JPH06161520A - Programmable logic controller system - Google Patents

Abstract

PURPOSE:To provide a programmable logic controller system uniting a machine control and a data processing and improving system performance. CONSTITUTION:An integrated tool which has a programmable controller provided with a computer module having an operating system and an input/output coordinator having a mediation function and a supervisor function and an operating system is capable of accessing to the computer module via the input/output coordinator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a programmable logic controller system (hereinafter referred to as PLC system),
In particular, it relates to an object-oriented PLC system.

[0002]

2. Description of the Related Art Conventional PLC systems have been developed and developed for the purpose of machine control. In other words, the primary goal of PLC is focused on how to control the machine efficiently. However, in recent years, not only machine control but also the need to perform various data collection / analysis accompanying it has been increasing. Further, the types of machines targeted for machine control itself have increased, and control has become complicated. At the same time, a man-machine interface for performing these complicated controls is required to be visual and easy to operate.

In the conventional PLC system, in order to meet these demands, a PC (personal computer) is prepared outside the PLC to realize data processing and a man-machine interface. The PC and PLC are generally connected by a serial interface. In such a system, it is difficult to integrate the work such as machine control and data processing. Further, even if a PC is connected, the system performance is limited by the CPU module of the PLC, so the load on the CPU module increases each time a function is added, and the system performance is likely to deteriorate, resulting in a bad environment. Has become.

FIG. 13 is a block diagram showing the configuration of such a conventional PLC system. In such a system, different types of hardware and software are connected together, and machine control and data processing are separated. Therefore, there are the following problems, there is a problem in system performance and maintainability, and a great deal of time and labor are required for system construction. a) Communication speed is slow. b) Each program is independent. c) The operating environment of each program is different. d) Data cannot be comprehensively managed. e) Not integrated as a system.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a PLC system in which machine control and data processing are fused to improve system performance.

[0006]

A PLC system according to the present invention has a PLC having a computer module having an operating system and an input / output coordinator having an arbitration function and a supervisor function.
In addition, it has an operating system and integrated tools for accessing computer modules via the I / O coordinator.

[0007]

In the present invention, the PLC and the integrated tool have the same operating system so that the integrated tool can access the computer module through the I / O coordinator. Therefore, the machine control and the data processing are integrated to be convenient.

[0008]

FIG. 2 is a diagram showing the difference in performance between a conventional PLC system and the object-oriented PLC system of the present invention. In conventional systems,
PLC functions can be enhanced by adding special modules at I / O level, networks in the family, and RLL (Relay Ladder Logic) commands, which can support individual applications, but the programs are complicated. It is difficult to expand, and as the system expands, the overall performance decreases. On the other hand, in the present invention, the special module at the PC level, the global network (the design by the open architecture,
The functions of the PLC can be enhanced by high speed scanning and distributed control by the I / O coordinator). Therefore, in the present invention,
When the system is expanded, the overall performance is improved, and because of the PC module, the OS can share a common control environment and data, and the entire PLC system looks like one high-performance PLC.

FIG. 3 is an explanatory view showing the concept of the PLC system of the present invention. In terms of hardware, the PC is modularized and incorporated into a part of the PLC system.
In other words, it can be directly attached to the backplane used in the PLC system, and data can be exchanged at high speed with other modules. The PC module mentioned here is a concept including a general-purpose personal computer and a personal computer specialized for a certain function. Furthermore, in order to improve system performance, multiple PCs can be installed on one backplane.
A pack plane bus with an arbitration function is available to allow modules to be installed. Also,
A special module called an I / O coordinator that actually arbitrates each PC module is also prepared. With these buses with arbitration function and I / O coordinator,
Multiple PC modules can operate in parallel in an optimal manner. That is, a distributed processing is realized in which a certain PC module controls one I / O, another PC module controls another I / O, and those are organically connected to each other.

As described above, in the PLC system of the present invention, all the PC modules are in the same position, and are recognized as intelligent "targets", that is, objects according to function or control range. These objects will be arbitrated by the I / O coordinator in the PLC system and behave as agents. The system engineer
By simply combining these objects (PC modules) as if they were blocks, it is possible to construct an advanced system. Also, from the form of distributed processing, the more the function is added, the more the system performance is improved.

FIG. 4 is an explanatory diagram of a PLC system network. Although the above description focuses on the systems on one backplane, the systems on these backplanes evolve further through the network as shown in FIG. The module that controls these networks is a network interface that is a specialized PC module. This I / F is basically a computer, and has the advantage that it is easy to construct a worldwide network such as Ethernet and ISDN. As a result, it is possible to network with many third-party product groups without being bound by the manufacturer's original network specifications.

By the way, in the conventional PLC system, C
There is a "king" existence called a PU module, and basically all processing is controlled by this CPU.
Therefore, every time we try to improve the functionality as a system, CP
The burden on the U module was increasing. In order to reduce the load on this CPU module, an intelligent module with a special control program built in in ROM has appeared, but the programming is done by a user program represented by RLL (relay ladder logic) in the CPU module. I was there. Therefore, detailed programming was impossible, and the environment for debugging was almost nothing.

However, as described above, in the object-oriented PLC of the present invention, since hardware is handled as an object as described above, software is also treated as an object. First, each PC module is equipped with a standard operating system excellent in real-time property and multitask environment, and each application is configured under the management thereof. On the other hand, access to each module is
The common task code is used regardless of the bus or serial port, and the task code is published. Based on the above idea of open architecture, it becomes possible to provide a common development environment for all software houses. This accelerates the development of the application and makes a great contribution to the developability and maintainability. In addition, a consistent system will be established for user-side education.

FIG. 1 shows an object-oriented PLC according to the present invention.
It is a block diagram which drew the objectification of the software in a system. The figure shows that each PC module by function has its control program (commander program) in its own module, which prevents heavy load on a specific module. is doing.

FIG. 5 is an explanatory diagram of the integrated programming / debugging tool. Here, how to link those application softwares is shown, and the link here is maintained not only through one backplane but also through the network. Although the model of FIG. 5 is written with the direct data exchange and object linking & embedded functions as models, the same can be said for other OSs. With the integrated tool, the control program of each PC module can be recognized in the form of an icon under the multi-window. In addition, a window for programming each PC module is opened by clicking an icon, and the operation can be performed.

However, it should be noted here that the programming screen opened on the window at this time is not owned by the integrated tool, and is different from each PC.
The point is that the module is what you have in your module. In other words, the programming screen of each PC module seen by the integrated tool is merely a virtual body. In this way, the software is also made into objects for each function. This is extremely effective in terms of advantages such as application development as a project, ease of version upgrade, and maintenance.

Next, the most important components of the object-oriented PLC system, the PC module, the I / O
The O coordinator and the integrated tool will be described respectively. (1) PC Module The PC module is a computer module having an operating system, provides a standard development / operation environment, and has the potential for future development. FIG. 6 is a block diagram of the PC module. This PC module is, as shown in the figure, basic hardware capable of operating an OS, a sub-board for realizing an interface with an external device and special functions, an operating system providing a standard development / operation environment, and each system. It consists of compatible applications. The PC module can realize the functions required for the system by combining these four elements, and it is possible to create a so-called "customized PC module". With this configuration, it is possible to realize a small variety and a wide variety of product groups. The PC module can be specialized not only as a user application but also as a functional module (for example, I / F module) of the object-oriented PLC system itself. A plurality of these PC modules can be attached to one backplane, and thus, distributed processing can be performed under the command of the I / O coordinator. This processing method will be described in detail in the next I / O coordinator.

(2) I / O Coordinator The I / O coordinator does not perform actual machine control or data processing, but has two important functions such as "arbitration function" and "supervisor function". (2-1) Arbitration Function The object-oriented PLC system has a plurality of agent-like modules and realizes distributed processing.
Therefore, an arbitration function is needed to direct these agent-like modules. FIG. 7 shows this function. FIG. 7 is a block diagram showing the arbitration function of the I / O coordinator. As shown in the figure, the operation of the PLC system includes a horizontal distributed processing and a vertical arbitration work, and the I / O coordinator controls the vertical arbitration work. Specifically, this arbitration function is realized by management of multiple processes, inter-process communication, and send / receive queues.

FIG. 8 is a flow chart showing the operation of the arbitration work of the I / O coordinator. The I / O coordinator operates in a real-time multitasking environment. First,
The I / O coordinator causes a process (execution unit) to be generated for a module (or module group) to be arbitrated. This process exchanges data with each module via send / receive queues. Also, note that the data exchanged here is a task code that indicates what you want the module to do, and is not a data stream. The task code is a data block that is common not only between the I / O coordinator and the module but also between networks. When a series of task code exchanges completes the required processing, the I / O coordinator terminates the process and erases it from the arbitration algorithm.

Although the above description is for the simplest operation, a case frequently occurs in distributed processing in which the user's own processing is performed using data generated by another module. In such cases, the I / O coordinator communicates between the processes to exchange data. Also, the process waiting for the data to be generated is converted to hibernation. In other words, the I / O coordinator, as shown in FIG.
We define three states: action, hibernation and erase.

(2-2) Supervisor Function Another function of the I / O coordinator is a supervisor function. To put it simply, the supervisor function is a function of performing integrated management in the same environment for all modules including those on the network through the I / O coordinator. FIG. 10 is a block diagram showing the supervisor function of the I / O coordinator. Figure 10
As shown in FIG. 3, the object-oriented PLC system has a commander program for controlling each PC module on each module. Furthermore, there is an integrated tool for linking those commander programs, and these are linked by the supervisor function of the I / O coordinator.
This allows each program to be very compact and maintainable. In addition, the integrated tool needs only each commander program, pit map data for display, and a small amount of data (roots data, etc.) for cooperation, and becomes a controlled tool. The supervisor function is implemented as part of the arbitration algorithm described above.

By the way, there is a process in which the modules in the process shown in FIG. 8 are not directly operated. However, paying attention to this point, these processes work together with various man-machine interfaces including the integrated tool. Used for. Here, using the integrated tool as an example, I
The delivery flow of the / O coordinator will be described.

FIG. 11 is a diagram showing the delivery flow of the I / O coordinator. As shown, the delivery operation is realized by a bucket transfer of task code and a send / receive bucket box. First, a task code string according to the purpose is sent from the integrated roots to the I / O coordinator. This is because the connection between the integrated tool environment and the I / O coordinator will be performed by serial transfer in most cases, so that task codes of the same level are transferred in buckets and transfer efficiency is improved. I'm aiming to let you. The I / O coordinator parses / decomposes the sent task code sequence and puts it in the reception bucket box for the target PC module. Requests / replies from each PC module are stored in the receiving task box, and the I / O coordinator collects them, converts them into a packet string of task codes, and delivers them to the integrated tool. Furthermore, the above delivery flow is performed through the I / F module via the network to another system (# 2
System).

(3) Integrated Tool The integrated tool is a software tool for integrally performing programming, debugging, monitoring, setting, etc. of the object-oriented PLC system. In addition, direct data change compatible with multi-window / multi-task and network,
It adopts a user-friendly architecture such as object linking and embedded. Figure 1
2 is an explanatory diagram of the integrated tool. As shown in FIG. 12, the "virtual body" of the commander program running on each PC module is present in the window.
The connection between "virtual" and "real" is a small amount of data such as bitmap data to be displayed in the window of the integrated tool and roots data indicating which commander program generated the data. Only. To call the commander program of each PC module from the integrated tool window, move the virtual body on the window to a pointing device (mouse, etc.).
You can do it just by clicking. By doing so, the volume load on the integrated tool is minimized, and efficient operation is possible. Access to the system from the integrated tool is described in I above.
It is realized by the supervisoring function of the / O coordinator.

[0025]

As described above, according to the present invention, the PLC and the integrated tool each have an operating system, and the integrated tool can access the computer module through the input / output coordinator. Control and data processing are integrated to make it easy to use. Therefore, it becomes possible to expand the PLC system, which has been accepted only in the FA field, to the general industry field as well as the FA field. In other words, computers are introduced in all industries, and those systems always have some kind of machine control.
The PLC system can be introduced into general business fields.

[Brief description of drawings]

FIG. 1 is a configuration diagram depicting objectification of software in an object-oriented PLC system of the present invention.

FIG. 2 is a diagram showing a difference in performance between a conventional PLC system and an object-oriented PLC system of the present invention.

FIG. 3 is an explanatory diagram showing the concept of the PLC system of the present invention.

FIG. 4 is an explanatory diagram of a network of the PLC system of the present invention.

FIG. 5 is an explanatory diagram of an integrated programming / debugging tool of the present invention.

FIG. 6 is a configuration diagram of a PC module of the present invention.

FIG. 7 is a block diagram showing an arbitration function of the I / O coordinator of the present invention.

FIG. 8 is a flowchart showing the operation of arbitration work of the I / O coordinator of the present invention.

FIG. 9 is an explanatory diagram of a process state in the distributed processing according to the present invention.

FIG. 10 is a block diagram showing a supervisor function of the I / O coordinator of the present invention.

FIG. 11 is a diagram showing a delivery flow of the I / O coordinator of the present invention.

FIG. 12 is an explanatory diagram of an integrated tool of the present invention.

FIG. 13 is an explanatory diagram showing a configuration of a conventional PLC system.

Claims (1)

[Claims] 1. A programmable controller having a computer module having an operating system and an input / output coordinator having an arbitration function and a supervisor function; and an operating system having access to the computer module via the input / output coordinator. Programmable logic controller system with integrated tools for performing.