JPS6162947A - Method for preventing runaway of computer - Google Patents

Abstract

PURPOSE:To prevent efficiently the runaway of a computer b providing a step, which resets an unprogrammable timer in a part of a program loop, resetting the timer each time the step passes and acting a monitoring means at time-up. CONSTITUTION:A computer monitoring device 30, which has an alarm device 28 is connected o a CPU 12 which is supplied with a signal from an input device 16. A timer 26 is connected with an output interface 22 between the CPU 12 and an output device 24 to supply a time-up signal top the device 30. The timer 26 is set to as not to be controlled by a computer program and to be reset by a reset signal from the CPU 12. At the time-up of the timer 26, the monitoring device 30 operates the alarm device 28 by the resulted signal, and resets and terminates te action of the CPU 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for preventing runaway of a computer, and more particularly to a method for preventing runaway of a computer that operates by a control program that forms a loop.

(Prior art and its problems) When various types of equipment are controlled by a computer, the computer may run out of control and become uncontrollable due to sensor abnormalities, external noise, operational errors, or programming errors. There is a risk of an accident occurring due to operation.

Therefore, the main object of the present invention is to provide a method that can effectively prevent such computer runaway.

(Means for Solving the Problems) This invention provides a step for resetting a timer that is not managed by the program in part G of the program loop, and each time the program passes through the step, a reset signal is sent to the timer. When that timer times up,
This is a method to prevent a computer from running out of control, assuming that an abnormality has occurred in the computer and causing the computer to perform processes such as resetting, stopping, and issuing an alarm.

(Operation) Normally, the timer is reset every time it passes through the control loop, so the timer never times up. If some abnormality occurs during the processing routine, the reset step is not executed, so the timer times out without being reset. The expiration of this timer will reset or stop computer operation and/or issue an alarm.

(Effects of the Invention) According to this invention, when a timer that is not managed by a computer program times up, the operation of the computer is automatically stopped, so it is very easy and reliable to prevent the computer from running out of control. be able to.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Embodiment) FIG. 1 is a flow diagram showing an embodiment of the present invention. This control program has a step for resetting the timer, as part of it, for example in the first step S1. Thereafter, the processing routine shown in step S3 is entered.

Each time the computer executes this step S1, the timer is reset. This timer is not managed by a computer program, and when reset, the timer stops its operation and starts counting again from there.

If no abnormality occurs in the processing routine shown in step S3, the program executes step S1 again and resets the timer. Therefore, as long as such normal operation is repeated, no time-up signal will be obtained from the timer.

However, if some abnormality occurs during the execution of the processing routine shown in step S3, for example due to sensor abnormality, external noise, operational error, or program flaw, the computer will execute step S1 again.
will never be executed. Therefore, the timer is not reset and eventually outputs a time-up signal. Therefore, in response to this time-up signal, the operation of the computer may be reset or stopped and/or an alarm may be issued.

The embodiment shown in FIG. 1 can be realized by a configuration as shown in FIG.

In FIG. 2, a CPU 12 is provided, and this CPU
2 is supplied with a signal from an input device 16 such as a keyboard or a sensor via an input interface 14. The CPU 2 includes a ROM 1B for storing control programs as shown in Figure 1, and an RA for storing data necessary for processing routines.
M20 is connected. The CPU 2 further outputs information to an output device 24 such as a printer or a display through an output ink face 22, and also controls each control unit (
(not shown).

A timer 26 is connected to the output interface 22 . This timer 26 is not controlled or managed by a computer program, and may be constituted by a conventional alarm clock circuit, a retriggerable monostable multivibrator, or the like. This timer 26 is reset (retriggered) by a reset signal given from the CPU 12 via the output interface 22 in response to the execution of step S1 in FIG.

A computer monitoring device 30 for resetting or stopping the operation of the CPU 12 is connected to the timer 26 . The computer monitoring device 30 includes, for example, a multivib break or relay circuit, and a visual and/or audible alarm device 28 is further connected to this device 30.

When normal operation is repeated, the timer 26 is reset by a set signal from the CPU 12 in step S1 in FIG. 1, and the timer 26 never times up. If an abnormality occurs and the timer is not reset, the timer will eventually time up and this time-up signal will be given to the computer monitoring device 30.

Therefore, a drive signal is given from the monitoring device 30 to the alarm device 2, and the operation of the CPU 12 is set or stopped in response to the signal from the monitoring device 30. or abnormal operation can be prevented.

Here, as the setting time of the timer 26, for example, the first
It will be readily understood that a time slightly longer than the longest time required to execute the processing routine leading to step S3 in the figure must be selected.

FIG. 3 is a flow diagram showing another embodiment of the present invention.

This embodiment shows a case where the present invention is applied to a control program loop having a plurality of processing routines.

Steps Sll and S13 in FIG. 3 are the same as steps S1 and S3 in FIG. 1 above. After executing the processing routine of step 313, it is determined in step S15 whether or not another processing is necessary.

If it is not necessary, return to the previous step Sll, and if necessary, in the next step 317, the timer 26 (second
(Fig.) is set again. Then, the next step S19
execute another processing routine.

Also in FIG. 3, if a runaway or abnormal operation of the computer occurs, steps Sll and/or S1
7 is unlikely to be executed again, the timer will expire, and accordingly, special control in the event of an abnormality, that is, resetting or stopping the computer operation (processing such as issuing an alarm) Do the following.

[Brief explanation of drawings]

FIG. 1 is a flow diagram showing one embodiment of the present invention. FIG. 2 is a block diagram showing an example of a circuit configuration in which the present invention can be implemented. FIG. 3 is a flow diagram showing another embodiment of the present invention. In the figure, 12 indicates a CPU, 26 a timer, 2B an alarm device, and 30 a reset circuit. Patent applicant Kubota Iron Works Co., Ltd. Agent Patent attorney Oka 1) Kei Zen (and 1 other person) Figure 1 Figure 3 18'20

Claims (1)

[Claims] 1. A step for resetting a timer that is not managed by this program is provided in a part of the program loop, and a monitoring means for controlling the operation of the computer is provided, and the timer is reset each time the program passes through that step. and controlling the operation of the computer by the monitoring means in response to the timer not being reset again within the set time and timing up. 2. the monitoring means resets the computer;
A method for preventing runaway of a computer according to claim 1. 3. The computer runaway prevention method according to claim 1, wherein the monitoring means stops operation of the computer. 4. A computer runaway prevention method according to any one of claims 1 to 3, wherein the monitoring means issues an alarm.