JPH05108102A - Controller - Google Patents

Abstract

PURPOSE:To continue the function to monitor a process variable even when a micro-processor to perform a main action as a controller becomes abnormal. CONSTITUTION:The controller is constituted of a control arithmetic part 1 constituted of a first micro-processor to perform a main action as a controller, a displaying operating part 2, a displaying control means 3 constituted of a second micro-processor to display respective kinds of operation information at the displaying operating part 2, a monitoring means 4 to monitor the action of the first micro-processor and an output means 5 to send the signal from the control arithmetic part 1 to a process side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller used for process control and the like. More specifically, it uses a full-dot display on the front surface to display various information for control operation. A controller that enables

[0002]

2. Description of the Related Art Conventionally, a single loop controller using a microprocessor has been widely put into practical use. Such a single loop controller is a distributed control system (DC
Compared to S), it has the advantages of less engineering burden and good operability. The conventional single-loop controller, as shown in Japanese Patent Publication No. 57-57721, for example, has an indicator on the front operation panel for displaying information necessary for control (process amount PV or control output MV). , The operation keys for changing the set values and the operation keys for changing the adjustment mode (automatic adjustment mode, manual adjustment mode, etc.) are arranged, and the control calculation operation as a controller and the information necessary for control are displayed. All the operations such as displaying were performed by the internal microprocessor.

[0003]

The conventional device having such a structure has a problem that all the main functions are lost when the internal microprocessor fails. Most of all, even if the microprocessor fails, the manual adjustment means is generally prepared, and the process can be controlled by the manual operation using the manual adjustment means. It can be avoided. However, if the microprocessor fails, there is a problem in that stable manual adjustment cannot be performed because the process amount and the like are not displayed. The present invention has been made in view of these points. Even if the control calculation cannot be performed due to a failure of the main microprocessor, the process amount (PV value) and the like can be continuously displayed. An object of the present invention is to provide a highly reliable controller that can be manually adjusted while monitoring the PV value.

[0004]

According to the present invention which achieves such an object, a signal related to a process amount and a control target value are respectively input, a predetermined control calculation is performed, and the calculation result is output as an operation signal. A control operation unit including a first microprocessor, a display operation unit having a display unit and a plurality of operation keys to which the functions are assigned in association with the information displayed on the display unit, and at least related to the process amount A control signal configured to include a second microprocessor, which inputs various signals including the signal and displays various operation information including the signal on the display operation unit, a monitoring means which monitors the operation of the first microprocessor, and the control. Latch means for latching the signal from the arithmetic unit, digital holding means for holding the latched signal as a digital signal, and this digital signal as an analog It converted to a an output unit including a D / A converter to be sent to the process side, if the monitoring means detects abnormal operation of the first microprocessor No.,
A controller characterized in that the latch operation of the signal from the control operation section by the latch means is prohibited, and the content of the digital holding means can be changed based on the manual operation signal from the operation key of the display operation section. is there.

[0005]

The first microprocessor performs the control operation, which is the main operation of the controller, and outputs the operation signal to the process side. The second microprocessor displays various operation information necessary for control operation and its monitoring on the display operation unit, and reflects the signal from the operation key having the function assigned by the display information (screen) on the screen information. Or transfer to the control calculation unit. The monitoring means detects an operation abnormality of the first microprocessor, and when detecting the abnormality, prohibits the latch operation of the signal from the control operation part by the latch means so that the abnormal output is not sent to the process side. To do. Even if the first microprocessor fails, the process amount is continuously monitored by the operation of the second microprocessor, and the manual operation can be performed while monitoring the process amount with the manual operation key.

[0006]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a configuration block diagram showing an embodiment of the present invention. In the figure, reference numeral 1 indicates a signal related to the process amount PV and a control target value SV, respectively.
It is a control arithmetic unit that performs a predetermined control arithmetic operation such as ID arithmetic operation and outputs the arithmetic operation result as an operation signal MV, and is composed of a first microprocessor. Reference numeral 2 denotes a display operation unit, which is provided on the front panel of the controller and is capable of displaying characters and figures in a mixed manner, and a full-dot display 21.
It has a plurality of operation keys KY1 to KY10 to which the function is assigned in association with the information displayed on the display. Here, the operation keys KY8 to KY10 function as manual operation keys for manually adjusting the operation signal MV in the manual adjustment mode. Reference numeral 3 is a display control means composed of a second microprocessor independent of the first microprocessor. The display control means 3 inputs at least a signal related to the process amount PV, and displays various operation information (screen) including the signal on the display 21 in relation to the function and the information displayed on the display 21. It has an operation key signal processing function of receiving signals from the operation keys KY1 to KY10 to which functions have been assigned, transferring them to the control calculation unit 1 and reflecting them on the display screen.

Reference numeral 4 is a monitoring means for monitoring the operation of the first microprocessor constituting the control arithmetic unit 1, and a watchdog timer is used, for example. An output unit 5 outputs the operation signal MV to the process side. This output means is a latch means 51 for latching the operation signal MV from the control calculation section 1, and a signal latched by this latch means 51 is held as a digital signal and its contents can be changed, for example, an up / down counter. And a D / A converter 53 for converting a digital signal into an analog signal and sending it to the process side.
It is configured to include. Reference numeral 6 is a manual backup means used when both the first microprocessor and the second microprocessor have failed. This manual backup means has a potentiometer 61 that outputs an adjustable backup signal, and a scale 62 that indicates the approximate value of the backup signal output from this potentiometer. Reference numeral 7 is a manual changeover switch, which is configured to select either the operation signal from the output means 5 or the signal from the manual backup means 6 and output it to the process side.
When the operation abnormality of the first microprocessor is detected, the monitoring means 4 gives a signal indicating the abnormality detection to the latch means 51 and prohibits the latch operation of the signal from the control operation part 1. Also, the digital signal holding means 5
The contents of 2 are the operation keys KY8 to KY10 of the display operation unit 2.
It is configured so that it can be changed based on the signal from.

FIG. 2 is a plan view showing the front surface of the instrument of the controller, and here shows the case where the display control means 3 displays an operation screen for performing a control operation on the display 21. In the operation screen displayed on the display 21, the measured value PV is displayed in the vicinity of the center of the screen as a bar graph BG1 that expands and contracts in the vertical direction according to the value, and the control output is displayed on the lower side of the screen. The bar graph BG2 is displayed so that the MV expands and contracts in the left-right direction according to the value. In the bar graph showing the control output MV, the sign "C" on the left side means that the control output MV becomes smaller and the valve is closed, for example, and the sign "O" on the right side indicates that the valve is It means to open. Further, the set value SV is a bar graph BG1 showing the measured value PV.
The triangular indication mark MK is displayed in association with the same scale SL. The position of the instruction mark moves up and down along the scale SL as the set value is changed (operation of the operation keys KY4 and KY5). This type of display simulates the front panel surface (instrument diagram) of a conventional controller, so that even an operator familiar with the conventional controller can monitor and operate the control operation status without feeling discomfort. I am doing it. In the operation screen, PV value, SV
Values and MV values are also displayed as digital values.
Also, at the top of the screen, the tag number (TIC-1000) attached to the control loop that this controller is in charge of.
Is displayed. According to such an operation screen, when monitoring away from the controller, PV value, which is the main data,
SV value and MV value can be recognized by analog display,
When approaching the controller, the specific numerical value of each data can be recognized on the digital display.

The operation keys K1 to K3 are assigned a function for switching the operation mode, and the operation keys K1.
When 1 is pressed, it becomes the upper computer operation mode in which the set value SV is given from the upper computer to perform the control operation, and when the operation key K2 is pressed, it becomes the automatic operation mode in which this controller alone performs the control operation, When key K3 is pressed, control output MV
It becomes a manual adjustment mode that can be manually adjusted. The operation keys K4 and K5 are assigned a function for setting the set value SV. By pressing these operation keys, the set value SV is set.
Can be changed. This set value can be recognized as the position of the set value mark MK on the display 21. Operation key K
Nos. 8 to K10 are assigned with a function for changing the control output MV when switched to the manual adjustment mode.
That is, in the state where it is switched to the manual adjustment mode,
The signals from these operation keys are given to the digital signal holding means 52. Here, the content of the digital holding means 52 is decreased by pressing the operation key K8 (the control output MV is decreased), and the control output MV can be increased by pressing the operation key K10. Further, by simultaneously pressing the operation key K8 or K10 and the operation key (acceleration key) K9, the speed of decrease or increase of the control output MV can be increased to promptly change to the desired control output value.

The operation of the apparatus thus configured will be described below. The control calculation unit 1 configured by the first microprocessor, based on the signal input thereto,
Performs control calculation operation as a controller. FIG. 3 is a flowchart showing an outline of the operation performed by the first microprocessor. Process amount PV and SV operation key KY
4, data such as set value SV set by KY5 is collected, necessary signal processing (for example, square root calculation, broken line calculation, etc.) is performed, and for example, PID control calculation is performed on the deviation between PV and SV, and if necessary. Calculations for tuning the PID calculation constants are performed. After that, output processing (for example, limiter processing) is performed on the calculation result, and the result is output to the process side through the output means 5 and the changeover switch 7. Second
Display control means 3 composed of a microprocessor
Performs screen display on the display 21 and signal processing operation from operation keys. FIG. 4 is a flowchart showing an outline of the operation performed by the second microprocessor. The process amount PV displayed on the display 21 and various data handled by the control calculation unit 1 are collected, and the process amount PV and the set value S are collected.
V is displayed on the display 21 as an operation screen as shown in FIG. 2, for example. In addition, when various operation keys are pressed,
Signal processing based on the function assigned to the operation key is performed, reflected in the information displayed on the screen, or transmitted to the control calculation unit 1. For example, in the operation screen shown in FIG. 2, when an on / off signal is received from the SV operation keys KY4 and KY5, the mark M indicating the set value SV is displayed.
K is moved and displayed, and an operation of giving the set value SV indicated by the mark MK to the control calculation unit 1 is performed. In the manual adjustment mode, signals from the manual operation keys KY8 to KY10 are given to the digital holding means 52, and an operation signal for manual adjustment is output to the process side.

When the first microprocessor, which is performing the control operation, which is the main operation of the controller, fails from the state where the normal operation of the controller is performed, the monitoring means 4 operates. Detect the failure. When the monitoring means 4 detects the failure of the first microprocessor, the latch means 51 and the fail display portion FL are provided with a signal indicating this. As a result, the fail display portion FL lights up. Further, the latch means 51 receives the abnormality detection signal from the monitoring means 4 and prohibits the latch operation of the signal from the control calculation section 1. When the latch operation is prohibited,
The digital holding means 52 holds the value immediately before the failure. In this way, even if the first microprocessor fails, no abnormal signal is output to the process side. Even if the first microprocessor fails, the second microprocessor is configured independently of the first microprocessor, so the process amount PV and the set value S
The display operation of V and the operation signal MV is continuously performed, and these values can be normally monitored. In this state, the operation key KY3 is pressed to enter the manual adjustment mode, and the manual operation keys KY8 to KY10 can be used to change the contents of the digital holding means 52 while monitoring the behavior of the process amount PV to perform the manual adjustment. Since such a manual operation can be performed while monitoring the PV value, it can be stably and accurately performed.

When both the first and second microprocessors have failed, the switch 7 is manually driven to select the signal from the backup means 6, and the manual backup signal M from the backup means 6 is selected.
Vb can be sent to the process side for manual backup. When the first and second microprocessors have failed and are in the backup state, the process amount PV cannot be monitored, but the approximate value of the operation signal output to the process side can be estimated by the scale 62. In the above embodiment, the display 21 displays the operation screen used for the controlled operation.
On this display, by a command from the operation key, for example, a trend graph showing a past transition of the process amount PV, an alarm screen showing alarm information, a tuning screen for setting various parameters used by the control calculation unit 1, It is possible to display an engineering screen for setting the environmental level such as the type of various signals handled by the controller and the type of communication. Further, although the controller that handles one process amount PV is illustrated here, a controller that inputs two or more process amounts and performs cascade adjustment or selector adjustment may be used.

[0013]

As described in detail above, according to the present invention, the microprocessor constituting the control operation unit and the microprocessor for performing the display control are independent of each other. Even if the microprocessor performing the main operation becomes abnormal, at least the function of monitoring the process amount PV can be continued. Therefore, the manual adjustment can be reliably performed while monitoring the PV, and a highly reliable controller can be provided.

[Brief description of drawings]

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

FIG. 2 is a plan view showing the instrument front surface of the controller.

FIG. 3 is a flowchart showing an outline of an operation performed by a first microprocessor.

FIG. 4 is a flowchart showing an outline of an operation performed by a second microprocessor.

[Explanation of symbols]

 1 Control Calculation Unit (First Microprocessor) 2 Display Operation Unit 3 Display Control Means (Second Microprocessor) 4 Monitoring Means 5 Output Means 6 Backup Means 7 Manual Changeover Switch 51 Latch Means 52 Digital Holding Means 53 D / A converter

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Yokomori 2-3-9 Nakamachi, Musashino-shi, Tokyo Yokogawa Electric Co., Ltd.

Claims (2)

[Claims] 1. A control arithmetic unit composed of a first microprocessor for inputting a signal related to a process amount and a control target value, performing a predetermined control arithmetic operation, and outputting the arithmetic operation result as an operation signal, and a display device. And a display operation unit having a plurality of operation keys to which the functions are assigned in association with the information displayed on the display unit, and a signal relating to at least the process amount is input, and various operation information including the signal is input to the A display control unit configured by a second microprocessor for displaying on the display operation unit, a monitoring unit for monitoring the operation of the first microprocessor, a latch unit for latching a signal from the control operation unit, and a latched signal Digital holding means for holding a digital signal, D / A converter for converting this digital signal into an analog signal and sending it to the process side When the monitoring means detects an abnormal operation of the first microprocessor, the latching operation of the signal from the control operation section by the latch means is prohibited, and the operation key from the operation key of the display operation section is provided. A controller characterized in that the contents of the digital holding means can be changed based on a manual operation signal. 2. A manual backup means, the output of which is manually adjustable and which outputs a manual backup signal of a position type output format, and a signal from the output means and a manual backup signal from the manual backup means are selected. 2. The controller according to claim 1, further comprising a manual change-over switch for sending it out to the process side.