JPH05250199A - Duplex switching system - Google Patents

Abstract

PURPOSE:To shorten the switching time of a system at the time of a fault and to perform the switching of the system, continuing a processing. CONSTITUTION:When there is no response to the output signal outputted by an A central processing part 2 within a preliminarily fixed period, a B central processing part 3 outputs the same signal as the A central processing part 2. Further, when there is no response, an information transmission control part 5 judges as the fault on the side of a station to be monitored, stops the transmission of control information to a station to be monitored 11 which does not response and moves the A central processing part 2 or the B central processing part to the polling of the next station to be monitored 11. When there is a right response to the signal of the B central processing part 3 when there is not a response to the signal outputted by the A central processing part 2, it is judged that a fault exist in the A central processing part 2, the information transmission control part 5 does not transmit a control signal to the A central processing part 2, the A central processing part is detached from a system and an operation is continued by the B central processing part 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a duplex switching system, and more particularly to a duplex switching system of a central processing unit of a centralized monitoring station in a centralized monitoring system.

[0002]

2. Description of the Related Art Conventionally, in the duplex switching system of this type, the central processing unit serving as a standby system has not been configured to output a signal by itself only by monitoring the central processing unit of the main system. In addition, as shown in FIG. 2, an operation confirmation unit 21 for monitoring both the standby system and the main system is provided for determining the other party's failure, and the system of the central processing unit is switched according to the determination of the operation confirmation unit 21. I was going. That is, the operation confirming unit 21 always communicates with the central processing unit, checks the operating states of both systems, and switches the systems when an abnormality is detected.

[0003]

In this conventional duplex switching system, since the standby system of the central processing unit is not operating, the processing is interrupted when the system switching occurs, and it takes time to complete the switching. However, if a failure is found by the operation check of the operation check unit, there is a problem that the entire system is brought into a stopped state.

[0004]

In the duplex switching system of the present invention, a plurality of monitored stations are provided in which a centralized monitoring station equipped with dualized first and second central processing units is connected to a downlink and an uplink. In the duplex switching method of the centralized monitoring system for monitoring the transmission by the polling method, the centralized monitoring station alternately sends control information to the downlink by adding the transmission source information indicating the transmission source from the first and second central processing units. Whether or not the first and second central processing units have transmitted the response information to which the transmission source information has been added to the control information from the monitored station, and whether or not the response information has been received is determined by the first and second central processing units. The monitored station or the first or second station receives from the processing section.
Control means for determining a failure of the central processing unit and stopping the sending of the control information from the failed central processing section to the downlink in the case of the failure of the first or second central processing section. is doing.

[0005]

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

FIG. 1 is a block diagram of a centralized monitoring system to which an embodiment of the present invention is applied.

In FIG. 1, the centralized monitoring system of this application example includes monitored stations 11-1 to 11-n and a monitored station 11-1.
11-n are provided with a centralized monitoring station 1 for monitoring by a down line 7 and an up line 8, and the centralized monitoring station 1 has a dual A central processing unit 2 and B central processing unit 3 and an A central processing unit. Control information is alternately transmitted from the unit 2 or the B central processing unit 3 to the downlink 7 via the OR circuit 6 by the polling method, and the monitored station for the control information from the A central processing unit 2 and the B central processing unit 3 is monitored. An information transmission control unit that receives the presence / absence of reception of response information from 11-1 to 11-n and determines a failure of the A central processing unit 2, the B central processing unit 3 or the monitored stations 11-1 to 11-n. And 5 are configured.

Next, the operation of one embodiment of the present invention will be described with reference to this application example shown in FIG.

A central processing unit 2 and B in the centralized monitoring station 1
The central processing unit 3 always executes the same processing, and is it the central processing unit 2 that sent this output signal to the output signal?
With the output signal format 9 to which the information indicating whether it is the central processing unit 3 is added, the control information is alternately output to the downlink 7 under the control of the information transmission control unit 5.

The monitored stations of the monitored stations 11-1 to 11-n which have received the control information of the output signal format 9 are "A" and B when the received signal is from the A central processing unit 2.
From the central processing unit 2, the response signal of "B" and the response signal format 10 is returned to the uplink 8.

The centralized monitoring station 1 receives this response signal, and if the response is the one to which "A" is added first, the next output signal is output from the B central processing unit 3 and if it is the response to which "B" is added,
The next output signal is processed by the A central processing unit 2.

If there is no response to the output signal from the central processing unit 2 within a predetermined period, B
When the central processing unit 3 outputs the same signal as the A central processing unit 2 and there is still no response, the information transmission control unit 5 judges that there is a failure on the monitored station side, and the control information to the monitored station that does not respond is sent. Is stopped and the A central processing unit 2 or B central processing unit 3 is caused to proceed to polling the monitored station.

Further, when there is no response to the signal output from the A central processing unit 2, and when there is a correct response to the signal from the B central processing unit 3, there is a failure in the A central processing unit 2. If the information transmission control unit 5 determines that the A central processing unit 2 does not send a control signal to the A central processing unit 2, the A central control unit 2 is disconnected from the system and the B central processing unit 3 continues to operate.

[0014]

As described above, according to the present invention, the centralized monitoring station provided with the duplicated first and second central processing units polls a plurality of monitored stations connected to the downlink and the uplink. In the dual switching method of the centralized monitoring system for monitoring by the centralized monitoring system, the centralized monitoring station alternately sends control information, to which the transmission source information indicating the transmission source is added, to the downlink from the first and second central processing units, and the monitored station Whether the response information to which the transmission source information is added to the control information is received by the first and second central processing units or whether the reception information is received from the first and second central processing units. A control means for determining a failure of the first or second central processing unit, and stopping the transmission of the control information from the failed central processing unit to the downlink in the case of the failure of the first or second central processing unit. By having the failure detection time and Shorter than conventional switching time of the system, also has an advantage of being able to switch the system while continuing the process at the time of the failure.

[Brief description of drawings]

FIG. 1 is a block diagram of a centralized monitoring system to which an embodiment of the present invention is applied.

FIG. 2 is a block diagram of a centralized monitoring system using a conventional duplex switching method.

[Explanation of symbols]

1, 1a Centralized monitoring station 2, 2a A Central processing unit 3, 3a B Central processing unit 5 Information transmission control unit 6 OR circuit 7 Downlink 8 Uplink 9 Output signal format from centralized monitoring station to monitored station 10 Monitored Response signal format from station to centralized monitoring station 11-1 to 11-n Monitored station 21 Operation check unit

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Claims (1)

[Claims] 1. A duplex switching of a centralized monitoring system in which a centralized monitoring station equipped with dualized first and second central processing units monitors a plurality of monitored stations connected to a downlink and an uplink by a polling method. In the system, the centralized monitoring station causes the first and second central processing units to alternately send control information added with transmission source information indicating a transmission source to the downlink, and the control information from the monitored station is transmitted. To the first and second response information to which the source information is added.
Whether the central processing unit of the
Received from the central processing unit of the monitored station or the first station.
Alternatively, control for determining a failure of the second central processing unit and stopping transmission of the control information from the failed central processing unit to the downlink in the case of the failure of the first or second central processing unit A duplex switching system having means.