JP2875677B2 - Temperature instrumentation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature instrumentation system for controlling, for example, a plurality of zones in a furnace so as to have a uniform temperature, and more particularly, to a method for realizing fine-grained control. It will improve.

[0002]

2. Description of the Related Art When the inside of a furnace or the like is controlled to have a uniform temperature, the inside of the furnace may be divided into a plurality of zones, and a temperature controller may be installed in each of the zones. For example, as shown in FIG. 2, the constant value control type controllers SC1 and SC2 are connected to the program controller PC via the signal line L, and the program pattern set values are transmitted from the program controller PC to the constant value control type controllers SC1 and SC2. To be controlled. That is, the program controller PC and the fixed value control type controller S
C1 and SC2 are in charge of controlling the temperature of different zones in the furnace, respectively. The program controller PC controls the temperature in accordance with a program pattern set value SP having a gradient that changes with time as shown in the example of FIG. 3, and sends this value SP to a signal line L. The fixed value control type controllers SC1 and SC2 receive the program pattern set value SP and perform a temperature control operation according to the value SP. FIG. 4 shows a fixed value control type controller SC1 or SC.
FIG. 7 is a diagram illustrating a change state of a set value SP in a second example.

[0003]

In the above-mentioned conventional temperature instrumentation system, the signal line L connecting the program controller PC and the fixed value control type controllers SC1 and SC2 is an analog signal line. The program pattern set value SP has been analog-transmitted as a current signal of 4 to 20 mA, a voltage signal of 1 to 5 V, or the like. For this reason, there were the following problems. (1) In each of the constant value control type controllers SC1 and SC2, an error may occur at the time of signal reception, and each device has a different value as a set value, which hinders uniform temperature control. There was something. (2) At the break points TSP1 and TSP2 of the value SP,
There is a possibility that the set value overshoot as shown by the dotted line in the figure may occur on the fixed value control type adjustment type SC1, SC2 side.
Temperature control could be adversely affected. (3) As shown in FIG. 3, each segment SEG1, SEG2,..., SEG5 of the program pattern set value SP
In the above, it is ideal to control using a different PID constant (PID group; PIDGR1, 2, 3) for each segment, but in the conventional system, one type of the constant value control type controller is used. Since the control is performed only with the PID constant, detailed control was impossible. (4) On the program controller PC side, the reset mode is initially set and the run mode is set when control is started. On the other hand, the constant value control type controllers SC1 and SC2 are in an auto mode (automatic control mode) from the beginning. For example, when the control operation is to be reset on the program controller PC side, the reset signal is set to the constant value control type controllers SC1 and SC2. SC2
Is sent as a set value "0", whereby the constant value control type controllers SC1 and SC2 start the control operation of the set value "0" and cannot shift to the correct reset state.

An object of the present invention is to solve such a problem, and an object of the present invention is to realize a temperature instrumentation system capable of performing fine-grained temperature control.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a program controller for generating a program pattern set value, and a program pattern setting method for receiving the program pattern set value by remote input. In a temperature instrumentation system comprising at least one or more constant value control type controllers for executing temperature control according to a value, a digital data transmission unit is provided in the program controller and digital data reception is performed in the constant value control type controller. And the program controller is connected to the program controller by digital transmission means. The program controller sets the current control target value and the segment attainment control target value based on the program pattern set value data, and the PID used in the current segment. The group number and operation mode data are stored in the data for each control cycle. A temperature instrumentation system characterized by through digital transmission means for transmitting to the constant value control type controller.

[0006]

In the thermometering system of the present invention, the current control target value and the segment attainment control target value based on the program pattern set value data and the current control target value and the current The PID group number and operation mode data used in the segment are transmitted for each control cycle.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is an embodiment of a thermometering system according to the present invention. In this figure, a program controller 10 corresponds to the program controller PC shown in FIG. 2, and is connected to a digital transmission line DL such as RS422 via a serial data transmission unit 10S that handles digital data. Features on hardware. A constant value control type controller 21 is connected to the digital transmission line DL via a serial data receiving section 21R. A plurality of fixed value control type controllers (for example, one
6) are connectable, and the example in this figure assumes a system in which n units are connected up to 2n. The program controller 10
The operation is started when the run signal RUN is supplied to the digital input terminal DI1, and the program pattern generator 11 outputs the temperature set value SP having a gradient. Specifically, the control target value SP at the present time, the attained target value TSP of the current segment, and further, the PID constant number PIDGRNO of the current segment are output. These control target values SP and the current target value TS of the current segment
P and the process temperature value PV1 are given to the overshoot suppression unit 12, and a suppression output SSP1 is generated. PI
The D calculation unit 13 calculates the suppression output SSP1 and the process temperature value P
Enter V1 and PID constant number PIDG for the current segment
The control operation is executed by determining the PID constant by RNO, and the operation output MV1 as the result is given to the output terminal OUT. When the reset signal RESET is supplied to the terminal DI2, the preset signal POUT is output to the output terminal OUT.
During the run, the operation output MV1 is continuously output. Further, the program controller 10 has the above-described run /
Reset signal RUN / RESET, control target value SP, target target value TSP, PID constant number PID of current segment
Each information of GRNO is given as digital data to the serial data transmitting section 10S, and the control cycle (200 ms)
The data is transmitted on the digital transmission line DL every time.

A plurality of constant value control type controllers 21,..., 2n
Are slave stations having the same hardware configuration and no address. The fixed value control type controllers 21,..., 2n transmit digital data (run / reset signals RUN / RE) on the digital transmission line DL from the serial data receiving units 21R,.
SET, control target value SP, attainment target value TSP, and PID constant number PIDGRNO of the current segment). Here, the constant value control type controllers 21,..., 2n will be described taking the constant value control type controller 21 as an example. In the constant value control type controller 21, information surrounded by “〇” is information transmitted from the program controller 10, and these control target value SP, attained target value TSP, and process temperature inputted to the controller 21. Based on the value PV21, the suppression output SSP21 is obtained from the overshoot suppression unit 211. On the other hand, P
The ID calculation unit 212 receives the given PID constant number PIDG
From the RNO, the optimum PID constant in the current segment is selected from the set values inside, the PID calculation is performed using the PID constant, the process temperature value PV21, and the suppression output SSP21 to obtain the operation output MV21 and output from the terminal OUT. I do. Then, the operation signal MV21 is output according to the transmitted run information RUN, and the preset output POUT is output from the terminal OUT according to the reset information RESET.
That is, in the constant value control type controller 21, since the operation mode is designated from the program controller 10, it is not necessary to always fix the automatic mode.
It can operate in the same operation mode as the program controller 10.

The operation of the system of the present invention as described above includes the program controller 10, the fixed value control type controller 21,
, 2n are completely the same as the operation of the program controller PC shown in FIG. That is, at first, all the devices are in the reset state, and the program controller 10 is activated by giving the run information RUN. In the segment SEG1, PIDGR1 is specified as the PID constant, and each device performs control by selecting an optimum PID constant set internally corresponding to the PIDGR1. When the control target value SP reaches the attainment target value TSP1, the processing shifts to the segment SEG2 and P
Control is performed to maintain a constant temperature while the ID constant remains PIDGR1. After a certain time, the segment SEG
The process proceeds to 3 and PIDGR2 is designated as the PID constant, and this control is continued until the control target value SP reaches the target value TSP2. Thereafter, control is continued in the same manner according to the segment transition and the designated number PIDGRNO of the PID constant. If it is desired to interrupt the control operation for some reason, a reset signal RESET is supplied to the program controller 10 so that the reset signal is transmitted through the digital transmission line DL to the fixed value control type controller 2.
,..., 2n, and a preset output POUT is output from all controllers.

[0010]

As described above, according to the present invention,
By transmitting various data by digital transmission, the controller in the system can perform the same operation as the program controller, so that the following effects are obtained. (1) The setting error that the control target value SP shifts for each constant value control type controller in the system is eliminated. (2) The target value TS at the gradient of the control target value SP
There is no overshoot near P1 and TSP2. (3) An optimum PID constant can be selected for each segment of the control target value SP that changes according to the gradient. (4) The operation mode of the constant value control type controller can be controlled from the program controller side.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of the configuration of a thermometering system according to the present invention.

FIG. 2 is a configuration diagram of a conventional temperature instrumentation system.

FIG. 3 is a diagram illustrating the operation of a conventional program controller and the operations of a program controller and a constant value control type controller in the system of the present invention.

FIG. 4 is a diagram illustrating the operation of a conventional constant value control type controller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Program controller 11 Program pattern generator 12 Overshoot suppression part 13 PID calculation part 10S Serial data transmission part 21,2n Constant value control type controller 211 Overshoot suppression part 212 PID calculation part 21R Serial data reception part DL Digital transmission line

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-70803 (JP, A) JP-A-62-137605 (JP, A) Full-scale application Sho-59-108902 (JP, U) (58) Field (Int.Cl. ⁶ , DB name) G05D 23/00-23/32

Claims (1)

(57) [Claims] 1. A program controller for generating a program pattern set value, and at least one or more constant value control type for receiving the program pattern set value by remote input and executing temperature control according to the program pattern set value. In a temperature instrumentation system consisting of a controller,
The program controller is provided with a digital data transmitting unit, and the fixed value control type controller is provided with a digital data receiving unit, and the program controller is connected to the program controller by digital transmission means. The current control target value and the segment attainment control target value based on the set value data, the PID group number used in the current segment, and the operation mode data are transmitted to the constant value control type controller via the digital transmission means for each control cycle. A temperature instrumentation system for transmitting.