KR20150084616A - System For Optimizing PLC Information Exchange - Google Patents

Abstract

A plurality of PLCs installed in a plurality of devices, respectively, for obtaining status information of the respective devices, by a plurality of threads based on IOCP, and simultaneously connected to the plurality of PLCs by a Modbus TCP / IP protocol, A status information monitoring device that simultaneously receives status information of the equipment, and a status information gathering server that receives the status information from the status monitoring device. The PIEC information exchange optimization system of the present invention connects a plurality of PLCs for acquiring status information of equipment to a single status monitoring device by a plurality of threads based on IOCP and a Modbus TCP / IP protocol, And it is also possible to set and operate the system easily and flexibly.

Description

Mr. Phel's Information Exchange System for System Optimization

More particularly, the present invention relates to a PLC information exchange optimization system, in which a plurality of PLCs for acquiring status information of equipment are managed by a plurality of threads based on IOCP and a status monitoring The present invention relates to a PI information exchange optimization system that can reduce the configuration cost of a system by connecting to a device and can easily and flexibly set and operate the system.

As the automation of the work site becomes rapid, PI is widely used as a control device for controlling the automation equipment. PLC (Programmable Logic Controller) is a device that controls the operation of a device according to a stored program, and includes a controller, an input / output module, and a memory.

1 and 2 show a system configuration diagram of a prior art system for collecting status information from PLCs installed in a plurality of devices used in an industrial field, respectively, by a PLC status information collection server.

Referring to FIG. 1, a PLC 110 is mounted on a plurality of devices 100 used in an industrial field. For example, the PLC 110 may be mounted on a tower crane used for loading and unloading at a port. The PLC status information collection server 300 collects status information from a plurality of status monitoring devices 210, 220 and 230. Each of the status monitoring devices 210, 220 and 230 is connected to one PLC to receive the status information of the PLC and transmits the received status information to the PLC status information collection server 300. [ Thus, the PLC status information collection server 300 collects status information from a plurality of PLCs 110. Normally, the connection between the PLC and the status monitoring device is made by dedicated communication setting.

2 is that the function of the status monitoring device is implemented in the PLC status information collection server 300. [ Accordingly, the PLC status information collection server 300 includes a plurality of status monitoring function units 310 and one central processing unit 320 for receiving status information from the plurality of status monitoring function units 310 and processing the status information.

The above-described prior art PLC information exchange system requires a state monitoring device or a state monitoring function unit as many as the number of PLCs to be connected. Therefore, the cost of constructing the system is high and communication between the plurality of state monitoring devices and the PLC state information collection server In order to smoothly and reliably communicate between the plurality of status monitoring function units and the central processing unit in the PLC status information collection server, the configuration and operation of the system should be strictly controlled. In other words, the flexibility of setting up and operating the facility is reduced.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems of the prior art. Accordingly, an object of the present invention is to reduce a configuration cost of a system by connecting a plurality of PLCs for acquiring status information of equipment to a single status monitoring device by a plurality of threads based on IOCP and by a Modbus TCP / IP protocol And to provide a PI information exchange optimization system that can easily and flexibly set up and operate the system.

According to an aspect of the present invention, there is provided an information exchange optimization system comprising: a plurality of PLCs installed in a plurality of devices for acquiring status information of each device, a plurality of threads based on IOCP, / IP protocol to simultaneously receive the status information of the equipment from the plurality of PLCs by simultaneously connecting with the plurality of PLCs, and a status information collecting unit that receives status information from the plurality of PLCs at the same time, Server.

The PIEC information exchange optimization system of the present invention can reduce the configuration cost of the system and can make setting and operation of the system easy and flexible.

FIG. 1 is a diagram showing an example of the configuration of a PIEC's information exchange system according to the prior art.
2 is a view showing another example of the configuration of the PIEC's information exchange system according to the prior art.
FIG. 3 is a diagram illustrating a configuration of a PIEC information exchange optimization system according to the present invention.
4 is a diagram for explaining a conventional IOCP operation scheme.
5 is a diagram illustrating an architecture of a status monitoring device of the PIEC information exchange optimization system in accordance with the present invention.

Hereinafter, the present invention will be described in detail with reference to Figs. 3 to 5. Fig.

As shown in FIG. 3, the PLC information exchange optimization system of the present invention includes a plurality of PLCs 110, a status monitoring device 200, and a PLC status information collection server 300.

A plurality of PLCs (110) are respectively mounted on a plurality of devices (100) to obtain status information of the devices (100). The equipment 100 may be, for example, a tower crane used for loading and unloading at a port, and the status information may be a motor voltage of a tower crane and a value of a cooling device sensor, an air pressure sensor, an atmospheric pressure sensor, or the like.

A feature of the present invention in comparison with the prior art is that one status monitoring device 200 simultaneously accesses a plurality of PLCs 110 and receives status information at the same time. That is, one status monitoring device 200 can receive status information from the second PLC while receiving status information from the first PLC. To this end, the status monitoring device 200 uses the Modbus TCP / IP protocol for communication with the PLC and also uses the IOCP.

There are three types of Modbus for communication with PLC: Modbus Serial, Modbus Plus and Modbus TCP / IP. Modbus serial is also divided into Modbus RTU and Modbus ASCII, serial communication method via RS-232 or RS-485. Modbus Plus is not an open standard, but a way to communicate via twisted-pair cable. Because Ethernet is a popular network structure, the evolution of Modbus using TCP / IP running over Ethernet is called Modbus TCP / IP.

Because TCP / IP is an open standard, Modbus TCP / IP is an open standard for true fieldbus. Modbus TCP / IP is widely used to manage information exchange, monitoring, and distributed I / O between devices.

Modbus TCP / IP can be seen as wrapping Modbus commands in TCP / IP. If you already have a Modbus driver and understand Ethernet and TCP / IP sockets, Modbus TCP / IP has the advantage of minimizing the time it takes to establish communications over a PC, It is advantageous that the cost is very low. In addition, Modbus TCP / IP does not require a separate and expensive chip set when setting up communication with a new device. Therefore, it is necessary to use a widely used Ethernet card, Selection is possible.

IOCP (Input Output Completion Port) is one of the kernel objects provided by Win32 in terms of operating system. It is similar to MUTEX or Thread Kernel Object. However, the special feature of the operation is the term "input / output completion port". A port is something that goes and goes. When I / O (IO) is completed, certain information units are created and transmitted / received through the port. IOCP maintains a reusable thread pool and coordinates the threads dispatched to the CPU.

IOCPs have concurrent servers, non-blocking sockets, asynchronous I / O, and asynchronous notification attributes. In the iterative server, the server processes one request at a time for the client's request, while the concurrent server can simultaneously process the requests for a plurality of clients. A blocking function is a function that is returned after completing a data transfer (normal send and recv functions) on the call, whereas a non-blocking function is a function that returns immediately without being interrogated immediately after being called.

4, the server opens a handle associated with a device (client) and connects the device handle that created the IOCP kernel object with the IOCP kernel object. Then create a thread pool by creating threads to receive completion events. Now you just have to wait for the IO to complete in the thread. The essential data structures of IOCP operation are Device List, IO Completion Queue, Waiting Thread Queue, Released Thread List, and Paused Thread List. .

In the system of the present invention, one state monitoring device 200 can simultaneously access the PLCs of the allowable number of threads using the above-described Modbus TCP / IP and IOCP to receive status information at the same time. As shown in FIG. 5, the status monitoring device 200 can interface with a plurality of PLCs at the same time. The status monitoring device 200 converts and manages the collected status information according to the system data format, To the server (300). The PLC status information collection server 300 may be a server computer for predicting a failure of the tower 100, for example, a tower crane, on which the PLC 110 is mounted. Since one state monitoring device 200 in the system of the present invention accesses a plurality of PLCs 110 at the same time by a plurality of threads based on Modbus TCP / IP and IOCP, the state monitoring device 200 and the PLC 110 can be simplified and the configuration and operation of such a connection configuration can be simply constructed.

Since the system of the present invention also collects status information from a plurality of PLCs using one status monitoring device 200 as compared with the prior art system, one PLC status information collection server 300 is provided with one status monitoring device (200). This not only simplifies the configuration between the status monitoring device 200 and the PLC status information collection server 300 but also simplifies the configuration and operation related to the communication between the status monitoring device 200 and the PLC status information collection server 300 Can be performed very simply, flexibly and stably. In other words, there is no need to strictly manage the configuration and operation of the system.

100: Equipment 110: PLC
200, 210, 220, 230: status monitoring device
300: PLC status information collection server

Claims (1)

A plurality of PLCs installed in a plurality of devices, respectively, for obtaining status information of the respective devices, by a plurality of threads based on IOCP, and simultaneously connected to the plurality of PLCs by a Modbus TCP / IP protocol, A status monitoring device for simultaneously receiving status information of the equipment, and a status information collection server for receiving the status information from the status monitoring device.

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