JPH1155346A - Communication equipment between program logic controller with different communication program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit and receive data between plural program logic controllers having different communication programs with a high speed in an I/O communication level. SOLUTION: Communication is operated between a PLC(program logic controller) 12A and a communicating part 16A by an exclusive communication program, and when data are obtained from the PLC 12A, the data are temporarily stored through a data managing part 18 in an A area 20A of a memory part 20, and communication is operated by the exclusive communication program between a PLC 12B and a communication part 16B. Thus, the data can be transmitted from the A area 20A of the memory part 20 through the data managing part 18 to the PLC 12B, and equivalent communication for transferring data between the PLC 12A and the PLC 12B by the common communication program can be apparently attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device between different communication program logic controllers for transmitting and receiving data between a plurality of program logic controllers having different communication programs at a high speed of an I / O communication level. .

[0002]

2. Description of the Related Art Communication between program logic controllers (hereinafter, referred to as PLCs) has different communication programs for each meter. In other words, so-called serial communication is possible at the same communication speed as the I / O level (so-called parallel communication wired for each signal) between the same manufacturers. Just a line.

On the other hand, for communication between PLCs of different manufacturers, for example, NEXUX or the like via an Ethernet for a large amount of data, high-speed communication in which I / O level response is compensated cannot be performed.

In view of the above facts, the present invention provides a communication device between logic controllers having different I / O levels and capable of performing serial communication between PLCs having a plurality of different communication programs. Is the purpose.

[0005]

According to a first aspect of the present invention, there is provided a communication system for transmitting and receiving data at a high speed of an I / O communication level between a plurality of program logic controllers having different communication programs. A communication device between program logic controllers, wherein a plurality of connected program logic controllers (hereinafter referred to as PLCs)
Communication means having a plurality of communication programs provided corresponding to the types of communication programs and capable of transmitting and receiving communication data to and from the respective PLCs;
Storage means provided with a plurality of storage areas for each of the communication data received by the communication program of each PLC, the storage means being provided in correspondence with the number of Cs, and receiving and storing from one PLC. The communication data that has been
It is characterized in that it is read out from the storage means and selectively transmitted to the other plurality of PLCs by each communication program of the LC.

According to the first aspect of the present invention, the storage means has a storage area corresponding to each different communication program.

Each storage area stores communication data received by the communication means from the program logic controller of each communication program.

That is, communication data received by different communication programs is stored separately.

[0009] Here, when it is desired to transmit and receive communication data from one PLC to another PLC (selected from a plurality of other PLCs), it is impossible to increase the speed because the communication program is different in the conventional device.

[0010] Therefore, from one PLC, this one PL
The communication data received by the communication program of C and stored in the predetermined recording area is transmitted to another PLC (other P
When transmitting to one of the LCs (selected from a plurality of LCs), the communication data from one PLC is temporarily stored in the storage unit. Next, the communication data stored in the storage means is read and transmitted by a communication program of another PLC.

As described above, transmission and reception of communication data between different communication programs are performed through the communication program corresponding to all the connected PLCs and the present apparatus having storage means for storing the communication data. Accordingly, processing equivalent to transmitting and receiving communication data between PLCs of the communication program can be performed. As a result, I / O for performing high-speed communication between different communication programs is performed.
As in the case of the / O communication, complicated wiring is not required.

[0012] The one PLC can be:
All PLCs connected to this device.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a network diagram including a communication device 10 according to the present embodiment.

A plurality of (three in this embodiment) program logic controllers (hereinafter, referred to as PLCs) 12A, 12B, and 12C are connected to the communication device 10. The plurality of PLCs 12A, 12B, 12
C is generically referred to as PLC12.

The line 14 connecting the communication device 10 and the PLC 12 is composed of three lines: a data transmission line, a data reception line, and a common ground line for the transmission and reception lines.

The communication device 10 has a PLC 12 connected thereto.
Communication units 16A, 16B, and 16C having communication programs compatible with dedicated communication programs are provided, and can transmit and receive data to and from the connected PLCs 12A, 12B, and 12CNO by different communication protocols (communication programs). It is possible.

The communication units 16A, 16B, and 16C are connected to a data management unit 18. The data management unit 18 stores data to be handled by the communication units 16A, 16B, and 16C in any of the connected PLCs 12A, 12B, 1
The data is managed together with a code capable of recognizing whether the data is obtained by communication with 2C.

The communication device 10 is provided with a memory unit 20 as storage means. The storage contents and storage area of the memory unit 20 are controlled by the data management unit 18. That is, the memory unit 20
A recording area necessary for communication is secured in advance for each of the previously connected PLCs 12A, 12B, and 12C by setting in advance.
As shown in the figure, the data obtained from the PLC 12A is stored in the A area 20A of the memory unit 20, the data obtained from the PLC 12B is stored in the B area 20 of the memory unit 20,
Data obtained from the PLC 12C is stored in the C area 20C of the memory unit 20.

By the way, the data stored in the memory unit 20 can be read through the data management unit 18 regardless of the command of the communication units 16A, 16B and 16C.

Therefore, for example, the PLC 12A and the communication unit 1
6A communicates with a dedicated communication program.
When the data is obtained from the LC 12A, the data is temporarily stored in the A area 20A of the memory unit 20 via the data management unit 18, and thereafter, the PLC 12B and the communication unit 16B perform communication by a dedicated communication program. 20
From the A area 20A through the data management unit 18
It is possible to transmit to C12B, apparently PL
The communication can be equivalent to that in which the C12A and the PLC 12B exchange data with a common communication program.

The form of communication using the present device (communication device 10) is as follows: PLC 12A → PLC 12B, PLC
12A → PLC12C, PLC12B → PLC12C,
PLC12C → PLC12A, PLC12C → PLC1
2B, PLC 12B → PLC 12A, and all such communications are apparently communications under the same communication program as in the above.

The operation of this embodiment will be described below. First, the PLC 12A will be described as a transmitting side, and the PLC 12B will be described as a receiving side.

The PLC 12A is started up, and another PLC 12A is periodically activated by a communication program of the PLC 12A.
Data to be transmitted to B and C is transmitted.

On the other hand, in the communication device 10, the communication unit 16A corresponding to the PLC 12A corresponds to the communication program,
By making data communication always possible,
The data sent from the PLC 12A is received.

The data received from the communication device 12A is temporarily stored in the A area 20A of the memory unit 20 via the data management unit 18.

On the other hand, the PLC 12B has its own read area 2
PLC12B with periodic read command to 0A20C
It is output by the communication program of.

In the communication device 10, the communication unit 16B corresponding to the PLC 12B keeps the data communication at any time in accordance with the above-mentioned communication program.
A read command from 2B is received.

According to this command, the stored data in the A area 20A and the C area 20C of the memory section 20 is read out via the data management section 18, and the communication section 16B reads out the PLC 12 data.
The communication program corresponding to B is sent to the PLC 12B.

Thus, the PLC 12 always has the latest PL
The output data of C12A can be obtained. By increasing the frequency, communication at a speed apparently equal to the I / O level becomes possible.

Table 1 shows that communication between PLCs is as follows.
The table shows whether input to each area (A area 20, B area 20, and C area 20) is possible (input possible:）) and whether output from each area is possible (output possible:）).

[0031]

[Table 1]

As described above, by applying the memory section 20 as a kind of buffer, data can be serially communicated between PLCs having different communication programs.
The level can be almost equal to the speed of the / O connection.

Although the real-time communication procedure has been described above, the memory unit 20 can be used as a database by interposing the memory unit 20. That is, without transmitting / receiving in real time, the transmitted data is stored in the memory unit 20,
By taking out the received data when necessary, it is possible to protect confidential and necessary data. In this case, it is necessary to notify the sender and the data transmission time to the receiving destination.

In this embodiment, since three PLCs 12 are connected to the communication apparatus 10, there are six types of communication. However, the number of connected PLCs 12 is not limited to three.
Any number is acceptable. In this case, the communication mode when connecting N units can be represented by _N P _2.

[0035]

As described above, the communication apparatus between different communication program logic controllers according to the present invention transmits and receives data between a plurality of program logic controllers having different communication programs at a high speed of I / O communication level. It has an excellent effect that it can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a PLC network including a communication device according to the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Communication apparatus (communication apparatus between different communication program logic controllers) 12A-C PLC (program logic controller) 14 lines 16A-C Communication section (communication means) 18 Data management section 20 Memory section (storage means) 20A A area 20B B area 20C C area

Claims (1)

[Claims] A communication device between different communication program logic controllers for transmitting and receiving data at a high speed of an I / O communication level between a plurality of program logic controllers having different communication programs, wherein the communication devices are connected. Communication means having a plurality of communication programs provided corresponding to the types of communication programs of the plurality of program logic controllers and capable of transmitting and receiving communication data to and from the respective program logic controllers; and the plurality of program logic controllers being connected Storage means provided with a plurality of storage areas for storing communication data received by a communication program held by each program logic controller, the storage means being provided with a plurality of storage areas. Communication data received and stored from Communication between different communication program logic controllers, wherein the data is read out from the storage means by the respective communication programs of the other plurality of program logic controllers and selectively transmitted to the other plurality of program logic controllers. apparatus.