JP2010152558A - Programmable controller and method of creating electronic message - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a programmable controller and a method of creating an electronic message that are capable of creating and transmitting the electronic message with respect to each node connected as an object to be controlled, without updating firmware in the PLC. <P>SOLUTION: The programmable controller 20 receives data used for creating the electronic message, which is data to be transmitted by the programmable controller 20 to communication equipment, from a definition setting loader 30; creates the electronic message to be transmitted to the communication equipment using the data to be used for creating the electronic message; and transmits the created electronic message to the communication equipment. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for creating data to be transmitted to a node by a programmable controller, that is, a telegram.

  In various control systems such as sequence control, programmable controllers (hereinafter referred to as PLCs) are widely used. Such a PLC performs control operations by exchanging data with, for example, a host communication device.

Conventionally, data (telegram) to be transmitted to a communication device (hereinafter sometimes referred to as a node) is created by the PLC.
As an example, for a certain node, as shown in FIG. 6, the node number 101 (in this case, “3”) is acquired from the first fixed part storage table 102 as the destination node information, and the message 100 to be created is created. Transfer (copy) to the first line and create fixed part (1). Subsequently, as shown in FIG. 7, the command number 103 (here, “2”) is acquired from the second fixed part storage table 104 as the destination node command information, and transferred to the second line of the message 100 to be created. (Copy) to further create the fixed part.

  Further, as shown in FIG. 8, the data area type (input / output memory, non-holding memory, holding memory, etc.) value (that is, an identifier indicating the memory type), a relative address value, and a data size value are included. The definition information table 106 in which the location of the user data of the transmission destination node is set is randomly searched based on the packet data 108, the user data is acquired in (2), and the third and subsequent lines of the message 100 to be created are acquired. The user data part is created in (3), and the message 100 is transmitted to the corresponding node in (4).

  Note that the definition information table 106 having a format as shown in FIG. 8 is generally used to facilitate the process of collecting user data when the PLC creates a message.

  However, the message creation processing shown in FIGS. 6 to 8 is conventionally executed by the PLC firmware. Since the format of the message to be created is different for each node, for example, it is not possible to create a message for any node by the procedure shown in FIGS. As a result, for example, when a node having a message format different from any of the existing nodes is newly connected to the PLC, the processing for the newly connected node must be added to the firmware, so the firmware needs to be updated. There is.

However, the PLC is often installed in the back of the control panel or in a remote place, making it difficult to update the firmware.
As a peripheral technique, Patent Document 1 discloses a system having an application mediation unit that mediates data transfer between a plurality of applications.
JP 2001-216226 A

  The present invention has been made in consideration of the above problems, and provides a programmable controller and a message generation method capable of generating and transmitting a message for each node connected as a management target without updating the PLC firmware. The purpose is to do.

The proposed programmable controller is connected to a communication device via a first network, and the definition setting loader is a programmable controller connected via a second network, and the programmable controller transmits the communication device to the communication device. The programmable controller receives data used to create a telegram that is data to be transmitted from the definition setting loader through the second network, and uses the data used to create the telegram to the communication device. A message to be transmitted is created, and the created message is sent to the communication device through the first network.

  According to the proposed programmable controller, it receives data used to create a message from the definition setting loader, interprets it in order, for example, from the top, creates a message, and sends it to the corresponding communication device. . For this reason, by executing the difference adjustment part of the message format for each node as a process on the definition setting loader side that makes it easier to update the software, the firmware of the programmable controller installed in the back of the control panel or remotely The burden of updating can be eliminated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a telegram transmission / reception system according to an embodiment of the present invention.

  As shown in FIG. 1, in this telegram transmission / reception system, a programmable controller (hereinafter referred to as PLC) 20 includes a plurality (three in the figure) of external communication devices 34-1, 34-2, and 34-3 and a first one. And the definition setting loader 30 are connected via a second network (eg, a general-purpose network) 32.

  The PLC 20 includes a CPU (Central Processing Unit) module 10. The CPU module 10 includes a CPU 11, a driver / receiver 13, a PLC specific bus interface 14, a system program memory (FLASH) 15, a system work memory (RAM (Random Access Memory)) 16, a user program memory (RAM) 17, and user data. A memory (RAM) 18 is connected through a bus 19. The CPU module 10 is connected to the communication module 23 through the PLC specific bus interface 14.

FIG. 2 is a block diagram illustrating a configuration of the packet generation unit of the present embodiment.
As shown in FIG. 2, the packet generation unit 40 includes a header unit transfer unit 41, a command unit transfer unit 42, and a packet data construction unit 43.

  The header part transfer part 41 and the command part transfer part 42 refer to the definition information used when creating a message to the node, and perform processing for creating a fixed data part in the message for the node that performs communication. The packet data construction unit 43 collects user data from the user data memory 18 in FIG. 1 with reference to the definition information used when creating a message to the node, and sets it in the message to be transmitted to the node To do. The user data is, for example, an operation parameter set in the node. In this embodiment, the definition information is created by the definition setting loader 30 and transmitted to the PLC 20.

  In the present embodiment, each unit in FIG. 2 is realized by software. This software is stored in the system program memory 15 of FIG. 1, read from the system program memory 15 to the system work memory 16, and executed by the CPU 11.

FIG. 3 is a diagram showing information resources used in the present embodiment.
In FIG. 3, the format definition information 51 is information used to create a telegram created on the definition setting loader 30 side as described above. By reading the definition information 51 in order from the top and executing the contents of the instructions, a telegram can be created. In this sense, it can be said that the definition information 51 is format definition information. Further, the definition information 51 is provided for each destination node, and, of course, has information for identifying the destination node at the head position, for example. When receiving this definition information 51 from the definition setting loader 30, the PLC 20 stores it in the system work memory 16 of FIG.

  The user data is stored in the user data memory 18 of FIG. 1 divided into a plurality of (three in FIG. 3) data areas 52, 53, and 54 for each memory type, for example. In order to access user data, the type of data area, the relative address from the head of the data area, and the data length (data size) are specified.

  The processing by the packet generation unit 40 shown in FIG. 2 is executed with reference to the definition information 51, necessary user data is collected from the data area, and an output information resource, that is, a telegram 55 to be transmitted to the node is created. The

FIG. 4 is a diagram showing in detail a method for creating a message.
On the left side of FIG. 4, definition information 61 is shown, a telegram 62 is shown on the upper right, and a data area 63 in which user data 64 is stored on the lower right.

  Node identification information 66 is set in the first line (top position) of the definition information 61. The node identification information 66 has a format of “%” + “serial number” (% 1 in FIG. 4).

  In the second row of the definition information 61 in FIG. 4, copy instruction identification information (its value is, for example, $ 1) 68 is set. A normal header, footer, or command is set after the line where the copy instruction is set. The packet generation unit 40 in FIG. 2 determines whether a header, a footer, or a command is set after the next line according to the data format, and according to the determination result, the header part transfer unit 41. And the command part transfer part 42 is activated to copy (transfer) the corresponding part from the next line on to the message 62 with justified (first justified). In the example of FIG. 4, the header 71 is described as “A1”, the header part transfer unit 41 is activated, and this is copied to the first line of the message 62. Even when it is determined as a footer, the header transfer unit 41 performs processing.

  In the definition information 61 of FIG. 4, the packet data 73 is set after the header 71. The packet data 73 includes data area identification information (its value is, for example, $ 2) 75 + data area type value (its value is “10” in the figure) 76 + relative address identification information (its value is, for example, $ 3) 77 + relative address value (its value is “1000” in the figure) 78 + data size identification information (its value is, for example, $ 4) 81 + data size value (its value is “16” in the figure) Is 82).

  When the packet generation unit 40 in FIG. 2 detects the identification information 75 of the data area, it issues an activation instruction to the packet data construction unit 43. The packet data construction unit 43 specifies that the data area is the data area 63 from the value 76 of the data area type, and determines the user data 64 in the data area 63 from the relative address value 78 and the data size value 82. Is identified as a collection target, and the user data 64 (here, “5”) is copied to the second line of the message 62.

In FIG. 4, reference numeral 84 is identification information for a copy instruction, reference numeral 85 is a footer, and reference numeral 86 is identification information indicating the end of the definition information 61.
FIG. 5 is a flowchart of the entire process including the message creation process. Steps S1, S2, and S9 of this flowchart are executed by a processing unit (upper program, not shown) higher than the packet generation unit 40 shown in FIG. As one of the processes executed by the upper processing unit, the flowchart of FIG. 5 is shown. Therefore, the flowchart of FIG. 5 starts with a broken line and ends with the broken line. The remaining steps are executed by the packet generator 40 of FIG. Note that step S9 may be executed by the packet generator 40.

  In FIG. 5, the presence or absence of a request for transmission of packet data, that is, a message, is determined by the upper processing unit in step S1. For example, this determination processing is information storing a message transmission request for each node, which is information different from the definition information stored in the system work memory 16 of FIG. 1 (that is, to which node the message should be transmitted now) This is executed by referring to the information).

If it is determined in step S1 that there is no message transmission request, the series of processes in this flowchart is terminated.
If it is determined in step S1 that there is a message transmission request, definition information for the destination node is acquired from the system work memory 16 in FIG. 1 in step S2, and the message is transmitted using the acquired definition information. 2 starts the packet generator 40 of FIG. Normally, there is only a transmission request for any one of the nodes.

  In step S3 subsequent to step S2, the packet generation unit 40 performs a generation unit determination process. As described above with reference to FIG. 4, the creation unit discrimination process reads data (row) from the current position of the definition information, and the row is the copy instruction identification information 68 or the data area identification. It is determined whether it is information 75. If the line is copy instruction identification information 68, it is determined from the data format of the subsequent data (line) whether it is a header (footer) or a command. Is done.

  When it is determined in step S3 that the data area identification information 76 is read and the packet data construction unit 43 is activated, in step S5, the packet data part construction process, that is, the type of data area, the relative address, A process of collecting data specified by the set of data sizes and transferring (copying) the data to the message in a front-aligned manner is executed, and the process proceeds to step S8.

  When the copy instruction identification information 68 is read in step S3 and it is determined that the command is based on the data format of the subsequent data and the command part transfer unit 42 is activated, the subsequent data is determined in step S6. A process of transferring (copying) the command to the message in the left-justified manner is executed, and the process proceeds to step S8.

  When the copy instruction identification information 68 is read in step S3 and it is determined from the data format of the subsequent data that it is a header or footer and the header transfer unit 41 is activated, the subsequent data is determined in step S7. A process of transferring (copying) the header or footer to the message in a justified manner is executed, and the process proceeds to step S8.

  In step S8, the next line of the definition information is prefetched, and it is determined whether or not the generation of data (message) has been completed by determining whether or not it is the identification information 86 at the end of the data.

  If it is determined in step S8 that the data generation has been completed, control passes from the packet generation unit 40 to the upper processing unit, and in step S9, the generated electronic message is transmitted to the corresponding node by the upper processing unit. Is done.

If it is determined in step S8 that the data generation has not been completed, the process returns to step S3, and the processing after the next line prefetched in step S8 is continued.
As described above, according to the programmable controller of this embodiment, the data used to create a message from the definition setting loader is received, and for example, the message is interpreted in order from the top, and the message is created. Is transmitted to the communication device (node). For this reason, the difference adjustment part of the message format for each node can be executed as a process on the definition setting loader side that makes it easier to update the software. The burden of renewing can be eliminated.

It is a block diagram which shows the structure of the message | telegram transmission / reception system which concerns on one Embodiment of this invention. It is a block diagram which shows the structure of the packet generation part of this embodiment. It is a figure which shows the information resource used by this embodiment. It is a figure which shows the preparation method of a message | telegram in detail. It is a flowchart of the whole process including a message | telegram preparation process. It is FIG. (1) which shows the conventional message | telegram preparation method. It is FIG. (2) which shows the conventional message | telegram preparation method. It is a figure (the 3) which shows the conventional message | telegram preparation method.

Explanation of symbols

10 CPU module 11 CPU
13 Driver / Receiver 14 PLC Specific Bus Interface 15 System Program Memory 16 System Work Memory 17 User Program Memory 18 User Data Memory 19 Bus 20 Programmable Controller

23 communication module 30 definition setting loader 31 first network 32 second network 34-1, 34-2, 34-3 external communication device (node)
40 packet generation unit 41 header unit transfer unit 42 command unit transfer unit 43 packet data construction unit 51, 61 definition information 52, 53, 54, 63 data area 55, 62 message 64 user data 66 node identification information 68, 84 copy instruction Identification information 71 Header 73 Packet data 75 Data area identification information 76 Data area type value 77 Relative address identification information 78 Relative address value 81 Data size identification information 82 Data size value 85 Footer 86 Data end identification information

Claims (5)

In a programmable controller that sends messages to external communication devices,
Corresponding to each of the communication devices, a receiving unit for receiving data used to create a message to be transmitted to each communication device as definition information from the outside,
A storage unit for storing the received definition information;
Using the definition information stored in the storage unit, a message creation unit that creates a message to be transmitted to the communication device of the transmission partner;
A programmable controller, comprising: a transmission unit that transmits the created electronic message to the communication device of the transmission partner. The data used to create the message includes at least one of data to be embedded in the message to be created, or identification information of a storage destination of the data to be embedded,
The data to be transmitted to the communication device is created by interpreting data used for creating the message in order from the beginning and sequentially embedding the data in the message to be transmitted to the communication device. Item 12. A programmable controller according to item 1.   The data to be embedded in the electronic message to be created is a header, a footer, or a command, and the identification information of the storage destination of the data to be embedded is user data to be output to the communication device. The programmable controller according to 2.   3. The programmable controller according to claim 1, wherein a message is created and transmitted to a communication device having a message transmission request with reference to information storing a message transmission request for each communication device. In the message creation method executed by the programmable controller connected to the communication device via the first network and the definition setting loader connected via the second network,
Receiving the data from the definition setting loader through the second network, the programmable controller receiving data used to create the telegram, which is data transmitted by the programmable controller to the communication device;
Creating a message to be transmitted to the communication device using data used to create the message;
Transmitting the created electronic message to the communication device through the first network.

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