JP2020024594A - Support device and support program - Google Patents

Abstract

To provide a development environment in which relationship between output result and actual input signal is easily recognized.SOLUTION: For a logic circuit including an intermediate contact turned ON/OFF based on calculation result in a ladder program, a support device expands the logic circuit including the intermediate contact to a logic circuit including no intermediate contact by rearranging the intermediate contact to a circuit combining an actual contact turned ON/OFF based on an input signal from the outside.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a support device that supports creation of a control program executed in a control device that controls a control target, and a support program for realizing the support device.

  At various manufacturing sites, control devices such as PLCs (Programmable Logic Controllers) have been introduced. Such a control device is a kind of computer, and executes a user program designed according to a manufacturing device or a manufacturing facility. Such a user program is created in a development environment prepared separately from the control device. A device that provides a development environment and provides a function of uploading a user program to the control device or downloading a user program to the control device is also referred to as a support device. The user program executed by the control device is described in a ladder language specified by, for example, IEC61131-3 or the like, and is described by a ladder logic circuit (logic circuit) or an instruction code of an operation expressed by a combination of ladder logic circuits. Program ".

  Ladder programs are represented by ladder diagrams. The ladder diagram has a configuration in which a logic circuit expressed by a combination of contacts, coils, and the like is drawn in a ladder shape. The coil indicates the output destination of the result of the logical operation combining the contacts. Also, the ladder diagram may be drawn in a hierarchical expression such that one logic circuit receives the result of another logic circuit, and another logic circuit receives the result of another logic circuit. . In such a case, there is a problem that it is difficult to identify the cause of the inoperability of the created logic circuit because one logic circuit is expressed in multiple layers.

  For example, Japanese Unexamined Patent Application Publication No. 2006-170662 (Patent Literature 1) discloses a technique in which a nearest branch circuit located before a ladder circuit to be confirmed is located for the purpose of easily finding the cause of a failure of a ladder circuit as a logic circuit. A device for searching and extracting a branch circuit to be displayed from a ladder program based on the type of the searched branch circuit and displaying the extracted branch circuit is disclosed.

JP-A-2006-170662

  The device disclosed in Patent Document 1 displays each extracted branch circuit separately, and does not become a single connected logic circuit. Therefore, the entire logic operation for obtaining the output result of one logic circuit is not performed. There remains a problem that the image is difficult to understand, in other words, the relationship between the output result and the actual input signal is difficult to understand.

  One object of the present disclosure is to provide a development environment in which the relationship between an output result and an actual input signal can be easily understood.

  According to an example of the present disclosure, a support device that supports creation of a ladder program executed by a control device that controls a control target is provided. The support device includes: a program display unit that displays a ladder program by a logic circuit in which a plurality of types of elements are combined; and a first type of logic circuit including a first type of contact indicating an operation result in the ladder program. All first-type contacts included in the logic circuit including the contacts are subjected to a logical operation for obtaining an operation result indicated by the first-type contacts by a second-type contact indicating a signal input from outside. Expanding means for expanding into a combined logic circuit.

  According to this disclosure, the logic circuit including the first type of contact can be represented by a combination of the second type of contact. Therefore, the relationship between the output result of the logic circuit and the signal actually input from the outside is obtained. Can be displayed clearly.

  In the above disclosure, the support device may further include an output unit that receives the execution result of the ladder program and outputs a conduction state of a logic circuit indicating the ladder program.

  According to this disclosure, the cause of the ladder program not functioning can be easily specified from the conduction state of the logic circuit. In particular, since the logic circuit can be represented only by the second type of contact, the direct cause of the failure of the ladder program can be more easily specified.

  In the above disclosure, the program display means, for a logic circuit combining the second type of contacts obtained by the developing means, includes a conductive contact and a non-conductive contact connected to the conductive contact. The display may be performed, and the elements located between the non-conductive contact connected to the conductive contact and the coil indicating the output result may not be displayed.

  According to this disclosure, only a portion necessary for identifying the cause of the ladder program not functioning is displayed, and unnecessary portions are not displayed, whereby the amount of information to be displayed is reduced, and the ladder program does not function. The cause of the failure can be more easily identified.

  In the above disclosure, the first type of contact receives the first type of contact when the first type of contact is a b-contact that becomes conductive upon receiving a false operation result. By replacing the logical expression of the operation with a logical circuit indicating an operation, the logical operation for obtaining the operation result indicated by the first type of contact can be expanded to a logical circuit combining the second type of contact. Good.

  According to this disclosure, a logic circuit that is difficult to expand can be expanded, the types of ladder programs that can be expanded increase, and versatility increases.

  In the above disclosure, the support device extracts the combination of the contradictory contacts from the logic circuit obtained by combining the second type of contacts obtained by the deployment unit, and deletes the circuit formed by the contradictory contact combinations. May be further included.

  According to this disclosure, the entire logic circuit can be simply represented. As a result, the flow of the entire logic circuit becomes easier to understand, and the cause of the non-functioning ladder program can be more easily specified.

  In the above disclosure, the support device optimizes a redundant circuit by extracting a redundant combination of contacts from a logic circuit obtained by the expanding means and combining the second type of contacts, and removing a contact included in the redundant combination of contacts. Means may further be included.

  According to this disclosure, the entire logic circuit can be simply represented. As a result, the flow of the entire logic circuit becomes easier to understand, and the cause of the non-functioning ladder program can be more easily specified.

  In the above disclosure, the support device may further include a storage processing unit that performs a process of storing a logic circuit obtained by combining the second type of contacts obtained by the deployment unit.

  According to this disclosure, the ladder program represented by the logic circuit obtained by combining the second type of contacts obtained by the developing means is of the first type compared to the ladder program represented by the logic circuit before being developed by the developing means. The size of the data is small because it does not include intermediate variables such as the contact point. By storing such a ladder program with a reduced data size, the ladder program with a reduced data size can be used, and the amount of memory used in the control device can be reduced.

  According to another example of the present disclosure, a support program that supports development of a ladder program executed by a control device that controls a control target is provided. The support program displays, on a computer, the ladder program by a logic circuit combining a plurality of types of elements including a first type of contact indicating an operation result in the ladder program, and a logic including the first type of contact. For the circuit, all the first-type contacts included in the logic circuit including the first-type contacts are subjected to a logical operation for obtaining an operation result indicated by the first-type contacts by a signal input from the outside. And developing the logic circuit into a combination of the second type of contacts shown.

  According to this disclosure, the logic circuit including the first type of contact can be represented by a combination of the second type of contact. Therefore, the relationship between the output result of the logic circuit and the signal actually input from the outside is obtained. Can be displayed clearly.

  According to an example of the present disclosure, a development environment in which the relationship between an output result and an actual input signal can be easily understood can be provided.

It is a figure which shows typically the application scene of the support apparatus which concerns on this Embodiment. It is a schematic diagram which shows the example of a structure of the control system which can apply a support apparatus. FIG. 3 is a schematic diagram illustrating a hardware configuration example of a support device. It is an example of a ladder diagram. It is a figure showing the outline of development. FIG. 9 is a ladder diagram reflecting execution results of a ladder program. FIG. 9 is a ladder diagram reflecting execution results of a ladder program. FIG. 4 is a diagram for explaining circuit optimization. It is an example of abbreviated display. It is a flowchart of a display process. It is a flowchart of a real contact point search process. It is a flowchart of a circuit change process. It is a figure for explaining inversion of a logical expression. It is a schematic diagram which shows the software configuration of a support device.

  Embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings have the same reference characters allotted, and description thereof will not be repeated.

§1 Application Example First, an example of a scene to which the present invention is applied will be described with reference to FIG. FIG. 1 is a diagram schematically illustrating an application scene of a support device 200 according to the present embodiment. The support device 200 provides an environment for developing a control program to be executed by a control device such as a PLC (programmable controller) that controls a control target.

  A control program executed by a control device such as a PLC generally includes a ladder diagram (LD) and a function block diagram (FBD) defined as a programming language of a PLC application in International Standard IEC61131-3. , A sequential function chart (SFC: Sequential Function Chart), an instruction list (IL: Instruction List), and a structured text (ST: Structured Text). The present invention is directed to a ladder program described by a ladder diagram among control programs executed by the control device.

  The support device 200 includes a program display unit 260a that displays a ladder program described by a ladder diagram by a logic circuit in which a plurality of types of circuit elements are combined, and a logic circuit including an intermediate contact 544 that indicates an operation result in the ladder program. , A developing means 262a for developing a logic circuit not including the intermediate contact 544.

  The plurality of types of circuit elements include contacts 542 and 544 that are turned on / off based on an external input signal, and a coil 560 that outputs a calculation result in the circuit. Note that the circuit element may include a function block in which predetermined processes are grouped.

  The contacts include a real contact 542 that is turned on / off based on a signal input from the outside, and an intermediate contact 544 that is turned on / off based on a calculation result in a ladder program.

  The expansion unit 262a expands the logic circuit including the intermediate contact 544 into a logic circuit not including the intermediate contact 544. Specifically, the developing unit 262a develops a logic circuit including the intermediate contact 544 into a logic circuit not including the intermediate contact 544 by rearranging the intermediate contact 544 into a circuit including the actual contact 542. Since the intermediate contact point 544 indicates the result of the operation in the ladder program, the operation can be represented by a combination of the actual contact points 542.

  In the example shown in FIG. 1, the developing unit 262a expands the logic circuit 520a including the contact (L) and the contact (M), which are the intermediate contacts 544. The contact (L) indicates the result of the coil (L). The coil (L) receives the result of the logic circuit combining the contact (h) and the contact (i), which are the actual contacts 542. Therefore, the contact (L) can be represented by a logic circuit combining the contact (h) and the contact (i). Similarly, the contact (M) indicates the result of the coil (M). The coil (M) receives the result of the logic circuit combining the contact (j) and the contact (k), which are the actual contacts 542. Therefore, the contact (M) can be represented by a logic circuit combining the contact (j) and the contact (k). As a result, the logic circuit 520a is developed into a logic circuit 520b, which is a combination of the contact (h), the contact (i), the contact (k), and the contact (j), which are the actual contacts 542 that do not include the intermediate contact 544.

  If any one of the contact (h), the contact (i), the contact (k), and the contact (j) is the intermediate contact 544, the intermediate contact 544 is further developed and the intermediate contact 544 is developed. The expansion is repeated until a logic circuit not including 544 is obtained.

  As described above, by expanding the logic circuit 520a including the intermediate contact 544 to the logic circuit 520b represented by the real contact 542 not including the intermediate contact 544, the result output from the coil (N) is externally input. It is easy to understand which of the signals depends. That is, the relationship between the output result and the actual input signal can be easily understood.

§2 Specific Example Hereinafter, as a specific example of the present invention, a more detailed configuration and processing of the support device 200 according to the present embodiment will be described.

<A. Example of overall configuration of control system 1>
FIG. 2 is a schematic diagram illustrating a configuration example of the control system 1 to which the support device 200 can be applied. Referring to FIG. 2, control system 1 includes a plurality of PLCs 100-1, 100-2, 100-3, 100-4,... (Hereinafter, also collectively referred to as “PLC 100”). Each of the PLCs 100 is an example of a control device that controls a control target that is a field device such as a relay and a sensor. The support device 200 is connectable to the PLC 100 and provides an environment that supports development of a control program of the PLC 100. The control system 1 may have a configuration including one PLC 100. Hereinafter, in order to simplify the description, a development environment for one PLC 100 will be described.

  The PLC 100 typically includes a CPU unit 10 which is a main body for executing various programs including a control program, a power supply unit 12 for supplying power to the CPU unit 10 and the like, and an I / O (I / O) for exchanging signals from a field. Input / Output) unit 14. The I / O unit 14 is connected to the CPU unit 10 via the system bus 11.

  The development support environment provided by the support device 200 can have an editor (edit) of a control program, a debugger, a simulator, and a monitor function for outputting the output information of the control program to a monitor such as a display. The support device 200 further has a function of acquiring a state value of the running PLC 100 and outputting the acquired value to a monitor such as a display.

  By installing the support program, which is an application program stored in the optical recording medium 8, in the support device 200, various functions for the development support environment as described above are realized. Instead of the optical recording medium 8, the support program may be downloaded from an external server device or the like via a network. The support device 200 is connected to the CPU unit 10 of the PLC 100 via a connection cable, for example. The support device 200 is typically realized by a personal computer.

<B. Example of hardware configuration of support device 200>
FIG. 3 is a schematic diagram illustrating a hardware configuration example of the support device 200. The support device 200 is typically configured by a general-purpose computer. Note that, from the viewpoint of maintainability at a manufacturing site where the PLC 100 is arranged, a notebook personal computer having excellent portability is preferable.

  The support device 200 includes a storage unit 201 and a CPU 202 that executes various programs including an operating system (OS). The storage unit 201 is executed by the CPU 202, a ROM (Read Only Memory) 204 for storing BIOS and various data, a memory RAM 206 for providing a work area for storing data necessary for the CPU 202 to execute a program. And a hard disk (HDD) 208 for storing programs and the like in a nonvolatile manner.

  The support device 200 further includes an operation unit 203 including a keyboard 210 and a mouse 212 operated by the user to input an instruction to the support device 200, and a display 214 for presenting information to the user. The support device 200 includes a communication interface 218 for communicating with the PLC 100 (CPU unit 10) and the like. The communication interface 218 may include a USB communication module for communicating with a USB interface provided in the PLC 100.

  The support device 200 includes an optical recording medium reading device 216 for reading a support program for providing a development support environment stored in the optical recording medium 8.

  FIG. 3 illustrates a configuration example in which a processor such as the CPU 202 provides necessary functions by executing a program. However, some or all of the provided functions may be replaced by dedicated hardware circuits (for example, , ASIC or FPGA). In this case, a plurality of OSs having different purposes may be executed in parallel using virtualization technology, and a required application may be executed on each OS.

<C. Ladder program display method>
The support device 200 can present a user program executed by the PLC to the user via the display 214. The user program is a type of control program executed by the PLC 100 and is a program created according to a control target. The user program includes a ladder diagram (LD: Ladder Diagram), a function block diagram (FBD: Function Block Diagram), a sequential function chart (SFC: Sequential Function Chart), an instruction list (IL: Instruction List) and structured text (ST: Structured Text) are described in any one of five programming languages.

  The user program according to the present embodiment is a "ladder program" described by a ladder logic circuit (logic circuit) or an operation instruction code represented by a combination of the ladder logic circuits described in a ladder language.

  The ladder program is represented by a ladder diagram 510 in which a logic circuit (hereinafter, also simply referred to as “circuit”) using circuit elements and connection lines between an input-side bus 512 and an output-side bus 514 is drawn in a ladder shape. You. FIG. 4 is an example of a ladder diagram.

  The circuit element includes a contact 540 that is turned on / off based on an input signal, and a coil 560 that outputs on / off. Hereinafter, the ON state is also referred to as a conductive state, and the OFF state is also referred to as a non-conductive state. The ladder diagram 510 is drawn by connecting circuit elements such as a contact 540 and a coil 560 with a connection line 580. One circuit includes a portion indicating a logical operation expressed by combining the contacts 540 and an output portion for outputting a result of the logical operation, and the coil 560 corresponds to the output portion. Note that the circuit element may include a function block in which predetermined processes are grouped.

  The contact 540 is turned on / off based on a signal input from the outside (hereinafter, also referred to as an “actual contact 542”) and a contact turned on / off based on a calculation result in a ladder program (hereinafter, referred to as “contact”). "Intermediate contact point 544").

  In the example shown in FIG. 4, the ladder diagram 510 includes, as the actual contacts 542, contacts (sensor 1) to contacts (sensor 5) that are turned on / off by receiving signals from the sensors 1 to 5, and an intermediate contact 544. Includes contacts (A) to (C) that are turned on / off in response to output results of the coils (A) to (C). In FIG. 4, some reference numerals are omitted for convenience. In FIG. 4, some circuits are omitted for convenience, and "..." indicates that the circuits are omitted.

  The ladder program shown in FIG. 4 is represented by a ladder diagram 510 including five logic circuits. Specifically, the ladder program is represented by a ladder diagram 510 including a first circuit 521, a second circuit 522, a third circuit 523, a fourth circuit 524, and a fifth circuit 525.

  The coil (A) indicates the calculation result of the first calculation 51. The contact (A) is turned on / off in response to the output result of the coil (A). That is, it can be said that the contact point (A) indicates the output result of the coil (A), in other words, the contact point (A) indicates the result of the first calculation 51.

  The coil (B) indicates the result of the second operation 52 including the combination of the contact (A) as the intermediate contact 544 and the contact (sensor 3) as the actual contact 542. The second operation 52 is executed with reference to the result of the first operation 51.

  The coil (C) shows the result of the third calculation 53 consisting of a combination of the contact (B) as the intermediate contact 544 and the contact (sensor 4) as the actual contact 542. The third operation 53 is executed with reference to the result of the second operation 52. The second operation 52 is executed by referring to the result of the first operation 51.

  The coil (D) indicates the result of the fourth operation 54 including the combination of the contact (C) as the intermediate contact 544 and the contact (sensor 5) as the actual contact 542. The fourth operation 54 is executed by referring to the result of the third operation 53. The third operation 53 is executed by referring to the result of the second operation 52. The second operation 52 is executed by referring to the result of the first operation 51.

  The support device 200 can represent a circuit including the intermediate contact 544 indicating the calculation result in a format not including the intermediate contact 544. Expressing a circuit including the intermediate contact 544 in a form that does not include the intermediate contact 544 is also referred to as “development”. FIG. 5 is a diagram showing an outline of the development. The ladder program shown by the ladder diagram 510 in FIG. 5 is equal to the ladder program shown by the ladder diagram 510 in FIG. In FIG. 5, the intermediate contact 544 is indicated by a thick line for convenience.

  The circuit is developed by a circuit indicating an operation received by the selected intermediate contact 544 or a circuit including the selected coil 560 when a predetermined operation is received in a state where the intermediate contact 544 or the coil 560 is selected. Done. In the example shown in FIG. 5, a predetermined operation is received in a state where the coil (D) shown in FIG. 4 is selected, and the fifth circuit 525 is developed into a form not including the intermediate contact 544.

  The fifth circuit 525 is developed in order from the input side bus 512 to the output side bus 514. Specifically, the development is performed sequentially from the contact (C) which is the intermediate contact 544 located at the left end of the fifth circuit 525. Since the contact point (C) indicates the result of the third operation 53, it can be replaced with the third operation 53.

  Even after the replacement with the third operation 53, the third operation 53 includes the contact (B) which is the intermediate contact 544, so that the intermediate contact 544 remains. Then, next, the contact (B) which is the intermediate contact 544 is developed. Since the contact (B) indicates the result of the second operation 52, the contact (B) can be replaced with the second operation 52.

  Even after the replacement with the second operation 52, the second operation 52 includes the contact (A) which is the intermediate contact 544, so that the intermediate contact 544 remains. Then, next, the contact (A) which is the intermediate contact 544 is developed. Since the contact point (A) indicates the result of the first operation 51, it can be replaced with the first operation 51.

  When the first operation 51 is replaced, the fifth circuit 525 is all represented by the actual contact 542. As described above, by expanding the circuit including the intermediate contact 544 to the actual contact 542 not including the intermediate contact 544, the relationship between the output result of the circuit including the intermediate contact 544 and a signal input from the outside can be easily understood. Circuit.

<D. Displaying execution results>
6 and 7 are ladder diagrams on which the execution results of the ladder program are reflected. The execution result includes a result of execution of the ladder program by the PLC 100 and a simulation result executed in the support device 200. 6 and 7, the output of the execution result is indicated by a so-called power flow display, which is represented by a bold line. The common execution result is reflected in the ladder diagram 510 shown in FIGS. In FIG. 7, it is assumed that the circuit X shown in FIG. 6 is developed. In FIG. 6, some circuits are omitted for convenience, and "..." indicates that the circuit is omitted. In addition, among the signals described above the contacts, a signal starting with “I” indicates an external signal, and a signal starting with “Q” indicates a result of a logical operation in the ladder program.

  In the ladder diagram 510 shown in FIG. 6, it can be grasped that the contact (Q2) and the contact (Q3) are not in a conductive state (non-conductive state), but the contact (Q2) and the contact ( The reason why Q3) is not conducting must be traced back to the circuit including the contact (Q2) and the coil that outputs the signal received by the contact (Q3).

  On the other hand, as shown in FIG. 7, by expanding the circuit X so as to be represented only by the actual contact 542, it is possible to easily identify the cause of the execution of the circuit X being stopped halfway. In particular, since the elements constituting the circuit X are represented as a series, it is easy to follow the circuit. As a result, the cause of the circuit being stopped halfway can be easily specified by sequentially following the elements.

<E. Circuit optimization>
When the circuit is developed, the support device 200 can delete a combination of redundant contacts and a combination of inconsistent contacts from the logic circuit in which the actual contacts 542 are combined. FIG. 8 is a diagram for explaining circuit optimization.

  An inconsistent combination of contacts means that different types of contacts that receive a common signal are connected in series. Specifically, the different types of contacts are a contact that conducts when the input signal is on, and a b contact that conducts when the input signal is off.

  For example, the circuit indicated by the logical operation X1 in the circuit X includes a point where a contact X1a that is turned on when a signal from I02 is on and a contact X1b that is turned on when a signal from I02 is off is connected in series. That is, when the signal from I02 is on, the contact X1a conducts but the contact X1b does not conduct, so that the circuit including the logical operation X1 does not conduct. Therefore, since the circuit indicating the logical operation X1 does not affect the result of the circuit X, the circuit indicating the logical operation X1 can be deleted from the circuit X.

  A redundant contact combination means that the contacts of the same type that receive a common signal are connected in series, or the contacts of different types that receive the common signal are connected in parallel. Say.

  For example, the circuit indicated by the logical operation X2 in the circuit X includes a portion where a contact X2a that is turned on when a signal from I04 is on and a contact X2b that is turned on when a signal from I04 is on is connected in series. That is, even if one of the contacts X2a and X2b is deleted, the result of the circuit X is not affected, so that one of the contacts X2a and X2b can be deleted.

  In the circuit indicated by the logical operation X3 in the circuit X, a contact X3a that turns on when the signal from I09 is on and a contact X3b that turns on when the signal from I09 is off are connected in parallel with each other. That is, when the signal from I09 is on, the contact X3a is conductive, and when the signal from I09 is off, the contact X3b is conductive. Therefore, the circuits connected in parallel have substantially no meaning. That is, even if the contacts X3a and X3b are deleted, the result of the circuit X is not affected, so that the contacts X3a and X3b can be deleted.

  The ladder diagram shown in the lower part of FIG. 8 is a ladder program after optimizing by deleting circuits and contacts that do not affect the result. As shown in FIG. 8, the entire ladder program can be simply represented by deleting circuits and contacts that do not affect the result. In addition, the simplified representation makes it easier to understand the flow of the entire process, and also makes it easier to identify the cause when the process is not executed.

<F. Omission of display>
As shown in FIGS. 5, 7, and 8, when the circuit is expanded, the display becomes long horizontally and may not fit in the display area of the display 214. The support device 200 can display the developed circuit by omitting a part of the circuit. FIG. 9 is an example of an abbreviated display.

  Specifically, the contact (I19) and the contact (I13), which are non-conductive contacts connected to the contact in the conductive state, the contact (I13), and the coil (Q5) are displayed while the contact (I19) is displayed. ) And the coil (Q5), and the elements between the contact (I13) and the coil (Q5) are omitted.

  When specifying the cause of the coil (Q5) not being driven, the search is performed sequentially from the input side of the circuit. Therefore, when identifying the cause of the coil (Q5) not being driven, first, the contact (I19) and the contact (I13) are examined. That is, even if the contact located on the output side from the contact (I19) and the contact located on the output side from the contact (I13) are not displayed, there is no influence in specifying the cause.

  In this way, by displaying only necessary portions and not displaying unnecessary portions, the amount of information to be displayed is reduced, and the cause of the non-functioning ladder program can be more easily specified. Further, by expanding, the width of the ladder diagram 510 can be reduced, and as a result, the entire ladder diagram 510 can be easily displayed on the display 214.

<G. Display processing>
FIG. 10 is a flowchart of the display process. The CPU 202 reads the instruction code included in the support program stored and provided in the optical recording medium 8, executes a display process, and displays a ladder diagram 510 on the display 214. Note that the display processing shown in FIG. 10 is described as displaying the execution result of the ladder program executed in the PLC 100.

  In step S1, the CPU 202 determines whether a ladder display instruction has been detected. The ladder display instruction is an instruction for displaying the ladder diagram 510 on the display 214, and includes a direct instruction for displaying the ladder diagram 510 and an instruction for displaying the execution result of the ladder program.

  If a ladder display instruction has not been detected (NO in step S1), CPU 202 ends the display processing. If a ladder display instruction has been detected (YES in step S1), CPU 202 switches the process to step S2.

  In step S2, the CPU 202 reads a ladder program. The ladder program is stored in a storage unit such as a flash memory provided in the CPU unit 10 of the PLC 100. The CPU 202 reads a ladder program from the storage unit of the CPU unit 10 via the communication interface 218. When displaying a simulation result executed in the support device 200 or displaying a ladder program to be edited, the CPU 202 reads the ladder program from the storage unit 201. When displaying the execution result of the ladder program together with the ladder diagram 510, in step S2, the CPU 202 also reads the execution result of the ladder program.

  In step S3, the CPU 202 displays a ladder diagram indicating the read ladder program and an execution result on the display 214. The CPU 202 displays the ladder diagram 510 before the circuit is expanded on the display 214 by executing the process of step S3, as shown in FIGS. 4 and 6.

  In step S4, the CPU 202 determines whether the intermediate contact 544 or the coil 560 has been selected. If it is determined that no selection has been made (NO in step S4), CPU 202 ends the display process. If it is determined that the selection has been made (YES in step S4), CPU 202 switches the process to step S5.

  In step S5, the CPU 202 determines whether a deployment instruction has been detected. The deployment instruction is a predetermined operation, and may be an operation set by a user or an operation predetermined by a program provider.

  If it is determined that a deployment instruction has not been detected (NO in step S5), CPU 202 ends the display process. If it is determined that a deployment instruction has been detected (YES in step S5), CPU 202 switches the process to step S6.

  In step S6, the CPU 202 performs an actual contact point search process. The CPU 202 executes the real contact point search process to express the circuit indicating the operation received by the selected intermediate contact point 544 or the circuit including the selected coil in the form not including the intermediate contact point 544. And the developed ladder program is stored in the storage unit 201.

  In step S7, the CPU 202 displays the ladder program stored in the storage unit 201, and ends the processing. That is, in step S7, an expanded circuit as shown in FIG. 5 or FIG. 7 is displayed. The display method may be to display the expanded circuit in a window different from the window in which the circuit before expansion is displayed, and to display the circuit before expansion and the circuit after expansion. The display may be updated.

<H. Real contact search processing>
FIG. 11 is a flowchart of the actual contact point search processing. The actual contact point search processing is processing for developing a circuit indicated by the selected intermediate contact or coil into a circuit that does not include the intermediate contact 544.

  In step S602, the CPU 202 determines whether a coil has been selected. More specifically, CPU 202 determines whether or not a coil has been selected in step S4. If it is determined that the coil has not been selected (NO in step S602), that is, if the intermediate contact 544 has been selected, the CPU 202 refers to the coil indicated by the selected intermediate contact 544 in step S604, and proceeds to step S604. Proceed to S606.

  If it is determined that a coil has been selected (YES in step S602), CPU 202 switches the process to step S606.

  In step S606, the CPU 202 stores the circuit including the coil in the storage unit 201.

  In step S608, the CPU 202 extracts a contact (N) included in the circuit stored in the storage unit 201. It is assumed that the number of contacts extracted in step S608 is n.

  In step S610, the CPU 202 determines whether or not all the contacts (N) are the actual contacts 542. If all of them are the actual contacts 542 (YES in step S610), the process ends, and the process returns to the display process. When a contact other than the actual contact 542 is included (NO in step S610), that is, when the intermediate contact 544 is included, the CPU 202 switches the process to step S612.

  In step S612, the CPU 202 substitutes m = 1. In the process in step S612, one contact (N) of the plurality of contacts (N) is selected. By substituting m = 1, the first contact point (N) is selected.

  In step S614, the CPU 202 determines whether or not the contact (N) is the actual contact 542. When the contact (N) does not have the actual contact 542 (NO in step S614), that is, when the contact (N) is the intermediate contact 544, the CPU 202 executes step S616, and then proceeds to step S618. If the contact (N) is the actual contact 542 (YES in step S614), the CPU 202 proceeds to step S618 without executing step S616.

  In step S616, the CPU 202 performs a circuit change process. In the circuit change processing, a circuit incorporating a logical operation of a circuit including a coil corresponding to the contact (N) is stored in the storage unit 201 instead of the contact (N).

  In step S618, the CPU 202 adds 1 to m. That is, in step S618, the point of contact (N) of interest is changed.

  In step S620, CPU 202 determines whether m is equal to or less than n. Until it is determined that m exceeds n, the CPU 202 repeats the processing of steps S614 to S618. The fact that m exceeds n means that for all the contacts (N) extracted in step S608, it is determined whether the contact (N) is the real contact 542 or the intermediate contact 544. In the case of the intermediate contact 544, it means that a circuit including a coil corresponding to the contact (N) is installed instead of the intermediate contact 544, and the circuit is stored in the storage unit 201.

  If it is determined that m exceeds n (YES in step S620), CPU 202 proceeds to step S608.

  In step S608, the CPU 202 extracts the contact point (N) again. That is, since the circuit stored in the storage unit 201 is changed by the circuit change processing in step S616, the CPU 202 performs the processing in steps S608 to S620 on the changed circuit, and in step S610, Steps S608 to S620 are repeated until it is determined that all of (N) are the actual contacts 542.

  As a result, a coil corresponding to the selected intermediate contact or a circuit including the selected coil is developed into a form not including the intermediate contact 544.

<I. Circuit change processing>
FIG. 12 is a flowchart of the circuit change processing. The circuit changing process is a process for incorporating a logical operation of a circuit including a coil corresponding to the contact (N) into the circuit instead of the contact (N).

  In step S702, the CPU 202 generates a circuit (D) including the coil indicated by the contact (N).

  In step S704, the CPU 202 determines whether the contact (N) is an a contact. That is, it is determined whether the contact (N) is an a-contact that turns on when the circuit (D) conducts or a b-contact that turns on when the circuit (D) does not conduct.

  If it is determined that the contact (N) is the a contact (YES in step S704), CPU 202 switches the process to step S706.

  In step S706, the CPU 202 changes the contact (N) of the circuit stored in the storage unit 201 to a combination of contacts not including a coil in the circuit (D), and ends the process.

  When it is determined that the contact (N) is not the a contact (NO in step S704), that is, when it is determined that the contact (N) is the b contact, the CPU 202 switches the process to step S708.

  In step S708, a circuit (E) is generated by inverting the logical expression indicated by the logical operation received by the coil of the circuit (D).

  In step S710, the CPU 202 changes the contact (N) of the circuit stored in the storage unit 201 to the circuit (E), and ends the processing.

  The fact that the contact (N) is the b-contact means that the contact (N) is turned on when the circuit (D) indicated by the contact (N) is non-conductive. That is, the contact (N) is turned on when the circuit (E) obtained by inverting the logical expression shown by the circuit (D) is turned on. Therefore, when the contact (N) is the b contact, the contact (N) is connected to the circuit. By replacing with (E), the processing can be developed without changing the processing contents.

  Here, the inversion of the logical expression performed in step S708 will be described with reference to FIG. FIG. 13 is a diagram for explaining inversion of the logical expression.

  For example, it is assumed that the contact (f) shown in FIG. 13 is the target contact (N). Since the contact (f) is a b-contact, the contact (f) generates a circuit (E) in which the logical expression of the circuit (D) receiving the result is inverted.

  The circuit (E) is a circuit that becomes non-conductive when the circuit (D) becomes conductive, and is generated by being developed according to De Morgan's law as shown in FIG.

  Here, for a contact that is turned on when the result of the logical operation received by the corresponding coil is false, such as a contact b, a circuit indicated by the logical operation received by the coil corresponding to the contact b is used instead of the contact b. Cannot be directly incorporated. It is possible to develop logic circuits that are difficult to develop, including contacts that can not directly incorporate the circuit indicated by the logical operation received by the coil corresponding to the contact, and the types of ladder programs that can be developed increase, Versatility increases.

<J. Software configuration of support equipment>
With reference to FIG. 14, the software configuration of the support device 200 will be described. FIG. 14 is a schematic diagram illustrating a software configuration of the support device 200. The instruction code included in the software illustrated in FIG. 14 is read at an appropriate timing, provided to the CPU 202 of the support device 200, and executed. The software shown in FIG. 14 is included in a support program stored and provided in the optical recording medium 8.

  Referring to FIG. 14, OS 240 and programming application 250 are mounted on support device 200. The support device 200 executes the OS 240 and provides an environment in which the programming application 250 can be executed. A support program for implementing the support device 200 according to the present embodiment includes at least a programming application 250.

  The programming application 250 includes an editor 252, a compiler 254, a debugger 256, a simulator 258, a GUI (Graphical User Interface) module 260, an expansion module 262, a result output module 264, an optimization module 266, and a data storage. Unit 270. Each module included in the programming application 250 is typically distributed while being stored as a support program in the optical recording medium 8 and installed in the support device 200.

  The editor 252 provides functions such as input and editing for creating an executable program (source program). More specifically, the editor 252 provides a function of saving the created ladder program 274 and a function of editing the created ladder program 274 in addition to the function of the user operating the keyboard 210 and the mouse 212 to create the source program of the ladder program 274. The editor 252 stores the created ladder program 274 in the data storage unit 270.

  The compiler 254 provides a function of compiling the source program of the ladder program 274 and generating an executable program in the form of an executable (object) program in the CPU unit 10.

  The debugger 256 provides a function for debugging an executable program (source program). The contents of the debugging include an operation of partially executing a range specified by the user in the source program and an operation of tracking a temporal change of a variable value during execution of the source program. That is, the functions provided by the debugger 256 include a function of acquiring the execution result of the ladder program 274.

  The simulator 258 establishes an environment for simulating the execution of a program in the CPU unit 10 of the PLC 1 in the support device 200.

  The GUI module 260 provides a function of displaying a ladder program as a ladder diagram 510. That is, the ladder diagram 510 described above is provided by the GUI module 260. The GUI module 260 provides the ladder diagram 510 based on the operation received by the operation unit 203, the ladder program 274, the variable setting 272 necessary for executing the program, and the object information 278 about the object. Further, the GUI module 260 displays the expanded ladder program 276 generated according to the operation received by the operation unit 203 on the display 214 as a ladder diagram 510. That is, the GUI module 260 provides the function of the program display unit of the present invention.

  The expansion module 262 provides a function of expanding a circuit including the intermediate contact 544 into a format not including the intermediate contact 544, based on an operation received by the operation unit 203. The expansion module 262 provides a function of storing the expanded ladder program 276 in the data storage unit 270. That is, the expansion module 262 provides the function of the expansion unit of the present invention and the function of the storage processing unit. The ladder program 276 after expansion is a program that does not include intermediate variables, such as the intermediate contact point 544, and therefore has a smaller data size than the ladder program 276 before expansion. By saving the developed ladder program 276, the developed ladder program 276 can be downloaded to the PLC 100. As a result, the memory usage of the PLC 100 can be reduced.

  The result output module 264 provides a function of receiving the execution result of the ladder program and outputting the conduction state of the logic circuit. That is, the result output module 264 provides the function of the output unit of the present invention. Specifically, the result output module 264 receives the execution result of the program executed by the simulator 258 and the execution result of the program obtained by the debugger 256, generates a conduction state of the logic circuit, and The generated conduction state is reflected in the displayed logic circuit. Thus, the power flow display shown in FIGS. 6 to 9 is performed.

  The optimization module 266 provides a function of deleting inconsistent portions or redundant portions from the expanded ladder program 276. That is, the optimization module 266 provides the function of the optimization unit of the present invention. The optimization module 266 may search for and delete an inconsistent portion or a redundant portion based on an operation received by the operation unit 203 while the ladder program 276 after expansion is displayed. Further, when the circuit including the intermediate contact 544 is developed by the developing module 262 into a format not including the intermediate contact 544, an inconsistent portion or a redundant portion may be searched and deleted. The optimizing module 266 may separately store the ladder program from which the contradictory part or the redundant part has been deleted in the data storage unit 270, or may store it as the ladder program 276 after expansion. As described above, the optimization module 266 stores the ladder program after removing the inconsistent portion or the redundant portion, so that the simplified ladder program can be downloaded to the PLC 100. As a result, the memory usage of the PLC 100 can be reduced, and the processing can be speeded up.

  The data storage unit 270 stores a ladder program 274, a variable setting 272, a ladder program 276 after expansion, and object information 278.

§3 Supplementary notes The present embodiment and the modifications described above include the following technical ideas.

<Configuration 1>
A support device (200) for supporting creation of a ladder program executed in a control device that controls a control target,
Program display means (260, 260a) for displaying the ladder program by a logic circuit (521, 522, 523, 524, 525, X) combining a plurality of types of elements;
For the logic circuit (520a) including the first type of contact (544) indicating the result of the operation in the ladder program, all the first type of contacts included in the logic circuit including the first type of contact Means for developing a logical operation for obtaining an operation result indicated by the first type of contact into a logic circuit (520b) in which a second type of contact (542) indicating a signal input from the outside is combined (262, 262a).

<Configuration 2>
The support device according to configuration 1, further comprising an output unit (264) that receives a result of execution of the ladder program and outputs a conduction state of a logic circuit indicating the ladder program.

<Configuration 3>
The program display means, for a logic circuit obtained by combining the second type of contacts obtained by the developing means, a conductive contact and a non-conductive contact (contact (contact ()) connected to the conductive contact. I17), the contact (I13)), and do not display an element located between the non-conductive contact connected to the conductive contact and the coil indicating the output result. apparatus.

<Configuration 4>
When the first type of contact is a b-contact which becomes conductive upon receiving a false operation result, the developing means receives the first type of contact by the first type of contact. Is replaced with a logic circuit (circuit (E)) indicating an operation in which the logic expression of the second type is combined with the logic operation for obtaining the operation result indicated by the first type of contact. The support device according to any one of Configurations 1 to 3, which is developed into a logic circuit.

<Configuration 5>
Optimizing means (266) for extracting a contradictory contact combination (X1) from a logic circuit obtained by combining the second type of contacts obtained by the developing means and deleting a circuit comprising the contradictory contact combination. The support device according to any one of Configurations 1 to 4, further comprising:

<Configuration 6>
Optimizing means for extracting a redundant contact combination (X2, X3) from a logic circuit obtained by combining the second type of contacts obtained by the expanding means, and deleting a contact included in the redundant contact combination The support device according to any one of Configurations 1 to 4, further comprising (266).

<Configuration 7>
The support device according to any one of Configurations 1 to 6, further comprising a storage processing unit (262) configured to perform a process of storing a logic circuit obtained by combining the first type of contacts obtained by the expansion unit. .

<Configuration 8>
A support program (250) for supporting development of a ladder program executed by a control device that controls a control target,
The support program is stored in a computer.
Displaying the ladder program by a logic circuit combining a plurality of types of elements including a first type of contact indicating an operation result in the ladder program (S3);
For the logic circuit including the first type of contact, all the first type of contacts included in the logic circuit including the first type of contact are represented by the operation result indicated by the first type of contact. Developing a logical operation to be obtained into a logical circuit combining a second type of contact indicating a signal input from the outside (S6).

  The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. Further, it is intended that the inventions described in the embodiments and the respective modified examples be implemented alone or in combination as much as possible.

  Reference Signs List 1 control system, 8 optical recording medium, 10 CPU unit, 11 system bus, 14 I / O unit, 12 power supply unit, 100 PLC, 200 support device, 201 storage unit, 202 CPU, 203 operation unit, 206 RAM, 210 keyboard , 212 mouse, 214 display, 216 optical recording medium reader, 218 communication interface, 250 programming application, 252 editor, 254 compiler, 256 debugger, 258 simulator, 260 GUI module, 260a program display means, 262 expansion module, 262a expansion means , 264 result output module, 266 optimization module, 270 data storage unit, 272 variable setting, 274 ladder program, 276 Ladder program after opening, 278 object information, 510 ladder diagram, 512 input bus, 514 output bus, 520a, 520b logic circuit, 540 contact, 542 actual contact, 544 intermediate contact, 560 coil, 580 connection line.

Claims (8)

A support device that supports creation of a ladder program executed in a control device that controls a control target,
Program display means for displaying the ladder program by a logic circuit combining a plurality of types of elements,
For a logic circuit including a first type of contact indicating an operation result in the ladder program, all the first type of contacts included in the logic circuit including the first type of contact are replaced with the first type of contact. Expansion means for expanding a logical operation for obtaining an operation result indicated by the type of contact into a logic circuit in which a second type of contact indicating a signal input from the outside is combined.   The support device according to claim 1, further comprising: an output unit that receives a result of the execution of the ladder program and outputs a conduction state of a logic circuit indicating the ladder program.   The program display means displays a contact in a conductive state and a non-conductive contact connected to the contact in the conductive state for a logic circuit obtained by combining the contacts of the second type obtained by the developing means. The support device according to claim 2, wherein an element located between the non-conductive contact connected to the conductive contact and the coil indicating the output result is not displayed.   When the first type of contact is a b-contact which becomes conductive upon receiving a false operation result, the developing means receives the first type of contact by the first type of contact. By replacing the logical expression with a logical circuit indicating an operation, the logical operation for obtaining the operation result indicated by the first type of contact is developed into a logical circuit combining the second type of contact, The support device according to any one of claims 1 to 3.   The optimizing unit further comprising: extracting a combination of contradictory contacts from a logic circuit obtained by combining the second type of contacts obtained by the expanding unit, and deleting a circuit including the contradictory combination of contacts. The support device according to any one of claims 1 to 4.   An optimization unit for extracting a combination of redundant contacts from a logic circuit obtained by combining the contacts of the second type obtained by the expansion unit, and deleting a contact included in the combination of redundant contacts, further comprising an optimization unit. The support device according to any one of claims 1 to 4.   The support device according to any one of claims 1 to 6, further comprising a storage processing unit configured to perform a process of storing a logic circuit obtained by combining the first type of contacts obtained by the expansion unit. . A support program for supporting the development of a ladder program executed by a control device that controls a control target,
The support program is stored in a computer.
Displaying the ladder program by a logic circuit combining a plurality of types of elements including a first type of contact indicating an operation result in the ladder program;
For the logic circuit including the first type of contact, all the first type of contacts included in the logic circuit including the first type of contact are represented by the operation result indicated by the first type of contact. Developing a logical operation to obtain a logical circuit in which a second type of contact indicating a signal input from the outside is combined.

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