JP2836336B2 - Power off control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system of a remote monitoring control system, and more particularly, to a control system for notifying power-off information to a higher-level monitoring device when a power failure of the remote monitoring device occurs.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram of the prior art.

In FIG. 2, a monitoring control circuit 8 constantly monitors the internal operation state of a remote monitoring device, controls the communication interface circuit 2 by a communication control bus 11 and transmits the information to a higher-level monitoring device 1 via a communication line. Notify as monitoring information.
Now, let us consider a method of notifying the upper-level monitoring device 1 of power-off information from the remote monitoring device when the input power 13 to the power supply panel 9 of the remote monitoring device is interrupted.

In the conventional control system shown in FIG. 2, the state of the input power supply 13 is constantly monitored by the power-off monitoring circuit 7, and when the power-off is detected, the monitoring and control circuit 8 is immediately notified of the occurrence of the power-off. The secondary output power supply 12 of the power supply panel 9 is connected to the power supply backup area 6 via the backup capacitor circuit 10.
Is supplied to Supervisory control circuit 8 receiving power-off notification
Suspends monitoring in the device and sends a power-off notification to the upper monitoring device 1.
Communicate to This control is limited within a period during which the monitoring and control circuit 8 can operate with the power supply backed up by the backup capacitor circuit 10 after the occurrence of the input power supply interruption. This time is determined by the capacitance of the backup capacitor and the current consumption of the monitoring control circuit 8 and the communication interface circuit 2.

[0005]

When the power of the remote monitoring device is turned off in the remote monitoring system, it is necessary to notify the information to a higher-level monitoring device. In this case, the remote monitoring device needs to monitor its own power input state and notify the higher-level monitoring device 1 of the power-off from the occurrence of the power-off until the power of the monitoring control circuit 8 is turned off. Generally, in order to guarantee the operation of the monitoring control circuit after the power is turned off, a backup is provided with a battery or a large-capacity capacitor. In the case of battery backup, the battery cannot be used under non-replaceable conditions due to the life of the battery. In such a case, a short-time backup is performed using a large-capacity capacitor.

However, when backing up with a capacitor, it is necessary to reduce the power consumption of the monitoring and control circuit as much as possible in order to secure a backup time due to the restriction of the capacitance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and accordingly, an object of the present invention is to provide a novel power-off control method capable of solving the above-mentioned problems inherent in the prior art. Is to do.

[0008]

In order to achieve the above object, a power cutoff control method according to the present invention is provided in a remote monitoring system comprising a host monitoring device and a remote monitoring device.
(1). A power supply circuit for supplying power to the remote monitoring device;
(2). A power-off monitoring circuit for monitoring input power-off supplied to the power supply circuit; (3). A monitoring control circuit for controlling the remote monitoring device; (4). A communication interface circuit that is controlled by the monitoring control circuit and communicates with the higher-level monitoring device;
(5). A buffer for electrically separating the monitoring control circuit and the communication interface circuit when the input power supply is detected; (6).
A microcomputer that is connected between the communication interface circuit and the buffer and outputs communication disconnection information to the communication interface circuit after the power supply of the monitoring control circuit is turned off;
(7). The communication interface circuit and a backup capacitor for backing up the power of the microcomputer are provided, and after the input power of the remote monitoring device is turned off, the power-off information is notified to the higher-level monitoring device.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a preferred embodiment of the present invention.

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

Referring to FIG. 1, a buffer 4 is provided between a monitoring control circuit 8 and a communication interface circuit 2 in a remote monitoring apparatus, and a one-chip microcomputer 3 is connected between the buffer 4 and the communication interface circuit 2. I do. The power supply backup by the capacitor after the power failure occurs is limited to the communication interface circuit 2, the buffer 4 and the microcomputer 3 only, and the microcomputer 3 controls the power consumption after the power failure. Reduce.

That is, in the control method according to the present invention, as shown in FIG.
Not included in each circuit inside. In this figure, when a power-off is detected, the operation of the monitoring control circuit 8 is not guaranteed.
However, the power-off detection information is also notified to the microcomputer 3, and after the power-off, the microcomputer 3 controls the communication interface circuit 2 to notify the host device of the power-off. The buffer 4 has a function of disconnecting the communication control bus 11 of the monitoring control circuit 8 whose power is turned off after the power is cut off.

When a one-chip LSI incorporating a control program is used as a microcomputer, it is possible to greatly reduce current consumption. Therefore, in the method according to the present invention, the capacitance of the backup capacitor can be reduced as compared with the method according to FIG.

[0014]

As described above, according to the present invention,
When notifying the upper-level monitoring device of the power-off occurrence information of the remote monitoring device in the remote monitoring system, the capacity of the capacitor for backing up the power can be reduced, and the power-off notification can be notified for a relatively long time than before. It becomes possible.

[Brief description of the drawings]

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

FIG. 2 is a system configuration diagram of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Upper monitoring apparatus 2 ... Communication interface circuit 3 ... Microcomputer 4 ... Buffer 5 ... Communication control local bus 6 ... Power supply backup area 7 ... Power supply cutoff monitoring circuit 8 ... Monitoring control circuit 9 ... Power supply panel 10 ... Backup capacitor 11 ... Communication control bus 12: Secondary power supply 13: Input power supply

Claims (1)

(57) [Claims] 1. A remote monitoring system comprising a higher-level monitoring device and a remote monitoring device, a power supply circuit for supplying power to the remote monitoring device, a power-off monitoring circuit for monitoring input power supply to the power supply circuit, A monitoring control circuit for controlling the remote monitoring device, a communication interface circuit controlled by the monitoring control circuit for communicating with a higher-level monitoring device, and electrically separating the monitoring control circuit and the communication interface circuit when input power supply interruption is detected A buffer that is connected between the communication interface circuit and the buffer, and that outputs communication disconnection information to the communication interface circuit after the power of the monitoring control circuit is turned off; the communication interface circuit and the microcomputer; A backup capacitor for backing up the power supply of the computer, The interface circuit and the my
Power backup for computer and buffer
The monitoring and control circuit in the power supply
A power-off control method, wherein the power-off control method is provided outside the top-down area and notifies the power-off information to a higher-level monitoring device after the input power of the remote monitoring device is turned off.