JP2010134591A - Control system and programmable controller for use in the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly efficiently control a control object by reducing the limitation or restriction of the installation position of each PLC from a host, eliminating the need for wiring, and validating communication without overlapping of an ID for use in communication with each PLC with an ID in the other system at all. <P>SOLUTION: A system includes PLC 5a to 5c having communication functions conforming to radio LAN specifications by using an MAC address as communication network ID and a host 3 connected through a communication network 1 to the respective PLC 5a to 5c, and configured to control the sequence program execution of the respective PLC 5a to 5c by using the MAC address as the communication network ID. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control system using a programmable controller (hereinafter, PLC).

  The PLC is installed in a production facility, executes a sequence program, and performs sequence control of control devices such as various machines and devices in the production facility connected to the PLC. In other words, the PLC is obtained by inputting ON / OFF information of an input device such as a switch or a sensor corresponding to the state of the control target, executing a logical operation in accordance with a sequence program written in a ladder language, etc. According to the calculation result, the control target is controlled by outputting an ON / OFF information signal to an output device such as a relay, a valve, or an actuator. There is a control system in which a plurality of such PLCs are distributed and commonly connected to a host via a bus. In this control system, while downloading a sequence program from the host to each PLC, each PLC executes the sequence program independently according to the information of the input device connected to each I / O according to the production instruction from the host. Each of the output devices is turned on / off to control a control target (see Patent Document 1).

In the above control system, in order for the host to control each PLC individually, an ID is assigned to identify each PLC, and even if each PLC is individually controlled by this ID, the ID is not the same as another control system or other It may be duplicated with the ID. In addition, connecting the host and each PLC with a wire and controlling each PLC by the host has various inconveniences such as a limited installation location and wiring restrictions.
JP 2008-059532 A

  In the present invention, when controlling each PLC from a host, there are few restrictions on the installation location and restrictions, and no wiring is required. On the other hand, each PLC has an ID that does not overlap with an ID used in other control systems. In other words, it is possible to communicate with each PLC to control those controlled objects with high efficiency.

  The control system according to the present invention includes a programmable controller having a MAC address as a network ID and a wireless LAN standard-compliant communication function, and is connected to the programmable controller on the network, and executes a sequence program of these programmable controllers using the MAC address as a communication ID. And a host controlled via a network.

  In the present invention, since the ID assigned to each PLC is a MAC address that does not have the same ID, the host can control each PLC, and the host communicates with each PLC via a wireless LAN. In the case of controlling each PLC from the above, the installation place is limited and restricted, and the wiring for connecting the host and each PLC is also unnecessary.

  In the present invention, when each PLC is controlled from the host, each PLC is controlled by a wireless LAN. Therefore, there are few restrictions on the installation location and restrictions, and no wiring is required. On the other hand, since it communicates wirelessly with a MAC address, it does not overlap with IDs used in other control systems, and can communicate with each PLC to control their control objects with high efficiency. Become.

  Hereinafter, a control system according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a schematic configuration of a control system according to the embodiment, and FIG. 2 shows a schematic configuration of a PLC used in the system.

  Referring to these drawings, 1 is an Internet line, 2 is a wireless LAN access point, 3 is a host, 4 is an Internet service provider, and 5a, 5b, and 5c are PLCs.

  Each of the PLCs 5a, 5b, and 5c is a building block type PLC including a CPU module, an I / O module, a communication module, and other modules. The CPU module has a built-in wireless communication unit compliant with the wireless LAN standard, and includes wireless LAN antennas 6a, 6b, and 6c. Reference numerals 7a, 7b, and 7c are control targets that are individually controlled by the PLCs 5a, 5b, and 5c. For example, the PLC 5a is disposed in a manufacturing line, the PLC 5b is disposed in a packing line, and the PLC 5c is disposed in a shipping line. IDs for data communication between the wireless LAN access point 2 and the PLCs 5a, 5b, and 5c are ID0, ID1, and ID2, and these ID0, ID1, and ID2 are MAC addresses unique to the PLCs 5a, 5b, and 5c.

  For example, the internal configuration of the PLC 5a will be described with reference to FIG. The other PLCs 5b and 5c have the same configuration. The PLC 5 a includes a CPU 8 that performs various calculations, a memory 9, an input unit 10, an output unit 11, a bus interface 12, an ID management unit 13, a wireless communication unit 14, and an antenna 15. The memory 9 is a collection of a memory for storing a system program, a sequence program, and the like, a memory used for a work of the CPU 8, and the like. ON / OFF information is input to the input unit 10 from an unillustrated input device such as a switch or a sensor corresponding to the state of the control target, and relays and valves are output from the output unit 11 in accordance with the calculation results on the sequence program. , An ON / OFF information signal is output to an output device (not shown) such as an actuator.

  The ID management unit 13 manages the MAC address as an ID.

  The wireless communication unit 14 is capable of performing wireless communication conforming to the wireless LAN standard, and is configured by a card-type wireless LAN adapter. As the wireless LAN, for example, a wireless LAN such as “Wi-Fi (wireless fidelity)” compliant with the international wireless communication standard IEEE 802.11 can be applied. Such wireless LAN connections may further include IR (IrDA), RF, LAN, WAN, IEEE 1394 network, Bluetooth (registered trademark), ZIGBEE network, and the like.

  In the control system having the above-described configuration, the host 3 instructs each of the PLCs 5a to 5c through the Internet line 1 for manufacturing, packing, and shipping. In this case, the PLCs 5a-5c are instructed with MAC addresses ID0, ID1, and ID2, respectively. This instruction is wirelessly transmitted from the wireless LAN access point 2 to each PLC 5a-5c. Each of the PLCs 5 a to 5 c receives the wireless transmission by the antenna 15, and the received signal is decoded by the wireless communication unit 14. The CPU 8 compares the MAC addresses ID0, ID1, and ID2 registered in the ID management unit 13 of each PLC 5a-5c with the ID included in the decoded received signal, and if the corresponding MAC address ID0, ID1, or ID2 is satisfied. The CPU 8 executes the instruction.

  From the above, in the embodiment, each PLC 5a-5c has a wireless LAN standard-compliant communication function using the MAC address as a network ID, while the host 3 is connected to each PLC 5a-5c on the Internet line 1 and communicates the MAC address. Since each PLC 5a-5c is controlled as an ID, when controlling each PLC 5a-5c from the host 3, there is less limitation on the installation location and restrictions, and wiring for connecting the host 3 and each PLC 5a-5c Is also unnecessary.

FIG. 1 is a diagram showing a schematic configuration of a control system according to an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the PLC used in the system of FIG.

Explanation of symbols

1 Internet line 2 Wireless LAN access point 3 Host 4 Internet service provider 5a-5c PLC
6a-6c Wireless LAN antenna

Claims (3)

A programmable controller having a communication function based on a wireless LAN standard using a MAC address as a communication network ID;
A host that is connected to the programmable controller on a communication network and controls the execution of the sequence program of these programmable controllers via the communication network with a MAC address as a communication network ID,
A control system comprising:   A programmable controller comprising: a MAC address storage unit that stores a MAC address; and a wireless communication unit that uses the MAC address as a communication network ID and has a wireless LAN standard-compliant communication function.   A CPU module, and a predetermined number of I / O modules connected to the CPU module via a bus. The CPU module is connected to input / output devices connected to the CPU module via the I / O module according to a sequence program. A programmable controller characterized by having a communication function conforming to a wireless LAN standard with a MAC address as a communication network ID while inputting and outputting signals between them.

Images