JPH07200493A - Decentralized controller - Google Patents

Abstract

PURPOSE:To perform signal processing selectively base on plural processing programs by the use of the decentralized controller, which is a controller for a plant and performs preprocessing for an input signal and postprocessing for an output signal. CONSTITUTION:The input signal 9 from the plant 11 is inputted to a communication processor 25 from the input/output basic circuit 28 in an input/output module 27, processed by a data processing subroutine 21, and sent to a control arithmetic module 22 through a serial communication bus 26. The communication processor 25 stores plural data processing subroutines 21 and a digital arithmetic processor 23 specifies a necessary program through a communication processor 25 and a serial communication bus 26 to perform necessary processing; and the input/output basic circuit 28 sends a command to the plant 11 as the output signal 10, so one module can have plural processing programs and the low-cost decentralized controller is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a plant or the like, which requires particularly high-speed control, pre-processing of input signals, and post-processing of output signals.
l) The present invention relates to a distributed control device applied to a device.

[0002]

2. Description of the Related Art FIG. 2 is a system configuration diagram of a conventional distributed control device. Reference numeral 1 is a distributed control device as a whole, which comprises a control operation module 2 and an input / output module 7, and is a DDC device which shares data processing. The control calculation module 2 is composed of a digital calculation processor 3, the input / output module 7 is composed of a data processing subroutine 12 that performs only one process, and an input / output basic circuit 8, and an input / output module 7 that performs different processes as necessary. Is equipped with a plurality of units, receives an input signal 9 from the plant 11, is processed by the data processing subroutine 12, and is sent to the control arithmetic module 2 from the data bus 13. The operation output from the processor 3 is sent to the input / output module 7 from the data bus 13, processed by the data processing routine 12, and output as the output signal 10 from the input / output basic circuit 8.

In the input / output module of such a distributed controller, only a single process is executed on the input signal 9 and the output signal 10 in the data processing subroutine 12 defined by hardware or software.

FIG. 3 shows a system configuration of a conventional distributed control device in which a data processing program of an input / output module is downloaded from a control arithmetic module or a terminal. In the figure, reference numerals 1 to 3, 7 to 11 and 13 are the same as those in FIG. 2, 14 is a communication circuit provided in the control calculation module 2 and the input / output module 7, and 15 is a communication line.
The terminal 16 such as C is connected to the communication circuit 14. This system requires a complicated communication circuit 14 in the input / output module 7 and cannot be expected to have a simplified circuit configuration, resulting in a high cost system.

[0005]

In the system shown in FIG. 2, of the sensor signals and operation signals of various plants and the like, a plurality of signals which require pre-processing and post-processing are provided in accordance with the specifications. The input / output module 7 has to be developed, and in the system of FIG. 3, one input / output module can support flexible processing specifications, but the internal configuration of the module and the terminal 16 by the communication line 15 are required. The communication circuit 14 and the like to be connected become complicated, resulting in a high-cost system.

Therefore, according to the present invention, an inexpensive input / output unit having a relatively simple internal structure and communication function and capable of processing data flexibly in one module and an arithmetic unit for performing a digital operation are provided at a low cost. It is intended to provide a distributed control device.

[0007]

SUMMARY OF THE INVENTION Therefore, according to the present invention, in a distributed control device in which an input / output unit and an arithmetic unit are connected by a communication bus, a plurality of signals are input / output at the input / output unit. Having a processing program, the arithmetic unit performs the arithmetic necessary for controlling the external device, issues a processing program selection command to the input / output unit, and selects the required program from a plurality of programs. It is configured to execute.

That is, the present invention provides an input / output circuit for inputting / outputting a signal from an external device, and a data processing for performing input / output processing on a signal after input from the same input / output circuit and a signal before output to the same input / output circuit. An input / output unit including a device, an arithmetic unit that performs arithmetic necessary for controlling the external device based on the data after the input processing from the input / output unit, and between the arithmetic unit and the input / output unit. In a distributed control device including a communication bus for transmitting and receiving data, the data processing device stores a plurality of types of input / output processing programs, and the input / output unit from the arithmetic unit via the communication communication bus. There is provided a distributed control device characterized in that a required program is selected from the plurality of types of input / output processing programs and executed based on the designation.

[0009]

According to the present invention, an input signal from an external device such as a plant is input to the input / output unit by the above-mentioned means, input processing is performed by a necessary program in the data processing device of the input / output unit, and the signal is transmitted via the communication bus. Is transmitted to the calculation unit. The data processing device of the input / output unit stores a plurality of programs required for input / output processing, and the types of programs required for processing the input / output signals are stored in the memory of the arithmetic unit. Of the plurality of processing programs stored in the data processing device from the arithmetic unit to the input / output unit, the output command obtained from the arithmetic result is transmitted to the input / output unit via the communication bus. Data is transmitted to specify execution for some of the signals required for processing, a program is selected and executed, and the processed result is output to an external device.

Therefore, a plurality of programs are stored in the data processing device of the input / output unit, and a necessary program is selected from these programs to be executed, so that high-speed control and pre-processing of input / output signals can be performed by the low-cost distributed control device. It becomes possible to execute it in a single module with a system that can easily perform post-stage processing.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a system configuration diagram of a distributed control device according to an embodiment of the present invention. 20 distributed controllers have 2
It is composed of two control calculation modules and 27 input / output modules, and transmission of input / output data and the like between the modules 22 and 27 is performed via 26 serial communication buses. The control operation module 22 includes a processor 23 for performing digital operation, a communication processor 25, and a processor 4 for transferring data between the two processors 23 and 25.
The memory shown in (1) is mounted, and a simple communication circuit for performing inter-module communication is configured by using the communication function of 25 processors and several kinds of interface elements.

The input / output module 27 is equipped with 25 communication processors and an input / output basic circuit 28 for inputting / outputting the input signal 9 from the plant 11 and the output signal 10 to / from the plant, The communication function of the communication processor 25 and several kinds of interface elements are used to form a simple communication circuit for inter-module communication. Further, some data processing subroutines shown by 21 are programmed in the communication processor 25 on the input / output module 27, and by specifying the processing from the control operation module 22, the input signal 9 and the output signal 10 are processed. Programmed data processing is performed.

The contents of the data processing subroutine 21 include pulse input processing, pulse output processing, key matrix processing, etc. as digital input / output modules for digital signals, and analog input / output for analog signals. As a module, a PID process, an input averaging process, a servo process, and the like, which are programs that can be completed by a single input / output module apart from the overall control, are programmed.

The method of designating the processing is the control calculation module 22.
When the program for causing the above-mentioned digital arithmetic processor 23 to write the processing designation data to the area determined in the memory 4 by the program, the communication processor 25 takes out this data and inputs / outputs it via the serial communication bus 26. The processing is designated for the module 27.

Regarding the processing for the input signal, the processing programs suitable for these controls are specified in advance in the memory 24 according to the type of plant control. Therefore, if the type of plant control is determined, the input signal A program required for processing is selected, data is processed by the corresponding data processing subroutine 21 in the communication processor 25, and the processed data is sent to the control arithmetic module 22 via the serial communication bus 26.

In the embodiment having such a configuration, the input signal 9 from the plant 11 enters the communication processor 25 via the input / output basic circuit 28, and is processed by the designated data processing subroutine 21 to be serially communicated. Bus 26
Through the communication processor 25 of the control calculation module 22
And stored in the memory 4 or sent to the digital arithmetic processor 23 as required. Further, the output command obtained from the result calculated by the digital calculation processor 23 of the control calculation module 22 is transmitted by the communication processor 25 to the input / output module 7 via the serial communication bus 26 and the digital calculation processor 23.
Writes processing designation data in the memory 24, and the communication processor 25 designates a necessary one of the digital processing subroutines 21 in the communication processor 25 of the input / output module 27 via the serial communication bus 26. The data processed thereby gives a command to the plant 11 as the output signal 10 by the input / output basic circuit 28.

In such an embodiment, the communication processor 25 is mounted on both the control operation module 22 and the input / output module 27 which constitute the control device.
The data communication between the modules 25 and 27 is carried out by the serial communication bus 26 by a relatively simple communication circuit, and further, some data processing subroutines 21 are programmed in the communication processor 25 on the input / output module 27, and the control operation module 22. Is a distributed control device capable of executing designated programmed data processing in the input / output module 27 by performing processing designation from the input / output module 27. As a result, high-speed control and input / output signal pre-stage and post-stage control can be performed in a low-cost control device. The processing can be executed by a single module.

[0018]

As described above in detail, according to the present invention, the arithmetic unit and the input / output unit constituting the distributed controller are provided with a communication function to perform data communication, and further the data processing of the input / output unit. The data processing programmed in the input / output unit can be executed by storing the programs of a plurality of data processing routines in the device and designating the processing of the necessary program from the arithmetic unit, which enables high-speed operation in a low-cost control device. It enables control and pre-processing and post-processing of input / output signals.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a distributed control device according to an embodiment of the present invention.

FIG. 2 is a system configuration diagram of a conventional distributed control device.

FIG. 3 is a system configuration diagram of a distributed control device for downloading data processing of a conventional input / output module from a terminal.

[Explanation of Codes] 9 Output Signal 10 Input Signal 20 Distributed Controller 21 Data Processing Subroutine 22 Control Arithmetic Module 23 Digital Arithmetic Processor 24 Memory 25 Communication Processor 26 Serial Communication Bus 27 Input / Output Module 28 Input / Output Basic Circuit

Claims (1)

[Claims] 1. An input / output circuit for inputting / outputting a signal from an external device, and a data processing device for inputting / outputting a signal after input from the same input / output circuit and a signal before output to the same input / output circuit. And an arithmetic unit for performing arithmetic necessary for controlling the external device based on the data after the input processing from the input / output unit, and data transmission / reception between the arithmetic unit and the input / output unit. In a distributed control device comprising a communication bus for performing the above, a plurality of types of input / output processing programs are stored in the data processing device, and designation from the arithmetic unit to the input / output unit via the communication communication bus is performed. A distributed control device for selecting and executing a required program from the plurality of types of input / output processing programs based on the above.