JPS58195328A - Remote monitoring device - Google Patents

Abstract

PURPOSE:To reduce number of components with common monitoring signals and to improve the reliability and profitability, by switching on and off failure alarm contacts in the timing assigned to each terminal station from a terminal station when a failure takes place in the terminal station. CONSTITUTION:When a terminal station in failure exists, a failure alarm contact 7c of the terminal station is on/off-controlled with a control circuit 7d periodically. Since the terminal station in failure intermits a supplied monitoring signal in the period of the failure alarm contact 7c, the monitoring signal is folded to a master station 1 via a line 8. A detector 11 in the master station 1 detects the supplied monitoring signal and the time interval of the detection signal is detected by a time detector 13. Since the time interval depends on each terminal station, the time detector 13 discriminates the terminal station in failure from this time interval and displayes the result on a display 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a remote monitoring device that monitors the status of a terminal station.

In general, it is possible to monitor the status of a plurality of terminal stations using a single master station based on remote monitoring values.

Stripe diagram 1 is a block diagram showing an example of a conventional far-field viewing device. In the diagram, 1 is a master station, which generates a monitoring signal for selecting a large number of terminal stations. It is equipped with oscillation!21~2m.Then, the supervisory signal generated by these oscillations 21~2n is transmitted to the switch 31.
.about.3nK, the independent signals 19 are supplied to the 1 amplifier 4 in parallel, and sent out to the path 6 via the transformer 5.

The signal is sent out to the friend monitoring signal terminal stations 71 to 7II, and in each terminal station, this signal is supplied to the amplifier 1b via the transformer 7a. In addition, the receiver 1b has frequency selectivity and is configured to pass only the nine-frequency monitoring signal assigned to each terminal station.

7cti is a failure alarm contact and is turned on only at a terminal station with a failure.

Therefore, each terminal station is supplied with the monitoring signal assigned to it and amplifies the signal ζ at 9 o'clock with the amplifier 7b, but among these, only the terminal station with ll[11 amplifies the output of the amplifier 1b, It is sent to the line 8 via the alarm contact 7c.

The master station 1ti supplies this signal to the detector [h~11nK via a transformer 9 and an amplifier 10. The detectors 111 to 11n are configured to detect only signals with frequencies corresponding to the oscillators 21 to 2mK, so that only the delayed monitoring signal returned from the faulty terminal station is detected and displayed on the display 12. be done.

Such conventional devices have the advantage of being able to detect faults by looping back the C+M signal sent from the master station without converting it into a signal of a different frequency.
Since a terminal station must have as many oscillators and detectors as the number of terminal stations, the increased number of parts has the disadvantage of lowering reliability and cost efficiency.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a remote monitoring device that uses a common monitoring signal, reduces the number of parts, and improves reliability and economy.

In order to combine these objectives, the present invention is designed to: □ When a failure occurs in a terminal station, the terminal station 11-1 alarm contact is turned on and off at the timing assigned to each terminal station. Out. In the following, the present invention will be explained using drawings showing embodiments.

FIG. 2 is a block diagram showing an embodiment of the present invention,
The same symbols are used for the same parts and corresponding parts as in Figure 1. In the figure, when a failure occurs in the control circuit 7diis connected to the terminal stations 71 to 7n,
The fault alarm contact IC is periodically turned on and off. The intermittent timing is then set to be different for each terminal station.
The on and off timings of the respective terminal stations do not coincide with each other. 13Fi, a time detector, which determines the time scale of the signal supplied from Detection-11 and detects the terminal station sending the signal. Note that there is only one supervisory signal oscillator for the master station 1 to monitor the status of the terminal stations 11 to 1m. . Oh, terminal station 7. -7.0 increaser 7
b#i, [no 1 number selectivity.
λ The operation of the apparatus according to the present invention constructed as described above is as follows. By turning on the switch 3 of the master station 1, the monitoring signal generated by the oscillator 2 is transmitted via the line 6 to the terminal stations 11-1. supplied to At this time, if a terminal station is experiencing a fault, the fault 111 notification contact IC of that terminal station is periodically on/off controlled by the control circuit 7d. Therefore, the terminal in which the fault has occurred cuts off the supplied monitoring signal by braking the fault alarm contact 1c, so that the monitoring signal is returned to the master station 1 via the line 8.

In the master station 1, a detector 11 detects the supplied monitoring signal, and a time detector 13 detects the time interval of the detected signal. As mentioned above, this time interval is determined to be different for each terminal station, so the detector 13Fi determines which terminal station is causing the failure from this time interval and displays it on the display 12. do. Also, the fault alarm contact 7c is turned on.
The turn-off timing is different for each terminal station and does not match each other, so even if multiple terminal stations are barracked at the same time, the time detector 13 determines the time interval between the signals output from the detector 11. It is possible to identify each terminal station. Therefore, even if a plurality of terminal stations are at fault, the faulty terminal stations can be individually identified and displayed on the display 12.

Although the above embodiments use AC signals as monitoring signals, terminal stations can be monitored using other signals such as unipolar pulses and bipolar pulses.

As explained above, the distant TL vision system # according to this invention is as follows.
The monitoring signal returned at the terminal station is turned on and off at a predetermined timing, and the on/off timing is determined for each terminal station.
J! Since the monitoring signal can be made common to each terminal station, the number of parts can be reduced because only one oscillator and detector for rounding and monitoring signals are required. At the same time, it has the excellent effect of improving economic efficiency and reliability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of the remote monitoring device f1 used from the beginning, and FIG. 2 is a block diagram showing an embodiment of the remote monitoring device according to this invention. 1... Master station, 2... Oscillator, 7t~111...
...Terminal station, Tc...Fault alarm contact, 7d...
Control i! Circuit, 11...detector, 13...time detector. Patent applicant Hitachi Electronics Co., Ltd. agent Masaki Yamakawa 01 or 1)

Claims (1)

[Claims] In a remote monitoring device that is composed of one master station and a plurality of terminal stations, and detects a terminal station failure by returning a monitoring signal sent from the master station to the master station only when the terminal station suffers an S problem, The terminal station is equipped with a control circuit that intermittents the above-mentioned looped back monitoring signal in a predetermined period for each terminal station, and the master station identifies the faulty terminal station based on the intermittent timing of the looped back monitoring signal at the faulty terminal station. A remote monitoring device characterized by being equipped with a time detector.