JPH0965459A - Monitor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct the time synchronization of a clock built in each of units 1-5 independently of an environment (transmission route, transmission speed, transmission system and complicatedness of processing) under which each unit is located in the monitor controller. SOLUTION: Each of units 1-5 needing clock information is provided with an FM receiver 11 receiving an FM radio wave including a time signal sent from a transmission source 10 at each correct time. Specific processing that might cause a delay in time synchronization processing such as long processing of an interrupt inhibit processing routine and access processing to a process file is inhibited till the time synchronization processing is finished in a prescribed time before the transmission of the time signal. Upon the receipt of the time signal from the transmission source 10, the time synchronization processing is executed based on the time signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supervisory control device for remotely controlling and monitoring various plants such as water treatment, electric power, roads, buildings and factories, and more particularly to supervisory control having a time synchronization function between each unit. It relates to the device.

[0002]

2. Description of the Related Art In recent years, in various plants as described above, in order to efficiently operate, maintain, and manage the plants, various equipments of the plant have been centrally monitored and controlled at remote locations. ing.

In such a supervisory control, as shown in FIG. 4, a master station for remotely controlling and monitoring facility equipment (not shown) connected to each slave station unit 52 ... via each slave station unit 52. Unit 51 and a plurality of slave stations that input monitoring information (display / measurement information) from the equipment and transmit it to the master station unit 51, and control the equipment based on various control information received from the master station unit 51. Unit 52 ...
And a monitoring control device having

In the above supervisory control apparatus, for example, if a failure occurs in the equipment monitored and controlled by a certain slave station unit 52 and the relay operates, then another slave station unit is provided to prevent the next failure. Consider the case where a relay sequence is incorporated in which the relays connected to 52 operate one after another in a short time. In such a case,
On the condition of a failure of a certain equipment, relay operation information is input to a plurality of slave station units 52 ... In a short time, and the slave station units 52 ... Monitor the master station unit 51 all at once. Information is sent. Master station unit 5
1 receives the monitoring information from each of the slave station units 52 ..., records and holds them in a time series in the order in which they are received, and performs an alarm operation such as ringing of an alarm device or display of a failure occurrence, Notify the operator that an abnormal situation has occurred. In order to deal with the abnormality, the operator remotely operates the equipment if necessary, and also operates each slave station unit 5
2. The main cause of the abnormality is clarified based on the monitoring information obtained from 2 ..., and the location of the abnormality is inspected.

A transmission system such as a cyclic digital system is used for transmission from each slave station unit 52 ... To the master station unit 51. In this case, indeterminate transmission such as retransmission due to transmission error occurs. Due to the delay, the slave station unit 52 that has input the monitoring information first cannot always transmit the monitoring information to the master station unit 51 earlier.

Therefore, conventionally, a clock is provided in each of the units constituting the monitoring control device, and time information when the monitoring information is input is added to the monitoring information and transmitted to the master station unit 51. ing. As a result, the operator, based on the monitoring information with time information from each slave station unit 52 ... Collected in the master station unit 51,
It is possible to specify which relay is activated first, that is, where the abnormality occurs.

However, even in the above case, it is necessary that the clock times of the respective units are always synchronized with a certain accuracy or more. Therefore, in the past, in order to synchronize the time between the units, the clock of any one unit (usually the master station unit 51) constituting the monitoring control device is used as the master clock, and the master clock is more important than the unit having the master clock. A unit that does not have a master clock shall issue a time synchronization request command at a promised arbitrary time, and a unit that does not have a master clock should set the time of its own clock after receiving the time synchronization request command. It is supposed to change.

[0008]

However, in the above-mentioned conventional time synchronization system, if the transmission route and the transmission speed to a plurality of units not having a master clock are different from those of a specific unit having a master clock, Time synchronization error occurs. For example, in the hierarchical structure as shown in FIG. 5, the transmission rate between the units B2 and B3 having no master clock is 200 bps, and the transmission rate between the units B2 and B4 having no master clock is 9600 bps. Considering such a case, a time synchronization error occurs due to a difference in transmission speed between the units B3 and B4 that do not have a master clock, and between the units B1 and B3 and B4 that do not have a master clock. Causes an error in time synchronization due to the difference in the transmission route.

Further, a time synchronization error also occurs depending on the location of the time synchronization request command in the transmission package and the reception timing of each station. For example, an example of a transmission package a from a unit A having a master clock to a unit B1 having no master clock is shown in FIG. 6, and an example of a transmission package b from a unit A having a master clock to a unit B2 having no master clock is shown. 7 shows. In such a case, the time of the clock of the unit B1 which receives the transmission package a is the unit B2.
~ It goes ahead of that of B4.

An error in time synchronization also occurs depending on the load state in each unit when the time synchronization request command is received, that is, the congestion of the processing being executed. In particular, when a time synchronization request command is received when a long interrupt prohibition processing routine or a process for accessing a process file is being executed, a relatively large delay occurs in the time synchronization processing.

The required time synchronization accuracy differs depending on what kind of post-processing is performed based on the monitoring information with time information accumulated in the master station unit 51. For example, in the relay sequence as described above, there is an abnormality. Although it depends on the operating speed of the relay, etc., the time synchronization accuracy of the order of 10 ^-1 second or 10 ^-2 seconds is usually required to specify the occurrence location. In the above conventional time synchronization method, depending on the system configuration of the supervisory control device, only time synchronization accuracy in units of seconds can be obtained, and it may not be possible to deal with processing that requires higher time synchronization accuracy.

The present invention has been made in view of the above, and an object thereof is not to be influenced by the environment in which each unit is placed in the supervisory control device, but to synchronize the time of a clock incorporated in each unit. An object of the present invention is to provide a monitoring control device that can perform with high accuracy.

[0013]

According to another aspect of the present invention, there is provided a supervisory control device, wherein a plurality of units including a master station unit and a slave station unit are communicably connected via a transmission line. In order to solve the above, the following measures are taken.

That is, each of the two or more units, which require time information and have a built-in clock, has a source (eg,
A receiving means for receiving a radio wave containing time synchronization information (for example, hourly hourly information) transmitted from a public FM broadcasting station every predetermined time, and a radio wave containing the time synchronization information transmitted from a transmission source. From the time before the specified time to the end of the time synchronization processing, the specification that prohibits specific processing that causes a delay in the time synchronization processing (such as long processing of interrupt prohibition processing routines and processing that accesses process files) And a time synchronization means for performing time synchronization processing on the timepiece based on the time synchronization information when the reception means receives a radio wave including the time synchronization information transmitted from the transmission source. There is.

According to the above arrangement, the time synchronization between the units including the timepiece is performed based on the radio wave including the time synchronization information wirelessly transmitted from the transmission source. The time at which the time synchronization information is wirelessly transmitted from the transmission source is predetermined, and each unit with a built-in clock executes a specific process that causes a delay in the time synchronization process from a predetermined time before the transmission time. Is prohibited by the specific processing prohibition means.

Thereafter, when the time synchronization information is wirelessly transmitted from the transmission source, the reception means of each unit receives the time synchronization information, and based on the time synchronization information, the time synchronization means of each unit has a built-in clock. The time synchronization processing is performed for

After the time synchronization processing is completed in each unit, the prohibition state of the above-mentioned specific processing is released, and each unit returns to the normal routine.

In each unit that requires time information in the supervisory control device, the above operation is performed at a predetermined time (for example, every one hour), whereby the environment in which each unit is placed, that is, The time synchronization of the clocks incorporated in each unit can be performed with high accuracy without being influenced by the transmission route, the transmission speed, the transmission method, and the processing congestion degree (the processing load state in the unit).

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the invention.
The following is a description with reference to FIG.

As shown in FIG. 1, the monitoring control apparatus according to the present embodiment includes a plurality of units 1 to 5 including one master station unit and a plurality of slave station units, and these units 1 to 5 are , Are connected via transmission lines 6 to 8 of various transmission methods to form a communication network. For example, the unit with the reference number 1 is the master station unit, and the units with the reference numbers 2, 4 and 5 are
Each unit is a slave station unit, and the unit with reference numeral 3 is a communication control unit. It is also possible to give the unit of reference numeral 3 a function as a slave station unit.

The master station unit includes a display unit such as a graphic panel and a display (not shown), a man-machine interface (input unit) for performing various operation inputs including control inputs, and a recording unit such as a printer. It is composed of a microcomputer, etc., and has a logic section for performing control data transmission processing and monitoring data reception processing, etc., and a data transmission / reception section, and performs remote control and monitoring of various facility equipment (not shown) connected to the slave station unit. .

The slave station unit is composed of an input / output unit (not shown) for controlling input / output to / from various equipments, a microcomputer, etc., a logic unit for performing control data reception processing and monitoring data transmission processing, and data. It is also equipped with a transmitter / receiver unit for monitoring and input monitoring information (display / measurement information) from the equipment to be monitored and controlled, and controls the equipment based on various control information received from the master station unit. To do.

Further, the supervisory control device of this embodiment is provided with a transmission source 10 for transmitting an FM (frequency modulation) radio wave including time information as a master clock. Then, the FM as a receiving means for receiving the transmission wave of the transmission source 10 to all the units 1 to 5 that require time information in the supervisory control device.
Receivers 11 ... Are provided.

As the above-mentioned transmission source 10, a dedicated one for the monitor and control device may be prepared, but a public broadcasting station is used as the transmission source 10 and the hourly signal transmitted from there every hour is used as the time synchronization information. You can also In particular, by using the public broadcasting station as the transmission source 10 and making the master clock a public clock (every hour on the hour), it is not necessary to prepare a dedicated transmission source 10 and the master clock is set to the absolute time. There is an advantage that you can. Sources of public FM broadcasting stations 1
The case where it is used as 0 will be described.

As shown in FIG. 2, the units 1 to 5 which require time information in the supervisory control device are provided with a frequency discriminator 12 for extracting only a signal in a specific frequency band from the received signal of the FM receiver 11. , An analog / digital converter for converting the extracted analog signal into a digital signal (hereinafter referred to as A
/ D converter) 13 and a synchronization detection unit 14 for detecting time synchronization timing by frequency detection of hourly hourly signals.

The synchronization detecting section 14 is configured as firmware in each unit, and the FM detecting unit 14 is provided at a predetermined time (for example, 1 to 2 seconds) before the hour when the time synchronization processing is performed.
When the power of the receiver 11 is turned on, a predetermined time before the time synchronization processing is expected to be performed (for example, about 100 mse
c), the CPU (Central Processing
(Unit) 16 to issue a time synchronization notice command.
Further, the synchronization detection unit 14 issues a time synchronization interrupt command to the CPU 16 by detecting the frequency of the hourly time signal. Further, the synchronization detector 14 issues the above-mentioned time synchronization interrupt command to the CPU 16 and then:
The power of the FM receiver 11 is turned off. The time management of the synchronization detection unit 14 is based on the clock 15 in which the CPU 16 performs the time synchronization processing every hour.

As shown in FIG. 3, the logic unit including the CPU 16 temporarily suspends execution of a specific process, which will be described later, on the basis of the reception of the time synchronization notice command. ) And a time synchronization processing unit 18 (time synchronization means) that performs time synchronization processing for changing the time of the clock 15 on the hour based on the reception of the time synchronization interrupt command.

When the specific processing prohibition unit 17 receives the time synchronization notice command from the synchronization detection unit 14, it delays the time synchronization process such as the long process of the interrupt prohibition process routine or the process of accessing the process file. In order to execute the possible specific process after the time synchronization process is completed, the execution of the specific process is prohibited during the period from the reception of the command to the end of the time synchronization process.
Then, the specific processing prohibition unit 17 includes the time synchronization processing unit 1
After the process of 8 is completed, the prohibition state of the specific process is released, and the logic unit returns to the normal routine.

The specific processing prohibition unit 17 and the time synchronization processing unit 18 are functional modules constituted by the CPU 16 of FIG. 2 for executing a predetermined program (application software) stored in a memory (not shown) of the logic unit. Is.

The operation of the supervisory control device having the above configuration will be described below.

Each unit 1 to 1 of the supervisory control device shown in FIG.
5 performs processing in each unit according to a normal routine until just before the hour (that is, 0 minutes). Just before the hour, the synchronization detector 14 in FIG. 2 supplies power to the FM receiver 11. By outputting the ON signal, the FM radio wave can be received, and thereafter, the time synchronization advance notice command is issued from the synchronization detection unit 14 to the CPU 16 to delay the time synchronization processing. Prohibit the execution of certain specific processing.

After that, in each of the units 1 to 5, the transmission source 1
By detecting the hourly frequency from 0, the synchronization detector 1
4 issues a time synchronization interrupt command to the CPU 16, and the time synchronization processing is executed. After the end of the time synchronization process, the prohibition state of the specific process is released, the process returns to the normal routine, and the power of the FM receiver 11 is turned off.

The above operations are performed in each of the units 1 to 5 before and after every hour, so that each of the units 1 to 5 is performed.
The relative time error between them is extremely small.

In the supervisory control device in which the units 1 to 5 are time-synchronized with high precision as described above, when each slave station unit receives the supervisory information from the equipment to be supervised and controlled, The information indicating the time of the clock 15 (time information) is added to the monitoring information which is the transmission data and transmitted to the master station unit. In the master station unit, the monitoring information received from each slave station unit is displayed on the display unit, and the monitoring information is recorded in chronological order in the order of reception (stored in a hard disk or printed by a printer). .
It should be noted that due to the uncertain transmission delay when transmitting from each slave station unit to the master station unit, the master station unit does not record the monitoring information that was input earlier,
By checking the time information added to the monitoring information, the relative time relationship of each recorded monitoring information can be easily and accurately known.

Therefore, even when the contact input information based on the above-mentioned relay sequence is collected from a plurality of slave station units to the master station unit, it is possible to determine which relay is activated first from the time information added to them. That is, it is possible to accurately specify where the abnormality occurs.

As described above, in the supervisory control apparatus according to the present embodiment, each of the units 1 to 5 which requires the time information and has the built-in clock 15 is time-synchronized by the transmission source 10 to transmit each hour. An FM receiver 11 that receives an FM radio wave containing information; a specific processing prohibition unit 17 that prohibits the above specific processing from a predetermined time before the time synchronization information is transmitted to the end of the time synchronization processing; When the time synchronization information is received from the transmission source 10, the time synchronization processing unit 18 that performs the time synchronization processing on the clock 15 based on the time synchronization information.
It is a configuration including and.

As a result, the units 1 to 5 are not affected by the environment (transmission route, transmission speed, transmission method, processing congestion, etc.) in which the units 1 to 5 are placed in the system of the supervisory control device. The time synchronization of the clocks 15 respectively possessed by each can be performed with high accuracy of the order of 10 ^-2 seconds or more.

Further, since the time synchronization information is transmitted by the FM radio wave, the structure of the receiving means can be simplified and the time synchronization system can be constructed at low cost. Further, by using the FM system having a relatively high signal-to-noise ratio (S / N ratio), it becomes possible to perform time synchronization processing at accurate timing.

Also, the FM only during the period from the predetermined time before the time when the time synchronization processing is performed to the time when the time synchronization processing is completed.
The receiver 11 is turned on, and the FM receiver 1 is used for other periods.
1 is turned off, so each unit 1
The power consumption of 5 can be suppressed.

Further, since the public broadcasting station is used as the transmission source 10 and the time signal included in the public radio wave is used as the time synchronization information, it is not necessary to prepare the dedicated transmission source 10 and each unit 1 to 5 is used. The difference between the time of the clock 15 and the absolute time can be made small. Note that there are many monitoring control devices that automatically control the operation of the equipment based on the absolute time (national standard time), and the above configuration is particularly effective for such monitoring control devices.

In the above embodiment, the time synchronization is performed for all the units 1 to 5 of the supervisory control device, but the present invention is not limited to this, and time information is required in the supervisory control device. If there are two or more units,
The present invention can be applied.

Further, in the above embodiment, the time synchronization processing is executed every hour, but the timing of time synchronization is not limited to this. Source 10
When a dedicated one is used as, it is possible to set the time synchronization timing to an arbitrary time. Also,
When using public electric waves, time synchronization may be performed, for example, every 2-3 hours. The frequency of time synchronization is
It is appropriately determined according to the required time synchronization accuracy and the accuracy of the built-in clock 15. The above-mentioned embodiment is only for clarifying the technical contents of the present invention, and should not be construed in a narrow sense by limiting only to such specific examples. It can be changed and implemented.

[0043]

As described above, the supervisory control device of the present invention is a time synchronization in which each of two or more units, which requires time information and has a built-in clock, is transmitted from the transmission source at a predetermined time. A receiving means for receiving a radio wave containing information and a delay in the time synchronization processing from a predetermined time before the radio wave containing the time synchronization information is transmitted from the transmission source to the end of the time synchronization processing. When the specific processing prohibiting means for prohibiting the specific processing and the receiving means receive the radio wave including the time synchronization information transmitted from the transmission source, the time at which the time synchronization processing is performed on the clock based on the time synchronization information. It is the structure provided with the synchronizing means.

Therefore, in the environment in which each unit that requires time information is placed in the supervisory control device, that is, in the transmission route, the transmission speed, the transmission method, and the congestion degree of the processing (processing load state in the unit). There is an effect that the time synchronization of the clock built in each unit can be performed with high accuracy regardless of the influence.

[Brief description of drawings]

FIG. 1 illustrates an embodiment of the present invention, and is a schematic overall configuration diagram of a monitoring control device.

FIG. 2 is a block diagram showing a configuration of a main part of each unit of the monitoring control device.

FIG. 3 is a functional block diagram showing a functional module configuration of a main part of each unit of the monitoring control device.

FIG. 4 is a block diagram showing a schematic configuration of a supervisory control device.

FIG. 5 is a block diagram showing a schematic configuration of a supervisory control device for explaining time synchronization in the conventional supervisory control device.

6 is an explanatory diagram showing an example of a transmission package sent from a unit A having a master clock of FIG. 5 to a unit B1 having no master clock.

7 is an explanatory diagram showing an example of a transmission package sent from a unit A having a master clock of FIG. 5 to a unit B2 having no master clock.

[Explanation of symbols]

 1 to 5 Units constituting the monitoring and control device 6 to 8 Transmission line 10 Transmission source 11 FM receiver (reception means) 14 Synchronization detection section 15 Clock 16 CPU 17 Specific processing prohibition section (specific processing prohibition means) 18 Time synchronization processing section (Time synchronization means)

Claims (1)

[Claims] 1. A supervisory control device in which a plurality of units including a master station unit and a slave station unit are communicably connected via a transmission line, and each of two or more units that incorporates a clock in need of time information. Is a receiving means for receiving a radio wave including time synchronization information transmitted from the transmission source at a predetermined time, and a time synchronization process from a predetermined time before the radio wave including the time synchronization information is transmitted from the transmission source. Until the end, the specific processing prohibiting means for prohibiting the specific processing that causes a delay in the time synchronization processing, and the time when the receiving means receives a radio wave including the time synchronization information transmitted from the transmission source. A supervisory control apparatus comprising: a time synchronization means for performing time synchronization processing on the timepiece based on synchronization information.