JPH0363801A - Control mechanism for controller - 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 (Field of Application on M Beams) The present invention controls a g4m meter, especially the set value in its control means, by inputting it as an analog signal from a host device such as a personal computer. This relates to the control WJ mechanism of the controller.

(Prior art) In the w4-section cylinder needle, which is controlled by inputting the set value in the control means as an analog signal from a host control device such as a personal computer, failure of the host controller, abnormal power supply, or signal connection Even if a normal set value signal cannot be input due to a defect, etc., the normal II till is jIvc
Conventionally, for example, as shown in Fig. 3, a high-level system such as a personal computer, etc.
A changeover switch e is provided on the manual input path d for the set value signal from the control means C1 to the input section for the set value signal.

This changeover switch e is configured to be switched by a switching command means f operated by an abnormality occurrence signal from the upper control device 2, and when a failure or power abnormality etc. occurs in the upper control device a of the upper control device 2, the changeover switch e is Before the abnormality occurs, the changeover switch e is switched via the switching command means f to cut off the set value signal input path d, and control is continued based on the set value that had been set in the control means C until then. .

For example, as shown in FIG. 4(a), the upper 1t11 device a
In this case, if the abnormality occurrence signal is normally issued prior to the abnormal output of the set value signal, after the changeover switch e is switched by this abnormality occurrence signal and the set value signal input path d is cut off. Since the set value signal becomes abnormal,
This abnormal set value signal is not input to the III1 means C, and therefore, this control means C can continue tIIIm normally based on the set value set up to that point.

(Problem to be Solved by the Invention) However, as shown in FIG. If an abnormal set value signal is generated in the set value signal input path d mentioned above,
is not shut off in time, and therefore an abnormal set value signal is input to the control means C, which poses a risk of causing the control loop q to run out of control, and the processes of which this control loop is a component to run out of control. In the figure, the symbol "i" is a controller, "i" is a flow rate sensor, and "j" is a flow control valve.

The present invention aims to solve this problem.

(Means and Examples for Solving the Problems) The aforementioned yI
Means for solving the problem will be explained with reference to FIG. 1 showing an embodiment of the mechanism described below.
The structure is: In 1g meter 1, setting i from upper side wJm device 2
A changeover switch 6 is provided in the set value signal input path 5 from the signal input section 3 to the control means 4, and the changeover switch 6 is switched by the change command means 7, and the setting f[of the signal input path 5] A signal delay means 8 is provided on the side of the upper control 2II equipment 2 than the changeover switch 6, and the switching command means 7 is operated by an abnormality occurrence signal from the higher order control equipment 2, and the changeover switch 6 causes the setting 1 signal input path to be set. This is a mechanism that shuts off 5.

Another control mechanism of the present invention will be explained with reference to the embodiment shown in FIG. [1] A change-over switch 6 is provided in the set-value signal input path 5 from the input section 3 for the set-value signal from the device 2 to the lltll means 4, and the change-over switch 6 is switched by the change-over command means 7. A signal 54 delay means 8 is provided in the value signal input path 5 on the side of the higher-order control equipment 2 than the changeover switch 6, and the switching command means 7 is arranged on the side higher than the signal delay means 8.
11 The changeover switch 6 is operated by an abnormality detection signal from the abnormality detection means 9 that detects an abnormality in the set value signal on the equipment 2 side or an abnormality occurrence signal from the upper TSVS equipment 2.
This is a mechanism for cutting off the set value signal input path 5.

(Operations and Examples) In the above configuration, when an abnormality such as a failure or power abnormality occurs in the host control device 2 and this generates an abnormality occurrence signal, the switching command means 7 issues a switching command based on this signal j. is emitted to operate the changeover switch 6 and cut off the set value signal input path 5.

On the other hand, when an abnormal setting value signal is output due to the occurrence of the abnormality in the upper control R unit 2, this abnormal setting value signal is transmitted from the input section 3 via the setting value signal input path 5 to the signal delay means 8. is input to the selector switch 6 after being delayed for a predetermined time.
There's more than enough. In this way, an abnormal set value signal is detected by the upper control rIA.
After being output from the device 2, it is delayed and reaches the selector switch 6 after a predetermined period of time has elapsed, so that, for example, as shown in Figure 2 (a), the abnormality signal and the abnormality signal for the set value are emitted at the same time. Even in such a case, the setting ft1 signal input path 5 can be reliably cut off by operating the changeover switch 6 during the predetermined time due to the delay, thereby preventing an abnormal setting signal from being input to the control means 4. This can be reliably prevented.

Next, due to an abnormality occurring in the signal connection in the upper tiIJ'gA machine S2 related to the set value signal or in the signal connection for the set value signal from here to the input section 3, for example, the second
As shown in Figure (b), when an abnormal set value signal occurs such as a sudden change in the set value signal without an abnormality occurrence signal being generated, this abnormal set value signal is transmitted to the delay means as described above. At the same time as the signal is input to 8, it is also input to abnormality detection means 9, and this abnormality detection means 9 issues an abnormality detection signal. In response to this abnormality detection signal, the switching command means 7 issues a switching command, operates the changeover switch 6, and changes the setting-signal input path 5 to '1jIIWi. Similarly to the above, the setting value signal input path 5 can be interrupted by the abnormality detection signal within the predetermined delay time by the signal delay means 8 described above, and therefore, the abnormality without the abnormality occurrence signal of the host control device 2 can be interrupted. What settings lol
It is also possible to reliably prevent one signal from being input to the control means 4.

The aforementioned signal@delay means 8 can be easily constituted by a delay circuit using appropriate elements, and the abnormality detection means 9 can be easily constituted by detecting sudden changes in the signal using a differentiating circuit. can do.

Furthermore, the abnormality occurrence detection means in the host control 11 equipment 2 can be appropriately constructed using a well-known watchdog timer or the like. In the figure, reference numeral 10 is a flow rate sensor, 11 is a flow flat control valve, and 12 is a fluid flow path.

(Effects of the Invention) As described above, the present invention provides a controller in which the settings f from the upper control 11 equipment are
Since the signal delay means is provided on the 111 equipment side, even if the abnormality occurrence signal of the upper control device A and the abnormality signal of the set value are issued at the same time, the changeover switch will be activated within a predetermined time due to the delay of the set value signal. It is possible to reliably cut off the setting It1 signal input path by operating t), thereby reliably preventing abnormal set value signals from being input to the control means, and thus preventing abnormalities in the upper control equipment. When it occurs,
This has the effect that control can be continued normally based on the set value that has been set up to that point in the control means.

Further, the present invention operates the switching command means of the changeover switch by an abnormality detection signal of an abnormality detection means for detecting an abnormality of a set value signal in a device higher than the signal delay means. Since the configuration is such that the set value signal manual path is cut off by a changeover switch, even if an abnormality occurs such as a sudden change in the set value signal without an abnormality occurrence signal being issued from the upper control 11 equipment, such abnormal settings can be prevented. This has the effect that it is possible to reliably prevent the value signal from being input to the l1il control means, and as described above, it is possible to continue normal control based on the set value that has been set up to that point. .

[Brief explanation of drawings]

FIG. 1 is a system explanatory diagram corresponding to an embodiment of the present invention, FIGS. 2(a) and (b) are time charts showing the operation of the present invention, and FIG. 3 is a system explanatory diagram corresponding to a conventional example. Figure 4 (
(a) and (b) are time charts showing the operation of the conventional example. Code 1...Controller, 2...Upper control*B, 3...
Input section, 4...l111! I1 stage, 5... Set value signal input path, 6... Changeover switch, 7... Switching command means, 8... Signal delay means, 9... Abnormality detection means, 1o... Flow rate Sensor, 11...8i quantity control valve, 1
2...Fluid channel.

Claims (2)

[Claims] (1) In the controller, a changeover switch is provided in the setpoint signal input path from the input part of the setpoint signal from the host control device to the control means, and the changeover switch is configured to be switched by the changeover command means, A signal delay means is provided on the higher-level control device side of the changeover switch in the set value signal input path, and the switching command means is activated by an abnormality occurrence signal from the higher-level control device to input the set value signal through the changeover switch. A controller control mechanism characterized by having a configuration in which a path is blocked. (2) In the controller, a changeover switch is provided in the setpoint signal input path from the input part of the setpoint signal from the host control device to the control means, and the changeover switch is configured to be switched by the changeover command means, A signal delay means is provided in the set value signal input path on a higher level control equipment side than the changeover switch, and the switching command means detects an abnormality in the set value signal on the higher level control equipment side than the signal delay means. A control mechanism for a controller, characterized in that the controller is configured to be operated by an abnormality detection signal of the abnormality detection means or an abnormality occurrence signal from the upper control device, and to shut off a set value signal input path by a changeover switch.