode also perform link-level error recovery, etc., transmit responses, and receive commands. When transmitting data from the primary station 1 to the secondary stations 2a to 2d, the primary station 1 sends information I to each secondary station.
Data is transmitted in frames. Then, the secondary station adds its own secondary station address and responds with an RR frame. A similar communication operation is also performed for sequential secondary stations.

[Problem to be solved by the invention]

Conventional data link communication control methods are performed as described above, so when transmitting the same data from a primary station to multiple secondary stations, the primary station must specify an address for each station. However, there was a problem in that the time efficiency and line efficiency for completing data transmission to multiple secondary stations were not good. This invention was made in order to solve the above-mentioned problems, and it is possible to transmit data with the same content from one primary station to multiple secondary stations in a short time, and also to confirm the delivery of the data. The purpose is to obtain a link communication control method.

[Means to solve the problem]

The data link communication control method according to the present invention includes a UI that has an address section in which a broadcast format address is set and an information section in which the address of each secondary station is set. The secondary station that has transmitted the frame and has been addressed continues to receive the inquiry frame and responds to the primary station that it has processed the UI frame.

[Effect]

In the data link communication control method according to the present invention, a UI frame having a broadcast-style address part is transmitted from a primary station to a plurality of secondary stations, so that the secondary stations can simultaneously receive data and information. Depending on the address set in the section, it can be determined whether or not to accept the frame.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the same parts as in FIG. 5 are indicated by the same reference numerals. In FIG. Assume that addresses a, b, and cd are assigned as follows. FIG. 2 is a frame configuration diagram of a UI frame used in the present invention. In the figure, A is an address section, C is a control section, ■ is an information section, F is a flag, and Fe2 is a frame check sequence. The information section I is divided into an address specification section and a data section, and the address specification section is designated by 2 in FIG.
The next station addresses a to d are stored, and the data section stores the contents of the data to be transmitted. When FF is set in the address part A, it becomes a global address and data is transmitted in a broadcast format. Next, the operations in FIGS. 1 and 2 will be explained below with reference to the flowchart in FIG. 3. First, in (a) of FIG. 1, the primary station 1 transmits data with the same content in a broadcast format as a command UI frame (step 5TI). All secondary stations 2a to 2d receive the frame (step 5T2). The secondary stations 2a to 2d refer to the address designation part in the information part I of the received UI frame, and only the secondary stations to which their own station address is designated simultaneously process the reception of the received UI frame. (Step 5T3). In this case, only the secondary stations whose addresses a, b, and c are specified in the address designation section of FIG. 2 accept the UI frame, and the secondary station 2d discards reception of the UI frame. Next, at (El), the secondary station 2a, which received the polling RR from the primary station 1 and accepted the above-mentioned UI frame,
2b and 2c respond with the (c) information frame, and the primary station 1 performs delivery & ILU of the data transmitted by the primary station 1 (steps ST4, 5T5). The secondary station 2d that did not accept the above-mentioned UI frame (d) does not respond to the primary station l with an information I frame (step 5T6).
). In addition, in the above embodiment, the delivery 611 of the secondary stations 2a to 2c
Although an example has been described in which a response is made using an information I frame for ii, it is also possible to respond using a DI frame. Further, the response is not only for confirming transmission, but also for returning processing results. When there is no need for delivery confirmation, there is no need to respond with an information I frame or UI frame.

【Effect of the invention】

As described above, according to the present invention, transmission data with the same content is transmitted from the primary station in broadcast format using a UI frame, and at the secondary station, only the secondary station whose address is specified in the information section responds. Since the data delivery can be confirmed at the primary station by returning , the line efficiency of high-level data link control is improved and data transmission with high responsiveness becomes possible.

[Brief explanation of drawings]

FIG. 1 is a control procedure diagram of a high-level data link according to an embodiment of the present invention, FIG. 2 is a UI frame configuration diagram according to the present invention, FIG. 3 is a flowchart showing the control procedure according to the present invention, and FIG. i-like high-level data link system+RIa diagram, FIG. 5 is a conventional high-level data link control procedure diagram. In the figure, 1 is the primary station, 2a, 2b, 2c. 2d is a secondary station, and 3 is a transmission line. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a data link communication control method in which a primary station and a plurality of secondary stations are connected via a transmission path and data communication is performed based on a high-level data link control procedure, a global address is transmitted from the primary station to the plurality of secondary stations. A UI that has an address section where the address of the secondary station is set and an information section where the address of the secondary station is set.
frame, and only the station whose own station address of the secondary station is specified in the UI frame executes the received frame acceptance process, receives the inquiry frame from the primary station, and the secondary station that accepted the UI frame A data link communication control method characterized in that only a station transmits a response to a primary station.