JP3893787B2 - Communication method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication method between a PLC and a personal computer .
[0002]
[Prior art]
Conventionally, there is a communication method of this kind shown in FIG. The communication device X is a personal computer, and includes a communication resource A and an application (communication means) B. The communication resource A is composed of a serial port and, when occupied, executes direct communication with the external device Y composed of a programmable controller. The application (communication means) B occupies the communication resource A 1 and executes predetermined communication with the external device Y via the communication resource A 1.
[0003]
[Problems to be solved by the invention]
In the conventional communication method described above, when there are a plurality of applications B, one of the plurality of applications B communicates with the external device Y through the occupied communication resource A. During the predetermined communication, other applications cannot execute the predetermined communication with the external device Y via the communication resource A 1.
[0004]
The present invention has been made paying attention to the above points, and an object thereof is to provide a technique in which a plurality of applications of a personal computer can perform predetermined communication with a programmable controller. .
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is a communication method between a personal computer and a plurality of programmable controllers, wherein the personal computer is provided with communication resources for transmitting / receiving commands, and communication resources. A plurality of first type communication means for performing predetermined communication via the second type communication means, and a second type communication means for occupying communication resources to communicate between the first type communication means and the programmable controller . The seed communication means has a work area for storing communication path information between the first kind communication means and the programmable controller, and when communication between the first kind communication means and the programmable controller is performed, the first kind communication means To the second type communication means is transmitted communication path information with a predetermined programmable controller for communication, the communication path information is When were those already different compared with the communication path information stored in the over-click area, stored in the work area as a new communication path information, a plurality of first type communication unit the second type communication The communication with the predetermined programmable controller is executed according to the communication path information corresponding to each of the first type communication means set by the means.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described below with reference to FIG. The personal computer 10 includes a communication resource 1, a first application (first first type communication means) 2, a second application (second first type communication means) 3, a third application (second type communication). Means) 4 is provided.
[0009]
Communication resources 1, for example, a serial port, via a serial cable or the like, is connected to the programmable controller 20, to perform a direct communication between the connected programmable controller 20. Specifically, when performing communication directly with the programmable controller 20 , the communication resource 1 transmits a command indicating that communication is performed to the programmable controller 20 , and receives a response to the command. To do.
[0010]
The first application (first type 1 communication means) 2 executes predetermined communication with the programmable controller 20 via the communication resource 1 in order to edit the user program and monitor data. To do. Similarly to the first application 2, the second application (second type 1 communication means) 3 is a programmable controller 20 via the communication resource 1 to edit the user program and monitor data. Predetermined communication is executed with
[0011]
The third application (second-type communication means) 4 occupies the communication resource 1 so that the first application 2 and the second application 3 execute predetermined communication with the programmable controller 20, and the programmable controller It is an application that allows direct communication with 20 . Specifically, the third application 4 has a first work area 4a, a second work area 4b, and a third work area 4c as its work areas. A process specific to the application 2 is performed, a process specific to the second application 3 is performed by the second work area 4b, and a process common to the first to third applications 2, 3 and 4 is performed by the third work area 4c. Processing is performed.
[0012]
Next, the operation of this will be described. For example, when the first application 2 executes predetermined communication with the programmable controller 20 , first, the first application 2 occupies the communication resource 1, and the occupying communication resource 1 is connected to the programmable controller 20 . A request signal indicating that the direct communication between the communication resource 1 and the communication resource 1 is to be transmitted is transmitted to the third application 4. Then, the third application 4 returns a response signal indicating that processing is to be performed based on the request signal to the first application 2, and occupies the communication resource 1 and directly communicates with the programmable controller 20. Causes communication resource 1 to execute.
[0013]
In the communication method between the personal computer 10 and the programmable controller 20 , the communication resource 1 is used so that the first application 2 or the second application 3 executes predetermined communication with the programmable controller 20. 1 is occupied by the third application 4 that allows direct communication, and is occupied by the first application 2 or the second application 3 itself that executes predetermined communication with the programmable controller 20 . Therefore, when one of the first application 2 and the second application 3 is performing predetermined communication with the programmable controller 20 via the communication resource 1, the other applications are also Programmable controller via communication resource 1 Predetermined communication with 20 can be executed.
[0014]
In addition, the portion that controls the occupation of the communication resource 1 is not distributed to the first application 2 or the second application 3 that is the first type communication means, but the third application that is the second type communication means. Since it will be provided only at 4, it will be easier to maintain.
[0015]
Next, a second embodiment of the present invention will be described below based on FIG. In addition, the same code | symbol is attached | subjected to the part which has the function substantially the same as 1st Embodiment, and only the difference from 1st Embodiment is described. This embodiment is basically the same as the first embodiment, but the first application 2 or the second application 3 executes predetermined communication with the N programmable controllers 20 , respectively. It is configured to do.
[0016]
Specifically, the programmable controller 20 which is connected directly to the communication resources 1, with the network, since the (N-1) is connected to a number of the programmable controller 20, as a result, communication resources 1 of the personal computer 10 Are connected to the N programmable controllers 20, and not only the directly connected programmable controllers 20 but also the (N-1) programmable controllers 20 described above using a predetermined path in the network. Direct communication with any of the above is executed.
[0017]
Predetermined paths used for communication are communicated from the first application 2 and the second application 3 to the third application 4 respectively. Then, the third application 4 stores the predetermined route notified from the first application 2 in the first work area 4a, and the predetermined route notified from the second application 3 to the second work. Store in area 4b. In the third work area 4c, a predetermined route used immediately before a new route is contacted from the first application 2 and the second application 3 is stored.
[0018]
Next, only the differences from the first embodiment will be described. For example, when a predetermined route is newly communicated from the first application 2 to the third application 4, the notified predetermined route is stored in the first work area 4a. The predetermined path stored in the first work area 4a is used immediately before the predetermined path stored in the third work area 4c, that is, the predetermined path from the first application 2 is newly communicated. If a different route is compared with the predetermined route, the newly contacted predetermined route is reset by the third application 4 as the predetermined route used for communication after the contact. It becomes.
[0019]
In the communication method between the personal computer 10 and the programmable controller 20 , when the predetermined route is set by one of the first application 2 and the second application 3, the predetermined route is When the setting is reset, the previous setting may have been set by the other application, so the predetermined route before and after the setting is changed between the first application 2 and the second application 3. Whether or not the predetermined route before and after the setting has been changed when the predetermined route is reset is set by the third application 4. Can be compared by the third application 4 itself, the first application 2 and the second application Without complicated processing, such as that compared with the publication 3 better.
[0020]
Next, a reference example of the present invention will be described below with reference to FIG. In addition, the same code | symbol is attached | subjected to the part which has the function substantially the same as 1st Embodiment, and only the difference from 1st Embodiment is described. This reference example is basically the same as that of the first embodiment, but the first application 2 and the second application 3 are divided by predetermined communication such as downloading a user program, for example. The divided communication means 30 executes a plurality of divided communications in succession.
[0021]
Specifically, the third application 4 sets a flag indicating that the divided communication is being executed when any of the first application 2 and the second application 3 is executing the divided communication. Stand in work area 4c.
[0022]
Next, only the differences from the first embodiment will be described. For example, when the first application 2 is executing the divided communication, when the request signal described above is transmitted from the second application 3 to the third application 4, it is set in the third work area 4c. Based on the flag, it recognizes that the first type of communication means different from the second application 3, that is, the first application 2 is executing the divided communication, and sends the first application 3 to the first application 3. “BUSY”, which is a response signal indicating that the application 2 of FIG. In addition, you may make it wait as it is, without replying.
[0023]
In the communication method between the personal computer 10 and the programmable controller 20 , when the first type communication means that is the divided communication means is performing the divided communication, the other first type communication means is connected to the programmable controller 20 . Even if the predetermined communication is attempted, the communication is limited until the predetermined communication is completed, so that it is not necessary to interrupt the predetermined communication.
[0024]
【The invention's effect】
Invention of claim 1, wherein the communication resource is a of being occupied by the two communication means first type communication unit to the communication to the communication resources to perform the predetermined communication between the programmable controller Since the first type communication means for executing the predetermined communication with the programmable controller itself is not occupied, any one of the plurality of first type communication means can communicate with the programmable controller via the communication resource. When performing the predetermined communication between the other, the other first-type communication means can also execute the predetermined communication with the programmable controller via the communication resource.
[0025]
According to the first aspect of the present invention, when the predetermined route is set by any one of the first type communication means, when the predetermined route is reset, the previous setting is changed to another type. Since it may be set by one type of communication means, it is necessary to compare whether or not a predetermined route before and after the setting has been changed between a plurality of first type communication means. Since it is set by the communication means, when the predetermined route is reset, whether or not the predetermined route before and after the setting is changed can be compared by the second type communication means itself, Complicated processing such as comparison between a plurality of first type communication means is not required.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a first embodiment of the present invention.
FIG. 2 is a configuration diagram of a second embodiment of the present invention.
FIG. 3 is a configuration diagram of a reference example of the present invention.
FIG. 4 is a configuration diagram of a conventional example.
[Explanation of symbols]
1 Communication resources
2 First application (first type 1 communication means)
3 Second application (second type 1 communication means)
4 Third application (Type 2 communication means)
20 programmable controllers
30 split communication means

Claims (1)

A communication method between a personal computer and a plurality of programmable controllers,
The personal computer includes a communication resource for transmitting / receiving commands, a plurality of first type communication means for executing predetermined communication via the communication resource, a first type communication means that occupies the communication resource, and a programmable controller, And a second type communication means for communicating
The second type communication means has a work area for storing communication path information between the first type communication means and the programmable controller, and the first type communication means and the programmable controller communicate with each other when the communication is performed . The communication path information is transmitted from the seed communication means to the second type communication means with the predetermined programmable controller that performs communication, and the communication path information is compared with the communication path information already stored in the work area. If there were those different, stored in the work area as a new communication path information, communications in which a plurality of first type communication means corresponding to each of the first type communication means which is set by the two communication means A communication method for executing communication with a predetermined programmable controller according to route information .

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