JP2000124926A - Method for measuring load factor of communication and control system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contribute to system design by enabling exact measurement of a load factor of communication by performing calculation so as to eliminate a difference in an acquisition time between pieces of information about each of required parameters. SOLUTION: Information about the entire communication network 100a is acquired by a first time I/O request processing, the number of active nodes on the network 100a, the number of vacancies as the discontinuous numbers of node numbers are acquired by continuously performing a second time I/O request processing, a token frequency and the load factor of the communication are calculated by a specified numerical formula and the load factor of the communication, the token frequency, the number of the nodes and the vacancies are displayed on a display means 6 or printed out by a control means 52. The I/O request processings are performed by data transfer between a program of the control means 52 and a communication controller 9 such as an other control node 51 via a communication driver. Thus, the exact load factor of the communication is obtained by eliminating a difference in an acquisition time by calculating the parameters to be required for calculation of the load factor of the communication by two times consecutive I/O request processings.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of measuring a communication load factor of a communication network of a token bus system, and more particularly to a measurement method capable of accurately measuring a communication load factor and a control system using the same.

[0002]

2. Description of the Related Art In a conventional communication network of a token bus system of a control system, a system design in consideration of a communication load factor of the communication network is required in order to ensure communication reliability.

A conventional control system includes a control operation monitoring node installed in a control room or the like and a control node distributed and installed in a field or the like. The nodes are mutually connected by a communication system such as a communication cable, and form a control system by performing data communication and the like with each other.

[0004] In the token bus system (IEEE 802.4 standard), a specific signal or frame called a token is circulated between the nodes, and only the node that has captured the token obtains an access right to the communication network and needs the access right. A signal or a frame is transmitted on a communication network. Then, by forming a logical ring for circulating the token, even if the physical shape is a bus shape, all nodes are sequentially given access to the communication network.

FIG. 6 is a configuration block diagram showing an example of a communication network of a conventional control system. In FIG. 6, 1 and 2 are control operation monitoring nodes, 3 and 4 are control nodes, and 100 is a communication network. The control operation monitoring nodes 1 and 2 and the control nodes 3 and 4 are each connected to a communication network 100.

Here, a conventional method of measuring the communication load factor in the control system shown in FIG. 6 will be described. In order to determine the communication load factor, the number of nodes operating on the communication network 100, the number of discontinuous node numbers (hereinafter referred to as the number of gaps), and the number of times the token has rotated the logical ring formed by each node. It is possible to obtain the number of token laps and the like indicating the above, and calculate them by using a formula as a parameter. More specifically, the control operation monitoring node 1 or the like individually starts software and executes the communication network 1
The number of active nodes, the number of gaps, and the number of token rounds were acquired on 00.

[0007]

However, in the conventional example as shown in FIG. 6, each parameter information can be obtained by individual processing such as communication between each node. However, there is a problem that the communication load factor obtained by the difference in the acquisition time of the communication is not accurate.

For example, the number of nodes, the number of gaps, and the number of token rotations operating on the communication network 100 change every moment, so that the time when the number of nodes is obtained and the time when the number of token rotations are obtained are temporally different. If there is a significant difference, the actual number of nodes at the time the token circulation number is obtained may not match the obtained number of nodes, so the accuracy of the required communication load factor is not guaranteed. There were challenges.
Therefore, an object of the present invention is to realize a measurement method capable of accurately measuring a communication load factor and a control system using the same.

[0009]

In order to achieve the above object, according to a first aspect of the present invention, there is provided a method for measuring a communication load factor of a communication network of a token bus system, comprising the steps of: An O request process is performed to obtain information on the entire communication network, and a second I / O request process is performed to obtain information on a node having an access right to the communication network. Determine the number of active nodes and gaps from the information, calculate the number of token rounds from the information of the node having the access right of the communication network and calculate the communication load factor from the number of nodes and the gap determined earlier, By displaying the obtained communication load factor, the token circulation number, the number of nodes, and the number of gaps, each of the obtained parameter information Since differences resulting time runs becomes possible to accurately measure the communication load factor.

According to a second aspect of the present invention, in the communication load factor measuring method according to the first aspect, the I / O request processing is such that a program issues an I / O request to a communication driver. Upon receiving the / O request, the communication driver writes the I / O request in the storage unit of the communication controller to be requested, and the communication controller performs necessary processing based on the written I / O request. The communication controller sends an interrupt signal to notify the communication driver of the end of the processing after writing the processing result or the requested value to the storage means, and the communication driver sends the interrupt signal according to the interrupt signal. By reading the information written in the storage means and returning this value to the program, it is possible to obtain between the respective obtained parameter information. Since the difference between is eliminated it is possible to accurately measure the communication load factor.

According to a third aspect of the present invention, in the communication load factor measuring method according to the first aspect of the present invention, the determined communication load factor, the number of token rounds, the number of nodes, and the number of gaps are printed. , Making reports and the like easier.

According to a fourth aspect of the present invention, in the communication load factor measuring method according to the first aspect of the present invention, the determined communication load factor, the token circulation count, the node count, and the gap count are periodically accumulated. In addition, by displaying the accumulated data in a graph and displaying or printing the data, trends such as the communication load factor can be known, thereby facilitating system design.

According to a fifth aspect of the present invention, in a control system for measuring a communication load factor of a token bus communication network, a display means, a first I / O request process for acquiring information of the entire communication network, and A second I / O request process for continuously acquiring information on a node having an access right to the communication network is performed, and the number of active nodes and the number of gaps are obtained from the information of the entire communication network. The number of token rotations is obtained from the information of the node having the access right, and the communication load factor is calculated from the number of nodes and the number of gaps previously obtained, and the communication load factor, the number of token rotations, the number of nodes and the number of gaps are calculated. And control means for displaying the parameter information on the display means, so that there is no difference in the acquisition time between the respective obtained parameter information. It is possible to accurately measure the communication load factor since.

According to a sixth aspect of the present invention, in the control system according to the fifth aspect, the I / O request processing is such that a program issues an I / O request to a communication driver, and The communication driver that has received the I / O request writes the I / O request to the storage unit of the communication controller to be requested, and the communication controller performs necessary processing based on the written I / O request and stores the I / O request. After writing the processing result or the requested value to the means, the communication controller transmits an interrupt signal to notify the communication driver of the end of the processing,
The communication driver reads out the information written in the storage means by the interrupt signal and returns this value to the program, so that there is no difference in the acquisition time between the respective obtained parameter information. It becomes possible to measure.

According to a seventh aspect of the present invention, in the control system according to the fifth aspect of the present invention, the printing is performed by printing the communication load factor, the token rotation number, the node number, and the gap number by a printing unit. Creation of books and the like becomes easy.

According to an eighth aspect of the present invention, in the control system according to the fifth and seventh aspects, the communication load factor, the number of token rounds, the number of nodes, and the number of gaps are periodically stored in storage means. By storing the accumulated data in a graph and displaying the data on the display unit or printing the data on the printing unit, a trend such as a communication load factor can be known, thereby facilitating system design.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration block diagram showing one embodiment of a control system using the communication load factor measuring method according to the present invention. In FIG. 1, 5 is a control circuit such as a CPU, and 6 is a CRT.
, LCD and other display means, 7 and 9 are communication controllers,
8 and 10 are storage means, and 100a is a communication network. 5 to 8 are control operation monitoring nodes 50, 9 to
10 constitutes a control node 51, and 5 and 7 constitute control means 52, respectively.

The control signal of the control circuit 5 is connected to the display means 6, and the input and output of the control circuit 5 are mutually connected to the communication controller 7 and the storage means 8. The input / output of the communication controller 7 is also mutually connected to the storage means 7, and the communication input / output of the communication controller is connected to the communication network 100a. On the other hand, the input / output of the communication controller 9 is mutually connected to the storage means 10, and the communication input / output of the communication controller 9 is connected to the communication network 100a.

The operation of the embodiment shown in FIG. 1 will now be described with reference to FIGS. FIG. 2 is a flowchart for explaining the operation of the control circuit 5, and FIG. 3 is an explanatory diagram showing an example of information of a communicable node at that time (hereinafter, referred to as a live list). An application program (hereinafter, simply referred to as a program) executed by the control circuit 5 is stored in the storage unit 8, and is read out from the storage unit 8 as appropriate and executed.

At "S001" in FIG. 2, the control circuit 5 performs a first I / O request process, and
a) Acquire information of the entirety. Then, "S002" in FIG.
In, the control circuit 5 performs the second I / O request processing continuously to acquire information on the node having the access right of the communication network 100a.

In FIG. 2, in "S003", the control circuit 5 transmits the communication network 10 acquired in the first I / O request processing.
The number of active nodes and the number of gaps on the communication network 100a are determined from the information of the entire network 0a.

For example, if the live list has the 64-bit value shown in FIG. 3, the first bit counted from the LSB,
Since the third bit, the 23rd bit, and the 24th bit are “1”, it can be understood that the nodes of the node numbers 1, 3, 23, and 24 are communicable. For this reason,
The control circuit 5 counts the number of “1” in the live list to obtain that the number of nodes operating on the communication network 100a is “4”.

On the other hand, the number of gaps (the number of discontinuities in the node numbers) indicates the number of locations where the node numbers are not continuous. For example, in FIG.
A discontinuous portion is between the bit 23 and the bit 23 and between the bit 24 and the bit 1. For this reason, the control circuit 5 counts the number of rises in which the live list changes from “0” to “1”, thereby controlling the communication network 10.
It is obtained that the number of gaps of 0a is “3”.

Then, in "S004" in FIG. 2, the control circuit 5 obtains the number of token rotations from the information of the node having the access right of the communication network 100a obtained in the second I / O request processing, and also obtains the node obtained earlier. The communication load factor is calculated from the number and the number of gaps.

Here, the number of token circulations per minute is "N
t ", the number of nodes is" Nn ", the number of gaps is" Ns ", and the communication load factor is" Rload ": Rload = (1−0.001 × ((Nt / 60) × (0.0292 × Nn) + 0.0104 × Ns + 0.011)) × 100 (1)

For example, if the number of token rotations per minute is "34"
Assuming that the number of nodes is “4” and the number of gaps is “3” as shown in FIG. 3, Rload = (1−0.001 · ((3400000/60) × (0. 0292 * 4 + 0.0104 * 3 + 0.011))) = 100 = 9.9 (2), and the communication load factor becomes "9.9%".

Further, in "S005" in FIG. 2, the control circuit 5 controls the display means 6 to display the communication load factor, the number of token rotations, the number of nodes on the communication network 100a, and the number of gaps. Finally, in "S006" in FIG. 2, the control circuit 5 determines whether or not to execute the scan at a fixed cycle. If the scan is to be executed at a fixed cycle, the process returns to "S001" in FIG.

Here, the I / O request processing will be further described in detail with reference to FIGS. FIG. 4 is an explanatory diagram showing a relationship between a program and a communication driver interface (hereinafter, simply referred to as a communication driver), and FIG. 5 is a flowchart showing details of I / O request processing.

In FIG. 4, reference numerals 52 and 100a denote the same reference numerals as in FIG. 1, 11 denotes a program, and 12 denotes a communication driver. The program 11 and the communication driver 12 operate on the control unit 52, and the program 11 exchanges data with the communication controller of another node via the communication driver 12.

In "S101" in FIG.
1 issues an I / O request to the communication driver 12. FIG.
In the middle “S102”, the communication driver 12 writes the I / O request in the storage unit of the communication controller to be requested.

For example, when the node having access right to the communication network 100 a is the control node 51 shown in FIG. 1, the communication driver 12 writes an I / O request to the storage unit 10 via the communication controller 9.

Further, for example, the communication network 100a
When the node having the access right is the control operation monitoring node 50 shown in FIG. 1, the communication driver 12 writes an I / O request to the storage unit 8 via the communication controller 7.

Then, in "S103" in FIG. 5, the communication controller performs necessary processing based on the contents of the written I / O request, and in "S104" in FIG. The requested value and the like are written, and the communication driver 1 in "S105" in FIG.
Then, an interrupt signal is transmitted to notify the end of processing.

For example, if the I / O request is a request for the number of token rotations, the communication controller 9 writes the information of the number of token rotations held by the communication controller 9 in the shared portion of the storage means 10 and sends the information to the communication driver 12. To send an interrupt signal.

Finally, in "S106" in FIG. 5, the communication driver 12 reads the information written in the storage means and returns this value to the program 11. For example, when receiving the interrupt signal from the communication controller 9, the communication driver 12 reads the token rotation number written in the storage unit 10 and passes the read token rotation number to the program 11.

As a result, the information of the entire communication network 100a and the information of the node having the access right to the communication network 100a are obtained by the continuous two I / O request processings, and the information required for calculating the communication load factor is obtained from the information. By obtaining the number of nodes, the number of gaps, and the number of token rounds, which are important parameters, there is no difference in the acquisition time between the obtained pieces of parameter information, so that the communication load factor can be accurately measured.

In the description of the embodiment shown in FIG. 1, the control circuit 5 controls the display means 6 to display the communication load factor, the number of token turns, the number of nodes on the communication network 100a, and the number of gaps. However, it is needless to say that the present invention is not limited to this, and the obtained communication load factor and the like may be printed by a printing unit such as a printer. In this case, since the requested information is printed, it is easy to prepare a report or the like.

Further, the communication load ratio or the like may be continuously and periodically obtained and stored in the storage unit 8 or the like, and then graphed to display a trend graph or the like on the display unit 6 or print it with the printing unit. . In this case, a trend such as a communication load factor can be known, so that the system design becomes easy. In addition, by periodically measuring the communication load factor of the existing system and determining the trend, it is possible to know a sign of occurrence of a communication failure due to a temporary communication overload.

In the description of the flowchart shown in FIG. 2, the steps from "S006" in FIG. 2 to "S00" in FIG.
Although the process immediately jumps to the step "1", in other words, the communication load ratio or the like is continuously obtained, the communication load ratio or the like may be intermittently obtained by providing a standby time based on a preset value. I do not care.

In the control operation monitoring node 50, the control circuit 5 and the communication controller 7 are separated from each other for the sake of simplicity, but one control means 52 may have two functions. is there. The storage unit 8 is not necessarily required if a storage unit such as a ROM or a RAM included in the control unit 52 is used.

For simplicity of description, the control node 51
Although the communication controller 9 and the storage unit 10 are described separately in the above, the storage unit 10 is not necessarily required if a storage unit such as a RAM or a register included in the communication controller 9 is used.

[0042]

As is apparent from the above description,
According to the present invention, the following effects can be obtained. Claims 1, 2,
According to the fifth and sixth aspects of the present invention, two consecutive I / Os
Obtain information on the entire communication network and information on nodes having access rights to the communication network by request processing, and obtain the number of nodes, the number of gaps, and the number of token rounds, which are parameters required for calculating the communication load factor, from the information. Accordingly, there is no difference in the acquisition time between the respective pieces of obtained parameter information, so that the communication load factor can be accurately measured.

According to the third and seventh aspects of the present invention, by printing the determined communication load factor, token circulation number, node number and gap number, it becomes easy to prepare a report or the like.

According to the fourth and eighth aspects of the present invention, the obtained communication load factor, token circulation number, node number, and gap number are periodically accumulated, and the accumulated data is graphed for display or printing. By doing so, the trend of the communication load factor and the like can be understood, so that the system design becomes easy.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram showing an embodiment of a control system using a communication load factor measuring method according to the present invention.

FIG. 2 is a flowchart illustrating an operation of a control circuit.

FIG. 3 is an explanatory diagram illustrating an example of information of a communicable node;

FIG. 4 is an explanatory diagram showing a relationship between a program and a communication driver interface.

FIG. 5 is a flowchart showing details of an I / O request process.

FIG. 6 is a configuration block diagram illustrating an example of a communication network of a conventional control system.

[Explanation of symbols]

 1,2,50 control operation monitoring node 3,4,51 control node 5 control circuit 6 display means 7,9 communication controller 8,10 storage means 11 program 12 communication driver 52 control means 100,100a communication network

Claims (8)

[Claims] In a method for measuring a communication load factor of a communication network of a token bus system, a first I / O request process is performed to obtain information of the entire communication network, and then a second I / O request process is performed. The information of the node having the access right of the communication network is obtained, the number of active nodes and the number of gaps are obtained from the information of the entire communication network, and the token is obtained from the information of the node having the access right of the communication network. Calculating the number of laps and calculating a communication load factor from the number of nodes and the number of gaps previously obtained, and displaying the obtained communication load factor, the number of token laps, the number of nodes and the number of gaps. Communication load factor measurement method. 2. The I / O request processing, wherein a program issues an I / O request to a communication driver, and the communication driver receiving the I / O request stores the I / O request in a storage unit of a communication controller to be requested. After writing the I / O request, the communication controller performs necessary processing based on the contents of the written I / O request and writes the processing result or the requested value to the storage unit. Transmits an interrupt signal to notify the communication driver of the end of the process, and the communication driver reads out the information written in the storage means by the interrupt signal and returns this value to the program. The communication load factor measuring method according to claim 1. 3. The communication load factor measuring method according to claim 1, wherein the determined communication load factor, the token circulation number, the number of nodes, and the number of gaps are printed. 4. The method according to claim 1, wherein the determined communication load factor, the number of token rounds, the number of nodes, and the number of gaps are periodically accumulated, and the accumulated data is graphed and displayed or printed. The communication load factor measurement method described. 5. A control system for measuring a communication load factor of a token bus communication network, comprising: a display unit; and a first I / O for acquiring information on the entire communication network.
O request processing and second I / O request processing for acquiring information on a node having access right to the communication network are continuously performed, and the number of active nodes and the number of gaps are obtained from the information of the entire communication network; Calculate the number of token rotations from the information of the node having the access right of the communication network and calculate the communication load factor from the number of nodes and the number of gaps previously determined, and calculate the communication load factor, the number of token rotations, and the number of nodes. And a control means for displaying the number of gaps on the display means. 6. The I / O request processing, wherein the program issues an I / O request to a communication driver, and the communication driver receiving the I / O request stores the I / O request in a storage unit of a communication controller to be requested. After writing the I / O request, the communication controller performs necessary processing based on the contents of the written I / O request and writes the processing result or the requested value to the storage unit. Transmits an interrupt signal to notify the communication driver of the end of the process, and the communication driver reads out the information written in the storage means by the interrupt signal and returns this value to the program. The control system according to claim 5. 7. The control system according to claim 5, wherein said communication load factor, said token circulation number, said node number and said gap number are printed by a printing means. 8. The communication load factor, the token rotation number, the number of nodes, and the number of gaps are periodically stored in a storage unit, and the stored data is graphed and displayed on the display unit or printed by the printing unit. The control system according to claim 5, wherein the control is performed.