JP2006301886A - Programmable controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit information such as data, status or the like which a specific programmable controller (PLC) manages to a communication node such as another PLC or the like not only by means which makes a user program intervene but also by means which does not make a user program intervene. <P>SOLUTION: A user program execution processing includes a first transmitting data generation processing which generates transmission data, which is designated by the user program, on a transmission buffer by executing a prescribed program when the prescribed program exists in a user program. A system service processing includes a second transmission data generation processing which generates designated transmission data on the transmission buffer according to contents of a transmission data designation table which is stored in a rewritable nonvolatile memory. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a programmable controller (hereinafter referred to as PLC) having a function of transmitting information specified by a user to other communication nodes among information such as data and status managed by itself. .

  Various PLCs having a function of transmitting information specified by a user to other communication nodes among information such as data and status managed by the user are conventionally known. This type of PLC realizes control specifications defined in the user program while cyclically executing input / output update processing, user program execution processing, and system service processing, and is generated on a transmission buffer. The transmission data is configured to be transmitted to a specified destination node at a predetermined timing (see, for example, Patent Document 1).

  As a method for generating transmission data on the transmission buffer, it is usual to incorporate a transmission data generation function in a user program created by the user. Standard PLCs (standard PLCs) and safety PLCs (safety PLCs) are known as PLCs used for controlling production equipment in factories. The language corresponding to the circuit diagram is adopted as the language for the.

  That is, for the standard PLC, a program language corresponding to a so-called ladder diagram (circuit diagram) is adopted, while for a safety PLC (safety master), as shown in FIG. 13 and FIG. A programming language corresponding to the function block (circuit diagram) is adopted.

The safety PLC user program shown in FIG. 13 basically includes an input tag (TAG-IN), a function block (FB), and an output tag (TAG-OUT). As shown in FIG. 14, the input tag (TAG-IN) and the output tag (TAG-OUT) include a node address a, a bit address b, and a registered I / O comment c.
JP 2003-295913 A

  However, in such a conventional PLC, since the user program execution means decodes and executes the created user program, transmission data is generated on the transmission buffer for the first time. For general engineers who have little knowledge about and function blocks, it is a little inconvenient and it is not always easy to import data and status information managed by a specific PLC into other communication nodes such as PLCs. It wasn't.

  The present invention has been made paying attention to the above-mentioned problems, and the object of the present invention is not only a method of interposing a user program with data and status information managed by a specific PLC, but also a user. An object of the present invention is to provide a programmable controller that can be easily transmitted to another communication node such as a PLC even by a method not involving a program.

  Still other objects and effects of the present invention will be easily understood by those skilled in the art by referring to the following description of the specification.

  The programmable controller according to the present invention realizes the control specifications defined by the user program while cyclically executing the input / output update process, the user program execution process, and the system service process, and on the transmission buffer. The generated transmission data is transmitted to a specified transmission destination node at a predetermined timing.

  This programmable controller is provided with a rewritable nonvolatile memory, and this nonvolatile memory stores a transmission data designation table that can be rewritten by the user via the configurator.

  Further, in the user program execution process, when a predetermined program exists in the user program, the user program is executed to generate a first transmission data for generating transmission data specified by the user program on the transmission buffer. Includes credit data generation processing.

  The system service process includes a second transmission data generation process for generating specified transmission data on a transmission buffer in accordance with the contents of the transmission data specification table stored in the rewritable nonvolatile memory. include.

  According to such a configuration, as in the past, if a predetermined program is incorporated in the user program, the first transmission data generation process executes it, so that the transmission program designated by the user program is executed. Data can be generated on the transmit buffer.

  On the other hand, if the transmission data specification table on the non-volatile memory is appropriately described via the configurator, the second transmission data generation process converts the specified transmission data according to the contents of the transmission data specification table. Generate on the send buffer. Therefore, according to the present invention, information such as data and status managed by a specific PLC can be easily transmitted to communication nodes such as other PLCs not only by a method involving a user program but also by a method not involving a user program. Can be sent to. For this reason, engineers who are familiar with the knowledge about ladder diagrams and function blocks can generate the desired data for transmission on the transmission buffer by using the user program as usual, but the knowledge is poor. For general engineers, through the method of directly rewriting the contents of the transmission data specification table using the configurator, the desired transmission data is generated on the transmission buffer, without any user program being involved, Information such as data and status managed by a specific PLC can be easily taken into a communication node such as another PLC.

  In a preferred embodiment of the present invention, the transmission data designation table may specify each data to be transmitted according to the transmission order of the data to be transmitted and the type of the data to be transmitted.

  According to such a configuration, it is possible to transmit arbitrary transmission data in a desired order simply by specifying the transmission order and type.

  In a preferred embodiment of the present invention, a release data list indicating a list of data released to a user as a transmission target is incorporated, and the second transmission data generation process includes the transmission data designation table and the transmission data designation table. The transmission data may be generated by referring to the open data list.

  According to such a configuration, the user can freely allow data transmission to the outside only within the range of the data list opened to the user on the target specific PLC side.

  The programmable controller of the present invention may be realized as a safety specification. In recent years, in production equipment in factories, while standard PLCs and safety PLCs are mixed, examples of forming a hierarchical structure by connecting a large number of slave units under safety PLCs are increasing. In such a case, there is a desire to control and manage the entire system in the standard PLC. In such a case, it is not preferable from the viewpoint of safety management to access the safety slave at the end from the standard PLC. In such a case, the entire safety control system is managed from the side of the safety PLC that exists above the safety slave. It is preferable to acquire data. In such a case, the present invention is particularly suitable for transmitting data and status from the safety PLC to the standard PLC.

  According to the present invention, information such as data and status managed by a specific PLC can be easily transmitted to communication nodes such as other PLCs not only by a method involving a user program but also by a method not involving a user program. There is an advantage that can be made.

  An example in which the PLC according to the present invention is realized as a safety specification PLC will be described in detail below with reference to FIG.

  A block diagram of a mixed safety / standard system to which the present invention is applied is shown in FIG. As shown in the figure, this safety / standard mixed system includes one safety PLC (safety master) 1, two safety slaves 2 and 2, and one standard PLC 3 via a network 4. It is composed of tied. In the figure, reference numeral 5 denotes a configurator composed of a personal computer.

  As will be described in detail later, the configurator 5 is used to rewrite a transmission data designation table stored in the nonvolatile memory 101 in the safety PLC 1.

  The safety PLC is a PLC that is set to the so-called safety specifications, and has a high-level self-diagnosis function related to input / output in addition to the normal standard PLC function, and always switches the input / output to the safe side if any abnormality occurs. It has a function. The function of such a safety PLC is detailed in Japanese Patent Application Laid-Open No. 2004-299797 proposed by the present applicant.

  The safety slave 2 includes a safety input slave, a safety output slave, a safety input / output slave, and the like, and all of them input data sucked from the safety slave 2 by cyclically communicating with the safety PLC 1. Is used for control by the safety PLC 1, and output data output from the safety PLC 1 is output to the outside via the safety slave 2. The safety slave 2 always performs self-diagnosis and always switches the control to the safe side if any abnormality is found.

  The standard PLC 3 is well known to those skilled in the art, and in this example, a building block type including a CPU unit, an I / O unit, various high-function units, and the like is shown. .

  Next, a block diagram schematically showing the electrical hardware configuration of the safety master is shown in FIG. As shown in the figure, the safety master 1 includes a CPU unit 100, a nonvolatile memory 101, an internal memory 102, and a communication unit 103.

  The CPU unit 100 is configured mainly with a microprocessor, a ROM, a RAM, and the like, and comprehensively manages the entire safety PLC.

  The non-volatile memory 101 stores a transmission data designation table that will be described in detail later. The contents of the transmission data specification table can be appropriately rewritten via the configurator 5.

  The internal memory 102 relays between the CPU unit 100 and the communication unit 102, and stores therein a transmission buffer according to the present invention. The transmission buffer stores transmission data generated by a first transmission data generation process or a second transmission data generation process described later.

  The communication unit 102 includes a transmission / reception circuit. In this example, the communication unit 102 transmits transmission data stored in a transmission buffer in the internal memory 102 to the standard PLC 3 and transmits to other nodes (for example, safety nodes). The transmission data from the slave 2 and the standard PLC 3 is received and stored in the reception buffer in the internal memory 102. The reception data stored in the reception buffer in the internal memory 102 is read from the CPU unit 100 at an appropriate timing and used for executing the user program. In addition, the transmission data stored in the transmission buffer in the internal memory is also read from the communication unit 103 at an appropriate timing, and in this example, is transmitted to the standard PLC 3 over the network 4. The

  Next, FIG. 3 shows a general flowchart schematically showing the entire control process executed by the safety master. In the figure, when processing is started by turning on the power, in step 301, initialization of the internal RAM and various initial settings are performed. In the subsequent step 302, diagnostic processing at power-on is performed. In this diagnosis process, the presence or absence of an abnormality is diagnosed in the input part and the output part of the safety PLC, and in the case of an abnormality, a predetermined safety process is performed.

  In the following step 303, it is determined whether there is a command for entering the setting mode. Here, if there is no command for entering the setting mode (NO in step 303), the process proceeds to the normal mode (step 304), whereas it is determined in the determination process (step 303) that there is a command for entering the setting mode. If so (YES at step 303), the mode is shifted to the setting mode (step 305).

  FIG. 4 shows a flowchart showing the entire control program executed in the setting mode. When the processing is started in the same figure, it enters a state of waiting for the presence or absence of a command. In this state, if any command is received (YES in step 401), command analysis processing and writing processing to the EEPROM which is the nonvolatile memory 101 are performed (step 402). In the subsequent step 403, response processing for the received command is performed. On the other hand, if any command is not received (step 401 NO), those steps 402 and 403 are skipped and the reception standby state is maintained.

  A flowchart showing details of the command analysis / EEPROM writing process is shown in FIG. When the processing is started in the figure, first, in step 501, the received data is read. In the subsequent step 502, it is determined whether the command type is an EEPROM write command or another command. If the command is another command, the process proceeds to other processing. On the other hand, if the read command is an EEPROM write command, the received data is written to the EEPROM in the subsequent step 503. In this writing process (step 503), it becomes possible to rewrite and write a transmission data designation table which will be described later.

  On the other hand, a flowchart showing the entire control program executed in the normal mode is shown in FIG. When the process is started in the figure, it is first determined whether or not there is an error (step 601), and if there is an error (YES in step 601), it is locked out.

  On the other hand, when there is no error (NO in step 601), first, in step 602, an input refresh process is executed. In this input refresh process, the input data stored in the memory inside the apparatus is updated with the input data taken from outside. At this time, in the case of a safety specification PLC, an input diagnosis process is performed, and if an abnormality is determined for any of the input terminals, a predetermined safety process is executed, and the input data fetched from the input terminal is The value is switched to the safe side.

  In the subsequent step 603, user program execution processing is performed. As described above with reference to FIGS. 13 and 14, in this type of safety PLC, users corresponding to input tags (TAG-IN), function blocks (FB), and output tags (TAG-OUT) are used. A user program is created and stored using a program language. In this user program execution process, the user program obtained in this way is executed with reference to input / output data in a certain order, so that the contents of output data are Determine. The user program execution process includes a first transmission data generation process.

  As is well known, in the first transmission data generation process, when a predetermined program exists in the user program, the transmission data specified by the user program is executed by executing the predetermined program. A function to generate on the transmission buffer is realized. The existence of the first transmission data generation process allows the user to generate transmission data in the transmission buffer in the internal memory 102 by describing a predetermined program in the user program. In this way, the transmission data stored in the transmission buffer in the internal memory 102 is read from the communication unit 103 and transmitted onto the network 4 at a predetermined timing defined by a timer or the like.

  In the subsequent step 604, an output refresh process is executed, and the output data generated in the user program execution process (step 603) is sent to an external output terminal (not shown) in the output refresh process 604. Also in this output refresh process (step 604), as long as it is a safety PLC, the output diagnosis process is executed, and for an output in which some abnormality has occurred, a measure such as disconnecting from the control is performed.

  In the subsequent step 605, system service processing is executed. This system service process (step 605) includes a second transmission data generation process which is the main part of the present invention.

  A configuration diagram showing an example of the transmission data designation table is shown in FIG. 8, and a configuration diagram showing an example of the open data list is shown in FIG.

  As is apparent with reference to FIG. 8, the transmission data designation table includes four items including “member number”, “data type”, “data size”, and “data name (character string)”. ing. “Member number” indicates the transmission order of data to be transmitted. “Data type” represents the type of data to be transmitted. “Data size” indicates the size of data to be transmitted. “Data name (character string)” represents a character string of data to be transmitted.

  That is, in the example of FIG. 8, first, data specified by the data type “4” is transmitted for the data size “1”. Second, the data specified by the data type “2” is transmitted by the size specified by the data size “2”. Third, the data specified by the data type “11” is transmitted by the size specified by the data size “1”. In this embodiment, the “data size” is included in the transmission data specification table. However, when the data size for each data type is uniquely determined in advance, the data size can be set by simply specifying the data type. Since it is not necessary to specify, “data size” can be omitted from the transmission data specification table.

  Next, FIG. 9 shows a configuration diagram showing an example of the open data list. This open data list is stored in the nonvolatile memory 101 in this example. However, the open data list stored in the nonvolatile memory 101 is configured so that it cannot be rewritten by the user.

  The 14 types of data stored in the open data list are the ones that the safety PLC 1 allows the user to transmit to the outside. In other words, the safety PLC 1 permits transmission of 14 types of data listed in the open data list to other nodes on the network. Then, as will be described in detail later, if any transmission data specification table is created, in the second transmission data generation process, the data type stored in the transmission data specification table is released. By accessing the actual data with reference to the data list, the data for transmission is generated on the transmission buffer by copying the corresponding data on the transmission buffer by the designated data size.

  Next, a flowchart showing the second transmission data generation process is shown in FIG. When the processing is started in the figure, first, in step 701, the member number N and the offset address A are initially set (N = 1, A = 0).

  In the subsequent step 702, the member number N is compared with the final number of the member to determine whether the processing has been performed up to the final data in the transmission data designation table. If the end of the member number has not been reached (NO in step 702), the process proceeds to step 703 to execute a process of copying the data of the member number N to the offset address A by a specified size.

  In the subsequent step 704, the member number N is updated by +1, and the offset address A is also updated by the data size.

  Thereafter, the above operation (steps 703 and 704) is repeatedly executed until the member number N reaches the end of the member. If the member number N reaches the end of the member (step 702 YES), the data update is completed (step 705), and the process is terminated.

  FIG. 10 shows an operation explanatory diagram of the transmission data generation processing until transmission data is generated from the transmission data specification table as a result of the processing shown in FIG.

  As shown in the figure, the predetermined storage area in the safety PLC 1 includes status data (status A, status B, status C), information group (information A, information B), and data group (data A, data B). , Data C, data D) are stored in a predetermined order.

  On the other hand, when the second transmission data generation process shown in FIG. 3 is executed, the contents of the transmission data are status C, status A, status B, status, as shown on the right side in the figure. It is converted into a state in which D is arranged in order. At this time, the copy method is determined by configuration.

  Thereafter, transmission data (status C, status A, information B, data D) is transmitted onto the network 4 by the action of the transmission unit 103.

  Next, a process of generating transmission data from original data will be described with reference to FIGS. 11 and 12 by giving a more specific example. Assume that the contents of the transmission data specification table are as shown in FIG.

Then, first, the write address is set to A ₁ = 0, and the data of the member number N = 1 is copied by 2 bytes [1]. Subsequently, the offset is updated by +2 [2]. Subsequently, the write address is A ₂ = 2 and the data of the member number N = 2 is copied by 1 byte [3]. Subsequently, the offset is updated by +1 [4]. Subsequently, the write address is A ₃ = 3, and the data of the member number N = 3 is copied by 2 bytes [5]. Subsequently, the offset address is updated by +2 [6]. Subsequently, the write address is A ₄ = 5, and the data of the member number N = 4 is copied by 2 bytes [7]. As described above, according to the transmission data designation table shown in FIG. 11, the corresponding data is sequentially arranged on the transmission buffer, and the transmission data is completed.

  Thereafter, the transmission data on the transmission buffer obtained in this way is sent to the network 4 by the action of the communication unit 103.

  Note that the timing of transmission may be set cyclically by a timer in advance, may be transmitted in an event, or transmitted based on the establishment of some logical condition. You may make it do. In any case, since the second transmission data generation process shown in FIG. 7 is included, the user incorporates the transmission data generation process into the user program using a complicated program language derived from the circuit diagram. Even if it is not necessary, as shown in FIG. 11, simply by specifying four types of information such as member number, data type, data size, and data name (character string), as shown in FIG. Can be generated in a necessary order, and can be sent to a separately designated destination at a desired timing.

  Therefore, according to the safety PLC 1 of this embodiment, the I / O communication is appropriately performed with the safety slaves 2 and 2 connected thereto, and the transmission timing set in the safety PLC 1 with the arrival of necessary timing is achieved. According to the data specification table, a corresponding series of data can be transmitted from the safety PLC 1 to the standard PLC 3. In particular, in order to enable data transmission from the safety PLC 1 to the standard PLC 3, it is not necessary to use a complicated programming language, so that the usability of the safety PLC is significantly improved as compared with the conventional method. In addition, according to this method, the safety PLC and the safety slave 2 constitute a safety system, while the standard PLC is positioned higher than that and can collect information on the entire system as appropriate. Reliability in a mixed safety / standard system can be improved.

  In the embodiment described above, the present invention is realized as a safety PLC. However, the application of the present invention is not limited to this and may be applied to a standard PLC.

  According to the present invention, information such as data and status managed by a specific PLC can be easily transmitted to communication nodes such as other PLCs not only by a method involving a user program but also by a method not involving a user program. There are advantages that can be made.

1 is a configuration diagram of a mixed safety / standard system to which the present invention is applied. It is a block diagram which shows roughly the electric hardware constitutions of a safety master. It is a general flowchart which shows roughly the whole control processing which a safety master performs. It is a flowchart which shows the whole control program performed in setting mode. It is a flowchart which shows the detail of a command / EEPROM writing process. It is a flowchart which shows the whole control program performed in normal mode. It is a flowchart which shows the 2nd transmission data generation process. It is a block diagram which shows an example of the data specification table for transmission. It is a block diagram which shows an example of an open data list. It is operation | movement explanatory drawing of the 2nd transmission data generation process. It is a figure which shows the example of preparation of the data specification table for transmission. It is explanatory drawing which shows the procedure which produces | generates the data for transmission according to the table of FIG. It is a figure which shows the example of the circuit diagram description of the user program of safety PLC. It is explanatory drawing of an input and an output tag.

Explanation of symbols

1 Safety PLC (Safety Master)
2 Safety slave 3 Standard PLC
4 Network 5 Configurator 100 CPU Unit 101 Non-Volatile Memory 102 Internal Memory 103 Communication Unit

Claims (4)

While executing the input / output update processing, user program execution processing, and system service processing cyclically, the control specifications specified by the user program are realized, and the transmission data generated on the transmission buffer is specified. A programmable controller configured to transmit to a designated destination node at a predetermined timing,
The programmable controller includes
A rewritable nonvolatile memory is provided, and this nonvolatile memory stores a transmission data designation table that can be rewritten by the user via the configurator.
In the user program execution process, when a predetermined program exists in the user program, the first transmission data is generated on the transmission buffer by executing the predetermined program by executing it. Generation processing is included, and the system service processing generates the specified transmission data on the transmission buffer according to the content of the transmission data specification table stored in the rewritable nonvolatile memory. A programmable controller comprising a second transmission data generation process.   2. The programmable controller according to claim 1, wherein the transmission data designation table specifies each data to be transmitted according to a transmission order of data to be transmitted and a type of data to be transmitted. .   A built-in open data list indicating a list of data released to the user as a transmission target, and the second transmission data generation process refers to the transmission data designation table and the open data list, The programmable controller according to claim 1, wherein the second transmission data is generated.   The programmable controller according to claim 1, wherein the programmable controller is realized as a safety specification.

Images