JP2005293310A - Node and tool, network system, and shared data communication method - Google Patents

Abstract

There is provided a communication method for shared data, in which only necessary data is transmitted to each node, and each node does not need to prepare a memory area larger than necessary, and can perform data communication efficiently.
Data is shared among a plurality of nodes (PLC1, RB1, RB2). Since the transmission data of PLC1 includes RB1 data that requires RB1 and RB2 data that RB2 requires, these RB1 data and RB2 data are grouped. Each group is a collection of data scattered in a memory area, and data can be transmitted in units of groups. Therefore, PLC1 transmits RB1 data to RB1, and transmits RB2 data to RB2. Since only necessary data is transmitted separately for each node, both RB1 and RB2 can receive only necessary data, and the memory capacity for storing received data can be reduced.
[Selection] Figure 4

Description

  The present invention relates to a node, a tool, a network system, and a shared data communication method.

  A programmable controller (PLC) is used as a control device for factory automation (FA) installed in a production factory (manufacturing site). This PLC is composed of a plurality of units. That is, a power supply unit of a power supply source, a CPU unit that controls the entire PLC, an output unit that inputs a switch or sensor signal attached to an appropriate place in an FA production device or facility device, an output that outputs a control output Various units such as a unit and a communication unit for connecting to a communication network are appropriately combined.

  The control in the PLC (CPU unit) takes a signal input from the input unit into the I / O memory of the CPU unit (IN refresh) and performs a logical operation based on a user program written in a pre-registered ladder language (calculation) Execution), the operation execution result is written in the I / O memory, sent to the output unit (OUT refresh), and then the so-called peripheral processing is cyclically repeated.

  By the way, in the system including this PLC, a plurality of master nodes such as PLCs and other controllers are prepared and connected through a network, and data is shared among the nodes (masters), thereby enabling synchronous control and cooperation. Control may be performed. In this case, as a method of sharing data between nodes such as PLCs, there is a data link method used between multi-masters.

In this data link method, as disclosed in Patent Document 1 and the like, a data link area is set in a predetermined area of a memory in each node. This data link area has its own node area for storing data to be shared (transmission data in FIG. 1) and another node area for storing data sent from other nodes (reception data in FIG. 1). ) Is prepared. These data link areas are set in a continuous memory area. Each node becomes a master node and transmits its own data stored in its own node area via the network. The transmitted data is acquired by all other nodes (masters) connected to the network, and each corresponding other node area (the other node area for the node that transmitted the acquired data (in FIG. 1, “RB1 Data ”,“ RB2 data ”). By this means, all the nodes participating in the data link are sent to other nodes by transmitting and outputting the data stored in their own node areas. Share data with nodes.
Patent No. 3329399

  However, when trying to share data by the above-described data link method, there are the following problems. That is, when attention is paid to a certain node (PLC1), data to be transmitted is not necessarily required by all other nodes. That is, the data stored in the own node area is data that is required by at least one of the nodes that perform data linking. Other PLCs that have received such data store all the data received in the corresponding other node areas, but normally other nodes use a part of the received data.

  As an example, if three nodes (PLC1, RB1, RB2) have a data link, the data sent from PLC1 includes data used only by RB (robot) 1 (RB1 data). ), Data used only by RB2 (data for RB2), and data used by both RB1 and RB2 (common data). Therefore, the PLC 1 transmits the data stored in its own node area, but the RB 1 that has received the data does not use the RB 2 data. Similarly, although PLC1 receives RB1 data and RB2 data from RB1 and RB2, respectively, there are many cases where PLC1 does not need all the received data. As an example, as shown in FIG. 2, only the inside of the RB1 data is required, and the other part is not required (used in another node (RB2)). In the above example, the data link is performed between the three nodes. However, as the number of nodes constituting the data link increases, the data that is not used increases even if it is received.

  Even if data that is received but not used is stored in the memory, it is a wasteful use of the memory, and not only is the data storage area required more than necessary, but also transmission / reception (communication) of data that is not used as such. Increase in the amount of data) and the operation of reading and writing the memory are necessary.

  Furthermore, even if a part of the received data is data used in the node, it is not continuously present in the other node area, but is scattered in the other node area. . Therefore, the setting when using data that is actually used becomes complicated.

  In the present invention, only the necessary data is transmitted to each node while adopting the multi-master method, so that each node does not need to prepare an unnecessarily large memory area and can perform data communication efficiently. It is an object of the present invention to provide a node and a tool capable of communication, a network system, and a method for communicating shared data.

  In order to achieve the above object, the node of the present invention is a node that transmits / receives IO data to be shared with other nodes connected to the network, and the node has a dot in its own memory area. Group information storage means for storing group information for grouping a plurality of existing IO data as a group, and association with a loop stored in the other node to be transmitted / received to / from the group stored in the group information storage means Connection information storage means for storing connection information, and communication means for communicating with the other node specified by the connection information in units of groups specified based on the group information.

  The tool according to the present invention is a tool for generating and downloading the group information and the connection information for a node, and IO data for storing and holding information specifying IO data of the node and the other nodes An information storage means and an input screen based on the information for specifying the IO data are displayed on the output unit, and group information for collecting a plurality of IO data selected from the displayed IO data as one group is generated. In addition, group information created by the group information creating means stored in the storage means and the group information creating means for the two nodes to be related is displayed on the output unit, and the group information of each of the displayed nodes is displayed. When the group information to be related is selected, connection information is created and stored. Constructed by a connection information generation means for storing the. The information stored in the IO data information storage means can be collected and stored from each node. Of course, it may be stored in advance or may be acquired from another tool or the like. The information for specifying the IO data corresponds to a variable table in the embodiment, and the IO data information storage means corresponds to a memory for storing the variable table in the embodiment.

  In the network system according to the present invention, a plurality of nodes configured as described above are connected to the network, and a plurality of IO data belonging to the group specified by the group information is grouped with another node specified by the connection information. It was configured to share data by sending and receiving.

  A shared data communication method according to the present invention is a shared data communication method for sharing data by transmitting / receiving shared IO data between a plurality of nodes connected to a network. IO data scattered in the memory area in the node is treated as one group and transmitted and received in groups. The IO data belonging to the group is IO data required by the receiving node. .

  The present invention is premised on a communication method used between multi-masters. Then, data is exchanged between the nodes, and at this time, data communication is performed in units of groups composed of a plurality of IO data scattered in the memory area. As a result, unnecessary data need not be transmitted, the data storage area of each master node and the amount of data communication can be optimized, and shared data usage settings can be simplified.

  In addition to the PLC and robot shown in the embodiment, the nodes of the present invention include a robot controller that performs advanced robot control, a motion system controller (MC), a numerical controller (NC), and the like.

  In the present invention, by adopting the multi-master method, only necessary data is transmitted to each node, so that each node does not need to prepare an unnecessarily large memory area and can perform data communication efficiently. it can.

  FIG. 3 shows an example of a network configuration to which the present invention is applied. In this example, three master nodes 10a to 10c (PLC1, RB1, RB2) and a configuration tool 20 are connected to the network 1, and these nodes 10a, 10b, 10c transmit and receive data to and from each other. Share data. In the figure, RB is a robot that operates by receiving a command from the PLC and transmits an operation status to the PLC.

  Here, in this embodiment, each node groups data (IO data) shared among a plurality of nodes owned by itself (not necessarily between all nodes) and associates them with other nodes (connections). ). Thus, by creating a group of data for a certain node connected to the network and transmitting data in units of the group, each node receives all the received data.

  That is, taking an example based on the node 10a (PLC1), as shown in FIG. 4, the transmission data of PLC1 includes RB1 data that requires RB1 and RB2 data that RB2 requires. Exists. Therefore, the RB1 data and RB2 data are grouped. In this embodiment, since data can be transmitted in units of groups, the node 10a (PLC1) transmits RB1 data to the node 10b (RB1), and to the node 10c (RB2). RB2 data is transmitted. Conventionally, all transmission data (RB1 data + RB2 data) is transmitted to each of RB1 and RB2, but in this embodiment, only necessary data is transmitted to each node. Thus, both RB1 and RB2 can receive only the data that they need.

  Similarly, RB1 data sent from RB1 to PLC1 is also grouped, and the received RB1 data is stored in a predetermined storage area that has been previously connected. As shown in FIG. 5, the RB1 data is composed only of data required by the PLC1. Similarly, RB2 data sent from RB2 is composed only of data required by PLC1. Therefore, the reception data (RB1 + RB2) received by the PLC 1 and stored in the memory is only data necessary for the PLC 1. As is apparent from a comparison between FIGS. 1 and 4 and FIGS. 2 and 5, the data to be transmitted and received and the forest area to be stored can be reduced.

  In FIG. 4, the transmission data of PLC1 includes data required by both RB1 and RB2. It is sufficient that such necessary data belongs to each group. In other words, it belongs to the RB1 data group and also belongs to the RB2 data. In this case, the data belonging to both groups is transmitted twice because each group is transmitted, so it is transmitted twice. The effect on the entire system is much smaller than if the memory capacity was taken up.

  Furthermore, in the present embodiment, predetermined data stored in the memory is appropriately selected and grouped, so that data belonging to one group is scattered on the memory. Therefore, data when a certain group is transmitted is not stored in a continuous memory area as in the prior art. In other words, since data existing in arbitrary discontinuous memory spaces can be appropriately extracted and grouped, only data necessary for each node can be transmitted, and unnecessary data need not be transmitted.

  Next, a specific configuration for realizing the function of grouping, connecting, and transmitting / receiving data in units of groups will be described. FIG. 6 shows the internal structure of the PLC that is the node 10a. The PLC includes a CPU unit 11 and a communication unit 12 in relation to the present invention. Of course, there are power supply units and various other units. The other nodes (RB1, RB2) also have the same functions and configurations, regardless of whether they are configured in units.

  The CPU unit 11 cyclically executes the calculation execution, I / O refresh, peripheral processing, etc. of the user program stored in the user memory 11a in the MPU 11b, and the data in the IO memory 11c (ON / OFF of the input / output device) OFF data, analog data detected by a measuring instrument, etc.) are updated sequentially. The predetermined data stored in the IO memory 11c is transmitted and received for sharing with other nodes. Although not shown because it is not directly related to the present invention, the CPU unit 11 includes a system ROM storing a system program, a RAM used as a work memory, and various other components. Each component is connected via a bus.

  In this embodiment, a variable table storage unit 11d that stores information about variables that are managed and used by the CPU unit 11 is provided. As shown in FIG. 8, this variable table is a table in which variable names (logical names), data types, and addresses are associated with each other. Of course, in addition to these three items, various types of information may be added as necessary, such as the number of elements and processing during power interruption. The variable table storage unit 11d is configured using a non-volatile memory, and is stored and held by being downloaded from a setting tool (either the configuration tool 20 or another tool). Furthermore, although the variable table storage unit 11d is drawn as an independent storage unit for the sake of illustration, the variable table storage unit 11d may be configured using the same physical memory as the user memory 11a and / or the IO memory 11b.

  The communication unit 12 includes an MPU 12a, a work memory 12b, a communication interface 12c, and a grouping information storage unit 12d. The communication unit 12 also includes other components such as a system ROM storing a system program such as communication control executed by the MPU 12a. These components are also connected via a bus. Furthermore, the cyclic processing in the CPU unit 11 and the transmission / reception processing in the communication unit 12 are performed asynchronously.

  The MPU 12a controls the communication unit 12, communicates with other nodes connected via the network, accesses the CPU unit 11 and the like based on the received information, and executes predetermined processing. Information to be transmitted is collected from the CPU unit 11 or the like.

  The work memory 12b is used to appropriately store data when the MPU 12a is executed. It is also used as a memory for temporarily storing data to be transmitted / received. That is, for example, when transmitting predetermined data stored in the IO memory 11c of the CPU unit 11, it is temporarily stored in a predetermined area of the work memory 12b and transmitted to the outside at a predetermined timing. The data received via the network 1 is temporarily stored in the work memory 12b, and transferred (written) to a predetermined storage area of the corresponding IO memory 11c. These processes are also performed by the MPU 12a.

  The communication interface 12 c is an interface for actually connecting to the network 1 and performing communication, and is set corresponding to the type of the network 1. The above-described basic processing functions of the MPU 12a, the work memory 12b, and the communication interface 12c are the same as those in the related art.

  Here, in the present invention, a grouping information storage unit 12d is provided, and according to the grouping information stored in the grouping information storage unit 12d, the data to be transmitted and received are grouped, and the connection with other nodes is achieved. Send / receive to / from a desired node in units. The grouping information includes group information for specifying variables belonging to the group and connection information for specifying which group of which node is associated (transmitted / received). These grouping information is generated by the configuration tool 20 and downloaded.

  FIG. 7 shows the internal structure of the configuration tool 20. The configuration tool 20 includes an input unit 21, an MPU 22, an output unit 23, a memory 24, and a communication interface 25. The input unit 21 includes a pointing device such as a mouse, a keyboard, and the like. It is used to specify a variable belonging to a certain group, input a group name of the group, or specify a group to connect.

  The output unit 23 is a display in the present embodiment. Displays an input screen for various condition settings. The communication interface 25 is an interface for actually connecting to the network 1 and performing communication, and is set corresponding to the type of the network 1.

  In relation to the present invention, the memory 24 stores a variable table, group information, and connection information for all nodes to be processed. That is, the MPU 22 stores variable table information created by a programming tool in a memory. Of course, when not stored in this way, a variable table stored and held by the node is acquired via the network 1 and stored in the memory 24.

  Then, while displaying the input screen based on the stored variable table on the output unit 23, group information is created and stored in the memory 24 according to the information given from the input unit 21. Further, while displaying an input screen based on the group information on the output unit 23, connection information is created and stored in the memory 24 according to the information given from the input unit 21. Each piece of information created and stored is downloaded to a predetermined node via the network 1. The functions of the MPU 22 that performs the above processing are as follows.

  FIG. 9 is a flowchart showing processing functions of the MPU 22 for realizing grouping means for performing grouping. First, a variable table is read from each node and stored in the memory 24 (S11). Of course, the configuration tool 20 is also a tool for creating a variable table to be set in each node. If the downloaded variable table is stored and held, the process of reading from each node can be omitted.

  Next, a variable table for one node selected from nodes sharing data is displayed (S12). For example, a list of target nodes is displayed, and the input unit 21 is operated and selected from the list. Then, the variable table corresponding to the selected node is read from the memory 24 and output to the output unit 23. At this time, for example, it is displayed in a table format as shown in FIG.

  Then, I / O group editing processing is performed based on the displayed variable table of nodes (S13). That is, by using the input unit 21 (for example, a pointing device), a variable belonging to the same group is clicked and selected. Since the clicked variable is highlighted or output in a tabular format, the user can easily understand it by adding a predetermined color to the line to which the variable belongs. In the upper column of the display window (not shown), for example, a list of pull-down menu methods such as “Edit”, “Display”, “Option”, “Window”, etc. is displayed. In this state, select “Group Edit” in “Edit”. Then, an editing screen as shown in FIG. 10 is displayed.

  Therefore, a desired group name is input in the “group name” column of this edit screen, and either “Out / In” is selected as the I / O type. In the member candidate column on the right column, all variables selected from the variable table are displayed. At this time, if the selected variable has a plurality of elements, they are displayed in units of individual elements so that they can be grouped in units of individual elements. In the example shown in the figure, “OrOt2_B” is selected in the variable table. Since there are 63 predictions in total, there are individual “OrOt2_b [1], OrOt2_b [2],. The element is displayed. Then, when an item to belong to a group is selected from among those displayed as candidate members, clicking the [<<] button adds it to the “group member” column in the left column. One item or a plurality of protons may be selected at this time. Conversely, if you want to remove a group member, you can return it by clicking the [>>] button while selecting the item you want to remove from the group member.

If all necessary items have been added to the group member column, the contents are confirmed by clicking the “OK” button and stored in the memory 24 as group information. Create as many groups as necessary.

  Next, it is determined whether or not I / O grouping for other nodes is necessary (S14). If necessary, the process returns to S12 to display the variable table of the next node, and grouping processing is performed based on the variable table (S14). S13). When the setting for all the nodes is completed, the branch determination in S14 is normally No, and the process ends. Of course, it is also possible to process the already set node again.

  FIG. 11 is a flowchart showing the processing function of the MPU 22 for realizing a connection means for establishing a connection. First, a new connection to be set is created (S21). This selects two nodes to relate. One selected is an original node, and the other is a target device (node). Which node is to be used can be dealt with, for example, by setting the first selected node to be the original node.

  Next, a connection allocation screen is displayed (S22). This connection allocation screen is as shown in FIG. Initially, the columns of connection name, connection type and packet interval are blank, and information regarding the originator device and the target device (OUT, IN) is read out from the group information stored in the memory 14 and displayed. That is, the originator device column displays group information for the original node selected in S21, and the target device column is group information for the target device (node) selected in S21. Since IN / OUT information is added to the group information, IN and OUT are displayed separately when displayed in the target device column.

  Next, using the connection allocation screen shown in FIG. 12, an I / O group to be connected in the original node is selected (S23). This process is performed by selecting and clicking one desired group from the display field of the originator device.

  Then, one group connecting the connection with the group selected in S23 is selected from the target device nodes (OUT / IN) to establish a connection (S24). Specifically, the pointing device is used to perform the association by dragging and dropping to disclose the drag in a state where the group selected in S23 is dragged and overlaid on the desired group displayed in the target device column. Accordingly, in FIG. 12, “Gr_OrOUT_0” of the original node is connected to Gr_TaIN_0 of the target device node. Also, predetermined information is input to blank items such as connection names during the execution of the processing from S22 to S24 or after S24.

  Note that there is one group that connects connections between a set of original nodes and target device nodes. Therefore, when the process of S24 is completed, it is determined whether or not to continue setting for other connections (S25). If so, the process returns to S21 to create another connection. If all necessary connections are made, the branch determination in S25 is No and the process is terminated. Note that the branch determination in S25 is performed by waiting for an instruction given from the user via the input unit 21 and recognizing the content of the instruction. Further, by performing the process of S24 and clicking the OK button shown in FIG. 10, the connection information associated so far is determined and registered in the memory 24 as the determined connection information.

  By repeatedly executing the flowchart shown in FIG. 11 between all the nodes, it is possible to establish a group connection between all the nodes. The connection information stored in the memory 24 is displayed in a list in the “registered device” field on the device parameter editing screen as shown in FIG. 13, for example.

It is a figure which shows a prior art example. It is a figure which shows a prior art example. It is a figure which shows one Embodiment of the network system of this invention. It is a figure explaining an operation principle (an effect). It is a figure explaining an operation principle (an effect). It is a figure which shows the internal structure of PLC used as one of the nodes. It is a figure which shows one Embodiment of a tool. It is a figure which shows an example of a variable table. It is a flowchart which shows the function of a group information generation part. It is a figure which shows an example of the input screen output with execution of a group information generation part. It is a flowchart which shows the function of a connection information generation part. It is a figure which shows an example of the input screen output with execution of a connection information generation part. It is a figure which shows an example of the connection information produced | generated by the connection information production | generation means.

Explanation of symbols

10a node (PLC1)
10b node (RB1)
10c node (RB2)
11 CPU unit 11a User memory 11b MPU
11c IO memory 11d Variable table storage unit 12 Communication unit 12a MPU
12b Work memory 12c Communication interface 12d Grouping information storage unit 20 Configuration tool 21 Input unit 22 MPU
23 Output unit 24 Memory 25 Communication interface

Claims (5)

A node that transmits and receives IO data to be shared with other nodes connected to the network;
The node includes group information storage means for storing group information for grouping a plurality of IO data scattered in its own memory area as a group,
Connection information storage means for storing connection information associated with the taloop stored in the other node to be transmitted / received to / from the group stored in the group information storage means;
A node comprising: communication means for communicating with the other node specified by the connection information in units of groups specified based on the group information. A tool for generating and downloading the group information and the connection information for the node according to claim 1,
IO data information storage means for storing and holding information specifying IO data possessed by the node and the other nodes;
An input screen based on the information specifying the IO data is displayed on the output unit, and group information for collecting a plurality of IO data selected from the displayed IO data as one group is generated and stored in the storage means. Group information generating means for storing;
When the group information created by the group information creating means for the two nodes to be related is displayed on the output unit, and the group information to be related is selected from the displayed group information of each node, A tool characterized by comprising connection information generating means for creating information and storing it in storage means.   3. The tool according to claim 2, wherein the information stored in the IO data information storage means is collected and stored from each node. A plurality of nodes according to claim 1 are connected to a network,
A feature is that data sharing is achieved by transmitting and receiving a plurality of IO data belonging to the group specified by the group information in units of groups with other nodes specified by the connection information. Network system. A shared data communication method for sharing data by transmitting / receiving shared IO data between a plurality of nodes connected to a network,
The IO data to be transmitted is handled as one group scattered on the memory area in the node, and is transmitted and received in groups.
The shared data communication method, wherein the IO data belonging to the group is IO data required by a receiving node.