JPH07184279A - Supervisory control system - Google Patents

Abstract

PURPOSE:To avoid the system stop due to an overload of a central processing unit caused by a status change alarm caused frequently in a predetermined time. CONSTITUTION:A repeater 3 is provided between a central processing unit 1 and a logger 4 and when the logger 4 logs a status change in an alarm, it is reported to the repeater 3 through contention. The central processing unit 1 always makes polling to the repeater 3 to log the status change alarm from the repeater 3 and counts the number of alarms from the repeater 3 obtained through the polling, and a polling interval to the central processing unit 1 is adjusted to suppress notice of the status change alarm from the logger 4 in which the status change alarm takes place more than an optional threshold value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention was developed as a system in which a single central processing unit comprehensively monitors a communication device in which a large number of monitored devices are mounted. It can be widely used for a system that collectively monitors devices, control devices, and many other units.

[0002] The present invention relates to an improvement that enables a central processing unit that collectively monitors monitoring information to be appropriately processed when a large number of monitoring information is simultaneously generated from a large number of monitored devices.

[0003]

2. Description of the Related Art FIG. 2 is a block diagram showing the configuration of a conventional supervisory control system. In the conventional monitoring control system, the central processing unit 1 directly polls each of the plurality of collecting devices 4 to collect a status change alarm, or the collecting device 4 directly changes the status to the central processing unit 1 by a contention method. I was giving an alarm.

Another example is Japanese Patent Laid-Open No. 4-260.
There is a method disclosed in Japanese Patent No. 242, in which a master station efficiently collects data on state changes of a plurality of slave stations by selectively using the features of the polling method and the contention method. Further, in the one disclosed in Japanese Examined Patent Publication No. 2-17998, a relay device for re-editing one frame of transmission information and transmitting it to the master station or each slave station is provided between the master station and a plurality of slave stations. Therefore, there is a method for reducing transmission cost and maintenance cost. Further, according to the one disclosed in Japanese Patent Laid-Open No. 4-150194, even if the number of slave stations connected to the master station increases, an edit relay device for editing data is provided between the master station and slave stations. There is one that suppresses an increase in the number of transmission paths and reduces transmission costs and maintenance costs.

It is extremely important for proper operation of the system that a large number of monitored devices are arranged in a communication device or another system, and the state of the monitored devices is collectively monitored by one central processing unit. This is a convenient method. When a state change occurs in the monitored device, in order to quickly transmit the information to the central processing unit, it is preferable that the monitoring information be transmitted from each monitored device to the central processing unit by contention.

[0006]

In such a conventional supervisory control system, even in the case of status change alarm collection by polling between the central processing unit 1 and the collection unit 4,
Further, even in the case of the notification of the state change alarm due to the contention from the collection device 4, when the large number of state change alarms occur, the load of the central processing unit 1 becomes high, and there is a problem that the operation of the central processing unit 1 is stopped.

In the case where a large number of monitored devices are installed in one relatively large communication device, a large number of monitored devices are caused by a power failure, large-scale noise, and one other common cause. May send status change alarms all at once. When such a situation occurs, it is extremely important to investigate the cause of the situation, and for that purpose, it is necessary not to miss the status change alarms that have occurred at the same time. In order to properly collect information from such a large number of monitored devices, it is possible to receive a large amount of information at high speed by contention if the central processing unit has a large capacity. Since such a phenomenon that the status change alarms are sent all at once is rare, it is impossible to deploy a high-speed and expensive central processing unit. Moreover,
In many cases, the central processing unit for monitoring is commonly used for other control as well as processing of monitoring information.

The present invention solves such a problem, and an object of the present invention is to provide a system capable of eliminating the operation stoppage due to the overload of the central processing unit caused by the state change alarms which frequently occur within a certain period of time. And A further object of the present invention is to provide a device that can reduce the load on the central processing unit and increase the time for which the central processing unit is dedicated to an additional process other than the collection of monitoring data.

[0009]

According to the present invention, N collecting devices (4) are connected to a large number n of monitored devices (6) to collect status data, and the N collecting devices (4). In a supervisory control system including a central processing unit (1) for receiving data collected by the communication line (2),
A relay device (3) having n (n <N) storage circuits is provided in the communication line, and each collecting device (4) is connected to any one of the relay devices (3). Is connected to the central processing unit, and the alarm detected by each collecting device (4) is transmitted from each collecting device (4) to the relay device (3) by contention and is once held in the storage circuit, The relay device (3) is characterized in that it is transmitted to the central processing unit (1) by polling.

The polling between the central processing unit (1) and the n relay units (3) is preferably changed in polling cycle according to the frequency of the status change alarm transmitted.

[0011]

The collecting device transmits the state change detection alarm from the monitored device to the relay device by the contention method. The relay device transmits the held data to the central processing unit in response to polling from the central processing unit. The central processing unit detects a state change alarm by the response data from the relay unit by this polling, and changes the polling period to the relay unit when the number of notified state change detection alarms exceeds an arbitrary threshold value. .

As a result, it is possible to suppress the alarm from the relay device in which the state change of the monitored device exceeds an arbitrary threshold value, reduce the load on the central processing unit, and stop the system due to overload. Can be prevented.

Even if a large number of monitored devices send out status change alarms at the same time, since the number of monitored devices connected to each relay device is small, the status change alarms are properly received. It can be held in the memory circuit of the relay device. Thereafter, the central processing unit can poll each relay device to receive the state change alarm held in its storage circuit according to the capabilities of the central processing unit. If a large number of state change alarms occur repeatedly and the polling process executed by the central processing unit is not in time, the central processing unit temporarily suspends the execution of other processing to increase the frequency or speed of polling processing. Good to do.

[0014]

Embodiments of the present invention will now be described with reference to the drawings. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG.
FIG. 3 is a block diagram showing a configuration of a relay device according to an embodiment of the present invention.

In the embodiment of the present invention, N collection devices 4 each connected to a large number n of monitored devices 6 to collect status data, and data collected by the N collection devices 4 are transmitted via a communication line 2. And a central processing unit 1 for receiving the data, and further, a relay device 3 having n (n <N) storage circuits 3a is provided in the communication line 2, and each collecting device 4 is connected to one of the relay devices 3. The relay device 3 is the central processing unit 1
The state change alarm detected by each collecting device 4 is transmitted to each of the collecting devices 4 to the relay device 3 by contention, is temporarily held in the memory circuit 3a, and is transmitted from the relay device 3 to the central processing unit 1. Are configured to be communicated by polling.

The polling period between the central processing unit 1 and the n relay units 3 is changed according to the frequency of the status change alarm transmitted.

The relay device 3 further includes a polling processing circuit 3b for performing polling processing, as shown in FIG.
Contention processing circuit 3c for performing contention processing
And are provided.

Next, the operation of the embodiment of the present invention thus constructed will be described with reference to the drawings.

When the collecting device 4 detects a change in the alarm state, the collecting device 4 notifies the relay device 3 by a contention method. The central processing unit 1 constantly polls the relay device 3 and collects status change alarms from the relay device 3. Further, the central processing unit 1 counts the number of alarms from the relay device 3 obtained by polling, and adjusts the polling interval for the relay device 3 in which an alarm occurs above an arbitrary threshold value. In this way, the notification of the state change alarm from the collection device 4 in which the state change alarm is generated above the arbitrary threshold value is suppressed. The interface 5 between the relay device 3 and the monitored device 6 may be either a contact interface or a serial interface,
Further, the present invention can be applied whether the connection between the relay device 3 and the collection device 4 is 1: 1 or 1: N.

By such an operation, even if a large number of monitored devices 6 send alarms indicating a state change all at once, the number of monitored devices 6 connected to each relay device 3 is small,
The status change alarm is properly received and held in the storage circuit 3a of the relay device 3, after which the central processing unit 1 executes polling for each relay device 3 and stores it according to the capability of the central processing device 1. The status change alarm held in the circuit 3a is received.

When a large number of state change alarms are repeatedly generated and the polling processing executed by the central processing unit 1 is not in time, the central processing unit 1
Can also suspend other processes to increase the frequency or speed of polling.

[0022]

As described above, according to the present invention, it is possible to suppress the notification from the relay device in which the status change alarm is generated at an arbitrary threshold value or more, thus reducing the load on the central processing unit. Therefore, there is an effect that the system stop due to the overload of the central processing unit can be eliminated and stable operation can be performed.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a configuration of a relay device according to the embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a conventional example.

[Explanation of symbols]

 1 Central Processing Unit 2 Communication Line 3 Relay Device 3a Storage Circuit 3b Polling Processing Circuit 3c Contention Processing Circuit 4 Collection Device 5 Interface 6 Monitored Device

Claims (2)

[Claims] 1. N collecting devices, which are respectively connected to a large number n of monitored devices and collect state data, and a central processing unit, which receives the data collected by the N collecting devices via a communication line. In the supervisory control system provided, a relay device having n (n <N) storage circuits is provided in the communication line, each collecting device is connected to one of the relay devices, and the relay device is the central processing unit. The state change alarm detected by each collector is connected to the relay device by contention from each collector,
A supervisory control system characterized in that it is temporarily held in the storage circuit and is transmitted from the relay device to the central processing unit by polling. 2. The supervisory control system according to claim 1, wherein polling between the central processing unit and the n relay units is changed in polling cycle according to the frequency of the transmitted state change alarm.