JPS60201498A - Remote abnormality monitor system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention is applicable to water damage in communication cables (optical cables) used in various communication lines, or water damage in buildings, warehouses, etc. scattered over a wide area. This invention relates to a remote abnormality monitoring method that can detect abnormalities such as fires and perform centralized monitoring from a remote location.

, [Example of prior art] As a method of installing a pair of communication lines to monitor faults at two or more remote points, transmitters with different frequencies that oscillate in the event of an abnormality are installed at fault detection points, and these are connected to the communication line. There is a so-called frequency multiplex monitoring method that detects the oscillation frequency after connecting the core wires in a multi-drop format (parallel).

However, in the conventional monitoring system, the number of applicable holes is limited because (1) the longer the monitoring distance, the more transmitters are connected between two wires (one pair), and the transmission loss increases.

■ During normal operation, there is no response from each transmitter and there is no signal, so even if a failure occurs in the transmitter itself, it cannot be detected.

There is a drawback.

Therefore, for the above-mentioned (■), it is conceivable to adopt a method in which calls are made at all times on the 1st floor and the calls are stopped in the event of an abnormality.
Even in this case, there is a problem in that reliability is low because it is not possible to identify whether it is a transmitter failure or other failure information.

[Summary of the invention]

This invention was made to solve these problems, and by making the signal source impedance of the oscillator a constant current output, it suppresses the increase in transmission loss caused by the multi-drop format, expands the applicable range, and By making the transmitter polar, the transmitter can be controlled from a central monitoring unit, thereby making it possible to check for failures in the failure detection device. Therefore, the transmission loss for abnormal signals is reduced, the fault detection area is increased, and 1. Since fault diagnosis is performed from the central monitoring unit at any time, the reliability of fault information is improved.

〔Example〕

FIG. 1 is a block diagram of a remote abnormality monitoring system showing an embodiment of the present invention, and C8S surrounded by a dashed line indicates a central monitoring station monitoring an abnormality detection point. This central supervisory station C8S has a line support section equipped with switches SW1 to SWn, a power supply section E1 equipped with a switch SWa for polarity conversion and a power source V, a frequency discrimination section F, supervisory control, data processing, etc. It consists of a control section C that performs the operations, and an output section that displays and prints out data.

The switches SW1 to SWn of the line corresponding section are sequentially closed by a signal from the control section C, and connect the monitoring lines 1 to N and the central monitoring station C3S in a time-division manner.

A plurality of detection devices SIl, SI2..., SW2. are connected to each monitoring line 1 to N. .

S22..., SN1 + SN2...
At the same time, the detection devices S are supplied with operating power from the power supply section E.

The plurality of detection devices S installed at the abnormality monitoring points include a sensor that detects flooding or fire, etc., as described later, a transmitter that is activated when the sensor indicates an abnormality, and an output signal of the transmitter. It consists of a constant current conversion circuit that converts the current into a constant current and sends it out.1. The oscillation frequency of each detection device S is 1
Each pair of lines has a different frequency f,, f2...
..., fn.

Note that T represents a coupling transformer and A represents an arrester.

FIG. 2 is a circuit diagram showing an embodiment of the detection device S.
is a rectifier circuit consisting of diodes D1 to D4, 2 is a constant current conversion circuit, 3 is a constant voltage circuit, 4 is an oscillator, 5 is a switch circuit formed of transistors Tr, 6 is a comparator,
7 is a bridge circuit composed of a resistor R, a sensor Rs, and a volume VR; 8 is a diode for polarity detection; and A is an aster.

The oscillation frequency of the oscillator 4 is set using, for example, a tuning fork, and the oscillation frequency of the oscillator 4 is set using, for example, a tuning fork.
K l + SK2..., SKn are all set to have different frequencies.

In this detection device S, for example, line L1 is positive and line L2 is positive.
When a negative power source is supplied, the polarity detection diode 8 is non-conductive, and when there is no fault, for example, when there is no flooding, the humidity detecting sensor Rs has a low resistance value. It becomes.

At this time, the volume VR is set so that the output of the comparator 6 is at a high level equal to the output of the constant voltage circuit 3, so the transistor Tr is off and no voltage is applied to the oscillator 4. It is in an inactive state.

In this state, when the sensor Rs detects water intrusion and its resistance value increases, the output of the comparator 6 is inverted to a low level and the transistor Tr becomes conductive.

Therefore, the oscillator 4 is activated and its oscillation output is made into a constant current by the constant current conversion circuit 2. And the constant current oscillation output is line L! It is superimposed on the supply current supplied from the + line L2, is output to the monitoring line (K), and is combined with the coupling transformer T shown in FIG.

On the other hand, under the control of the central monitoring station C3S, lines L, ,L
When the polarity of the power supply supplied to 2 is reversed, and line L1 becomes negative and line L2 becomes positive, the polarity detection diode 8
conducts, and the voltage at the positive phase input terminal of the comparator 6 decreases.

Then, even if the resistance value of sensor Rs is low 1 all the time, comparator 6
The output of is inverted to low level and! - Make the transistor Tr conductive.

In this case as well, since the polarity of the power supply applied to the constant current conversion circuit 2, constant voltage circuit 39, and oscillator 4 by the rectifier circuit 1 has not changed, the oscillator 4 is activated by the conduction of the transistor Tr, and the polarity of the power supply applied to the constant current conversion circuit 2, the constant voltage circuit 39, and the oscillator 4 by the rectifier circuit 1 has not changed. Similarly, the oscillation output is made constant current and is connected to line L1.

Sent to L2.

Since the remote abnormality monitoring system of the present invention has the configuration as described above, it is possible to accurately detect abnormalities (failures) at each detection point as described below.

First, when the central monitoring station C8S performs abnormality monitoring, it connects the switch SWa of the power feeding section E to the position shown in the figure according to a signal from the control section C, and then connects the switch SWa of the line corresponding section to the position shown in the figure.
-swN is controlled to be closed in order.

Through this control, a DC voltage in which line L is positive and line L2 is negative is applied to each monitoring line 1-N in a time-sharing manner, and each detection device S is put into an operating state.

At this time, if there is no abnormality at each detection point, the sensor Rs of the detection device S installed at each detection point has a low impedance, and each transmitter 4
are in an inactive state, so no abnormal signal is detected from each monitoring line 1-N.

However, for example, when the detection device SIN of the monitoring line 1 senses a fault (flooding), the frequency fn of the oscillator 4 output from the detection devices SW and N within the timing period when the switch SwI is closed changes to the coupling transformer. The signal is input to the frequency discriminator F via T. Then, the detection signal is supplied to the control section C.

In the control unit C, this detection signal is sent to the detection device 31 of the monitoring line 1.
It determines that the data is being output from n, outputs the data to the output section 111, displays the location where the abnormality has occurred on the display section, and performs processing when the abnormality occurs as necessary.

Since the abnormality signal of frequency fn outputted from the detection device Sln is sent through the constant current conversion circuit 2 as described above, it is hardly affected by the line resistance of the monitoring line 1.

Moreover, other detection devices (S
ll, 312...) are provided with a constant current conversion circuit 2 and a constant voltage circuit 3, so that the detection device S1n
The abnormal signals output from these detection devices (31
1, S12...).

By the way, the remote abnormality monitoring method of this invention is based on each detection device S.
It is possible to check whether or not the system is operating normally.

This failure diagnosis can be carried out by controlling the switch SWa of the power feeding section E in reverse as shown by the dotted line.

In this case, as mentioned above, line L1 of monitoring line 1-N
Since the power is supplied so that the line L2 side is negative and the line L2 side is positive, the polarity detection diode 8 of the detection device S becomes conductive, and as explained in the circuit of FIG. 2, each detection device S is powered off. In the applied state, the transmitter 4 can be activated if the resistance value of the sensor Rs is normal.

Therefore, when the switch SWI in the line corresponding section is turned on, the frequencies fI+f2 and 2 are transmitted from all the detection devices S11+s, 2..., S, N connected to the monitoring line 1, respectively. Old...The fn signal is sent to the central monitoring station C3S, and the switch SW in the line response section
2 is on, all detection devices 11s21, S22, etc. connected to the monitoring line 2 are turned on.
. . , from S2n, the frequencies f, , f2 . . .
..., fn signals are transmitted to the central monitoring station C8S.

Therefore, signals of frequencies f,, f2, ..., fn transmitted from each monitoring line 1-N are detected by the frequency discriminator F, and if signals can be received from all detection devices S, a failure occurs. It can be determined that there is no such thing.

However, for example, if a signal of frequencies f3 to fn is not received during the period when the monitoring line N is selected, it is determined that the line between the detection devices SN2 and SN3 of the monitoring line N is disconnected. When only the frequency f3 is missing, it is determined that the detection device SN3 is malfunctioning.

In this way, the remote abnormality monitoring method of the present invention uses the detection device S.
and a check function for monitoring lines 1 to N, making fault detection extremely reliable, for example, by performing fault diagnosis before performing abnormality monitoring or once a day. .

FIG. 3 shows the constant current conversion circuit 2 of FIG. Constant voltage circuit 3
An example of a simplified circuit is shown below. As is well known, this circuit consists of an i transistor Q, a Zener diode D2
The alternating signal of the oscillator 4 is supplied via a coupling capacitor C1 to a simple constant voltage circuit consisting of the following.

When the switch S is off and the oscillator 4 is inactive, the current is constant and the operating current ■ is flowing due to the output voltage Vout. However, when the switch S is on and the oscillator 4 is activated, the oscillation output causes the transistor to Q is controlled and the abnormal signal Is is made constant current as shown by the dashed line.
flows through the transistor Q and the capacitor C2, superimposes on the operating current (2), and flows out to the monitoring line.

〔Effect of the invention〕

As explained above, the remote abnormality monitoring method of this invention is
Since a check function is added to each detection device to perform fault diagnosis by reversing the polarity of the power supply, there is an effect that fault detection becomes extremely reliable. Additionally, since each detection device outputs a constant current abnormality signal, the applicable distance of the detection device connected to the monitoring line becomes longer, which has the advantage of making it easier to implement a wide-area, multi-point monitoring system. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a circuit diagram showing one embodiment of a detection device, and FIG. 3 is a circuit diagram showing one embodiment of a constant current circuit. In the figure, 1 is a rectifier circuit, 2 is a constant current conversion circuit, 3 is a constant voltage circuit, 4 is an oscillator, 5 is a switch circuit, 6 is a comparator, and 7
represents a bridge circuit, Rs represents a sensor, and E represents a power supply section. 3

Claims (1)

[Claims] A monitoring unit; a sensor capable of detecting an abnormality at the installed location; and a transmitter that is activated when the sensor detects an abnormality and outputs a signal of a unique frequency to notify the monitoring unit of the abnormality. In a frequency multiplexed remote abnormality monitoring system in which one or two or more detection devices are arranged at one or two or more remote points, the monitoring unit:
comprising a polarity reversing means for reversing the polarity of a power source supplied to the detection device, and a means for sensing that the polarity has been reversed by the polarity reversing means and activating the transmitter; A remote abnormality monitoring system characterized in that the output of the transmitter is a constant current source.