JPH0683507B2 - Supervisory control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a supervisory control method suitable for remote monitoring using a wireless line, and in particular, to a monitored signal for a calling signal sent from a supervisory station. The present invention relates to a supervisory control method in which a station returns a response signal and the state of a monitored station is monitored according to the returned information.

[Prior Art] Conventionally, in a remote monitoring system using a wireless line, a monitored station receives an FSK-modulated call signal from the monitor station, demodulates the call signal, and then the demodulated call signal is transmitted by itself. If it is a calling signal addressed to itself, multiple monitoring items are multiplexed and coded to generate a response signal, which is FSK-modulated and sent back to the monitoring station. Was there.

[Problems to be Solved by the Invention] However, in such a conventional supervisory control system, a large number of communication stations such as an FSK demodulation circuit, a ringing signal detection circuit, a multiplexing / encoding circuit, and an FSK modulation circuit are provided in a monitored station. Circuit is required. Therefore, there is a problem that the power consumption of the monitored station also increases. In particular,
When the monitored station is installed at each of a large number of monitoring points, the conventional system has a problem that the power consumption of the entire system becomes extremely large.

The present invention has been made in view of such problems,
An object of the present invention is to provide a supervisory control method capable of significantly reducing the power consumption of a monitored station.

[Means for Solving the Problems] A supervisory control system according to the present invention includes a supervisory station supervisory controller provided in a supervisory station and a supervisory station supervisory controller provided in a supervised station as follows. It is characterized by being configured in.

The monitoring control device for the monitoring station is a means for transmitting a calling signal of a specified frequency assigned to the monitored station to be monitored to the monitored station via a communication line, and the calling signal is sent back from the monitored station as a response signal. In the case where the detection is made, it is provided with means for detecting this and means for determining the state of the monitored station depending on the presence or absence of this detection.

The monitored control device for the monitored station includes means for outputting a monitoring item signal indicating the presence or absence of abnormality of the monitoring item, means for detecting a calling signal of the specified frequency received via the communication line, and calling by this means. A return switch is provided for sending back the detected calling signal to the monitoring station via the communication line when the signal is detected and the monitoring item signal indicates that there is no abnormality.

[Operation] According to the present invention, when the calling signal of the specified frequency from the monitoring station is detected, if the monitored item is normal, the return switch is operated to send the calling signal as a response signal back to the monitoring station at the same frequency. If there is an abnormality in the monitored item, there is no response. Therefore, the monitoring station can determine the state of the monitored station based on the presence or absence of the response signal. Further, according to the present invention, the monitored station only needs to perform an operation of sending back a calling signal according to the state of the monitored item, so that the conventional system requiring an FSK modulation / demodulation circuit, a multiplexing / encoding circuit, etc. Compared with this, the configuration is remarkably simple and the power consumption can be reduced.

[Embodiment] Next, an embodiment of the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a diagram showing the configuration of a supervisory control system according to an embodiment of the present invention. The monitoring control device 1 for the monitoring station provided in the monitoring station and the monitoring control device 2 for the monitoring station provided in each of the plurality of monitored stations can bidirectionally transmit and receive via the up transmission channel 3 and the down transmission channel 4. Is bound to.

The monitoring station supervisory controller 1 includes a monitoring station logic circuit 11, a specified frequency oscillation circuit 12, and a specified frequency detection circuit 13. The monitoring station logic circuit 11 applies a signal for specifying the specified frequency assigned to the monitored station to be monitored to the specified frequency oscillation circuit 12, and introduces the detection result of the specified frequency detection circuit 13 to monitor the monitored station. Determine the state. The prescribed frequency oscillation circuit 12 generates a calling signal having a prescribed frequency designated by the supervisory station logic circuit 11 and sends it to the upstream transmission channel 3. The specified frequency detection circuit 13 detects the response signal of the specified frequency returned from the monitor / control apparatus 2 for the monitored station via the downlink transmission channel 4.

The monitored station supervisory control device 2 includes a specified frequency detection circuit 21, a monitoring item signal generation circuit 22, an AND gate 23, and a loopback switch 24. The specified frequency detection circuit 21 detects a calling signal of a specified frequency assigned to the local station. The monitoring item signal generation circuit 22 is a signal indicating whether or not there is an abnormality in the monitoring item, and displays "1" if the monitoring item is normal and "0" if the monitoring item is abnormal. The AND gate 23 outputs "1" if the specified frequency is detected and there is no abnormality in the monitoring item, and outputs "0" otherwise. The output of the AND gate 23 of the folding switch 24 is "1".
When this occurs, it is turned on, and the calling signal of the specified frequency detected on the upstream transmission channel 3 is returned to the downstream transmission channel 4.

Next, the operation of the supervisory control system thus configured will be described.

Different prescribed frequencies are assigned to the plurality of monitored stations. When checking the status of one of the monitored stations, the monitoring station logic circuit 11 first instructs the specified frequency oscillation circuit 12 of the monitored station or its specified frequency. In response to this instruction, the specified frequency oscillation circuit 12 sends out the calling signal of the specified frequency to the upstream transmission channel 3. Specified frequency detection circuit 21 of supervisory control device 2 for monitored station
When detects the specified frequency assigned to itself, the output of the detection circuit 21 becomes "1" and is given to one side of the AND gate 23. At this time, if there is no abnormality in the monitoring item, "1" is also given to the other input of the AND gate 23. Therefore,
The output of the AND gate 23 also becomes "1", and the return switch 24
Is driven into the on state. As a result, the detected signal of the specified frequency is sent back to the monitoring station side via the downlink transmission channel 4. In the supervisory station supervisory controller 1, the prescribed frequency detection circuit 13 detects the signal (response signal) of the prescribed frequency sent back and recognizes that the monitored item of the monitored station is normal. However, if the frequency is not returned within the fixed time, it is recognized that an abnormality has occurred in the monitored station.

As described above, according to the system of the present embodiment, since the return switch 24 is provided in each monitored station monitoring control device 2 and only the calling signal of the detected specified frequency is sent back, a large power is consumed. Is not required, and the configuration is simple.

It should be noted that the present invention can use both wired and wireless communication systems. In these systems,
The two upstream and downstream channels may be physically secured or may be secured by time division. For example, in a wireless system, it is possible to secure two channels by delaying a response signal to the calling system. In this case, a delay line may be used as a line connecting the input terminal of the specified frequency detection circuit 21 and the input terminal of the folding switch 24.

[Effects of the Invention] As described above, according to the present invention, when a loopback switch is provided in a monitored station and a ringing signal of a specified frequency is detected,
Since the call signal is simply sent back only when the monitored item is normal, there is an effect that a large power is not required and the configuration is simplified.

[Brief description of drawings]

FIG. 1 is a block diagram of a supervisory control system according to an embodiment of the present invention. 1; monitoring control device for monitoring station, 2; monitoring control device for monitored station,
3; uplink transmission channel, 4; downlink transmission channel, 11; monitoring station logic circuit, 12; specified frequency oscillation circuit, 13, 21; specified frequency detection circuit, 22; monitoring item signal generation circuit, 23; AND gate, 24 Return switch

Claims (1)

[Claims] 1. A supervisory station supervisory controller provided in a supervisory station, and a supervisory station supervisory controller provided in a supervised station,
And a communication line connecting them, the monitoring station supervisory control device sends a calling signal of a specified frequency assigned to the monitored station to be monitored to the monitored station via the communication line. , Means for detecting that the ringing signal sent by this means is returned from the monitored station as a response signal, and the status of the monitored station based on whether or not the response signal is detected by this means. The monitoring control device for a monitored station is provided with a means for outputting a monitoring item signal indicating whether or not there is an abnormality in the monitoring item, and a specified frequency assigned to itself monitored via a communication line. A means for detecting a calling signal, and a means for detecting the calling signal by this means and transmitting the detected calling signal as a response signal when the monitoring item signal indicates that there is no abnormality in the monitoring item. Monitor and control system, characterized in that those comprising a folded switch back to the line.