JPS58184603A - Process controller - Google Patents

Abstract

PURPOSE:To reduce the frequency of data transmission and a load, to eliminate the need for the intervention of operators in case of a shutdown of a host device (computer), and to obtain a device which is controllable in an optimum state by providing a subordinate device with a memory for storing data on the host device and performing process control. CONSTITUTION:The subordinate device is provided with a timer and the memory for storing the data on the host device and the process control is performed on the basis of the memory contents and a timer signal. For example, the host device 10 outputs command value data, etc., found on the basis of the current process value to the subordinate device 30 through a transmission part 20 together with a timer reset signal. Then, data on the command value, etc., inputted from the host device 10 is stored in the memory 32 and the timer 31 is reset by the timer reset signal to clock time. An arithmetic control part 33 performs arithmetic for finding the command value, etc., on the basis of the output signals of the memory 32 and timer 31 and the command value, etc., is used to sent out an operation signal for the process control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention is directed to, for example, 8CC (Sup@rvisory C
The present invention relates to a process control device that is useful when applied to control, etc., and particularly relates to a process control device that allows a lower-level device to continue control for a certain period of time even if a higher-level device goes down.

[Technical background of the invention and its problems]

In general, %l1CC control is an online closed loop in which a computer, which is a higher-level device, calculates target values every moment and sets them in a controller, which is a lower-level device, for control. It is control.

Generally, this type of device transmits target value data, etc. from a higher-level device to a lower-level device at regular intervals or when the target value changes due to calculations. There is. In this way, the higher-level device has fine control over the lower-level device regarding the target value data, etc. desired by the lower-level device, and the transmission timing of that data. Therefore, from the perspective of the lower-level equipment, all lower-level equipment uses a control method that depends on the upper-level equipment. However, in the process control equipment described above, if the upper-level equipment goes down due to an abnormality in the upper-level equipment or transmission line, for example, In this case, it is not possible to determine the target value of the process, and in the case of process control where the target value and the like must be changed from time to time, human intervention is forced. In addition, in the case of manual operations, only the "pa", "qua", and "f" operations can be performed in a predetermined manner, making it impossible to perform optimal control for the process. Especially in the case of SCC control,
The higher-level computer constantly calculates target values, etc., and if there is a change in the value, it transmits the changed value to the lower-level device, which has the drawback of increasing the load.

[Purpose of the invention]

The present invention was developed in consideration of the above-mentioned circumstances, and aims to reduce the frequency of data transmission of the host device as much as possible to reduce the load. Continuous PcIK under optimal conditions
The purpose of the present invention is to provide a process control device that controls the process.

[Summary of the invention]

In the present invention, a higher-level device calculates future target value data from current values, and a lower-level device is provided with a memory for storing the data of the higher-level device and a timer if necessary. This is a process control device that attempts to achieve the above objectives by performing its control based on the content and tights signals.

[Embodiments of the invention]

Next, regarding one embodiment of the present invention, FIG. 1 and 1112
This will be explained with reference to the figures. In the same figure, the xofi host device uses an SCC computer in the case of SCC control, for example.Normally, in the case of process control, the values to be transmitted to the lower level can often be determined in the future. Focusing on this point, the host device 10 calculates target value data, etc. for a certain period in the future based on the current process value as a function of time, and the calculated data is shown in FIG. 2 together with the timer reset signal. Output as a broken line pattern.

20 converts data from the host device 10 into a signal suitable for transmission and outputs the signal 1;

It is a transmitter. Jo is a lower-level device, and normally corresponds to a controller/toller. This lower-level device 10 includes a timer S1 that resets and ticks time in response to a timer reset signal from the lower-level device 10, a memory 12 that stores data such as a target value converted into a polygonal line, and a memory 12 for storing data such as a target value converted into a polygonal line. It is composed of an arithmetic control 11sJJ that performs arithmetic operations based on the outputs of IJJJ and obtains operation outputs.

The memory 32 is, for example, a RAM@0, and includes a plurality of memory elements JJ-1, J2-j-, etc., and these memory elements xx-x, xx-x-, K are time data t@a tl. e"' and target value day 18V * *
8Vt *... etc. are stored.

Next, the operation of the device configured as above will be explained.

First, the host device 10 calculates target value data for a certain period in the future from the current value as a function of time.
Each time data and target value data obtained by calculation for each time are sequentially transmitted to the lower-level device 80. Therefore, nine coordinate data is sent from the host device 10 in a broken line pattern as shown in Figure 2.

At this time, timer reset signal 4 is sent.

On the other hand, in the lower device SO, when receiving the timer signal, the tie ffjf uses that signal to execute the timer signal.
From that point on, the time is counted again and a time signal is output. In addition, the lower device 10 transmits the data transmitted from the higher device 10 to each time data t, tl, . . . and target value data av, , IIVi, . . . [Sequentially stored in the corresponding memory elements J J -1, J 1-1 m, . . .

After storing data 1 as described above, the arithmetic control unit 11
calculates a target value etc. using the time signal of the timer 11 and the contents of the memory J2, and outputs an operation signal for controlling the process using the target value. Note that when changing the data of the lower-level device JO, if the higher-level device 10 transmits the above-mentioned data to the lower-level device 10 within a certain period,
The contents of memory 12 are rewritten.

Next, 3812 is a diagram showing another embodiment of the present invention. In the figure, 41 is a heating furnace, 42. ...is--2,
41 is a conveyance path, 44m, 44be44e are objects to be conveyed. That is, in this apparatus, in the continuous heating furnace 41, the objects 44*, 44b, 44 that are commonly transported in the furnace 41Yt are
mK, if it is necessary to change the setting fuze of the furnace temperature, the transported object 441° 44b passing through the heating furnace 4Jt in advance,
44. If the scheduled order of types is fixed, the upper device 1
o is a conveyed object 44a passing through the furnace.

The horizontal axis of the upper broken line/f turn of the sequence numbers 44b and 44. and the corresponding furnace temperature set value t are plotted on the vertical axis and transmitted to the lower-order device 30. In this case, the horizontal axis does not necessarily represent the transported object 44a.

44b, . . . , and may transmit numerical data only on the horizontal axis corresponding to the points where the furnace temperature setting value on the vertical axis changes.

The higher-level device 10 collects the data of the line graph drawn as described above and sends it to the lower-level device J.

Transmit to. On the lower unit SO side, the number of objects to be transported entering the furnace is t count, and the objects to be transported currently entering the furnace are 44 a.
After determining the necessary furnace temperature setting value by checking with the broken line darts, an O furnace temperature operation signal is obtained for control.

Note that the present invention is not limited to the above embodiments. Generally, a digital controller is used as the lower-order device 3o, but an analog controller may also be used. In this case, the vertical axis indicates, for example, the furnace temperature. The set value tube analog value may not be a value corresponding to the loader amount to be set, but may be data that is displayed at a status, and the present invention can be implemented with various modifications without departing from the gist thereof. .

〔Effect of the invention〕

As described in detail above, according to the present invention, data for a certain period in the future can be set in a series of broken lines based on the current point in time, or only when it is necessary to change data
Since only the I" turn or necessary data is set, the frequency of data transmission is greatly reduced, and this also contributes to reducing the load on the host device. Furthermore, if the higher-level device goes down, the lower-level device only has to execute the process according to the memory contents, so it is possible to provide a process control device that can continuously control the process tube in an optimal state without human intervention.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a process control device according to the present invention, FIG. 2 is a diagram explaining a data transmission type II, and FIG. 3 is a configuration diagram explaining the present invention in detail. . DESCRIPTION OF SYMBOLS 10... Upper device, 20... Transmitter, JO... Lower device, 31... Timer, I j-... Memory, J3
- Arithmetic control unit. Applicant's agent Takehiko Suzue Figure 3 41

Claims (1)

[Claims] In a process control device in which a lower-level device controls a process based on data from a higher-level device, means for allowing the higher-level device to upload necessary data over a certain period of time in the future based on process values at a time point; means for transmitting the data for a certain period obtained by the means as a polygonal line pattern; and means for controlling the process until the data is changed based on the theta transmitted by this means. A process control device comprising: