JPH07104842A - Data collecting system - Google Patents

Abstract

PURPOSE:To quickly deal with the rapid change of data by collecting data at the rate of priority from a controller for which the change rate of collecting data is large. CONSTITUTION:When returning the collecting data from controllers A-F, the controllers A-F calculate the change rate between the data collected the last time and the data collected this time, when this change rate exceeds a prescribed limit vague, a data request frequency change flag is set for executing the data collection preferentially rather than the other controller, this data request frequency change flag and a response data transmission text containing the data collected this time are transmitted to a monitoring device 11, this monitoring device 11 decides the level of the change rate based on the data request frequency change flag inside the response data transmission text transmitted from the controllers A-F and when this decided result shows the larger change rate, a polling signal is transmitted to that controller preferentially rather than the other controller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data collection system in which a monitoring device sequentially sends a polling signal to each controller to collect data from a destination controller, and in particular, a controller having a large change rate of collected data is given priority. The present invention relates to a data collection method capable of promptly responding to a sudden change in data by collecting data at a ratio.

[0002]

2. Description of the Related Art Conventionally, when collecting data from a plurality of controllers by a monitoring device, the monitoring device transmits a data request command (polling signal) to each controller in a predetermined order such as a station address and receives the data request command. A polling / selecting method in which the controller sends collected data to a monitoring device is widely used.

FIG. 8 is a schematic diagram showing a transmission procedure by such a data collection method. In the figure, the monitoring device 1
Is connected to a plurality of controllers 2 ₁ to 2 _n, sequentially transmits the data request command to each controller 2 ₁ to 2 _n,
The collected data returned from the destination controller 2 is displayed.

9 to 11 are flowcharts for explaining the operation of such a monitoring device or each controller, and FIGS. 12 and 13 are schematic diagrams showing the structure of the transmission text of this monitoring device or each controller. is there.

As shown in FIG. 9, the monitoring device sets the data request destination controller station number to an initial value of 1 (ST
1) As shown in FIG. 12, a data request command text including a header, a data request destination controller number, a data request command, and an FCS (frame check sequence) is created (ST2), and this data request command text is transmitted to the controller 1. Yes (ST3).

As shown in FIG. 10, the controller determines whether or not a data request command destined for its own station has been received (ST4), and when the determination result indicates no reception, the process returns to step ST4 and the determination result is When indicating that there is reception, FIG.
As shown in, header, own controller number, PV
Value, MV value, ..., Digital input value, Analog input value and FCS are created (ST)
5) Execute the process of transmitting this response data transmission text to the monitoring device (ST6) When step ST3 is completed, the monitoring device determines whether or not there is a response from the controller as shown in FIG. 11 (ST
7), when the determination result shows that there is no response, step ST7
When the determination result indicates that there is a response, it is determined whether or not there is an error in the response data transmission text (ST8).
Note that transmission processes such as retries and timeouts may be executed in steps ST7 to ST8.

When the determination result in this step ST8 indicates that there is an error, the monitoring device returns to step ST2 to request the data again, and when the determination result indicates that there is no error, the received collected data is stored in the RAM, It is also displayed (ST9).

Further, the monitoring device judges whether or not such collected data has been collected from all the n controllers (ST10), and when the judgment result indicates that the collected data has not been collected from all the controllers, Update the data request destination controller station number by +1 to calculate the next station number (ST
11) Return to step ST2, and when the determination result indicates that collection has been completed from all controllers, repeat step S to collect new data from the first controller.
Return to T1. Hereinafter, as described above, the monitoring device sequentially executes data collection from each controller.

[0009]

However, in the above-mentioned data collection method, since the monitoring device collects data from each controller in a predetermined order, there is a problem that the display update cycle of data is always constant. .

That is, since the display update cycle of the data is constant, it may take some time before the data changed by the controller is displayed on the monitoring device. For example, the display is updated immediately if the collection order is changed immediately after the data is changed, but if the data is changed immediately after the collection order has passed due to poor timing, do not wait until the next collection order is reached. Then, there is a problem that the display is not updated.

This problem does not have a bad influence particularly when the number of controllers is small because the time until the next collection order comes around is short. However, when the number of controllers increases, the control of the plant begins to be adversely affected.

Further, since the data collection frequency is the same in the controller in which the data changes frequently and in the controller in which the data hardly changes, it takes time to display the data of the controller in which the data changes suddenly, which causes inconvenience in plant operation. Can occur.

The present invention has been made in consideration of the above situation, and by collecting data at a priority rate from a controller having a large change rate of collected data, it is possible to quickly respond even when the data changes suddenly. The purpose is to provide a collection method.

[0014]

According to the present invention, a plurality of controllers are connected to a monitoring device, and when each controller receives a polling signal transmitted individually from the monitoring device, the corresponding controller collects the collected data. In the data collection method of returning to the monitoring device, when the controller returns the collected data, the controller obtains a change rate between the previous collected data and the current collected data, and the change rate is a predetermined limit value. When it exceeds the above, the data request frequency change flag for executing data collection with priority over other controllers is set, and the response data transmission text including this data request frequency change flag and the collected data of this time is monitored. The response data sent text sent to the device, and this monitoring device sent from the controller. Based on the data request frequency change flag, the data for transmitting the polling signal to the controller at a rate prioritized over other controllers when the change rate is determined to be large or small It is a collection method.

[0015]

Therefore, according to the present invention, by taking the above means, when the controller returns the collected data,
The controller obtains the rate of change between the previously collected data and this time's collected data, and when this rate of change exceeds the specified limit value, a data request to execute data collection with priority over other controllers. The frequency change flag is set, and the response data transmission text including the data request frequency change flag and the collected data of this time is transmitted to the monitoring device, and the monitoring device transmits the response data transmission text in the response data transmission text transmitted from the controller. As the change rate is judged based on the change flag, and when this judgment result shows that the change rate is high, the polling signal can be sent to the controller at a priority over other controllers. By collecting data from the controller that has a large change rate of It is possible to respond quickly even when.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a monitoring system applied to a data collection method according to an embodiment of the present invention. In this monitoring system, the monitoring device 11 is a LAN 1
, F are connected to a plurality of controllers A, B ,.

The monitoring device 11 includes controllers A, B,
..., F, sequentially send the data request command text to
A data request frequency change flag included in the response data transmission text returned from the destination controllers A to F;
A data collection process for preferentially collecting suddenly changing data based on the count value of the priority ratio counter indicating the number of times of data collection execution after the priority station is set, and the preset unique value of the system, and It has a function to execute update display processing of collected data. Here, the unique value of the system is a system-specific priority ratio set corresponding to the system, and indicates how many times of data collection one data collection is executed from the priority controller. .

The data request command text is the same as the conventional one, and as shown in FIG. 12, the header, the data request destination controller number, the data request command and the F
It is composed of CS.

Further, each controller A, B, ..., F,
When receiving the data request command text destined for its own station from the monitoring device 11, refers to the previous value areas a, b, ... The rate of change of data is calculated, and when this rate of change exceeds a predetermined limit value, a data request frequency change flag is set in the response data transmission text, and a response including this data request frequency change flag and this time's collected data It has a function of transmitting the data transmission text to the monitoring device 11.

The response data transmission text is a conventional response data transmission text to which a data request frequency change flag is added. As shown in FIG.
Controller number of own station, data request frequency change flag,
A PV value, an MV value, ..., A digital input value, an analog input value, and an FCS are included. Also, PV value, M
The V value, ..., The digital input value and the analog input value are data parts.

The previous value areas a, b, ..., F,
As shown in FIG. 3, the previously collected data is stored in the same format as the data part of the response data transmission text.
Next, a data collection method in such a monitoring system will be described with reference to the flowcharts of FIGS.

First, the monitoring device 11 sets the initial values of the priority station number and the priority ratio counter to zero (ST2
1), the initial value of the station number is set to 1 (ST22). Subsequently, the monitoring device 11 determines whether or not the priority ratio counter has reached the unique value "m", for example, the unique value "3" (ST23), and the determination result reaches the unique value "3" of the priority ratio counter. , The priority ratio counter is reset to zero, and the collection station number is used as the priority station number to interrupt the collection from the priority station in the order of collecting from the regular collection station, and 1 is further subtracted from the station number. But (ST2
4) In this case, since the determination result does not yet indicate that the priority ratio counter has reached “2”, the collection station number (= 1) is set as the station number (= 1) (ST25), and the collection station number is handled. A data request command text is created by transmitting the data request command text to the controller A to execute data collection (ST26).

Controller A determines whether or not it has received a data request command text for its own station (ST2
7) When the determination result shows that no reception has been made, the process returns to step ST27 for standby. When the determination result shows that there is reception, the analog input value is read from the previous value area a, and the result is expressed by the following equation (1). Then, the rate of change between the previously collected data and the currently collected data is calculated (ST28).

Change rate = (collected data of this time-collected data of previous time) / range (1) Subsequently, the controller A compares this change rate with a predetermined limit value and determines whether the change rate exceeds the limit value. It is determined whether or not (S
T29), when the determination result shows that the change rate is large and exceeds the limit value, the data request frequency change flag is set to "1" (ST30), but in this case, the determination result is the change rate limit. Since it indicates that the value is within the value, the data request frequency change flag in the response data transmission text is reset to "0" (ST31).

In this way, the controller A creates the response data transmission text (ST32) and transmits the created response data transmission text to the monitoring device 11 (ST33). Further, the controller A stores the collected data transmitted this time in the previous value area a (ST34).

On the other hand, when the monitoring device 11 receives the response data transmission text from the controller A, the data request frequency change flag included in the response data transmission text is "1" in order to determine the magnitude of the data change rate. It is determined whether there is any (ST35).

When the result of determination in step ST35 indicates that the flag is "1", the monitoring device 11 determines whether or not the priority station number is zero in order to determine whether or not the priority station is already set. If it is judged (ST36) that the priority station number is zero, the priority station number is set to the current collection station number (ST37), and the station number (= 1) is updated by +1 (ST38). When the result shows that the priority station number is not zero, the process goes to step ST38.

In this case, since the determination result in step ST35 indicates that the flag is "0", the priority station number and the collection station number are subsequently determined to determine whether or not the flag of the current priority station is reset. Is determined (ST39), and when the determination result shows a match, the priority station number and the priority ratio counter are reset to zero (ST4).
0), in this case, the determination result indicates non-coincidence, so the process proceeds to step ST38.

When the station number update (= 2) in step ST38 is completed, the monitoring device 11 determines whether or not the priority station number is not zero in order to determine whether or not the priority station number is set (ST41). ), When the determination result indicates that the priority station number is not zero, the priority ratio counter is updated by +1 (ST42). In this case, however, since the determination result indicates that the priority station number is zero, the priority ratio is zero. The counter is set to zero (ST43).

Thereafter, the monitoring device 11 determines whether or not the data collection from all the controllers A to F has been completed (ST
44), when the determination result shows that the data collection from all the controllers A to F has been completed, the station number is initialized and the process returns to step ST22 to repeat the data collection. Since it indicates that the data collection from F to F is not completed, the process returns to step ST23 to execute the data collection from the next controller B.

This completes the data collection for the controller A. Next, the data collection for the controller B will be described. It is assumed that the data is suddenly changed in the controller B.

Since the priority ratio counter (= 0) has not reached the eigenvalue "3" in step ST23, the monitoring device 11 sets the collection station number to match the station number (= 2) in step ST25, In step ST26, the data request command text is transmitted to the controller B.

As described above, the controller B receives the data request command text, and then performs step S.
At T29, a sudden change in data is detected and step ST3
The data request frequency change flag is set to "1" at 0, and the response data request text including the data request frequency change flag "1" is sent to the monitoring device 11 at step ST33.

The monitoring device 11 determines that the data request frequency change flag is "1" in step ST35, determines that the priority station number is not set yet (= 0) in step ST36, and prioritizes in step ST37. The station number is set so as to match the collection station number (= 2), and thereafter, in step ST38, the station number is updated by +1 (= 3).

Subsequently, the monitoring device 11 determines in step ST41 that the priority station number (= 2) is not zero, and in step ST42 updates the priority ratio counter by +1 (=
1) Then, in step ST44, the process returns to step ST23.

Next, the data collection for the controller C will be described. It is assumed that the data is not suddenly changed in the controller C. As described above, the monitoring device 11 determines the count value (= 1) of the priority ratio counter in step ST23.
Has not reached the eigenvalue “3”, step ST25
In step ST26, the collection station number is set to match the station number (= 3), and the data request command text is transmitted to the controller C in step ST26.

The controller C receives the data request command text, sets the data request frequency change flag to "0" in step ST31 so as not to detect the sudden change of data in step ST29, and in step ST3.
In 3, the response data request text including the data request frequency change flag “0” is sent to the monitoring device 11.

In step ST35, the monitoring device 11 determines that the data request frequency change flag is "0", and in step ST39, since the priority station number (= 2) and the collection station number (= 3) are different, the flag "0" is set. It is determined that "" is not the reset of the current priority station, and the station number is updated by +1 (= 4) in step ST38.

Subsequently, the monitoring device 11 determines in step ST41 that the priority station number (= 2) is not zero, and in step ST42 updates the priority ratio counter by +1 (=
2) Then, in step ST44, the process returns to step ST23.

Subsequently, the monitoring device 11 collects data from the controller D as described above. The controller D
Indicates that there is no sudden change in the data. In addition, after collecting the data, the station number is updated by +1 in step ST38 and becomes 5
The priority ratio counter is updated by + in step ST42 to become 3.

Next, the case where the controller B, which is the priority station, interrupts the data collection for the controller E will be described. It is assumed that the data is suddenly changed in the controller B.

The monitoring device 11 determines in step ST23 that the count value (= 3) of the priority ratio counter has reached the eigenvalue "3", resets the priority ratio counter to zero in step ST24, and sets the collecting station number to the priority station number ( = 2)
And 1 is subtracted from the station number (= 5) (=
4) Do.

After that, the monitoring device 11 performs step ST2.
In 6 the data request command text is collected station number (=
It transmits to the controller B corresponding to 2). As described above, the controller B receives the data request command text, thereafter detects a sudden change in the data in step ST29, sets the data request frequency change flag to "1" in step ST30, and then, in step ST33, this data. Monitoring device for response data request text including request frequency change flag "1"! Send to 11.

The monitoring apparatus 11 determines in step ST35 that the data request frequency change flag is "1", determines in step ST36 that the priority station number has already been set (= 2), and determines in step ST38 that the station number ( = 4) is updated by +1 (= 5).

Subsequently, the monitoring device 11 determines that the priority station number (= 2) is not zero in step ST41, and updates the priority ratio counter by +1 in step ST42 (=
1) Then, in step ST44, the process returns to step ST23.

Thereafter, as described above, the monitoring device 11 collects data from the next controller E. As described above, the monitoring apparatus sets the system unique value for the priority ratio counter to “3”, and thus sequentially executes the data collection process, with one of the three data collections as the collection from the priority station.

That is, as shown in FIG. 7, this data collection processing is performed by A, B, C, D, B, E, F, B, A,
B, B, ..., The data collection of the controller B, which is the priority station, is interrupted at the priority rate corresponding to the eigenvalue.

Further, when the sudden change in the data is resolved in the controller B, the monitoring device 11 proceeds to step ST3.
In step 5, the data request frequency change flag is determined to be "0". In step ST39, it is determined whether the priority station number (= 2) and the collection station number (= 2) match. In ST40, the priority station number and the priority ratio counter are reset to zero and step ST38
go to.

After that, since the priority station number and the priority ratio counter are reset to zero, the priority processing is not performed and the data collection processing is executed in the order of the normal controller numbers. Further, when the data is suddenly changed in another controller while the sudden change in the data is not resolved in the controller B, the monitoring device determines that the data request frequency flag is "1" in step ST35, and the priority station number is "0" in step ST36. Or not.

Here, the priority station number of controller B (=
Since 2) has already been set, the monitoring apparatus 11 goes to step ST38. That is, the monitoring device 11 stores only one priority station number, and until the data request frequency change flag of the currently prioritized controller B is reset to "0",
Do not store a new priority station number. Thereby, the monitoring device 1
1 reliably executes data collection for priority stations.

As described above, according to this embodiment, when returning the collected data, each of the controllers A to F obtains the change rate between the previous collected data and the current collected data, and When the predetermined limit value is exceeded, the data request frequency change flag is set to "1" and the response data transmission text is transmitted to the monitoring device 11, while the monitoring device 11 is transmitted from each of the controllers AF. Based on the data request frequency change flag in the response data transmission text, the data request command text is transmitted to the controller B indicating the large change rate at a priority over the other controllers. By collecting data from a controller having a large number at a priority rate, it is possible to quickly respond to a sudden change in data.

Further, according to the present embodiment, the data collection frequency from the monitoring device 11 is changed without using the state change notification, which is a technique of spontaneously transmitting a sudden change in data from the controllers A to F. It is possible to give priority to the data collection from the controller B in which the sudden change has occurred.

Further, since the state change notification is not used as described above, there is a problem that the protocol is complicated and time-consuming due to the state change notification, and when the state change notifications are simultaneously issued from the respective controllers, Problems such as control difficulty can be avoided. In addition, the present invention can be modified in various ways without departing from the scope of the invention.

[0054]

As described above, according to the present invention, when the controller returns the collected data, the controller obtains the change rate between the previous collected data and the current collected data, and this change rate is When the specified limit value is exceeded, the data request frequency change flag for setting the data request frequency change flag to set the data collection priority over other controllers is set, and the response data transmission text including this data request frequency change flag and the collected data this time. To the monitoring device, and the monitoring device determines whether the change rate is large or small based on the data request frequency change flag in the response data transmission text sent from the controller, and the determination result indicates the large change rate. At this time, the polling signal is sent to the controller at a priority over other controllers. By collecting data at a rate that is preferentially from a large controller rate, it can provide a data collection method that can respond quickly even when data is suddenly changed.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a monitoring system applied to a data collection method according to an embodiment of the present invention.

FIG. 2 is a diagram showing a response data transmission text in the same embodiment.

FIG. 3 is a diagram showing a previous value area in the embodiment.

FIG. 4 is a flow chart for explaining the operation of the monitoring device in the embodiment.

FIG. 5 is a flowchart for explaining a controller operation in the embodiment.

FIG. 6 is a flowchart for explaining the operation of the monitoring device in the embodiment.

FIG. 7 is a diagram for explaining an interrupt operation of data collection in the embodiment.

FIG. 8 is a schematic diagram showing a transmission procedure by a conventional data collection method.

FIG. 9 is a flowchart for explaining the operation of the conventional monitoring device.

FIG. 10 is a flowchart for explaining the operation of a conventional controller.

FIG. 11 is a flowchart for explaining the operation of the conventional monitoring device.

FIG. 12 is a diagram showing the structure of a conventional data request command text.

FIG. 13 is a diagram showing a structure of a conventional response data transmission text.

[Explanation of symbols]

11 ... Monitoring device, 12 ... LAN, AF ... Controller, af ... Previous value area.

Claims (1)

[Claims] 1. A data collection system in which a plurality of controllers are connected to a monitoring device, and when each controller receives a polling signal that is sequentially and individually transmitted from the monitoring device, the corresponding controller returns collected data to the monitoring device. In the method, when the controller returns the collected data, the controller obtains the rate of change between the previously collected data and the currently collected data, and when the rate of change exceeds a predetermined limit value, another A data request frequency change flag for setting data collection priority over the controller is set, and a response data transmission text including the data request frequency change flag and the collected data of this time is transmitted to the monitoring device. The device changes the data request frequency in the response data transmission text sent from the controller. Based on a flag, the size of the rate of change is determined, and when the result of this determination indicates a high rate of change, the polling signal is transmitted to the controller at a priority over other controllers. Collection method.