JP4492778B2 - Communication system in monitoring system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication system in a monitoring system that transmits and receives communication data between a plurality of application programs and a target system via communication means.
[0002]
[Prior art]
As a conventional communication system, one disclosed in JP-A-11-327612 is known. This is because multiple monitor devices perform processing on the multitasking OS, and when a certain monitor device communicates with the programmable controller, the monitor device that wants to communicate stores its monitor ID in the monitor ID. The data request is stored in the transmission data storage unit. Then, when the monitor device receives a data response from the program controller set in the received data storage means by the communication means by one communication means, the monitor device receives the monitor ID storage means. The monitor ID stored in is reset to enable communication processing of other monitor devices. While one monitor device is performing communication processing, when another monitor device checks the monitor ID storage means and the monitor ID is set, the monitor ID is reset because the data request cannot be stored in the transmission data storage means. Until the next opportunity. Thereby, a some monitor apparatus communicates asynchronously and performs the data display of a some programmable controller.
[0003]
[Problems to be solved by the invention]
In the prior art described above, a plurality of monitor devices (application programs) can communicate asynchronously, but only one monitor device can make a communication request, and one monitor device communicates. The other monitor devices cannot set data requests (communication data), and there is a problem that the communication processing is completely occupied by one monitor device. In addition, the monitoring device that wants to communicate must confirm whether or not the communication processing of the monitoring device that has previously set the communication data is completed, and it takes time for the confirmation processing and the communication of the monitoring means that has set the communication data There is a problem in that the communication efficiency is low because it waits for the processing to complete and communication data is set after the processing is completed, so that it takes time to wait for communication. In addition, communication is executed by one communication means, but there is no description that the communication means supports a plurality of communication protocols, and there are mixed program controllers (target systems) that communicate by different communication protocols. Since the communication means corresponds to one communication protocol, it can communicate only with a programmable controller of the same type of communication protocol and cannot communicate with a target system of another communication protocol.
An object of the present invention is to provide a monitoring system that does not occupy a communication means with a single communication request of one application program, has high communication efficiency, and can communicate even when a plurality of different communication protocols coexist. A communication system is provided.
[0004]
[Means for Solving the Problems]
  In order to solve the above-mentioned problems, the present invention connects a programmable controller as a target system and a monitor computer, and exchanges communication data between a plurality of application programs of the computer and the target system. In the communication system in the monitoring system that transmits and receives between the computer and the programmable controller by the communication means via the communication data storage means provided in theThe computer has a queue;The communication data storage meansAssign allocation areas for multiple application programsCan store communication data more than onceMultiple assignments toShared memory,The queue is a memory number for identifying each allocation area in which communication data is set by the application program is set in the communication request order of each application program, and controls the communication order according to the communication request order.Communication data stored in shared memory isSaidTransmission and reception are performed by the communication means in accordance with the order set in the queue for controlling the communication order (claim 1). According to this, since a shared memory capable of storing communication data twice (two sets) or more is provided, a data request of another application program can be set in the shared memory even during communication by one application program. One application program does not completely occupy the communication means.Further, since communication is performed according to the memory numbers set in the queue in the order of communication request, it is not necessary to check all shared memories during communication and to confirm the presence / absence of communication and the communication order with communication data, which is preferable because communication processing time is shortened. .
[0005]
The communication means includes a correspondence table between each target system and a communication protocol corresponding to each target system, and refers to the correspondence table and corresponds to the target system to which the application program requests communication and the target system. Transmission / reception of communication data is executed by a communication protocol (claim 2). The communication means is preferable because it can communicate with a plurality of target systems having different communication protocols based on the correspondence table. Further, since the application program communicates with each target system via the communication means, communication can be performed in the same manner even with target systems of different protocols. In addition, since the application program and the communication means are independent, it is possible to communicate even if the communication protocol is not supported by changing only the communication means without changing the application program. This is preferable because it can be shortened.
[0006]
The communication means includes a master communication manager program and a plurality of slave communication manager programs having a communication protocol corresponding to each target system. The master communication manager program is based on communication data set in a shared memory. Referring to the correspondence table, communication data is transmitted and received by a slave communication manager program corresponding to a target system for communication (claim 3).
[0007]
When a part of the shared memory is allocated to each application program that requests communication as an allocation area by the shared memory control program, and no communication data needs to be transferred between the application program and the target system, the allocation area of the application program Is released by the shared memory control program. According to this, a part of the shared memory is allocated to each application program as an allocation area depending on whether or not communication data needs to be transferred between the application program and the target system (for example, activation and termination of the application program). Therefore, when an application program is terminated and the allocation area is released, an allocation communication request can be set to another application program that requests communication by using a part of the released shared memory as a new allocation area. Therefore, the shared memory can be used effectively and the efficiency is improved. The same application program can also allocate a plurality of allocation areas to the shared memory.
[0009]
The shared memory control program is included in each application program (claim 6). According to this, since the same shared memory control program can be incorporated into each application program, it can be reused every time an application program is created, and the efficiency of creating the application program is improved.
[0010]
The application program exchanges communication data with a storage device in the hardware of the computer as the target system via the communication means (claim 7). According to this, since communication data is transferred to and from the storage device via the communication means, it is not necessary to set which area of the storage device and data should be transferred to the application program and specify the storage device. These data areas can be used as data areas that can be used by different application programs, rather than as dedicated data areas for specific application programs.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to FIGS. As shown in FIG. 1, a personal computer for monitoring (hereinafter referred to as PC) and each programmable controller (hereinafter referred to as PLC1 to PLCn) as a target system are each a communication interface (this application) of the PC and each of PLC1 to PLCn. In the embodiment, the serial interface) 1 and 2 are connected by a communication cable 3 to constitute a monitoring system. Monitored objects (for example, machine tools) 4 are connected to the PLCs 1 to PLCn via general-purpose I / O 5, and each of the PLCs 1 to PLCn includes monitor means 6 for controlling and monitoring each monitored object 4. The collected data as monitor information obtained by the above is sent to the PC via the serial interfaces 1 and 2. In addition, the setting data for each PLC1 to PLCn is transferred from the PC to each PLC1 to PLCn via the serial interfaces 1 and 2. Further, PLC1 to PLCm and PLCm + 1 to PLCn have different communication protocols pr1 and pr2, respectively, and perform communication processing with a PC in accordance with each communication protocol.
[0012]
As shown in FIG. 1, the PC includes a communication control unit 7 as communication means, a monitor program composed of a plurality of application programs A1 to An, and storage devices such as a hard disk 8 and a working memory 9 which are one of target systems. And. The communication means 7 includes a shared memory 10, a queue 11, a master communication manager program 12, slave communication manager programs 13 to 16, a communication interface 2, target systems 8 and 9, PLC 1 to PLCn shown in FIG. The correspondence table 17 with the communication managers 13 to 16 of the slaves that perform actual communication with the communication protocols corresponding to the target systems 8 and 9 and PLC1 to PLCn is included. The communication means 7, the monitor program, the communication interface 1, and the communication cable 3 constitute a communication system.
[0013]
In the shared memory 10, a part of the memory provided in the PC is allocated to the master communication manager program 12 by a shared memory control program 18 which will be described later. A plurality of allocation areas can be appropriately allocated to each of the application programs A1 to An that have requested communication so that two or more communication data can be stored, and the application program A1 is assigned to each allocation area. Communication data exchanged between ~ An and the target systems 8 and 9, PLC1 to PLCn is set. For example, as shown in FIG. 4, the communication data includes a communication flag in which “1” and “0” indicating completion or incompletion of communication with the target system are set, a target designation number “PLC1” for specifying the target system, a target Device number “d001” for designating system devices (various data storage areas in the target system), number of data “12”, read / write designation command (R or W), communication request of which application program A1 to An is “A1”, etc. And the exchange data exchanged between the PC and the target system. The exchange data includes collection data indicating operation information such as abnormality information and processes, setting data from the PC to the PLCs 1 to PLCn, read / write data with the HDD, and the like.
[0014]
The queue 11 stores memory numbers for identifying the respective allocation areas allocated to the shared memory 10 corresponding to the communication requests of the respective application programs A1 to An in the order in which the communication data is set in the allocation areas. FIG. 5B shows a first-in first-out system that sequentially passes to the communication manager program 12 of the master. For example, when communication data is sequentially set in the allocation area of the memory number “1” and the memory number “2”, as shown in FIG. In the queue 11, the memory number “1” and the memory number “2” are set in order, and at the time of communication, communication is performed using the communication data in the allocation area of the memory number “1”. Communication is performed using communication data in the allocation area of the memory number “2”.
[0015]
The master communication manager program 12 and the slave communication manager programs 13 to 16 process communication between the application programs A1 to An and PLC1 to PLCn and between the application programs A1 to An and a storage device inside the PC hardware. It is. The master communication manager program 12 includes a shared memory control program 18 which will be described later, and is based on communication data from the application programs A1 to An stored in the shared memory 10 in response to a communication request from the application programs A1 to An. Confirm whether it is desired to communicate with the target systems 8, 9, PLC1 to PLCn, and the slave communication manager programs 13-16 having communication protocols corresponding to the target systems 8, 9, PLC1 to PLCn as communication destinations. Communication selected by referring to the correspondence table 17 and instructing communication to the communication manager programs 13 to 16 of the slaves, and transmission / reception between the target systems 8 and 9 and PLC1 to PLCn specified by the command Reading data to shared memory 10 To.
[0016]
The communication manager programs 13 to 16 of each slave correspond to the communication protocols pr1 to pr4 of the respective target systems 8, 9 and PLC1 to PLCn, and are actually designated by commands according to commands from the communication manager program 12 of the master. Data communication is performed with the target systems 8, 9 and PLC1 to PLCn. The slave communication manager programs 13 to 16 correspond to the serial interface when the serial interface is used as the communication interface 1 and 2, and correspond to the LAN when the LAN is used as the communication interface 1 and 2. Each is incorporated in the communication means 7, and even if the communication interfaces 1 and 2 are the same, for example, if the communication protocol of PLC1 to PLCn is different for each manufacturer, only the type of communication protocol is incorporated in the communication means 7. . In the embodiment of the present application, the communication means 7 corresponds to the communication protocols pr1 of PLC1 to PLCm, the communication protocol pr2 of PLCm + 1 to PLCn, the communication protocol pr3 of the hard disk 8, and the communication protocol pr4 of the working memory 9, respectively. Thus, four slave communication managers 13 to 16 are incorporated.
[0017]
When the shared memory control program 18 is incorporated in the master communication manager program 12, as described above, as the shared memory allocation means for allocating the shared memory 10 to the master communication manager program 12, and the application programs A1 to An. 3, the shared memory 10 functions as an allocation area operation means for allocating or releasing the shared memory 10 as an allocation area to the application programs A1 to An that are communication requests, as shown in FIG. The memory 10 stores the position and size of the allocation area, stores the memory number corresponding to each allocation area, and stores the memory number in the queue 11. The shared memory control program 18 is produced as a program that can be incorporated into the master communication manager program 12 and the respective application programs A1 to An, and produces the master communication manager program 12 and the application programs A1 to An. Can be reused at the same time, improving the efficiency of program production.
[0018]
FIG. 6 shows a flowchart of the master communication manager program 12, and each step shows a function realizing means. Step S61 is initial setting means for setting the queue 11 in the memory of the PC as an initial setting and securing the shared memory 10 by the shared memory control program 18. In step S63, the queue 11 is checked to determine whether the memory number is stored. If the memory number is stored, the communication order of the communication data stored in the shared memory 10 is confirmed according to the storage order of the memory numbers. It is a communication order confirmation means. Step S64 is communication data confirmation means for confirming the content of the communication data in the allocation area corresponding to the memory number in which the communication order stored in the queue 11 is first. The step S65 selects the slave communication manager programs 13 to 16 corresponding to the target systems 8, 9, and PLC1 to PLCn with reference to the correspondence table 17 shown in FIG. Communication command means for transferring communication data from the shared memory 10 to the communication manager programs 13 to 16 for communication. Step S66 is means for waiting for communication completion of the slave communication manager. Step S67 receives communication data exchanged between the slave communication manager programs 13 to 16 and the target systems 8, 9, and PLC1 to PLCn to perform communication. This is a setting means for changing the flag from “0” indicating that communication has not been completed to “1” indicating that communication has been completed, and setting the communication data in the original allocation area of the shared memory 10 again. Step S68 is communication completion notifying means for notifying a communication completion message to the application programs A1 to An set in the communication data when transmission / reception of communication data is completed with the target systems 8, 9, and PLC1 to PLCn. .
[0019]
In step S69, when the application program A1 to An secures an allocation area in the shared memory 10 and a message for operating the allocation area indicating that the communication data is set in the allocation area is notified from the application program A1 to An, The interrupt means that receives the message and interrupts between step S63 and step S68. Step S610 assigns a memory number to the allocation area in which the communication data is set by the application programs A1 to An by the allocation area operation message. And a memory number setting means for setting the memory number in the queue 11. Steps S69 and S610 are executed by the shared memory control program 18 included in the master communication manager program 12.
[0020]
FIG. 7 shows a flowchart of the communication manager programs 13 to 16 of each slave, and each step shows a function realizing means. Step S71 is a communication data receiving means for receiving communication data together with a communication command from the master communication manager program 12. Step S72 is a communication protocol pr1 to pr4 corresponding to the target system 8, 9, PLC1 to PLCn based on the communication data. Is a communication processing means for transmitting and receiving communication data. In step S73, when transmission / reception of communication data is completed with the target systems 8, 9, and PLC1 to PLCn, a communication completion message is sent to the master communication manager program 12. Communication completion notifying means for transmitting communication data to the master communication manager program 12 as well as communication data for which the communication has been completed.
[0021]
  FIG. 8 is a flowchart showing an outline of each of the application programs A1 to An constituting the monitor program. Step 81 is an initial setting means, and the application program communicates with the target systems 8, 9, PLC1 to PLCn. Is required, an allocation area is secured in the shared memory 10 by the shared memory control program 18 incorporated in the application programs A1 to An, and communication data in which the communication flag is set to “1” is set in the allocation area. Step S82 is a normal operation means for performing an appropriate normal operation such as setting of the target systems 8, 9, PLC1 to PLCn, and displaying or recording collected data as appropriate. Step S83 is a means for determining the end of the application program (necessary / unnecessary to exchange communication data with the PLC). Step S84 is a message reception determination means for determining whether a communication completion message has been received from the master communication manager program 12, and step S85 determines whether the communication flag of the communication data in the allocation area is “1”. In step S86, communication data with the communication flag set to “0” is set in the allocation area, and a message for operating the allocation area (communication data set message) is set as the master communication manager program 12.InIt is a communication data set means to notify. Step S87 is a communication data receiving means for receiving the communication data set in the allocation area when the communication completion message is received from the master communication manager program 12 in step S84. Step S88 is an application program end setting means for releasing the allocation area by the shared memory control program 18, and sending a message for allocation area operation (allocation area release message) to notify the release of the memory to the master communication manager program 12. Memory release means for notifying the
[0022]
Next, the operation will be described. The PC is equipped with a multitasking operating system and can always process a plurality of programs in parallel. After the start-up operation of the PC and each of the PLCs 1 to PLCn, the data collection of the monitoring target 4 is performed in each of the PLCs 1 to PLCn, and in the PC, the master and slave communication manager programs 12, 13 to 16 and the respective application programs A1 ~ An is executed. The master communication manager program 12 performs initial setting in step S61, secures the shared memory 10 by the shared memory control program 18, secures the queue 11, and continues to steps S62 and S63 until the memory number is set in the queue 11. Waiting repeatedly.
[0023]
Further, when the respective application programs A1 to An are executed, steps S81 to S87 are executed, and the application programs A1 to An are transferred to the communication data 7 via the target system 8, 9, PLC1 to PLCn and the communication means 7, respectively. Send and receive and perform normal operation using the communication data. For example, when the application program A1 is executed, first, in step S81, an allocation area is secured in an appropriate range of the shared memory 10 (an empty area of the shared memory 10) as an initial setting, and a communication flag is set in the allocation area. 1 ”communication data is set. Next, normal operation is performed in step S82, and when communication with the PLC 1 as the target system is requested, it is confirmed in step S84 whether a communication completion message is notified from the master communication manager 12 in step S84. Since “NO”, the process proceeds to step S85. In step S85, since the communication flag is "1", the process proceeds to step S86, communication data with the communication flag set to "0" is set in the allocation area secured in step S81 as shown in FIG. The communication manager program 12 is notified. Then, steps S82 to S85 are repeated until a communication completion message is notified from the master communication manager 12.
[0024]
When the communication data set message is output in step S86, the master communication manager program 12 executes steps S69 and S610, and the master communication manager program 12 sets the memory number in the allocation area in which the communication data of the application program A1 is set. “1” is assigned, and the memory number “1” is set in the queue 11 as shown in FIG. When the master communication manager program 12 confirms that the memory number is set in the queue 11 in step S63, the master communication manager program 12 executes steps S64 to S68. When the memory number “1” set in the queue 11 is at the head of the communication order (FIG. 5B), the communication data set in the allocation area of the memory number “1” is confirmed in steps S64 and S65. Referring to the correspondence table 17, the communication data is passed to the slave communication manager program 13 having the PLC1 communication protocol pr1, and the slave communication manager program 13 waits for completion of communication with the PLC1 in step S66. When the slave communication manager program 13 receives the communication data from the master communication manager program 12 in steps S71 to S73, the slave communication manager program 13 communicates with the PLC 1 to transmit / receive the communication data, and passes the communication data to the master communication manager program 12. . In steps S67 and S68, the master communication manager program 12 changes the communication flag of communication data exchanged with the PLC 1 from “0” indicating incomplete communication to “1” indicating completion of communication. The memory number “1” is set in the allocation area, and a communication completion message is notified to the application program A1.
[0025]
Then, the application program A1 receives a communication completion message in step S84, proceeds to step S87 to receive communication data from the allocation area, returns to step S82 to perform normal operation using the communication data, and repeats steps S82 to S87 again. New communication data is set in the allocation area of the memory number 1, and communication is performed with any of the target systems 8, 9, PLC1 to PLCn. In step S83, for example, when the communication of the communication data between the application program A1 and the PLC 1 becomes unnecessary due to the end of the application program A1, the process proceeds to step S88, the end setting is performed, the allocation area is released, and the allocation area is released. The release message is notified to the master communication manager program 12.
[0026]
  Further, after the memory number “1” is set in the queue 11, when the application program A3 is executed and communication with the work memory 9 is requested, it is initialized in step S81 as in the communication between the application program A1 and the PLC1. Setting is performed to secure an allocation area, communication data is set in the allocation area allocated to the shared memory 10 in steps S86 through steps S82 to S85, and the memory number “2” is stored in the queue 11 in steps S69 and S610. Is set next to the memory number “1” (FIG. 5B). When communication is performed using the communication data set in the allocation area of the previous memory number “1” and the memory number “2” is at the head of the queue (FIG. 5C), steps S64 and S65 are performed. The correspondence table 17 is referred to, and communication data is passed to the slave communication manager program 16 having the communication protocol pr4 with the working memory 9, and the slave communication manager program 16 is transmitted in steps S71 to S73.InTherefore, communication data is exchanged with the work memory 9. Then, through step S66, the application program A3 receives the communication data after communication set in the allocation area of the memory number “2” by the master communication manager program 12 in steps S67, S68 and steps S84, S87. Since a plurality of communication data can be set in the communication means 7 in this way, the communication means 7 is not occupied by one set of communication.
[0027]
At this time, even if communication with the previous memory number “1”, that is, communication with the PLC 1 is performed, the communication with the work memory 9 is performed using a communication protocol pr 4 different from the communication protocol pr 1 with the PLC 1. Since the communication is performed by the slave communication manager program 16, communication may be executed simultaneously. Further, when the communication performed first and the communication performed next are executed by the slave communication manager program of the same communication protocol, in the present embodiment, one slave communication manager program for one communication protocol. Therefore, after the previous communication is completed, the next communication is performed. Each of the application programs A1 to An can also secure a plurality of allocation areas in the shared memory 10. For example, as shown in FIG. 3, the application program A1 can secure the allocation areas of the memory numbers 1 and 3, It is possible to set communication data for each.
[0028]
As described above, when it is not necessary to transfer communication data between the application program and the target system, the allocation area is released from the shared memory 10, so that a part of the shared memory 10 is occupied by the application program allocated as the allocation area. Therefore, the application programs A1 to An can secure a new allocation area in the free space of the shared memory and set communication data, thereby improving the communication processing efficiency. Further, communication between the PC and the target systems 8, 9, PLC1 to PLCn is executed by the master communication manager program 12 by the slave communication manager programs 13 to 16, and the communication data exchange with the application programs A1 to An is shared. Since the master communication manager program 12 processes via the memory 10, the application programs A1 to An are the same as the target systems 8 and 9, PLC1 to PLCn having different communication protocols without being aware of the difference between the communication protocols pr1 to pr4. Communication can be performed by operation.
[0029]
【The invention's effect】
As described above, the present invention includes a shared memory capable of storing communication data twice (two sets) or more, and communicates the communication data stored in the shared memory according to the order set in the queue for controlling the communication order. Since transmission / reception is performed by means, communication data can be set in the shared memory even if communication is performed between the PC and the PLC. Therefore, the communication means is not occupied by one communication, and communication efficiency is improved. Further, the communication means includes a correspondence table corresponding to the communication protocol, and communication data can be transmitted / received to / from a plurality of target systems having different communication protocols with reference to the correspondence table. Also, since communication is performed according to the memory number set in the queue in the order of the communication request of the application program, the process of directly checking the shared memory at the time of communication as if there is no queue and confirming the presence of communication data and the communication order Becomes unnecessary, the communication processing time is shortened, and the efficiency is improved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall configuration.
FIG. 2 is a diagram showing a correspondence table.
FIG. 3 is a diagram illustrating a shared memory.
FIG. 4 is an explanatory diagram showing communication data.
FIG. 5 is an explanatory diagram showing a queue.
FIG. 6 is a flowchart of a master communication manager program.
FIG. 7 is a flowchart of a slave communication manager program.
FIG. 8 is a flowchart of an application program.
[Explanation of symbols]
7 Communication means
8, 9 Storage device (target system)
10 Communication data storage means (shared memory)
11 Queue
12 Master communication manager program
13-16 Slave communication manager program
17 Correspondence table
18 Shared memory control program
A1-An application program
PC computer
PLC1 to PLCn Programmable controller (target system)

Claims (6)

When a programmable controller as a target system is connected to a monitor computer and communication data is exchanged between a plurality of application programs of the computer and the target system, the communication data is stored via communication data storage means provided in the computer. In a communication system in a monitoring system that transmits and receives between a computer and a programmable controller by communication means,
The computer includes a queue, the communication data storage means is a shared memory that can be allocated a plurality of assigned areas for a plurality of application program capable of storing two or more communication data, queue A memory number for identifying each allocation area in which communication data is set by the application program is set in the order of communication requests of each application program, and the communication order is controlled according to the order of communication requests, and stored in the shared memory. communication data, the communication system in the monitoring system, characterized in that transmitted and received by the communication means in accordance with the set order in the queue for controlling the communication order that.   The communication means includes a correspondence table between each target system and a communication protocol corresponding to each target system. With reference to the correspondence table, the target system to which the application program requests communication and the communication corresponding to the target system. The communication system in the monitoring system according to claim 1, wherein transmission / reception of communication data is executed by a protocol.   The communication means includes a master communication manager program and a plurality of slave communication manager programs having a communication protocol corresponding to each target system, and the master communication manager program responds based on communication data set in the shared memory. 3. The communication system in the monitoring system according to claim 2, wherein the communication data is transmitted and received by a slave communication manager program corresponding to the target system that performs communication with reference to the table.   When a part of the shared memory is allocated to each application program that requests communication as an allocation area by the shared memory control program, and no communication data needs to be transferred between the application program and the target system, the allocation area of the application program is 4. The communication system in the monitoring system according to claim 1, wherein the communication system is canceled by a shared memory control program. 5. A communication system in a monitoring system according to claim 4, wherein the shared memory control program is included in each application program. 6. The communication system in the monitoring system according to claim 1, wherein the application program exchanges communication data with a storage device inside hardware of a computer as a target system via a communication unit.

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