JP2590635B2 - Data transmission processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a secondary station connected by a central control system / branch system to a primary station via a communication line. The present invention relates to a data transmission processing method when transmitting data in the NRM procedure.

[0002]

2. Description of the Related Art In a digital communication network or the like, it is necessary to quickly detect a failure of a plurality of transmission devices constituting the network and take a recovery procedure. Data is collected at regular intervals.

FIG. 3 is a configuration diagram of a data communication system connected by a central control / branch method to which the present invention is applied. The central control station (primary station having a host computer; hereinafter referred to as a primary station) A transmits and receives data to and from the connected terminals (hereinafter referred to as secondary stations) B1 to B3. Sends a data transmission request RR at a time determined by itself, and the secondary station transmits data in response to this request.

At this time, data transmission between the primary station and the secondary station is performed by the HDLC / NRM procedure. That is, for example, the terminal of the secondary station B2 assembles in a form capable of transmitting data to be transmitted, prepares for transmission, and transmits when receiving a transmission request from the primary station.

FIG. 4 shows a conventional secondary station data transmission processing method in the HLDC / NRM procedure. In FIG.
Data generated at random timing from a data generator (not shown) is received in the data input processing 1 and stored in the reception buffer 11, and the reception buffer 11 always holds the latest data. The transmission / reception completion notification process 4 constantly monitors the driver 5 and, when detecting that the driver 5 has received a data transmission request from the primary station, notifies the data transmission process 3. Then, the data transmission process 3 includes a transmission buffer
The assembled data prepared in 31 is transmitted to the communication line via the driver 5. When the data transmission is completed, the transmission / reception completion notification process 4 notifies the data assembling process 2 of the completion of the transmission. Therefore, the latest data at that time is taken out from the reception buffer 11 and arranged in a predetermined order. The data is assembled, a transmission request is sent to the data transmission process 3, and the assembled data is stored in the transmission buffer 31.

When the driver 5 receives a transmission request from the primary station in the next polling cycle, the driver 5
The assembled data prepared in 31 is transmitted to the communication line.

[0007]

In a transmission device monitoring system or the like, it is desirable to transmit the latest data generated to the primary station. The primary station usually polls the secondary station at a fixed polling cycle. However, in the above-described conventional method, the data assembled at the time of the previous transmission completion is transmitted in response to the current transmission request, and there is a problem that if the polling cycle is long, old data is transmitted correspondingly.

There is also a method in which a time interval for assembling data is fixed in advance, and data is assembled and prepared in a transmission buffer irrespective of a transmission request from a primary station. If the polling cycle is short, there is a problem in that a transmission request is issued before the next transmission data is assembled, and the transmission data is lost.

When such a situation occurs, a problem occurs in the supervisory control system in that the reliability of data collected by the central control station by polling is reduced. The present invention has been made in view of the above problems, and has as its object to enable the secondary station to transmit the latest data to a transmission request from the primary station even if the polling interval is long.

[0010]

FIG. 1 is a block diagram of a data transmission processing method according to the present invention. As shown in FIG. 1, the above-mentioned problem is a data transmission processing method in a secondary station for transmitting data to a communication line via a driver 6 in response to polling from a primary station.
A data input process 1 for overwriting the latest data 11 and retaining the latest data, a data assembling process 2 for assembling transmission data using the data in the input buffer 11, and storing the assembled data in the transmission buffer 31 via the driver 6. It includes a data transmission process 3 for transmission, a transmission / reception completion notification process 4 for detecting the completion of transmission / reception in the driver 6, and a timer monitoring process 5, wherein the timer monitoring process 5 is transmitted from the primary station detected by the transmission / reception completion notification process 4. A polling interval is calculated based on the transmission request time, and a data assembling timing at which data assembling is performed immediately before the polling is calculated, and the data assembling process 2 is requested to perform data assembling at the timing. The problem is solved by the data transmission processing method of the invention.

[0011]

The timer monitoring process monitors the polling interval and calculates the data assembling timing from the polling interval. Therefore, even if the polling interval from the primary station is changed, the latest data is always transmitted.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a block diagram of a data transmission processing method according to the present invention.
FIG. 3 is a diagram showing a data transmission state in the present invention.

In FIG. 1, reference numeral 7 denotes a data generating unit in which generated data changes at an arbitrary timing; 1 denotes data received from the data generating unit, which is written by overwriting a reception buffer 11 so that the latest data is always written; A data input process for storing data from the reception buffer 11 upon request and a data assembling process for receiving the data from the data input process 1 and assembling the data into a form that can be transmitted to a communication line;
A data transmission process 3 receives the assembled data from the data assembling process 2 and accumulates the data in the transmission buffer 31, and sends the assembled data to the driver 6 in response to a transmission request reception notification from the transmission / reception completion notification process 4. 6 is a transmission / reception completion notification process of detecting completion of transmission / reception and notifying each unit. Reference numeral 5 denotes a timer monitoring process which measures a time interval for receiving a transmission / reception completion notification from the transmission / reception completion notification process 4 and calculates a polling cycle from the primary station. Then, the next transmission request time is obtained from the current reception completion processing notification time and the calculated polling cycle, and a request for data assembling processing 2 is made to the data assembling processing 2 at a time before the time required for data assembling. I do.

In calculating the polling period, the next polling time is estimated by averaging the latest three polling intervals from the primary station, for example. When the polling interval from the primary station is changed, the changed polling cycle is obtained at least three cycles later, and from the fourth cycle, the latest data immediately before the transmission request can be assembled and prepared.

Reference numeral 6 denotes a driver which sends the assembled data from the transmission processing unit 3 to a communication line and receives data from the communication line. The data transmission process based on the above configuration is performed in the following procedure. When the driver 6 receives the transmission request RR from the primary station, the reception completion notification process detects this and notifies the data transmission process 3 of the completion of the data transmission request reception, and the data transmission process 3 has been prepared at that time. The assembled data is immediately transmitted from the transmission buffer 31 to the primary station via the driver 6. The transmission / reception completion processing 4 detects the completion of the transmission and notifies the timer monitoring processing 5. Upon receiving this notification, the timer monitoring process 5 requests the data assembling process 2 to assemble the data after a predetermined delay time. The data assembling process assembles the transmission data using the data stored in the reception buffer at the time requested, and requests the transmission process 4 to transmit the assembled data.
Store in 31.

By doing so, as shown in FIG. 2, even if the polling interval Tp is long,
After receiving the data transmission completion notification this time, the application program delays the start of the data assembling process until immediately before data transmission by the next transmission request (before Ts) (delay time Td = Tp−Ts). Even if the input data changes from a to b, the latest data b after the change can be transmitted for the next polling from the primary station.

When the polling interval is changed, the timer monitoring process detects the change. After a predetermined period, the data assembling process is performed at the time corresponding to the changed interval to prepare for the next polling. No loss occurs, and the reliability of transmission data is improved.

[0018]

As is apparent from the above description, according to the present invention, the timer monitoring process monitors the polling interval and calculates the data assembly timing from the polling interval. Even if it is changed, the latest data is always transmitted, so that the reliability of the transmitted data is improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a data transmission processing method of the present invention.

FIG. 2 is a diagram showing a data transmission state according to the present invention.

FIG. 3 is a configuration diagram of a data communication system to which the present invention is applied;

FIG. 4 is a diagram showing a conventional data transmission processing method in the HDLC / NRM procedure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Data input processing, 11 ... Input buffer, 2 ... Data assembly processing, 3 ... Data transmission processing, 31 ... Output buffer, 4 ...
Transmission / reception completion notification processing, 5: timer monitoring processing, 6: driver,

Claims (1)

(57) [Claims] 1. A data transmission processing method in a secondary station for sending data to a communication line via a driver (6) in response to polling from a primary station, wherein data to be input is input to an input buffer (11). Data input processing (1) to overwrite and retain the latest data, data assembling processing (2) to assemble transmission data using the data in the input buffer (11), and storing the assembled data in the transmission buffer (31) Data transmission processing for transmission via the driver (6)
(3), a transmission / reception completion notification process (4) for detecting the completion of transmission / reception in the driver (6), and a timer monitoring process (5), and the timer monitoring process (5) is a transmission / reception completion notification process (4). , A polling interval is calculated based on the transmission request time from the primary station detected, a data assembling timing at which data assembling is performed immediately before the polling is calculated, and a data assembling process 2 is requested at this timing. A data transmission processing method characterized by the above-mentioned.