JP2002278606A - Programming tool and controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a programming tool for efficiently generating a system environment in which it is possible to easily perform access to shared data without caring about any communication processing. SOLUTION: In a distributed control system, shared data are defined with a logical name, and relevant information obtained by relating the address of the data specified by the logical name with the logical name is stored by a controller 1, and when the data are called during the execution of a program, the relevant information is accessed based on the logical name so that the address can be obtained, and that data transfer can be performed. When performing name solution for generating the relevant information, the name solution is performed by a static name solving part 5 of a programming tool 3 as necessary so that any dynamic name solution quantity through actual communication at the controller side can be reduced. The name solution by the tool 3 can be performed in a short time by making it unnecessary to perform any communication processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programming tool and a control device. More specifically, the present invention relates to an improvement in a process for sharing data in a system for sharing data among a plurality of nodes, control devices, and processors (for example, a distributed control system).

[0002]

2. Description of the Related Art In some cases, a plurality of control devices such as PLCs are connected to a network, and the plurality of control devices execute cooperative / synchronous control while sharing data. The data includes input data as a state of a contact point of a control device such as a switch or a sensor, and output data as a state of a controlled device controlled by the control device. In such a case, in order for each control device to share such data, each I / O must be physically connected, that is, a control device or a controlled device is electrically connected to an input / output terminal of the control device. A method is known in which a user program for connecting or sharing data is separately created and executed.

As another system for sharing data between control devices, there is a system called a data link system. The data link system is a system in which data is cyclically exchanged (linked) between a plurality of control devices. For example, each node as a control device has a memory table, and data is shared by exchanging data with each other to make the contents of each table the same. At this time, access for exchanging data is performed by designating a memory address (physical address) with each other. Further, the table is collectively set by another tool other than the control device. This method has an advantage that it is not necessary to consider communication when developing a user program.

[0004] Each node shares data only by exchanging data necessary for its own node with a partner node having the data, so that unnecessary data is not shared by its own node. There is also a method.

[0005]

However, the conventional method described above has the following problems. That is, in the former method using the user program, the control device (P
It is necessary to embed communication logic in a ladder program for operating LC), which complicates user program development and makes maintenance difficult.

In the case of the latter data link system, the setting of the memory area allocation itself when linking data becomes troublesome. Once the allocation of the memory area is set, if there is a change in the allocation of the memory area, it is necessary to redo the allocation setting. Moreover, when a new control device is added to the network, the change of the reallocation of the memory area may extend to the control device already connected to the network.
There was a problem that the system had to be stopped.

According to the present invention, shared data can be easily accessed without being conscious of communication processing, development for such access and subsequent modification in accordance with a system change can be easily performed. It is an object of the present invention to provide a programming tool and a control device that can connect a new node / control device or the like to a network without stopping, and can efficiently resolve collation of references of logical name / variable data. .

[0008]

SUMMARY OF THE INVENTION A programming tool according to the present invention is a programming tool for a control device for realizing a distributed control system for sharing data among a plurality of control devices connected to a network. The shared data is defined by a logical name, and relative related information is generated by associating the logical name with relative storage location information storing data corresponding to the logical name, and stored in the related information storage unit. And a means for downloading the relative related information to the control device.

Further, a control device according to the present invention is a control device capable of sharing data with another control device connected to a network, wherein the control device communicates with the other control device via a network. A communication unit that exchanges data, a storage unit that stores shared data obtained by the communication unit, and the shared data is defined by a logical name, and the logical name corresponds to the logical name. A related information storage unit that stores related information that associates storage location information of the storage unit that stores data, and accesses the related information storage unit based on the logical name, and stores the location information corresponding to the logical name. A control execution unit having a function of accessing a storage area of the storage unit in which the acquired and corresponding data is stored; and a control execution unit in front of the related information storage unit based on a change in storage location information in the storage unit. And updating means for updating the relevant information,
And a function of communicating with the other control device and updating the relative storage position information of the relative relation information provided from the programming tool according to claim 1 to actual storage position information. At least some of the information
The information is generated based on the relative relation information.

Here, the storage unit for storing the shared data corresponds to the "link memory 15" in the embodiment.
In the embodiment, the storage location information of the storage unit is “address,
Pointer "and the like. In the embodiment, the related information storage unit stores the “indirect reference table 16 and the variable database 1”.
7 ". Changing the storage location information in the storage unit is a broad concept including addition and deletion. The updating unit corresponds to the “logical name arbitration unit 19” in the embodiment.
The function of updating corresponds to the “static name resolution result conversion unit 25” in the embodiment. The relative storage location information corresponds to a “relative address” in the tenth embodiment.

Preferably, the related information storage unit includes an indirect reference table storing storage position information used to access data stored in the storage unit, a logical name, and a storage position for the logical name. And a correspondence table that associates storage location information in the indirect reference table in which information is stored. Of course, such a configuration may not be necessary. The correspondence table in which the storage location information is associated corresponds to a “variable database” in the embodiment.

According to the present invention, since the static name resolution is performed in the programming tool, the communication between the control devices is not required, and the processing time is shortened. Then, by downloading the relative related information obtained by the solution to the control device, the relative related information can be incorporated into the related information of the control device. Then, for the data (variable) for which the relative position information has been generated by the programming tool, the process of changing the relative position information to the actual existing position information may be performed. Data (variables) to be processed for acquiring information is reduced. Therefore, even when the control device generates such related information,
The processing time is shortened.

The components described above of the present invention can be combined as much as possible. Each means and functions constituting the control device and the programming tool according to the present invention can be realized by a dedicated hardware circuit, or can be realized by a programmed computer.

[0014]

FIG. 1 shows a preferred embodiment of the present invention. As shown in the figure, a control device 1 such as a PLC is connected to a programming tool 3, and a user program created by the programming tool 3 is downloaded to the control device 1.

Before giving a detailed description of each part, the premise and outline of the present invention will be described. A plurality of the control devices 1 described above are prepared, and each is connected to a network. Then, the present invention is applied to a distributed control system in which the plurality of control devices 1 execute cooperative / synchronous control while sharing all data or necessary data.

A control device having a mechanism for sharing such data using a network global variable (hereinafter abbreviated as a net variable) is connected via a network, and the control devices 1 automatically resolve the reference of the net variable. To do
By combining different control programs stored for each control device 1, it is possible to easily integrate them as a distributed control system.

The control device 1 in the present embodiment is
It has a mechanism (name resolution processing) for automatically exchanging variable information with each other and allocating variables collectively to memory before data transfer, and executes this name resolution processing at the time of power-on or when joining a network. This name resolution processing is called dynamic pre-resolution processing because it is performed while actually operating the control device 1. The specific algorithm of the dynamic name resolution process will be described later.

By the way, if name resolution is dynamically performed for all data defined by the logical name (network global variable) of each control device connected to the network, the variable information is controlled through communication. Since the devices are exchanged, if the communication is slow, the time required for name resolution becomes longer. A similar problem occurs when the number of net variables to be processed increases.

On the other hand, the programming tool 3 is an environment for developing a program to be executed by the control device. The user compiles a program created in a ladder language or the like, or links a library to execute the program on the control device. It has a function to convert to an executable format. Then, on the programming tool 3, information on programs and variables (data) of the plurality of control devices 1 is managed as one project.

Therefore, when the programming tool 3 knows in advance the information of the variables (data) used in the programs of the plurality of control devices 1 included in the project, a function for performing name resolution on the programming tool 3 is provided. I have it. This is called static name resolution. This static name resolution can be processed on the tool according to the same algorithm as the dynamic name resolution, or the tool can collectively process all variables since the tool knows all the variables. Then, dynamic name resolution is performed as needed for the remaining variables for which static name resolution has not been performed.

Even when static name resolution is performed, the absolute address of each device or the like is unknown because it is not actually connected to the network, so that it is defined by a relative address. Therefore, a function for converting a relative address to an absolute address with the execution of dynamic name resolution when actually connected to a network is provided.

Next, each part will be described. First, the control device 1 will be described. The control device 1 includes a control unit 11 and a communication unit 12. The control unit 11 executes a ladder system and performs the original control of the control device (such as a PLC) 1.
The communication unit 12 is connected to a network and has a function of communicating with another control device. Specifically, a communication controller 12a that connects to a network and performs data transmission / reception (common data exchange in the context of the present invention) according to a predetermined communication protocol, and a protocol for controlling communication by the communication controller 12a. RAM 12b for temporarily storing data when performing conversion, performing protocol conversion, and storing and holding information (database) for specifying transmission and reception destinations
have.

On the other hand, the control unit 11 stores a control program for a connected device, a control program for cooperating with another control device 1 connected to the network, and the like, and a ROM 11a stored in the ROM 11a. It has an MPU 11b for executing a program and a RAM 11c for storing data (management data) necessary for executing various processes in the MPU 11b. This hardware configuration itself is basically the same as the conventional one.

In the present invention, as shown in the conceptual diagram of FIG. 2, each data is defined by a logical name (network global variable) and a user program (object code) incorporated in each control device (PLC) 1 is defined. ) Specifies a logical name and acquires data to be shared. Thereby, each control device 1 can share data without being conscious of the physical address where the corresponding data is stored, and since it is not conscious of the physical address, once registered, the physical address for storing the shared data is changed. Can be changed freely.

As an example of this concept, it is assumed that Switch is defined in a certain control device (1) 1 (in the case of the drawing, the variable name: the value is defined as "Switch1"). Then, when another control device (3) 1 wants the data of Switch 1 of the control device (1) 1,
The user program of the control device (3) 1 can acquire specific data associated with Switch 1 by specifying a variable name “Switch 1” and executing an instruction to acquire the data. . In other words, data having the same content is defined by the same logical name, and the logical name exists only on the network. That is, different logical names are assigned to different data.

When there is a change in the data content, a predetermined control device 1 rewrites the content,
The content stored in another control device 1 that shares the data is also rewritten.

Next, a specific configuration for realizing the above functions will be described. As shown in FIG.
Link memory 1 for storing data (variable data) logically shared via a network inside 11c
5, an indirect reference table 16 used to refer to each variable data stored in the link memory 15, and a variable database 17 in which a logical name is associated with a memory address (the address of the indirect reference table 16). I have. The detailed description of each unit will be described later.

On the other hand, the MPU 11b manages a control execution unit 18 for executing a control operation of the PLC 1 having a function of accessing the link memory 15 through the indirect reference table 16, and a variable database 17, and manages the variable A logical name arbitration unit 19 that changes the indirect reference table 16 based on the information stored in the database 17 is provided.

Next, each part will be described. First, the link memory 15 is a memory for storing data that is logically shared via the network as described above, and has a data structure as shown in FIG. 4, for example. That is, since the same logical name exists only on the network and is shared by each control device (PLC),
Processing such as updating data for a certain logical name
One controller on the network has the authority to execute, and the other controller will get the data sent from that one controller. In other words, for the data of a certain logical name, the one control device has a function of updating the data and the like, and a function of giving the data to another control device.

Therefore, as shown in the figure, the own node area for storing the data on the logical name (the public logical name) having the function of updating itself and the like, There is another node area for storing a copy of the data for the logical name in which is stored. In the present embodiment, the link memory 15 is divided for each node in order to improve the data transfer efficiency. However, the present invention is not limited to this.

Further, the same logical name (variable name) to be shared
The offset value in the area for storing the data (variable data) is common to each node. That is, when the variable data x for a certain logical name X is stored by a predetermined size from the offset value N of the own node area of the node (1) (the corresponding pointer in the indirect reference table described later is N). ), At another node, it is stored at a predetermined position in the other node area. And
This storage position is stored in an area of a predetermined size from the offset value N of the other node area for the node (1). In other words, when storing variable data published by another node that is required by itself in its own other node area, it is set to the same offset value as the offset value from the top of its own node area in the published other node. Will be stored. In this way, by making the offset values in each node area coincide between the public side and the use side, various processes for maintaining data commonality can be easily performed.

Regarding the actual data transmission / reception, the control device having the above-described function may output the data, or another control device may read the data from the control device having the original data. , You may get.

As shown in FIG. 5, the data structure of the variable database 17 is "logical name", "type", "size", "input / output attribute", "memory address", "static pre-resolution". , A data link area offset, and a bit position. Here, “size” is the data size of the information related to the logical name, and “input / output attribute” specifies the transmission / reception direction of the data specified by the logical name.

That is, when the input / output attribute is “output”,
This means that information about the logical name stored in the node (PLC) is output to another node. Then, data on the logical name whose input / output attribute is output is stored in a predetermined area of the own node area of the link memory 15.

When the input / output attribute is "input", it means that information on a logical name used in the node is obtained from another node. Then, data on the logical name whose input / output attribute is input is stored in a predetermined area of the other node area of the link memory 15.

The "memory address" stores address information in the indirect reference table in which a pointer for specifying the position of the link memory 15 where the actual data for the logical name is stored is stored. In this embodiment, the offset of the indirect reference table is used.
Therefore, in order to access the indirect reference table 16 by referring to the memory address stored in the variable database 17, the value is obtained by adding the above offset to the base address of the indirect reference table 16.

In this embodiment, the indirect reference table 16
It is assumed that the address (pointer) of the link memory 15 to be specified and stored in the variable database 17 is represented by 4 bytes, and thus a multiple of 4 is stored in the memory address of the variable database 17.

The "static name resolved flag" is a flag for distinguishing whether or not name resolution for the variable has already been performed by the programming tool 3 described later. Because it is a resolution, normal dynamic name resolution is performed. If "TRUE", since the static name resolution has been performed, the relative address set at the time of the static name resolution is changed to an absolute address. The “link link area offset” is an area for storing a relative address of a variable obtained as a result of performing static name resolution.

In the example shown, the logical name is "Swi
Since the memory address of “tch1” is “0000”, the data in the link memory 15 indicated by the pointer stored in the head (first) storage area of the indirect reference table 16 shown in FIG. ". Similarly, since the memory address of the logical name “Motor1” is “0004”, FIG.
The data in the link memory 15 indicated by the pointer stored in the second storage area of the indirect reference table 16 shown in FIG.
The data for "Motor1" is obtained.

As shown in FIG. 6, the data structure of the indirect reference table 16 stores a pointer in the link memory 15 in which data on each logical name is stored. In this embodiment, the pointer for specifying the storage area in the link memory 15 is specified by 4 bytes, the upper 3 bytes specify the word position, and the lower 1 byte specifies the target data in the word position. Specifies the bit position in which is stored.

Then, each of these stored pointers is
The pointer to which logical name is specified by the correlation between the logical name stored in the variable database 17 and the memory address as described above. In other words, it is registered in advance that the n-th pointer from the top of the indirect reference table 16 is a pointer for a predetermined logical name, and it is invariable as long as the storage content (memory address) of the variable database 17 is not changed. Become.

That is, when the storage area of the data for a certain logical name is changed, the pointer stored in the area storing the pointer for the logical name in the corresponding indirect reference table 16 is updated to a new one. Corresponding. Even in this case, the storage contents of the variable database 17 need not be changed. Therefore, when the program which the control device actually controls needs to know the information on the logical name for data sharing, the program first accesses the indirect reference table 16 in accordance with the memory address stored in the variable database 17. To get a pointer. Next, the data pointed by the pointer is obtained. Thus, the program can acquire data and operate correctly regardless of whether there is a specific change in the storage area.

Further, in the present embodiment, the data stored in the indirect reference table 16 and the data corresponding to the actual logical name are transmitted and received in the RAM 11c, and the Export variable is used to smoothly and surely share the data. Listing 2
0, an Import variable list 21 and a Remote variable list 22 are provided. Each of these variable lists 20 to 22 is created based on the information stored in the variable database 17, and is specifically as follows.

First, the Export variable list 20 is a list of network global variables output from the own node. The data structure is, as shown in FIG. 7, a variable name (logical name), a variable type and size (the number of bytes), and its own node area (FIG. 4) (hereinafter referred to as “Export conversion information table”).

The table in which the input / output attribute column of the variable database 5 shown in FIG. 5 is "output" is extracted, and the indirect reference table (FIG. 6) is accessed from the memory address column to access the own node. By acquiring the offset of the area (the area for storing the data on the logical name managed by itself), a list as shown in FIG. 7 can be created.

On the other hand, the Import variable list 21 is a list of network global variables input from other nodes, and has a data structure of variable names (logical names), variable types and sizes (bytes) as shown in FIG. number),
In addition to the offset of the other node area (see FIG. 4) in the link memory 15 in which the data of the variable is stored, a table having a flag indicating whether the variable is valid or invalid (hereinafter referred to as “Import conversion information table”) ").

Such a table is extracted when the input / output attribute column of the variable database 5 shown in FIG. 5 is “input”, and the indirect reference table (FIG. 6) is accessed from the memory address column to link the table. By obtaining the offset of the other node area in the memory 15 (the area for storing data sent from the other node), a list as shown in FIG. 8 can be created.

Further, the Remote variable list 22 is expressed as follows:
The received other node variable list is classified and stored for each node. As shown in FIG. 9, the data structure includes a table storing a node number and a head pointer of an Export variable list (hereinafter, referred to as a “Remote conversion information table”).

Each of the above table information is performed using the programming device (tool) 3. That is, FIG.
Suppose that each control device 1 is network-connected to the LAN 2 as shown in FIG.
In such a case, before adding a new control device (X) 1 'to the network, a programming device 3 is connected to the control device (X) 1', and predetermined data and information are transmitted from the programming tool 3 to the control device ( X) Download to 1 '.

More specifically, as shown in FIG. 11, first, a user creates a source program 3a in a ladder or a high-level language using a programming tool 3. At this time,
Data shared by a plurality of control devices (1), (2), (3),... (X) is defined as the same logical name among the control devices, and an attribute of network sharing is added.

Then, the compiling function 3b of the programming tool 3 is executed to compile the source program 3a created as described above, and the object code 3c for the control device to execute the original control has the same logical name as the object code 3c. A variable database (see FIG. 5) 3d required for data sharing is generated.

Next, the programming tool 3 downloads the generated object code 3c and the variable database 3d to the control device (X) 1 '. Then, the downloaded object code and variable database are stored in the nonvolatile memory of the control device (X) 1 '.

The programming tool described above is
In the illustrated example, an example is shown in which the control device (X) 1 'is connected to and downloaded to the control device (X) 1'. However, for each of the control devices (1), (2),. Before (at the time of) connection to a network, a programming tool is connected and predetermined data and information are downloaded.

Next, the logical name arbitration unit 19 will be described. The logical name arbitration unit 19, based on the information stored in the variable database 17 downloaded as described above,
It has a function of generating an Export variable list 20 and an Import variable list 21. The specific generation processing is as described in the description of the Export variable list 20 and the Import variable list 21 described above.

That is, the export variable list 20 is created by setting the offset value to 0 (ST1) and setting the variable database 1 as shown in the flowchart of FIG.
7 is searched for an output variable whose input / output attribute is output, that is, a network global variable that the own node discloses to other nodes (ST2).

Each time a search is performed, an Expo that stores an Export conversion information table for the variable is stored.
An rt conversion table is secured (ST3, ST4). Then, the conversion database 17 is stored in the secured table.
The variable name, type, and size information stored in the file are copied (ST5).

Next, the data of the variable (variable data)
Get offset information of the own node area that stores
The information obtained in step 5 and step 6 is
It is added to the t variable list (ST7). Therefore, in the first case, the offset is registered from 0, that is, from the head of the own node area.

Thereafter, the variable size is added to the current offset value to obtain a new offset value (ST8), and the process returns to step 2. Thereafter, the above process is repeatedly executed until all output variables are searched. As a result, areas for storing the respective variable data from the head of the own node area are secured in order without being empty.

On the other hand, the creation of the Import list 21 is as follows.
The flowchart shown in FIG. 13 is executed. That is, an input variable whose input / output attribute is input, that is, a network global variable of another node used by the own node is searched from the variable database 17 (ST11).

Each time a search is performed, an Impo that stores an Import conversion information table for the variable is stored.
An rt conversion table is secured (ST12, ST13).
Then, the variable name, type, and size information stored in the conversion database 17 are copied into the secured table (ST14). Further, an invalid flag is set (ST15), and the information obtained in steps 14 and 15 is added to the Import variable list (ST1).
6). Thereafter, the process returns to step 11. Thereafter, the above process is repeatedly executed until all input variables are searched.

Further, the logical name arbitration unit 19 has the following conversion table updating and other functions in addition to the above-described conversion table creation function. That is, the control device 1
Is connected to the existing operating network, the logical name arbitration unit 19 broadcasts its own Export variable list 20 and exchanges information of network global variables with other control devices. .

That is, as shown in FIG. 14, the logical name arbitration unit 19 on the side transmitting the export variable list first transmits the export variable list by broadcast (ST21). As will be described later, since the other control device (node) on the receiving side that has received the broadcast transmits a response signal, it is determined whether or not the response signal has been received (S
T22). If there is a response signal, the response station that issued the response signal is recorded (ST23).

It is checked whether or not a response signal has been received until a timeout occurs (ST24), and if a timeout occurs, the table update is completed (ST25). This gives E
Who sent the xport variable list is who
You can receive the ort variable list and determine who has not.

As for the transmission timing of the Export variable list, the storage contents of the variable database 17 are changed due to a user program correction or compile execution, in addition to the above-described time of newly adding or connecting to the network. The variable database 17 of the control device being executed by the
This is also performed when the stored contents of the file are changed. And every time it is changed, the version is updated, and Ex
To send (broadcast) the port variable list,
The version information is also sent. Therefore,
The receiving node may receive the Export variable list for the first time or may have already received it. In the present invention, the version information does not always have to be provided. A table synchronization method using version information will be described later.

On the other hand, the other existing node (control device) that has received the Export variable list has a function of executing the flowchart shown in FIG. That is, E
It is determined whether or not the xport variable list has been received (ST
31) If it has been received, it is determined whether or not the version of the Export variable list matches the version previously received and stored (ST32).

If they do not match, Exp
It is determined that the ort variable list has been updated, and the stored table (Import for the receiving node)
The variable list is updated (ST33). When the Export variable list is received for the first time, it is determined that the versions do not match, and the table is updated.

Then, after updating the table in step 33,
If the versions match in the branch determination in step 32 (update is unnecessary), a response signal is transmitted to the transmission source node of the Export variable list, and the process ends (ST34).

Further, the logical name arbitration unit 19 receives the received Ex
It has a function of creating a Remote variable list based on the port variable list. That is, in the processing on the receiving side shown in FIG.
When the port variable list is received, it is
Manage as a te variable list for each node. That is, regardless of whether the received node is required variable data, information on all Export variable lists is once fetched into the control device, and stored and retained. This list is held in the non-volatile memory. Specifically, FIG.
As shown in the figure, the Export sent from node 1
The variable list is stored in the table area of the node 1.

The logical name arbitration unit 19 compares the Remote variable list 22 obtained as described above with the Impo
The indirect reference table 16 is created and updated based on the rt variable list 21. To explain conceptually, the remote variable list 22 is used as a key with the variable name (logical name) used in the own node stored in the import variable list 21 as a key.
To obtain a matching variable name, obtain a pointer to the link memory 15 of the own node in which the variable data relating to the variable is stored,
6 in the memory area.

When a new network is joined as in the case of the control device (X) 1 ′, the Expo
Exp for nodes that have not received the rt variable list
Request an ort variable list. As a result, the received E
Remote based on the xport variable list
Creation of the variable list 22 and thus the indirect reference table 16
Perform an update. Specifically, the flowchart shown in FIG. 17 is realized.

First, the Import variable list 21 is searched in order (ST41, ST42), and the following processing is performed for each searched variable name (logical name). That is, the Remote variable list is searched using the obtained variable name as a key, and the node address of the control device that discloses the variable and the own node area offset in the link memory of the device are obtained (ST43).

Next, the base address (head address) of the other node area corresponding to the link memory (the area for the node that discloses its variables) is calculated (S).
T44). Then, in the base address, step 4
The value obtained by adding the offset obtained in step 3 is obtained (ST
45). That is, in the corresponding node area, the offset values of the areas storing variable data of the same logical name (variable name) are made equal, so that the obtained value is the head address of the link area for storing the variable data. Becomes

Next, the variable database 17 is searched based on the variable name, and the position of the indirect reference table (the location where the pointer of the variable name is stored) is obtained (ST46). That is, the offset address registered in the memory address column shown in FIG. 5 is obtained. Then, in accordance with the obtained offset address, the value calculated in step 45 (a pointer indicating the head position of the area for storing the variable data in the link memory 15) is stored in the storage area of the corresponding indirect reference table. As a result, the indirect reference table can be updated.

As a result, if the variable database 17 shown in FIG. 5 is used, as shown in FIG. 18, for example, the storage area in the link memory 15 for the variable data whose logical name (variable name) is "Switch1" is as shown in FIG. In the case of, the first address (pointer) of the storage area is stored in the field of Switch 1 (offset address 0000: head) of the indirect reference table 16.

As described above, the contents of the lists 20 to 22 and the indirect reference table 16 in each node (control device 1) are updated by the logical name arbitration unit 19 each time, so that the links are stored in the link memory 15. Even if the content of the stored variable data or the storage area of the variable data changes, the storage position (offset address) of the indirect reference table 16 for a certain variable name (logical name) remains unchanged (even if it is changed, The control execution unit 18 accesses the link memory 15 via the indirect reference table 16 to obtain desired variable data, and A control system can be implemented. The function of the control execution unit 18 is as shown in a flowchart of FIG.

That is, after the initialization process (ST
51), IN refresh is performed (ST52). That is, the area network global variable (variable data) stored in the other node area of the link memory 15 is read. And user program (normal control)
Is performed (ST53), and OUT refresh is performed (S53).
T54). That is, a network global variable (variable data) disclosed by itself is written in its own node area of the link memory 15. Next, peripheral I / F processing is executed (ST55). Thus, the link memory 15
While accessing (reading and writing variable data)
The processing for executing the user program is repeatedly executed until the system stops (ST56, ST57). FIG. 20 shows a conceptual diagram of the control devices 1 and 1 'when executing the user program while accessing the link memory 15 described above (the static name resolution part will be described later).

Further, transmission and reception of the actual variable data stored in the link memory 15 are performed via the communication unit 12 by the control unit 1.
(Node). First, conceptually,
The data (variable data) allocated to the own node area in the link memory 15 is transmitted to another node by a broadcast communication method or the like, and the data (variable data) allocated to the other node area is transmitted from the corresponding other node. Receive.

That is, as shown in FIG. 21, necessary data is transferred between the RAM 11c on the control unit 11 side where the link memory is stored and the RAM 12b on the communication unit 12 side.

Therefore, as shown in FIG. 20, the data allocated to the own node area of the link memory 15 is once copied and transferred to the communication side RAM 12b of the communication unit 12, and between the control units, the communication side RAMs 12b communicate with each other. (Strictly via the communication controller 12a) performs data transfer accompanying simultaneous broadcasting, thereby enabling other nodes (control devices)
Send to the side. On the other node side receiving this,
Based on the transfer data size calculated from the Export variable list and the Import variable list, data necessary for the own node is transmitted from the communication unit 12 (communication RAM 12b) to the control unit 1.
1 (control side RAM 11c). The communication unit 1
The two sides perform the predetermined processing based on the received data as described above.

The data transfer processing function between the communication unit 12 and the control unit 11 in the control device is as follows. First, in the present embodiment, the communication unit 12 includes the control unit 11
A cyclic communication service is started in response to a request. That is, the communication unit 12 controls the control unit 1
Import variable list, Expor received from 1
The communication parameters are calculated and set based on the t variable list, and the cyclic communication service is started or subscribed.

The cyclic data contains valid / invalid information indicating whether the data can be used by the receiving side (valid data) or cannot be used. The valid / invalid information is set on the transmitting side. When the valid / invalid information is "valid", it can be determined that the cyclic data received by the communication unit on the receiving side may be transferred to the control unit.

Further, the communication side RAM 12b can be accessed from both the communication controller 12a side of the communication unit 12 and the control unit 11 side. Therefore, if no control is performed, the communication RA
Since the M12b may be accessed, in order to avoid this, in the present embodiment, the control unit 11 is in charge of exchanging data. That is, the control unit 11 notifies the communication unit 12 of access permission / prohibition. The communication unit 12 can be accessed only while the control unit 11 permits access to the communication-side RAM. Specifically, FIG. 22 (control unit) and FIG. 23 (communication unit)
The flowchart shown in FIG.

First, the function of the control unit 11 is as shown in FIG.
As shown in (5), read / write of data, that is, access to the communication side RAM 12b is performed (ST6).
1). When the access process is completed, the communication side is notified of the completion of the access (ST62). This access completion notification is an access permission notification to the communication unit 12.

Then, normal controller processing (execution of a user program) is performed (ST63). Further, when it is necessary to access the communication side RAM 12b again, an access request notification is sent to the communication unit 12 (ST64). As will be described later, the communication unit 12 that has received the notification returns an access permission notification.
1 judges whether or not an access permission notice has been received from the communication unit 12 (ST65), and upon receiving the permission notice, clears the access status (ST66) and returns to step 61, where the control unit 11 Access to the communication side RAM 12b.

On the other hand, as shown in FIG. 23, the function of the communication section 12 first determines whether or not an access completion notice has been sent from the control section 11 (ST71). Then, when the completion notification is received, the communication side RAM 12b is accessed (Read / Write of data) (ST72). Next, it is determined whether an access request notification has been sent from the communication unit 12 (ST73). If no communication is received, the communication unit 12 still has an access right to the communication side RAM 12b, so that access is made as necessary.

On the other hand, when the access request notice is received, the access to the communication side RAM 12b is terminated and the access permission notice is returned to the control unit 11 (S
T74). At this time, if the communication unit 12 receives the access request notification during the transfer of one node, the access unit waits for the completion of the transfer of one node in order to guarantee the synchronization of the received data on a node basis. The permission notice will be returned. When the access completion notification is received again from the control unit 11 after the interruption by the notification in step 74, the communication side RA of the node next to the interrupted node is received.
The transfer to M12b is started.

Next, the static name resolution which is a main part of the present invention will be described. This static name resolution is executed by the static name resolution unit 5 (see FIG. 1) of the programming tool 3, and the basic algorithm is the same as the above-mentioned dynamic name resolution. First, the programming tool 3 will be described. As is well known, the programming tool 3 is an environment for developing a program to be executed by the control device 1, and compiles a program created by a user in a ladder language or the like, and links a library to control It has a function of converting to a format executable by the device 1.

The programming tool 3 can manage the programs of the plurality of control devices 1 collectively. That is, as shown in FIG. 24, on the programming tool, the program / variable information of the plurality of control devices 1 can be managed as one project.

In other words, since the programming tool 3 manages the programs of the plurality of control devices 1 as one project, it is possible to know which program is reading and writing the net variables. Actually, at the time of compiling or linking, the information of the net variables used in the programs of a plurality of control devices included in the project is known, so the static name resolution unit 5 performs the analysis at the time of compiling or linking. To perform name resolution.

The function of the static name resolution unit 5 is as shown in the flowchart of FIG. That is, first, one of the control devices included in the project is selected and processed (ST81).

Then, Exp for the target control device
An ort variable list is created (ST82). This Exp
The specific processing procedure for creating the ort variable list is the same as that performed at the time of dynamic name resolution, and a detailed description thereof will be omitted. Then, the control target to be processed is sequentially switched, and the list is created for the control target for which the Export variable list has not been created (ST83, ST84).

In this way, E for all control devices
If the xpor variable list has been created, the branch determination in step 83 becomes Yes, so the process proceeds to step 85, and variable address assignment is performed. That is, the control devices included in the project are sequentially selected one by one as processing targets, and the address assignment of the net variables, that is, name resolution is performed with reference to the Export variable list created in step 82. Then, the result of the name resolution (address assigned to the net variable) is stored in the variable database 6 of the programming tool 3 (ST85 to ST88).

This name resolution processing can also be performed basically according to the same procedure as for dynamic name resolution. However, in the case of dynamic name resolution, an absolute address can be obtained in order to perform name resolution by exchanging information of net net variables between the control devices 1 via the network 2. In this case, since it is not actually connected to the network, it is not known which part of the link area is an area for which control device, so that an absolute address in the link area cannot be determined. Therefore, in the static name resolution, the address of the net variable is assigned by the relative address from the head of the link area of each control device.

That is, the data structure of the variable database in the programming tool 3 is basically the same as that shown in FIG. 5, and the result of name resolution is stored in each column as in the case of dynamic name resolution. For the net variable whose name has been resolved, the “static name resolved flag” in the variable database (FIG. 5) is set to TRUE, and the relative address is stored in the “data link offset”.

For the net variables whose names could not be resolved in the project, the “static name resolved flag” in the variable database 6 is set to FALSE. In this case, the “data link offset” remains at the default 0.

The result of the static name resolution (data stored in the variable database 6) is downloaded at runtime. That is, the program is downloaded from the programming tool 3 to the control device 1 together with the control program. Then, the data stored in the variable database 6 is registered in the variable database 17 in the control device 1.

Therefore, at the time of dynamic name resolution, for a net variable whose static name resolved flag is "FALSE",
Execute the above processing. For a net variable whose static name has been resolved (the flag is “TRUE”), a process of converting a relative address to an absolute address is performed. Specifically, as shown in FIG. 26, the address is converted by adding the head offset of each area to the result of the static name resolution, and predetermined data is stored in the indirect reference table based on the obtained absolute address. Store. Such address conversion is performed by the static name resolution result conversion unit 25.

In the above-described embodiment, all the static names that can be resolved by the programming tool 3 are resolved. However, the present invention is not limited to this. The solution may be performed.

For example, at the time of debugging, the net name of the control device for which debugging has been completed is subjected to static name resolution, and the program which is being debugged is frequently corrected. Even if it does not, do dynamic name resolution. As a result, it is possible to reduce the time required for reflecting the result of the program correction on the control device 1 and confirming the result.

Other examples include "do not perform static name resolution for a certain logical name (variable)" and "do not perform static name resolution for a certain control device". In either case, the programming tool 3 sets (eg, specifies using a flag or the like) whether or not to perform static name resolution in each unit (variable, control device, and the like). Then, the static name resolution unit 5 compiles or links only the relevant one to resolve the name.

Further, in the above-described embodiment, the dynamic name resolution is performed before the control program starts running, such as when the control device is activated or when it joins the network. However, the present invention is not limited to this. The present invention is not limited to this. For example, name resolution may be performed while running a control program. As a result, dynamic name resolution processing at the time of system startup or the like can be omitted, and the system can be started quickly. At this time, the communication of the net variable is not performed until the name resolution is completed, so that the user sets an appropriate initial value to the net variable so that the control device does not perform a dangerous operation.

[0102]

As described above, according to the present invention, it is possible to access by a logical name without knowing the storage location information of the specific data, so that the shared data can be accessed without being aware of the communication processing. Can be easily accessed. In addition, in order to obtain such an environment, not only the storage location information is dynamically generated and changed, but also at least a part of the data can be statically resolved by the programming tool in advance, so that the actual The number of processes for dynamically generating the storage location information by performing communication between the control devices can be reduced.
Therefore, as a whole, the above environment can be constructed efficiently and in a short time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating an outline of functions of the embodiment.

FIG. 3 is a diagram illustrating an example of an internal structure of a control unit.

FIG. 4 is a diagram illustrating an example of a data structure of a link memory.

FIG. 5 is a diagram illustrating an example of a data structure of a variable database.

FIG. 6 is a diagram illustrating an example of a data structure of an indirect reference table.

FIG. 7 is a diagram illustrating an example of a data structure of an Export variable list.

FIG. 8 is a diagram illustrating an example of a data structure of an Import variable list.

FIG. 9 is a diagram illustrating an example of a data structure of a Remote variable list.

FIG. 10 is a diagram showing a preferred embodiment of a network system.

FIG. 11 is a diagram illustrating an operation of downloading to a control device using a programming device.

FIG. 12 Expor is a part of the function of the logical name arbitration unit.
It is a flowchart which shows the creation function of a t variable list.

FIG. 13 shows Impor which is a part of the function of the logical name arbitration unit.
9 is a flowchart illustrating a function for creating a t variable list.

FIG. 14 is a flowchart illustrating a processing function of a side that delivers an Export variable list.

FIG. 15 is a flowchart illustrating a processing function on the side that receives an Export variable list.

FIG. 16 is a diagram illustrating a function of creating an indirect reference table from a Remote variable list and an Import variable list.

FIG. 17 is a flowchart illustrating an update function of an indirect reference table, which is a part of the function of the logical name arbitration unit.

FIG. 18 is a conceptual diagram showing a specific example of a function of updating an indirect reference table, which is a part of the function of the logical name arbitration unit.

FIG. 19 is a flowchart illustrating functions of a control execution unit.

FIG. 20 is a diagram illustrating an example of an execution phase of the control device.

FIG. 21 is a diagram showing a control unit side RAM and a communication side RAM in the control device;
FIG. 3 is a diagram for explaining data transfer between the devices.

FIG. 22 is a diagram showing a control unit side RAM and a communication side RAM in the control device;
6 is a flowchart showing a sequence of data transfer between the control units (the control unit side).

FIG. 23 is a diagram showing a control unit RAM and a communication RAM in the control device;
9 is a flowchart showing a sequence of data transfer between the communication units (communication unit side).

FIG. 24 is a diagram showing a management unit configuration of a project.

FIG. 25 is a flowchart illustrating a function of a static name resolution unit.

FIG. 26 is a diagram illustrating an example of conversion between a relative address and an absolute address performed in the control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control apparatus 2 Network 3 Programming tool 5 Static name resolution part 6 Variable database 11 Control part 12 Communication part 15 Link memory 16 Indirect reference table 17 Variable database 18 Control execution part 19 Logical name arbitration part 20 Export variable list 21 Import variable list 22 Remote variable list 25 Static name resolution result converter

Continuation of the front page (72) Inventor Hiroshi Yoshida 801 Shimogyo-ku, Shimogyo-ku, Kyoto Shimogyo Higashi-iri, Minami-Fudo-cho F-term (reference) 5H220 BB05 CC09 CX04 CX09 DD04 EE10 HH01 HH04 JJ13 JJ24 JJ59

Claims (2)

[Claims] 1. A programming tool for a control device for realizing a distributed control system for sharing data among a plurality of control devices connected to a network, wherein the shared data is defined by a logical name, and Logical name,
Static name resolution means for generating relative relation information in which relative storage position information storing data corresponding to the logical name is stored and storing the relative relation information in a relation information storage unit; and means for downloading the relative relation information to the control device. A programming tool characterized by comprising: 2. A control device capable of sharing data with another control device connected to a network, and exchanging data with the other control device via a network. A communication unit, a storage unit for storing shared data obtained by the communication unit, and the shared data is defined by a logical name, and the logical name,
A related information storage unit that stores related information in which storage location information of the storage unit that stores data corresponding to the logical name is stored; andthe related information storage unit is accessed based on the logical name. A control execution unit having a function of acquiring a corresponding location information and accessing a storage area of the storage unit in which corresponding data is stored; and a related information storage unit based on a change in storage location information in the storage unit. And updating means for updating the related information, and communicating with the other control device, and storing the relative storage position information among the relative related information provided from the programming tool according to claim 1 as an actual storage. A control device having a function of updating to position information, wherein at least a part of the related information is generated based on the relative related information.