JPH0481044A - Remote supervisory system - Google Patents

Abstract

PURPOSE:To speedily and easily restore from a fault an entire system by disconnecting a slave supervisory equipment from a common transmission line when a carrier signal is continued even after the lapse of time decided in advance. CONSTITUTION:In the case of a fault to continuously output the carrier signal from a slave supervisory equipment 3a, a carrier detection circuit 5 continuously outputs a carrier detection signal 8. When the carrier detection signal 8 is maintained for more than time decided in advance, a timer circuit 6 outputs a signal 9 larger than the carrier output, a disconnecting circuit 7 is turned to an open state, and the slave supervisory equipment 3a is disconnected from a common transmission line 2. Thus, since the carrier signal continuously transmitted up to the moment on the common transmission line 2 disappears when the slave supervisory equipment 3a as the cause of the fault is disconnected from the common transmission line 2, a main supervisory equipment 1 can normally collect supervisory information from the remaining slave supervisory equipments in a normal state.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a remote monitoring system, and particularly when monitoring information is collected from a plurality of slave monitoring devices onto a carrier using a common transmission path to a main monitoring device. The present invention relates to a remote monitoring system configured to automatically identify a slave monitoring device that causes the failure and disconnect it from the common transmission path when a failure occurs that causes carrier signals to continue being output on a common transmission path.

[Conventional technology]

Conventionally, this type of remote monitoring system outputs a carrier signal to a main monitoring device to multiple slave monitoring devices, or to the main monitoring device for a period of time allotted to itself, and transmits monitoring information to this carrier signal. The monitoring information was then reported to the main monitoring device.

[Problem to be solved by the invention]

In the conventional remote monitoring system described above, if a failure occurs that causes a slave monitoring device to continue outputting a carrier signal, the common transmission path will be occupied by the failure, so that the remaining normal slave monitoring devices will not be able to output the carrier signal. It becomes impossible to collect monitoring information, and the only way to identify a fault is to dispatch maintenance personnel to the remote locations where each sub-monitoring device is installed and investigate which sub-monitoring device is at fault. However, there was a problem in that it took a long time to recover from a failure.

An object of the present invention is to automatically remove the slave monitoring device that is the cause of the failure, even if it becomes impossible to collect monitoring information across the entire system due to a failure such as the slave monitoring device continuing to output carriers. It is an object of the present invention to provide a remote monitoring system that can quickly and easily identify and recover from failures as a whole system.

[Means to solve the problem]

The remote monitoring system of the present invention includes a plurality of slave monitoring devices that collect monitoring information generated in a monitored system and sequentially transmit carrier signals containing the monitoring information within their own assigned time slots; A remote monitoring system comprising: a main monitoring device connected to the plurality of slave monitoring devices via a common transmission path and collecting monitoring information by receiving carrier signals sent from the slave monitoring devices; Located between the common transmission path and each slave monitoring device,
(B) carrier detection means for intercepting the carrier signal on the common transmission path and outputting a carrier detection signal while the carrier signal is present; (B) receiving the carrier detection signal and measuring the duration of the carrier detection signal; (C) a timer means for outputting a carrier output abnormality signal when the duration of the detection signal exceeds a predetermined time, and for continuously outputting the carrier output abnormality signal while the carrier detection signal continues; A fault disconnection device is provided on the common transmission path side of the carrier detection point of the carrier detection device, and has a disconnection device that disconnects the slave monitoring device from the common transmission path when a carrier output abnormal signal is received. There is.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

The remote monitoring system shown in FIG. 1 includes a plurality of slave monitoring devices 3a that collect monitoring information generated in a monitored system and sequentially transmit carrier signals containing the monitoring information within their own assigned time slots. ~3b1 A main monitoring device 1 that is connected to a plurality of slave monitoring devices 3a to 3b via a common transmission path 2 and receives carrier signals sent out from the slave monitoring devices 3a to 3b to collect monitoring information, and a common transmission path 2 and each slave monitoring device 3a to 3b, and when the carrier output is abnormal,
It is comprised of fault isolation devices 4a to 4b that open and close connections between the common transmission line 2 and each slave monitoring device 3a to 3b.

Further, the fault isolation devices 4a to 4b are located between the common transmission path 2 and each of the slave monitoring devices 3a to 3b, and intercept the carrier signal on the common transmission path 2 to generate a carrier detection signal while the carrier signal is present. A carrier detection circuit 5 that outputs a carrier detection signal 8 receives the carrier detection signal 8, measures the duration of the carrier detection signal 8, and outputs a carrier output abnormality signal 9 when the duration of the carrier detection signal 8 exceeds a predetermined time. The timer circuit 6 continuously outputs the carrier output abnormal signal 9 while the carrier detection signal 8 continues, and the carrier output abnormal signal is located on the common transmission line 2 side of the carrier detection point of the carrier detection circuit 5. 9 is received, the slave monitoring devices 3a to 3b are disconnected from the common transmission path 2, and when the carrier output abnormality signal 9 is not received, the slave monitoring devices 3a to 3b are connected to the common transmission path 2. There is.

Next, the operation will be explained.

In FIG. 1, a main monitoring device 1 collects monitoring information from a plurality of slave monitoring devices 3a to 3b via a common transmission path 2. Further, one slave monitoring device is connected to the common transmission path 2 via one fault isolation device. Although the configuration of the fault isolating device 4a connected to the slave monitoring device 3a is illustrated here, the fault isolating devices connected to other slave monitoring devices have the same configuration.

As shown in FIG. 1, in the normal state of the system, the disconnection circuit 7 is in a closed state, and the slave monitoring device 3a is connected to the common transmission path 2, and sends monitoring information to the main monitoring device 1. It is transmitting. When the carrier detection circuit 5 detects a carrier signal on the common transmission path 2, it outputs a carrier detection signal 8 to the timer circuit 6. In a normal state, when the main monitoring device 1 collects monitoring information from each slave monitoring device via the common transmission path 2, the carrier signal duration time for one transmission of monitoring information is determined in advance. Since the time is less than the specified time, the timer circuit 6 does not output the carrier output abnormality signal 9. Therefore, the disconnection circuit 7 remains closed.

However, if a failure occurs such that the slave monitoring device 3a continues to output the carrier signal, the carrier detection circuit 5 continues to output the carrier detection signal 8.

When the carrier detection signal 8 is maintained for a predetermined time or longer, the timer circuit 6 outputs a carrier output abnormality signal 9, opens the disconnection circuit 7, and disconnects the slave monitoring device 3a from the common transmission line 2.

In this way, when the slave monitoring device 3a, which is the cause of the failure, is disconnected from the common transmission path 2, the carrier signal that has been continuously sent out on the common transmission path 2 disappears, so the main monitoring device 1 is disconnected from the common transmission path 2. Monitoring information can now be normally collected from the remaining subordinate monitoring devices that are in a normal state.

On the other hand, when the slave monitoring device 3a is in a normal state, if another slave monitoring device, for example, the slave monitoring device 3b, has a failure such that it continues to output the carrier signal, the slave monitoring device 3b that is the failure will be in the above-mentioned state. Similarly, until it is disconnected from the common transmission path 2, the carrier detection circuit of the fault disconnection device 4a outputs the carrier detection signal 8, and if the carrier detection signal 8 is detected even after a predetermined time, , the timer circuit 6 outputs a carrier output abnormality signal 9 to open the disconnection circuit 7. In this way, when the normal slave monitoring device 3a is disconnected from the common transmission path 2, the carrier detection circuit 5 no longer detects the carrier signal, so it stops outputting the carrier detection signal 8, and then the timer circuit 6 Since the carrier detection signal 8 is no longer input, the carrier output abnormal signal 9
stop sending. When the carrier output abnormality signal 9 is no longer input, the disconnection circuit 7 becomes closed, and the secondary monitoring device 3a
is connected to the common transmission line 2 again. During this time, the obstructing secondary monitoring room 3b has already been automatically disconnected from the common transmission line 2 in the same manner as described above, so it remains on the common transmission line 2 for a certain period of time. There is no continuing carrier signal, and the slave monitoring device 3a remains connected to the common transmission path 2.

In this way, only the secondary monitoring device causing the failure is disconnected from the common transmission path 2, and the normal secondary monitoring device remains connected to the common transmission path 2, so the main monitoring device 1 is disconnected from the common transmission path 2. 2, collection of monitoring information can be resumed from a normal slave monitoring device.

〔Effect of the invention〕

As explained above, the present invention intercepts a carrier signal on a common transmission path and measures its duration, and if the carrier signal continues even after a predetermined time, it is determined that the carrier signal is continuing. By installing a fault isolation device that has the function of isolating the slave monitoring device from the common transmission path between the common transmission path and each slave monitoring device, it is possible to eliminate obstacles that would cause the slave monitoring device to continue outputting carriers. Even if it becomes impossible to collect monitoring information across all systems, the secondary monitoring device that is causing the failure is automatically identified and disconnected from the common transmission path, allowing for quick recovery from the failure of the entire system. It also has the effect of being easy to perform.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention. 1...Main monitoring device, 2...Common transmission line, 3a-3b...Sub-monitoring device, 4a-4b...
...Fault isolation device, 5...Carrier detection circuit, 6...Timer circuit, 7...Disconnection circuit, 8...Carrier detection Signal, 9...
・Carrier output abnormal signal. Agent Patent Attorney Susumu Uchihara

Claims (1)

[Scope of Claims] 1. A plurality of slave monitoring devices that collect monitoring information generated in a system to be monitored and sequentially transmit carrier signals containing the monitoring information within their own assigned time slots; A remote monitoring system comprising: a main monitoring device connected to the plurality of slave monitoring devices via a common transmission path and collecting monitoring information by receiving carrier signals sent from the slave monitoring devices; Located between the common transmission path and each slave monitoring device,
(B) a carrier detection unit that intercepts the carrier signal on the common transmission path and outputs a carrier detection signal while the carrier signal is present; (B) a carrier detection unit that receives the carrier detection signal and measures the duration of the carrier detection signal; (C) a timer means for outputting a carrier output abnormality signal when the duration of the detection signal exceeds a predetermined time, and for continuously outputting the carrier output abnormality signal while the carrier detection signal continues; A fault isolation device is provided on the common transmission path side of the carrier detection point of the carrier detection device, and includes a disconnection device that disconnects the slave monitoring device from the common transmission path when a carrier output abnormality signal is received. A remote monitoring system characterized by: 2. A plurality of slave monitoring devices that collect monitoring information generated in a monitored system and sequentially transmit carrier signals containing the monitoring information within their own assigned time slots; and the plurality of slave monitoring devices. a main monitoring device connected to the sub-monitoring device via a common transmission path and collecting monitoring information by receiving a carrier signal transmitted from the sub-monitoring device, a carrier detecting means for detecting the carrier signal; , a timer means for measuring the duration of the carrier, and a disconnection means for disconnecting the slave monitoring device from the common transmission path, and the carrier detection means intercepts the carrier signal on the common transmission path and detects the carrier signal. transmits a carrier detection signal in which the carrier detection signal exists to the timer means, and the timer means outputs a carrier output abnormality signal when the carrier detection signal is received and the duration of the carrier detection signal exceeds a predetermined time. , while the carrier detection signal continues, the carrier output abnormality signal is continuously sent to the separation means, and when the carrier output abnormality signal is received by the separation means, the slave monitoring device is transmitted from the common transmission path. A remote monitoring system characterized by the separation of