JP4554570B2 - Programmable display, control program and recording medium recording the same, and control system, client program and recording medium recording the same - Google Patents

Description

  The present invention relates to a programmable display capable of operating from a client computer connected to a network and viewing a display screen, and a control system including the programmable display.

  The programmable display has an interface with the host controller (PLC, inverter, temperature controller, etc.), and displays the operating status of the devices connected to the host controller and gives control instructions to the devices. This is an operation-type display with a function to accept input from the screen. In general, since the programmable display has a graphic display function, it can display an operation panel, a switch, an indicator lamp, and the like, and serves as an operation terminal in the control system.

  Such a programmable display is operated by an operator who is generally engaged in production work, for example, at a production site. When a problem occurs in the control system, it may be difficult for the operator to deal with the problem depending on the problem. In such a case, the manager of the control system may solve the problem. However, there is an annoyance that the person in charge of management must go to the site every time a problem to be solved occurs and check the status of the control system on the screen displayed on the programmable display.

  Alternatively, if the production line manager wants to monitor the operation status of the production line, the manager must go to the site and check the status of the control system on the screen displayed on the programmable display. There is annoyance that it must not be.

In order to eliminate such an inconvenience, for example, as disclosed in Patent Document 1, the same screen as the screen displayed on the programmable display can be viewed at a place away from the site where the programmable display is installed. The technique which can be operated similarly to a programmable display on the displayed screen is disclosed. In this technique, an applet (Java (registered trademark) applet) created by converting screen data in a host computer is transmitted to a client device via the Internet. The client device displays the same screen as the screen displayed on the programmable display by executing the received applet, and operates the PLC on the displayed screen in the same manner as the programmable display. Can do.
JP 2001-268106 A (published on September 28, 2001) Japanese Unexamined Patent Publication No. 2000-20113 (published on January 21, 2000) JP 2004-348605 A (published on December 9, 2004)

  In the above technique, in order to realize the same display / operation as the programmable display by the applet, it is necessary to develop an applet that performs the same operation as the display execution program (runtime) of the programmable display. For this reason, when the display execution program is upgraded, the applet must be upgraded as well. Along with this version upgrade, it is also necessary to upgrade the version of communication processing for screen data conversion function support and operation (data update) using an applet.

  The present invention has been made in view of the above problems, and is displayed on a programmable display from a remote location without causing the trouble of upgrading the applet following the upgrade of the display execution program. The purpose is to display the same screen and to operate on the displayed screen in the same manner as a programmable display.

  A programmable display according to the present invention includes a display processing means for executing display processing for displaying a screen based on screen data, an input processing means for executing input processing by an input operation, and a client computer connected via a network. In order to solve the above-mentioned problem, the display processing means creates image data that is image data of the screen to be displayed. Screen sharing means for sharing the screen with the client computer by transmitting the image data to the client computer in response to an access request from the client computer, and input on the screen displayed on the client computer Accept the operation and enter by the input operation It is characterized by comprising a server means for executing processing to the input processing means.

  In the above configuration, in the programmable display, the image data of the screen displayed by the display processing means is transmitted to the client computer by the screen sharing means in response to an access request from the client computer. Thereby, the screen currently displayed with the programmable display can be displayed on a client computer by displaying the image data. As a result, the screen can be shared between the programmable display and the client computer.

  Further, when the user performs an input operation on the screen displayed on the client computer, the server unit accepts the input operation and causes the input processing unit to execute an input process based on the input operation. Thereby, operation can be performed with the same feeling as operation performed on the screen displayed on the programmable display on the screen displayed on the client computer. In addition, a remote access function for such a programmable display from the client computer can be realized without following the upgrade of the display execution program of the programmable display.

  In the programmable display, the server means accepts an input operation only for one client computer among the plurality of client computers, and finishes accepting the input operation for the client computer. It is preferable to lower the priority order of accepting than other client computers.

  Thereby, since only one client computer can accept an input operation, it is possible to avoid malfunction caused by a plurality of client computers performing an input operation. In addition, if an operation right is requested for a client computer that has not yet received an input operation on the programmable display, the input operation can be received more preferentially than a client computer that has already been received. .

  Further, if the server means accepts an input operation for only one client computer while accepting transmission of the image data to another client computer, the input operation is accepted. Image data can also be transmitted to client computers other than one client computer to display the screen displayed on the programmable display. Thereby, display screen information can be shared between client computers.

  The programmable display includes ladder program execution means for executing a ladder program, and ladder monitor means for changing a display state of a circuit on a ladder monitor screen created in the same format as the screen according to the execution status of the ladder program. The display processing means creates image data that is image data of the ladder monitor screen to be displayed, and the screen sharing means converts the image data of the ladder monitor screen created by the display processing means to the image data. The ladder monitor screen can be viewed on the client computer by transmitting it to the client computer in the same manner as the screen image data.

  The control program of the present invention causes a computer that realizes any of the programmable displays described above to function as each of the means. The control program is provided by being recorded on a computer-readable recording medium. As a result, without following the upgrade of the display execution program of the programmable display, the screen displayed on the programmable display is displayed from a remote location, and the same operation as the programmable display is performed on the displayed screen. be able to.

  The control system of the present invention includes any one of the programmable displays, the network, and the client computer, and the client computer executes display processing by client-side display processing means that performs display processing, and input processing by input operation. Client-side input processing means and a client-side screen that sends an access request to the screen sharing means, receives the image data sent from the screen sharing means, and causes the client-side display processing means to display the screen as the screen It is characterized by comprising sharing means and client means for transmitting an input operation on the screen displayed by the client side input processing means to the server means.

  In the above configuration, when the access request is transmitted to the server unit by the client unit, the screen sharing unit transmits the image data of the screen displayed by the display processing unit to the client computer in response to the access request. To do. In the client computer, the screen displayed on the programmable display can be displayed by displaying the image data by the client-side display processing means. When an input operation performed by the user by the client side input processing means is executed on the screen displayed on the client computer, the input operation is transmitted to the server means by the client means. When the server unit accepts the input operation, the server unit causes the input processing unit to execute an input process based on the input operation. Thereby, operation can be performed with the same feeling as operation performed on the screen displayed on the programmable display on the screen displayed on the client computer.

  The client program of the present invention causes a computer that realizes the client computer in the control system to function as the client unit. The client program is provided by being recorded on a computer-readable recording medium. As a result, without following the upgrade of the display execution program of the programmable display, the screen displayed on the programmable display is displayed from a remote location, and the same operation as the programmable display is performed on the displayed screen. be able to.

  As described above, the programmable display device according to the present invention includes the server unit, so that the programmable display can be performed from a remote location without causing the trouble of upgrading the applet following the upgrade of the display execution program. The screen displayed on the display device is displayed, and the same operation as the programmable display device can be performed on the displayed screen.

  The embodiment of the present invention will be described with reference to FIGS. 1 to 5 as follows.

  As shown in FIG. 1, the control system 1 according to the present embodiment includes a programmable display 2, a client computer 3, a network 4, a PLC 5, and a target system 6.

  The programmable display 2 is connected to the client computer 3 via the network 4. The network 4 is a communication network including a local area network (LAN) made up of Ethernet (registered trademark) or the like capable of performing communication using a common communication protocol (common communication protocol) and the Internet. In the present embodiment, a configuration in which three client computers 3 of A station, B station, and C station are connected to a network 4 will be described.

  In accordance with a sequence program (such as a ladder program) created by the user, the PLC 5 captures the state of the input device 7 via the input unit and outputs it at every predetermined scan time such as several tens of ms. A control instruction is given to the device 7 for use.

  As the input device 7, devices such as sensors (temperature sensors, optical sensors, etc.) and switches (push button switches, limit switches, pressure switches, etc.) are used. As the output device 7, an actuator, a relay, a solenoid valve, a display, or the like is used. These devices 7 are arranged in required parts of various target systems 6 such as a production line and constitute a part of the control system 1.

  The device 7 may be a specific area in a data memory (not shown) for storing data manually input from an input device such as the touch panel 25 described later. The device 7 may be a specific area in the memory in the PLC 5.

  The memory (device memory) in the PLC 5 stores data (word data or bit data) indicating the state of the device 7 (output value from the device 7 or set value to the device 7) in an area specified by the device address. is doing. In the memory, a word device and a bit device are set. The word device is set as an area for storing word data such as numeric values as input / output data, and is designated by a word address (device address). The bit device is set as an area for storing bit data such as an on / off state, and is set by a bit address (device address). With such a setting, the device 7 can be controlled simply by accessing an arbitrary word device or bit device in the memory by specifying the device address, or information regarding the state can be individually taken out.

  In the following description, the device address is appropriately referred to as an address.

  The programmable display 2 is provided with an arithmetic processing unit such as a CPU, and is a dedicated computer that realizes an operation function and a display function unique to the programmable display by displaying input operation and display screen data created by the user. is there. The programmable display 2 that is preferably used as an HMI device of the control system 1 is an operation for displaying the state of the device 7 on the screen based on screen data determined by combining processing definition information (tag) described later. The operation for controlling the state of the device 7 according to the operation on the screen is specified.

  The programmable display 2 acquires the state of each device 7 that displays the state on the display screen via the PLC 5 by communication with the PLC 5 via the serial cable 8. For example, the programmable display 2 displays the state of each device 7 on the display 24 described later. It has a function to display the status. The programmable display 2 has a function of instructing the device 7 to control the state of the device in response to an operation on the touch panel 25 described later.

  The acquisition / change of the state of the device 7 may be instructed each time, or a temporary memory space is prepared in the programmable display 2, and when acquiring / changing, the memory space is accessed and a predetermined It is also possible to communicate with the PLC 5 at every time interval or every predetermined event to synchronize with the entity to which each address is assigned.

  In order to realize the above functions, the programmable display 2 has an HMI control unit 21, a data memory 22, a work memory 23, a display 24, a touch panel 25, and an interface unit (I / F in the figure) 26. , 27. Hereinafter, each main part of the programmable display device 2 will be described in detail.

  As the display 24, a flat panel display such as a liquid crystal display, an EL display, or a plasma display is preferably used in order to make the programmable display device 2 thin. The touch panel 25 is an input device provided for performing touch input on the display screen of the display 24.

The interface unit 26 is a communication control unit for the programmable display 2 to communicate with the client computer 3, and is connected to the network 4. The interface unit 26 is configured to perform network communication based on the IP address of the client computer 3.

  On the other hand, the interface unit 27 is a communication control unit for the programmable display 2 to perform serial communication with the PLC 5, and each is connected by a serial cable 8. Further, the interface unit 27 includes the same number of communication ports as the number of connectable PLCs 5 so that a plurality of PLCs 5 can be connected. Here, the correspondence relationship between the manufacturer and model name of the PLC 5 and the communication port to which the PLC 5 is connected is set in advance as connected device data by the user. Further, the PLC 5 is given a connected device name such as PLC-A, PLC-B, PLC-C,... According to the communication port to be connected, and this connected device name is also added to the connected device data. included. Reading / writing data to / from the PLC 5 bit device and word device as described above is performed by designating the connected device name together with the address.

  The interface unit 27 performs communication using a communication protocol corresponding to the manufacturer and model of the PLC 5 based on the connected device data. The connected device data and the communication protocol are stored in, for example, a data memory 22 described below.

  The data memory 22 is a memory for storing a project file, the above communication protocol, client specific data, an interlock table, and the like, and FEPROM (Flash Erasable and Programmable ROM) is used. Since FEPROM is a rewritable read-only flash memory, it plays the role of a hard disk drive in a general personal computer. A flash memory does not have a movable part and is resistant to impacts, and thus operates stably even in a poor ambient environment.

  The project file is a screen file in which data of one or more user screens (unit screens configured by screen data for one frame) displayed on the programmable display 2 are collected. In many cases, the project file usually includes a series of related screen data corresponding to the target system 6 or a product manufactured by the target system 6. This project file is stored in a different file format (file format readable by the HMI control unit 21) from a project file created by a screen editor, which is screen creation software.

  The programmable display device 2 selects one screen data based on a unique screen number assigned to each screen number from the project file, and displays a user screen based on the screen data.

  The screen data includes a base screen to be displayed on the display 24, part data, processing definition information to be described later assigned to each part, and the like. This screen data includes a graphic data part and an address data part. The graphic data section stores graphic data and selected parts for the mark created by the user, and the address data section stores the addresses and addresses for the input marks and parts so as to correspond to the graphic data section. The comment corresponding to is stored. Specifically, each mark or part in the graphic data part is associated with a corresponding comment and address in the address data part.

  Comments include event names such as the operating status (start, stop, etc.) of the device 7, codes corresponding to the device 7 such as SW and lamp corresponding to the switch, LAMP, operation instructions, and control targets The physical quantity that becomes. Comments can also be handled as variables. The comment defined in this way is associated with a desired device address corresponding to the device 7 in advance.

  The screen data includes process definition information (tag) that defines various processes performed in relation to the user screen. This processing specification information is created for each event to be executed on the base screen. Basically, the file number (screen number) of the base screen on which the display processing is to be executed and the base screen are executed. An event name for specifying the operation content to be performed and reference information including one or a plurality of data referred to for each execution event are provided as a set.

  In the programmable display device 2 according to the present embodiment, as the above-described tag, a display tag indicating the correspondence between the region (display range) on the base screen and the device address of the device corresponding to the display in the region, and the screen A touch input tag indicating the correspondence between an area (input range) and an address corresponding to a touch input to the area is defined. Furthermore, in this embodiment, each tag can be associated with at least one of a plurality of user screens.

  The client specifying data is data (identification code) for specifying the client computer 2, and the IP address, account name, password, etc. of the client computer 2 are set as this data.

  The interlock table is provided for restricting the input processing of the programmable display 3 to one of the client computers 3 by the input restricting unit 211a described later. This interlock table includes a correspondence relationship between an ID (for example, an IP address) for identifying each client computer 3 and a flag indicating whether the input process is occupied or not. This flag is turned on when the input process is in the occupied state, and turned off when the input process is in the unoccupied state. In the interlock table, a priority order for acquiring an operation right for the programmable display device 2 is set for each client computer 3.

  The work memory 23 is constituted by, for example, a DRAM, and is used for temporary storage of data exchanged with the PLC 5 in addition to being used for work during arithmetic processing such as display control. In particular, the DRAM has a state memory area for transferring the state of the device 7 (the contents of the device address) stored in the PLC 5 memory to and from the PLC 5 memory. The work memory 23 also includes a VRAM that develops an image to be displayed on the display. In this VRAM, the image of the screen data output from the data memory 22 is stored as dot data in the order displayed in the horizontal direction.

  The HMI control unit 21 is a functional block realized by causing an arithmetic processing means such as a CPU provided in the programmable display 2 to execute the HMI control program. The above-mentioned HMI control program can be recorded on a recording medium configured to be separable from the programmable display 2 and may be installed in the programmable display 2 from the recording medium. The HMI control program is individually prepared for each model in order to exhibit a function corresponding to the model of the programmable display device 2.

  The above recording media include tape systems such as magnetic tapes and cassette tapes, magnetic disk systems such as flexible disks and hard disks, optical disk systems such as CD-ROM, MO, MD, and DVD, IC cards (including memory cards), optical A card system such as a card is preferred. In addition, the program medium may be a medium that carries a fixed program including a semiconductor memory such as a mask ROM, EPROM, EEPROM, flash ROM, or the like.

  Further, if the control system 1 is configured to be connectable to a communication network including the Internet, it may be a medium that carries the program in a fluid manner so as to download the program from the communication network. However, when the program is downloaded from the communication network in this way, the download program may be stored in advance in the programmable display 2 or may be installed from another recording medium.

  The HMI control unit 21 performs central control operations of the HMI function such as display control of the user screen, control of input operation via the user screen, and control of communication with a connected device such as the PLC 5. The HMI control unit 21 includes an access server unit 211, a display processing unit 212, and an input processing unit 213.

The access server unit 211 accepts access from each client computer 3, displays the screen displayed on the programmable display 2 on each client computer 3, and enables operations on the screen from each client computer 3. Process to do. Specifically, the access server 21 1 Accepting access from the client computer 3, and is expanded in the VRAM to be described later by the display processing unit 212, the screen displayed on the programmable display device 2 images ( Image data) is acquired from the display processing unit 212 and transmitted to each client computer 3. Further, the access server unit 212 causes the input processing unit 213 to execute the contents operated on the screen displayed on each client computer 3.

  The access server unit 211 has a VNC (Virtual Network Computing) server function applied to, for example, a general personal computer in order to perform the above processing.

  By the way, when an operation right is simultaneously given to a plurality of client computers 3 and an input process is accepted, different data is given to the device 7 at the same time, which causes a malfunction. In order to avoid such inconvenience, the access server unit 211 includes a processing restriction unit 211a that performs exclusive control.

  When a specific client computer 3 requests acquisition of an operation right in a state where input processing is not occupied by each client computer 3, the processing restriction unit 211a turns on the flag for the client computer 3 in the above-described interlock table. Thus, only the client computer 3 is given an operation right. As a result, only the client computer 3 occupies the input process.

  Further, when an event for canceling the occupied state of the input process occurs, the process restricting unit 211a turns off the flag of the interlock table and releases the occupied state of the client computer 3. As the above-mentioned event, for example, it is recognized that a request for releasing the occupied state is received from the client computer 3 in the occupied state of the input process given the operation right, or the operation of the client computer 3 in the occupied state is not performed for a certain period of time. It can be mentioned.

  Further, the processing restriction unit 211a lowers the priority order for acquiring the operation right for the client computer 3 whose occupied state is released, as compared with the other client computers 3. Thereby, if acquisition of the operation right is requested to the client computer 3 that has not yet set the occupancy state of the input processing in the programmable display device 2, it is more preferential than the already accepted client computer 3. Set the occupancy status of input processing.

Note that the processing restriction unit 211a can also be set to reject an input operation by the touch panel 25 on the programmable display device 2 side in a state where the operation right is given to any of the client computers 3 and the input process is accepted. The client computer 3 or the programmable display 2 may be set to be preferentially handled. Further, the operation right is applied to only one client computer 3, the access server 211 accepts a connection request for performing display processing for a plurality of client computers 3.

  The display processing unit 212 is a display execution program (runtime) that performs processing to acquire the state of the device 7 and display it on the user screen. The display processing unit 212 reads necessary information among the state information indicated by the bit device or the word device set in the memory in the PLC 5 to the work memory 23 in a timely manner, and repeatedly reads the display tag. Then, the part of the expression format designated by the display tag is displayed on the display 24 in the designated area on the screen in a form corresponding to the read value. As a result, a display operation that changes according to a change in the state of the bit device or the word device is executed, and the state of the device 7 acquired from the PLC 5 is reflected in the display state of the parts on the user screen.

  The display processing unit 212 displays the screen on the display 25 by reading the screen data on the VRAM provided in the work memory 23 and the like and developing the screen image.

  The input processing unit 213 performs processing for giving a control instruction to the device 7 by input (touch input or numerical input) via the touch panel 25 on the user screen. The input processing unit 213 repeatedly reads out the above-described input tag and specifies a range (an effective input coordinate range in which the input is valid) for specifying an input position in a predetermined area of the user screen included in the reference information in the input tag ), And the operation specified by the event name specifying the operation of the touch panel 25 (numerical value input operation, ON / OFF operation, etc.) is set as a bit device or a word device in the memory in the PLC 5. For example, in the case of a numerical input operation, numerical data or the like is written as a control instruction to the word device, and in the case of an ON / OFF operation, a new bit state is written as a control instruction to the bit device. Thereby, in the PLC 5, the set control instruction is executed as the above operation, and the state of the device 7 changes.

  Next, the client computer 3 will be described. The client computer 3 includes a CPU, a memory (RAM, ROM, etc.), an external storage device (hard disk drive, MO drive, etc.), a display device and an input device (keyboard, mouse, etc.) as in a general-purpose personal computer. ing. The client computer 3 includes an access client unit 31, a display processing unit 32, and an input processing unit 33.

The access client unit 31 is communicably connected to the programmable display unit 2 and communicates with the access server unit 211 described above to request an operation right to the access server unit 211 or transmit from the programmable display unit 2. The screen data thus transferred is transferred to the display processing unit 32, or the input operation data from the input processing unit 33 is transmitted to the access server unit 211. The access client unit 31 has the above VNC client function in order to perform the above processing. The client computer 3 functions as a remote access client that remotely controls the display and input of the programmable display 2 by including the access client unit 31 described above.

  The display processing unit 32 is a functional block provided as a part for performing OS display processing. The input processing unit 32 displays a desktop (basic operation screen). When the display processing unit 32 receives the image data from the programmable display 2 via the access client unit 31 of the programmable display 2, the display processing unit 32 develops the image data in a VRAM (not shown), and in response to an instruction from the access client unit 31. And displayed as a user screen on a window opened on the desktop. As a window for displaying the user screen, a window prepared by arbitrary application software (for example, a text editor) included in the client computer 3 is used.

  The input processing unit 33 is a functional block provided as a part for performing OS input processing. The input processing unit 33 also passes input operation data generated by a user input operation using an input device (mouse, keyboard, etc.) on the user screen displayed on the desktop to the access client unit 31.

  Here, the remote access operation in the control system 1 configured as described above will be described with reference to the flowchart of FIG. In the description here, the client computer 3 is appropriately referred to as a client.

First, the access server unit 211 of the programmable display 2 and the access client unit 31 of the client are activated. When activated, the access server unit 211 reads the interlock table from the data memory 22 and develops it in the work memory 23. In the programmable display device 2, the display processing unit 212 reads the screen data of the user screen from the project file stored in the data memory 22, and expands the screen data as image data in the VRAM in the working memory. This is displayed on the display 24.

  In this state, it is determined whether or not an input event (connection request) from the client has been received (S1).

  At this time, for example, it is assumed that the client of station A (client A) is requested to connect. In the client A, when the user instructs to shift to the remote access mode by an input operation, the access client unit 31 receives the instruction via the input processing unit 33 and receives a dialog box (not shown) for access. Is displayed on the display processing unit 32. The dialog box includes an input box for an IP address of the programmable display 2, an input box for an account name set in the programmable display 2, an input box for a password for login, and a connection button. Is provided. When the user inputs each input item in each box and clicks the connection button, the access client unit 31 requests the access server unit 211 to connect.

  In S <b> 1, when the input restriction unit 211 a of the access server unit 211 receives an input event from the access client unit 31, the input restriction unit 211 a refers to the interlock table to determine whether or not the client A has the highest priority for acquiring the operation right. Determine (S2). If it is determined that the operation right acquisition order of the client A is not the highest, the process returns to S1 to wait for a connection request from the client with the highest operation right acquisition order. On the other hand, when it is determined that the operation right acquisition order of the client A is the highest, the flag of the client A is turned ON in the interlock table to make the client A occupy input processing. Thereby, the access server unit 211 handles the client A as an exclusive client. At this time, the access server unit 211 instructs the display processing unit 212 to acquire the image data of the user screen currently displayed on the programmable display device 2 from the VRAM in which the image data is expanded, and the client To the access client unit 31 of A.

  When the access client unit 31 receives the image data, it passes it to the display processing unit 32. The display processing unit 32 expands and displays the screen data on the VRAM in the client A. Thereby, as shown in FIG. 3, the user screen 102 is displayed on the desktop 101, so that the user can see the user screen currently displayed on the programmable display 2.

  When the user performs an input operation using the input device on the displayed user screen, the input processing unit 32 generates input operation data based on the input operation, and the input operation data is used as the access client unit 31. To pass. The input operation data here is data in the same format as the input operation data generated by the input processing unit 213 based on the input operation to the touch panel 25 in the programmable display device 2. The access client unit 31 transmits input operation data from the input processing unit 213 to the access server unit 211.

  In the programmable display device 2, when the input processing unit 213 receives the input operation data via the access server unit 211, the input processing unit 213 performs input processing based on the input operation data (S3). For example, when an operation to turn on the bit switch on the user screen displayed on the client A is performed, the input processing unit 213 rewrites the bit data of the device address for the bit switch to ON. As a result, the bit switch is switched to the ON state.

  This state is reflected on the user screen displayed on the programmable display 2 by the display processing unit 212. Further, when the display processing unit 212 is notified that the display content of the user screen has been updated, the access server unit 211 acquires the updated user screen from the VRAM via the display processing unit 212, and accesses the access client. It transmits to the part 31. The access client unit 31 causes the display processing unit 32 to display the screen data as an updated user screen. Thereby, in the client A, the user screen of the programmable display 2 updated by operation can be displayed.

  It is determined whether or not an input event has occurred from a client other than the occupied client (for example, client B or C) while the occupied state of client A is maintained (S4). If an input event from another client has occurred, the input restriction unit 211a rejects the input event (S5) and returns the process to S4. If no input event from another client has occurred, the access server unit 211 determines whether or not the exclusive state of the client A has been released (S6). Specifically, a request to release the occupied state is issued from the client A, and the state in which the access server unit 211 accepts the request and cuts off the connection with the client A is regarded as the released state of the occupied state.

  Here, if the occupied state of the client A is not released, the process returns to S4. On the other hand, if the occupied state of the client A is released, the priority order for obtaining the operation right of the client A is set in the interlock table. Rewrite lower than B and C. Further, it is determined whether or not to terminate the remote access process (S7). If the end of the remote access process is instructed, the process is terminated. On the other hand, if the end of the remote access process is not instructed, the process returns to S1.

  Even when the input processing is occupied by the client A, the display processing by the display processing unit 212 can accept connection requests with other clients B and C and display the user screen on the clients B and C. It is. As a result, information can be shared among the clients A to C.

  As described above, in the control system 1 of the present embodiment, the programmable display device 2 includes the access server unit 211, while the client computer 3 includes the access client unit 31. Thereby, the user screen currently displayed on the programmable display 2 with the client computer 3 can be displayed. Further, on the user screen displayed on the client computer 3, the programmable display 2 can perform an input operation similar to the input operation on the user screen. Moreover, since it is not necessary to upgrade the applet by following the upgrade of the display execution program as in the prior art, the user is freed from such annoyance.

  Therefore, various display functions such as alarm display, trend data display, and ladder monitor screen display executed by the programmable display 2 in the client computer 3 can be used. Next, display of the ladder monitor screen will be described.

  The ladder monitor screen is a screen for monitoring a state in which the ladder program is executed when a ladder program is used as a sequence program for operating the PLC 5 as a user screen. Provided. In order to display the ladder monitor screen, the programmable display device 2 has the same control function as the PLC 5 as shown in FIG.

  As shown in FIG. 4, the programmable display 2 further includes a controller unit 28 and an I / O unit 29.

  The controller unit 28 is a part that performs a PLC function, and is a functional block that is realized by causing the above-described arithmetic processing device included in the programmable display 2 to execute a control function program. The controller unit 28 includes a control program execution unit 28a and a ladder monitor unit 28b. The data memory 22 in the programmable display 2 stores a ladder file that is a ladder program file and a ladder monitor file that is a ladder monitor screen.

  The ladder program includes a command data part and an address data part. The command data part stores operands (addresses) used for coding corresponding to ladder instructions corresponding to the entered ladder symbols. The ladder symbol selected when creating the ladder program is saved as a ladder command in the ladder file. On the other hand, the address data part stores the address set in the ladder editor and the comment associated with the address for the ladder instruction corresponding to the entered ladder symbol so as to correspond individually to the operand of the command data part. Yes.

  Examples of the comment include an event name such as the operating state of the device 7, a code corresponding to the device 4 such as SW and LAMP corresponding to the switch, and an operation instruction.

  The ladder monitor file is a file of screen data (ladder monitor screen data) for ladder monitor. Ladder monitor screen data is displayed by the programmable display device 2 as with general screen data, but the ladder monitor screen is programmable in the same manner as the user screen in order to display the state of the device 7 while the ladder program is executed. In addition to displaying on the display device 2, it is necessary to include an executable ladder program. For this reason, the ladder monitor file is created in advance so as to have the same format as the screen data created by the screen editor for creating the user screen. The ladder monitor file includes a command data portion similar to the command data portion described above, an address data portion corresponding to the address data portion, and a graphic data portion corresponding to the graphic data portion.

  The control program execution unit 28 a reads the ladder file from the data memory 22 and develops it as a ladder program in the work memory 23. The control program execution unit 28a scans the ladder program read from the work memory 23 at a predetermined cycle such as several tens of ms and executes the ladder instructions one by one.

  A variable is associated with a device address called by a unique name for each PLC5 manufacturer. The variable is a name that can be arbitrarily set by the user, and a comment described later can be handled as a variable.

Ladder monitor unit 28b, in a state where the target system 6 is running from the ladder monitor file read in the work memory 23 is read out repeatedly the display tag, the parts of the specified expression format by the display tag, the working memory The bit device or the word device set to 23 is changed to a form corresponding to the state information. In addition, the ladder monitor unit 28b instructs the display processing unit 212 to perform display processing based on data on the ladder monitor screen in which the form of the part has changed. Thereby, the state of the device 7 acquired by the ladder program being executed by the control program execution unit 28a is displayed on the ladder monitor screen. Specifically, for example, in a ladder program (ladder circuit) on a ladder monitor screen, a portion (part) that is conductive on the circuit is displayed thickly or brightly. The ladder monitor unit 28b displays a ladder monitor screen by a method similar to the method disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-2011.

  The control function program can also be installed in the programmable display device 2 from a recording medium configured to be separable from the programmable display device 2 in the same manner as the above-described HMI control program.

  The work memory 23 is also used as a work area when the controller unit 28 performs control processing. Specifically, the working memory 23 passes data (contents of the address) indicating the state of the device 7 stored in the area specified by the address in the memory of the PLC 5 to and from the memory by the above-described state memory area. To do.

  In the programmable display 2 configured as described above, the ladder monitor is performed as follows.

  First, when the ladder monitor file is read from the data 22 into the work memory 23 by the ladder monitor unit 28b, the display processing unit 212 of the HMI control unit 21 displays the ladder monitor screen as image data in the VRAM based on the ladder monitor file. Expanded and displayed on the display 24. In this state, when the control program execution unit 28a starts executing the ladder program, the ladder monitor unit 28b acquires the state of the device 7 captured by the programmable display device 2, and displays the state on the ladder monitor screen. For example, a portion that is conductive on the circuit (on the connection line) is displayed as a thick line or brightly, a non-conductive portion is displayed as a thin line, or a contact or coil is lit. Thereby, it can be confirmed on the ladder monitor screen which device 7 is conducting on the circuit.

  Thus, the ladder monitor screen displayed as the user screen on the programmable display 2 can also be displayed on the client computer 3 by using the access server unit 211 and the access client unit 31. In particular, the display processing unit 212 of the programmable display device 2 can activate the ladder monitor unit 28b to display the ladder monitor screen on the user screen when an abnormality occurs while the user screen is displayed. it can.

  For this reason, the display processing unit 212 performs a process of displaying a user screen by an input operation from a certain client computer 3 and a process of displaying a ladder monitor screen by an input operation from another client computer 3 independently. It is configured. The input processing unit 213 is also configured to independently accept and perform input operations from the different client computers 3 described above.

  As a result, the execution status of the ladder program can be confirmed on the ladder monitor screen while the user screen is displayed. The client computer 3 can also reproduce such a display state. In the client computer 3, as shown in FIG. 5, the ladder monitor screen 103 is displayed so as to overlap the user screen 102 displayed on the desktop 101. The ladder monitor screen 103 is also displayed in a window provided by the application program of the client computer 3 as with the user screen 102.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The programmable display of the present invention has a remote access server function, receives access from a computer having a remote access client function, displays the same user screen on the computer, and displays the same on the user screen. Since the operation is accepted and executed, the function of providing the user screen to the connected computer and accepting the input operation can be maintained regardless of the version upgrade of the display execution program. The present invention can be suitably used for a control system for monitoring a user screen from a computer installed in the computer and remotely operating a programmable display.

It is a block diagram which shows the structure of the control system which concerns on embodiment of this invention. It is a flowchart which shows the procedure of the process in operation | movement of the remote access of the said control system. It is a figure which shows the state by which the user screen was displayed on the client computer in the said control system by remote access. It is a block diagram which shows the structure of the control system which concerns on other embodiment of this invention containing the programmable display provided with the function to perform a ladder monitor. It is a figure which shows the state by which the user screen and the ladder monitor screen were displayed on the client computer in the control system of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control system 2 Programmable display 3 Client computer 4 Network 5 PLC
21 HMI control unit 28 controller unit 28a control program execution unit (ladder program execution means)
28b Ladder monitor unit (ladder monitor means)
31 Access client part (client side screen sharing means)
32 Display processing unit (client side display processing means)
33 Input processing unit (client side input processing means)
211 Access server section (screen sharing means, server means)
211a Input restriction unit 212 Display processing unit (display processing means)
213 Input processing unit (input processing means)

Claims (6)

Display processing means for executing a display process for acquiring a device state and displaying the device state;
Input processing means for executing an input process for giving a control instruction to the device by an input operation via the touch panel on the screen;
In a programmable display comprising interface means for controlling communication with a plurality of client computers connected via a network,
In response to an access request from the client computer, in order to display the displayed screen on the client computer, image data that is an image of the screen is transmitted to the client computer and displayed on the client computer. Server means for causing the input processing means to execute input processing by an input operation on the screen;
Ladder program execution means for executing the ladder program;
Ladder monitor means for displaying the status of the device acquired by executing the ladder program on a ladder monitor screen created in the same format as the screen,
The display processing means independently performs a process of displaying the screen on a programmable display by an input operation from a certain client computer and a process of displaying the ladder monitor screen on a programmable display by an input operation from another client computer. And accept,
In order to display the displayed ladder monitor screen on the client computer in response to the access request , the server means sets the image data of the ladder monitor screen in the same manner as the image data of the screen. A programmable display device, characterized in that: The control program for functioning the computer which implement | achieves the programmable display of Claim 1 as said each means.   A computer-readable recording medium on which the control program according to claim 2 is recorded. A programmable display according to claim 1;
The network;
The client computer,
The client computer is
Client-side display processing means for performing display processing;
Client side input processing means for executing input processing by input operation;
On the screen displayed by the client-side display processing unit, the access request is transmitted to the server unit, the image data transmitted from the server unit is received and displayed on the client-side display processing unit as the screen. And a client means for transmitting an input operation by the client-side input processing means to the server means.   A client program for causing a computer realizing the client computer in the control system according to claim 4 to function as the client means.   A computer-readable recording medium on which the client program according to claim 5 is recorded.

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