JPH10154005A - Input/output control system for programmable controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high speed scanning by providing two input memories of data memories with the same capacity on the same memory map, freely switching the two memories and making them to be usable. SOLUTION: The two input memories 2-(1) and 2-(2) with the same capacity are provided on the same memory map. When one of the input memories 2, 2-(1), for example, is mapped in a data memory space as the input memory of an operation part, the other memory 2-(2) is used as the input memory from an input module. Both memories can freely be switched and used. Two output memories 3-(1) and 3-(2) are similarly provided. When one memory 3-(1) is used as the output memory from the operation part, the other memory 3-(2) is used as the output memory and it is freely switched and used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a programmable controller, and more particularly to an input / output control system capable of high-speed scanning.

[0002]

2. Description of the Related Art Generally, a programmable controller comprises a CPU (central processing unit) module.
The CPU module includes an operation unit, a data memory, a program memory, and the like. The CPU module and the plurality of input / output modules are connected by a system bus running on a base.

FIG. 3 is a conceptual diagram of the configuration of this general programmable controller.
1 is an arithmetic unit, 12 is a data memory, and an input memory 12
a, an output memory 12b, and an internal memory 12c. Reference numeral 13 denotes a program memory, and reference numeral 14 denotes a plurality of input / output (I / O) modules. The input / output module 14 and the CPU module 10 are connected by a system bus 15 running as a base.

This programmable controller (hereinafter, referred to as a programmable controller)
As shown in FIG. 4, the basic flow of the processing of the PC is as follows. An external signal is fetched by the input module and written into the input memory 12a via the system bus 15. The operation unit 11 performs control operation using the input memory 12a, the output memory 12b, the internal memory 12c, and the like in accordance with the contents of the program memory created by the user, and internally holds data to be output to the outside in the output memory 12b. The data to be stored is written to the internal memory 12c, and this is repeated.

The contents written in the output memory 12b are transferred to an output module via the system bus 15 and output to the outside.

The transfer from the input module to the input memory 12a and the transfer from the output memory 12b to the output module are generally performed by the CPU module, which depends on the speed performance and scale required of the system.
Or a dedicated controller. These processes are sequentially performed in series, and are repeatedly executed with input-operation-output as one scan.

[0007] The input memory is used for calculation in the operation unit after data is transferred from the input module, and the output memory is used for transfer to the output module after writing in the output memory from the calculation unit. .

[0008]

According to the above-mentioned prior art, the processing for scanning is performed sequentially in series according to a predetermined order. Therefore, the processing from the input module to the input memory is performed in addition to the processing time of the arithmetic unit. And the transfer from the output memory to the output module are also performed in one scan and cannot be ignored as the processing time.

In general, a bus in a module has a short access time because of short signal lines, but a bus outside the module has a long access time because of long signal lines and susceptibility to disturbance. . Therefore, this is a major factor in extending the scan time, making high-speed scanning difficult.

In view of the above, the present invention realizes high-speed scanning by superimposing and processing the transfer time of the input / output memory and the input / output module and the calculation time of the calculation unit, and realizes the input signal. The purpose is to speed up the response from taking in to outputting an output signal.

[0011]

According to the present invention, there is provided means for solving the above-mentioned problems, in which an input memory and an output memory of a CPU (Central Processing Unit) module of a programmable controller have the same capacity on the same memory map. With two sides. In the input memory, when one surface (hereinafter, referred to as one surface) is used by the arithmetic unit, the other surface (hereinafter, referred to as another surface) is used for updating input data from the input module.

When one surface of the output memory is used for the arithmetic unit, the other surface is used for updating data from the output memory to the output module.

When each processing is completed, switching of both sides of the input memory and switching of both sides of the output memory are performed, and the use of each other side is switched.

As described above, by alternately using two memories, it is possible to perform processing by superposing the transfer time of the input / output memory and the input / output module and the calculation time of the calculation unit. By performing such processing, the scan time of the programmable controller is limited to the longer one of the above processing times, and high-speed scanning can be realized.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of a main part of a CPU module for explaining an embodiment of the present invention. When a high-speed scan is required, transfer from an input module to an input memory and data transfer to an arithmetic unit are performed. This is a part related to how to interface and how to interface to transfer from the operation unit and the output memory to the output module.

In FIG. 1, reference numeral 1 denotes an operation unit corresponding to the operation unit 11 shown in FIG. 3, and reference numerals 2 and 3 denote input memory and output memory, respectively, the input memory 12a and the output memory 12b shown in FIG.
Is equivalent to

The input memory 2 has two surfaces (1) and (2) with the same capacity on the same memory map.
When the input memory 2 of the surface maps one surface, for example, 2- (1) to the data memory space as the input memory of the arithmetic unit, the 2- (2) of the other surface is used as the input memory from the input module, Both sides can be freely switched and used.

Similarly, the output memory 3 has two output memories (1) and (2), and when one surface 3- (1) is used as the output memory from the arithmetic unit, the other surface is used. 3
-(2) is used as an output memory for storing data to be transferred to the output module, which can be freely switched and used.

FIG. 2 is a time chart for calculation of the present invention.
When the data transferred from the input module is written to one surface (1) of the input memory 2 and the data of one surface (1) of the output memory 3 are used for calculation, the other surface (2) of the input memory 2 The other side (2) of the output memory 3 is used for updating data from the output memory to the output module for updating input data from the input module.

When each process is completed, switching of both sides of the input memory and switching of both sides of the output memory are performed, and the other side (2) of the input memory 2 and the other side (2) of the output memory 3 are switched. One side of input memory 2 used for calculation (1)
Are used for updating input data, and one side (1) of the output memory is used for updating data to the output module.

As described above, when one side of the input memory is used by the operation unit, the other side is used for updating input data from the input module, and one side of the output memory is used by the operation unit. When used, the other side is used to update data from the output memory to the output module. Then, when each processing is completed, the input memory is switched and the output memory is switched, and the other side of the application is switched, and the two sides of the memory are used alternately. High-speed scanning can be performed by processing the transfer time and the calculation time of the calculation unit in a superimposed manner.

[0023]

As described above, according to the present invention, the input memory and the output memory each have two surfaces with the same capacity on the same memory map. The other side is used to update the input data from the input module. In the output memory, when one side is used by the arithmetic unit, the other side is used to update the data from the output memory to the output module. The transfer time of the input / output memory and the input / output module is superimposed on the operation time, and the processing time is superimposed, so that the scan time of the programmable controller can be limited to the longer one of the above. High-speed scanning can be realized as compared with the case where processing is performed in series, and the response from input signal capture to output signal output is extremely fast. Achieve the effect.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the present invention.

FIG. 2 is a time chart for calculation of the present invention.

FIG. 3 is a configuration diagram of a programmable controller.

FIG. 4 is a conventional operation time chart.

[Description of Signs] 1 ... Calculation unit 2 ... Input memory 3 ... Output memory 10 ... CPU 11 ... Calculation unit 12 ... Data memory 12a ... Input memory 12b ... Output memory 12c ... Internal memory 13 ... Program memory 14 ... Input / output module 15 ... system bus.

Claims (5)

[Claims] 1. A programmable controller in which a CPU module having an arithmetic unit, a data memory, and a program memory is connected to a plurality of input / output modules via a system bus, wherein the input memory of the data memory is the same on the same memory map. When two planes are provided with the capacity, and one plane is mapped to the data memory space as the input memory of the operation unit, the other plane is used as the input memory from the input module, and these two planes can be freely switched and used. An input / output control method for a programmable controller, which is made possible. 2. The programmable memory according to claim 1, wherein when one side of the input memory is used by an arithmetic section, the other side is used for updating input data from an input module. Controller input / output control method. 3. A programmable controller in which a CPU module having an arithmetic unit, a data memory, and a program memory is connected to a plurality of input / output modules and a system bus.
When two surfaces are provided with the same capacity on the same memory map, and one surface is used as an output memory from the arithmetic unit, the other surface is used as an output memory for storing data to be transferred to the output module. An input / output control method for a programmable controller characterized in that two surfaces can be freely switched and used. 4. An output memory according to claim 3, wherein one surface of the output memory is used by an operation unit, and the other surface is used for updating data from the output memory to an output module. I / O control method of programmable controller. 5. A programmable controller in which a CPU module having an operation unit, a data memory, and a program memory is connected to a plurality of input / output modules via a system bus, wherein the input memory and the output memory of the data memory are respectively assigned the same memory map When the arithmetic unit uses one surface of the input memory, the other surface is used for updating input data from the input module, and one surface of the output memory is used for the arithmetic unit. Is used, the other side is used for updating data from the output memory to the output module, and when each processing is completed, switching between the input memory and the output memory is performed and the purpose of each side is switched. An input / output control method for a programmable controller, characterized in that: