JPS62229301A - Runaway detecting device for control system using cpu - Google Patents

Abstract

PURPOSE:To prevent the CPU runaway by using the interruption given to a pulse generating program which produces pulse signals in a prescribed cycle to carry out a working program and resetting the system in case the pulse signals are not produced for a prescribed period. CONSTITUTION:A working program 2a which performs the load control of a material tester T in response to the outputs of various detectors is written to a ROM 2 together with a pulse generating program 2b which produces pulse signals through a pulse monitor input/output port 4 in a prescribed cycle. A CPU 1 usually carries out the program 2b and the program 2a is executed as necessary with generation of an interruption signal. In case the CPU 1 has a runaway and does not carry out the program in a correct procedure, no pulse signal is supplied to a pulse check circuit 6 from the port 4. Then a system is reset by the output of the circuit 6 and the CPU runaway is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a device for detecting CPU runaway in a control system using a CPU, such as a material testing machine.

<Conventional technology and its problems> In recent years, the number of materials testing machines that use microcomputers to control them has been increasing. If a disturbance such as severe noise occurs during the control of such a test machine, the CPU of the microcomputer may run out of control.

In such a case, there is a problem in that accurate test results cannot be obtained or it becomes impossible to continue the test, resulting in a waste of valuable samples.

An object of the present invention is to provide a CPU that can automatically detect CPU runaway and prevent the above problems from occurring.
An object of the present invention is to provide a runaway detection device for a control system using the U.

Means for solving the above problems〉 The configuration for achieving the above object is shown in the first example drawing.
To explain with reference to the drawings, the present invention is applicable to a device that controls a system such as a material testing machine T by executing a work program 2a in a ROMZ by a CPU.
A pulse generation program 2b for outputting a pulse signal from a predetermined port (input/output port for pulse monitoring) 4 at a predetermined period is written in the program. A pulse check circuit 6 is connected to this port 4, which generates an output when there is no pulse input for a preset period of time.

The CPU is configured to execute a pulse generation program 2b, and execute the work program 2a by interrupting the pulse generation program 2b.

The control system is configured to be reset by the output of the pulse check circuit 6.

<Operation> During normal system operation, work program 2a
is executed by interrupt processing and returns to the pulse generation program 2b. Therefore, at this time, a pulse is generated within a certain time from ports 1-4. CP due to noise etc.
When the UI starts running out of control, it does not return to the pulse generation program 2b, and as a result, generation of pulses from ports 1-4 is delayed. At this time, the pulse check circuit 6 automatically generates an output to reset the system, so the system is stopped at the initial stage of runaway.

<Example> Embodiments of the present invention will be described below based on the drawings.

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

Microcomputer is CPUI, ROM2゜RAM3
, and a plurality of input/output ports 4, 5, . . . 5, one of which is used as a pulse monitoring input/output port 4 connected to a pulse check circuit 6, which will be described later. In addition, other input/output ports 5...5 may be connected to various detectors of the material testing machine T via an A-D converter, or a load waveform generator that generates load waves for the material testing machine T, etc. connected to.

In addition to a work program 2a for controlling the load on the material testing machine T in response to outputs from various detectors, a pulse generation program 2b whose flowchart is shown in FIG. 2 is written in the ROM 2. ing. In this pulse generation program 2b, as shown in FIG. 2, a pulse signal is generated at a predetermined period T, and its output is supplied to the check circuit 6 via the pulse monitoring input/output port 4.

The CPUI normally executes this pulse generation program 2b, and the work program 2a is configured to be executed when necessary by generating an interrupt signal. Also,
This work program 2a is designed to immediately return to the pulse generation program 2b after completing the required routine.

The pulse check circuit 6 is a circuit that outputs an output when no pulse signal is input for a preset period of time or more, and can be configured by, for example, a timer that is reset by an input pulse signal. The output of this pulse check circuit 6 is configured to be input to the microcomputer through the pulse monitoring input/output port 4, and the microcomputer is configured to be forcibly reset by this signal.

According to the above-described embodiment of the present invention, when the system is operating normally, the pulse generation program 2b is immediately returned to after execution of the work program 2a, so that a regular pulse signal is always input to the pulse check circuit 6. and no output is generated.

However, if the CPU goes out of control due to severe noise or the like and the program is no longer executed in the correct procedure, the work program 2a will not return to the pulse generation program 2b, and as a result, the pulse signal will not be input to the pulse check circuit 6, and the output will be This will cause the system to automatically reset.

In addition, although the above embodiment describes the case where the present invention is applied to a control device for a material testing machine, the present invention is not limited to this and can of course be widely applied to a control system using a CPU. .

Effect> As explained above, according to the present invention, when the CPU 1 goes out of control due to disturbance etc., it is automatically reset by the output of the pulse check circuit 6. It is possible to prevent things from going to waste.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a flowchart showing a pulse generation program written in the ROM 2. In FIG. 1...CPU 2...ROM 4...Input/output capotro for pulse monitoring...Pulse check circuit

Claims (1)

[Claims] In a device that controls the system by executing a work program in the ROM by the CPU, there is a pulse generation program that is written in the ROM and outputs a pulse signal from a predetermined port at a predetermined cycle, and a pulse generation program that is connected to the port and set in advance. a pulse check circuit that generates an output when the pulse signal is not input for a period of time or more, and the CPU is configured to execute the work program by interrupting the pulse generation program; A runaway detection device for a control system using a CPU, characterized in that the control system can be reset by the output of a pulse check circuit.