JPH04258050A - Data collection system - Google Patents

Abstract

PURPOSE:To allow a master station side to easily revise a collected data number and a sampling period with respect to a slave station device in the case of polling in response to the collected data quantity, to improve the utilizing efficiency of a line and to reduce the wait time for data collection. CONSTITUTION:A master station device 2 designates a collected data number and a sampling period to a polling start request from a data processing unit 1, adds them to a communication text and sends the result to a slave station device 3. The slave station device 3 implements data sampling according to the designated parameter and returns the result to the master station device 2. Moreover, the slave station device is provided with a collection data number table and a sampling period table, and the slave station device 3 reads the collection data number and the sampling period corresponding to the parameter designated in the case of polling by the master station respectively from the table and generates and collects the data and returns it to the master station device 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data collection method using polling.

0002

[Prior Art] In conventional polling, information on the number of sampling data and sampling period was not added on the master station side, so a fixed number of data was sampled at a fixed interval set on the slave station side. It was only sent to the station. Therefore, when changing the cycle and the number of data, the program on the slave station side had to be changed.

0003

[Problem to be Solved by the Invention] In this conventional polling method, the amount of data that the master station acquires and its time are fixed by the synchronization and number of data, which are sampling parameters set on the slave station. Even when the amount of data is small, it takes the same amount of time to collect the maximum amount of data in the system, resulting in lower line usage efficiency and longer waiting times for data collection. In addition, in order to avoid these problems, the program on the slave station side must be changed each time, which has the disadvantage of being costly and time consuming.

0004

[Means for Solving the Problems] The data collection method of the present invention adds destination designation information that designates the data collection destination, sampling collection data number designation information, and sampling cycle designation information to a communication message and performs polling. and at least one slave station that detects the destination designation information, sampling collection data number information, and sampling period information, and generates data by sampling at the specified sampling collection data number and sampling period. and polling is performed by arbitrarily setting the number of data to be sampled and the sampling period on the slave station side on the master station side. In addition, it is equipped with a collection data number table that stores multiple items of values for the number of data to be collected in the slave station device, and a sampling period table that stores multiple items of sampling period values. Specify the item number of the table and the item number of the sampling period table, add it to the communication message, and send it.
The slave station device searches both tables, detects an item number corresponding to the specified number of collected data and an item number corresponding to the sampling period, and generates and collects the data.

An object of the present invention is to provide a data collection method that allows the master station to arbitrarily specify the data sampling period and the number of data on the slave station during polling.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the system configuration of an embodiment of the present invention. A data processing device 1 is a data processing device equipped with an input/output device, and has a sampling period (hereinafter referred to as ST) and The number of sampling data (number of collected data: hereinafter referred to as SN) can be easily changed via the input/output device, and when starting polling, the set sampling period and number of sampling data are added. It shall be. In response to the polling activation request from the data processing device 1, the master station device 2
, SN and performs polling, and the slave station device 3 samples data according to the specified parameter value in response to the polling of the master station device 2, and sends it to the master station device 2. This is a slave station device that transmits data. Furthermore, it is assumed that the data processing device 1 starts up the data collection.

The data processing device 1 has a sampling period (ST) set in advance via a man-machine system (consisting of an input device such as a keyboard and an output device such as a CRT), and the number of sampling data (including infinity). SN
) to activate the master station device 2 for polling.

[0009] When the master station device 2 receives this message,
It adds the ST and SN information sent from the data processing device 1 and sends a polling message to the slave station device 3 to collect data.

[0010] The slave station device 3 receives the received ST and SN.
The data is sampled according to the data and sent to the master station device 2.

[0011] Also, when polling is performed next time, ST,
If it is desired to change the value of SN, the sampling period (ST a) and the number of sampling data (SN a) are reset via the man-machine system of the data processing device 1. Then, when the data processing device 1 initiates polling to the master station device 2, the data processing device 1 adds the changed parameters ST a and SN a and sends the message.

[0012] When the master station device 2 receives this message, the S
It adds T a and SN a and sends a polling message to the slave station device 3 .

[0013] The slave station device 3 samples the data according to ST a and SN a, which are different from the previous data sent, and sends it to the master station device 2 . The master station device 2 sends the collected data to the data processing device 1 and
Predetermined processing is performed.

As described above, data can be collected by easily changing the period and the number of sampling parameters on the slave station side. Generally, when there are n slave stations, the data processing device 1 specifies the station and the ST
,SN and start polling,
Similarly, data can be collected by easily changing ST and SN.

FIG. 2 is a flowchart showing the data sampling process of the slave station device 3, and shows the procedure for setting parameters in the slave station device 3 and inputting data using the parameters.

The number of collected data is used as the upper limit value of a counter that increments by one each time data is input. The period is used to determine the data sampling interval. By sampling using these two parameters, it becomes possible to collect discrete data that is continuous in time series.

There are two general methods for specifying parameters in the slave station device 3. The slave station device 3 has a table containing the values of the number of data to be collected and the sampling period, and the table number is specified by the master station device 2. In the method, the slave station device 3 does not have a table and the master station device 2
There is a method of sending numerical values more directly.

Next, a method of specifying parameters in the slave station device 3 will be explained. FIG. 3 shows a message when the parameter values sent from the master station device 2 are directly used. The number of collected data and the sampling period are added to the polling command, and this value is sent to the slave station device 3 using the flowchart shown in FIG. It is used to substitute the sampling period (S1) and the number of sampling data (S2) in . In this case, the data format of the number of collected data and the period can be binary, BCD, hex (hexadecimal), etc.

It is determined whether the sampling period and number of sampling data designated by the master station 2 have been input (S3), and if the required number of data has been input, data sampling is ended. If the number of data is not entered,
Initialize the timer that sets sampling synchronization. When this initialized sampling period passes the set value (S5), the measurement data is input (S6).
Then, when the number of input data reaches a predetermined number (S7
), the number of required data is determined again (S3), and if there is the required number of data, data sampling is completed.

FIG. 4 shows a method for specifying messages and parameters when the slave station device 3 has a table containing the number of collected data and sampling period values. The message is shown in Figure 3.
is almost the same as , but what is added to the polling command is not a direct numerical value, but a collection data number item number to specify the item number of the table held by the slave station device 3,
This is the sampling cycle item number.

[0021] Collection data number item number i in the message,
By specifying the sampling period item number j, the slave station device 3
The numerical value stored in the i location of the storage unit is used as the number of collected data, and the numerical value stored in the j location is used as the sampling period during substitution in the flow of FIG. The following operation is the same as the above-mentioned example in which parameters from the master station are directly used, so a description thereof will be omitted. However, this method requires a storage unit to store each parameter value, and continuous designation requires a corresponding capacity.

[0022]

[Effects of the Invention] As explained above, the present invention allows the data sampling period and the number of sampling cycles on the slave station side to be easily changed during polling without changing the program on the slave station side. Therefore, it can be varied according to the amount of collected data, which has the effect of improving line usage efficiency. It also has the effect of shortening the waiting time for data collection.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the system configuration of an embodiment of the present invention.

FIG. 2 is a flow chart showing the operation of the present invention.

FIG. 3 is a diagram showing a data format of a message sent from a master station to a slave station when parameter values sent by the master station are directly used.

FIG. 4 is a diagram illustrating a message sent from a master station to a slave station and a table configuration of the slave station when specifying desired parameters from the number of collected data and a sampling period table held by the slave station.

[Explanation of symbols]

1 Data processing device 2. Master station device 3. Slave station device

Claims (2)

[Claims] 1. A master station device that performs polling by adding destination designation information that designates a data collection destination, sampling collection data number designation information, and sampling cycle designation information to a communication message, the destination designation information, at least one slave station device that detects sampling collection data number information and sampling period information and generates data by sampling with the specified sampling collection data number and sampling period, and the sampling on the side of the slave station device. A data collection method characterized by polling by arbitrarily setting the number of data to be collected and the sampling period on the master station side. 2. A collected data number table that stores a plurality of items of values of the number of data to be collected in the slave station device, and a sampling period table that stores a plurality of items of sampling period values, and the table includes a collection data number table that stores a plurality of items of values of the number of data to be collected in the slave station device, and a sampling period table that stores a plurality of items of sampling period values, and the table includes a table that stores a plurality of items of values of the number of data to be collected in the slave station device, and a sampling period table that stores a plurality of items of values of sampling period. The item number of the collection data number table and the item number of the sampling period table are specified and added to the communication message and sent, and the slave station device searches both tables and determines the item number corresponding to the specified number of collection data. 2. The data collection method according to claim 1, wherein said data is generated and collected by detecting an item number corresponding to a sampling period.