JP3005379B2 - Communication system between programmable controllers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-PC communication system for communicating data between a plurality of programmable controllers (hereinafter referred to as PCs).

[0002]

2. Description of the Related Art A PC is a device for controlling a machine tool or the like according to a sequence program. Also, using a PC,
It is possible to construct a system for controlling facilities such as factories in an integrated manner. That is, P which controls each machine tool, etc.
A system has been developed in which C is generally controlled by a PC or the like positioned above these PCs.

In this type of system, data communication between PCs is indispensable in order for each PC to operate while suitably cooperating. For example, by transmitting and receiving interlock information (information for prohibiting the operation of another machine during the operation of a certain machine) and the like, it is possible to suitably execute equipment control. When performing data communication between PCs, a PC for controlling a machine tool or the like and a communication module (slave station) thereof are connected to a master station via a bus or the like. The master station is a station that includes a PC for general control of equipment and a communication module thereof. The communication modules (usually PC cards) of the master station and slave stations and the bus connecting them both function as a communication control device. In order to perform communication, it is necessary to allocate data related to communication to a series of addresses in the memory in the PC. The memory in the PC is a storage space of a predetermined scale used for controlling a corresponding machine or controlling a lower-order PC.

As a data link method that can be used for data communication between PCs, for example, there is a method as shown in FIG. In the method shown in this figure, communication between PCs is always performed via a master station. That is, communication such that the slave station 1 transmits data to the master station and the master station transmits data to the slave station 1 is performed for each slave station, and a data link of master station: slave station of 1: n is formed. You. The storage space for the communication between the master station and the slave station is set by the same head address and the same number of communication bytes in the master station and the slave station, and is set to a different space for each slave station. In order to implement this method, it is necessary to write or read data to be communicated to / from a storage space (address) used for communication. Other data link methods that can be used for data communication between PCs include:
For example, there is a method as shown in FIG. This method is similar to the method disclosed in Japanese Patent Application Laid-Open No. 4-39705. In this method, each station shares a storage space for communication, and each station occupies a predetermined storage space for storing data received by itself. In this method, there is no need to distinguish between the master station and the slave stations, so that an n: n data link is formed. Even when implementing this method, it is necessary to write or read data to be communicated to or from a storage space (address) used for communication.

As a data link method which can be used for data communication between PCs, there is a method as shown in FIG. 9, for example. The method shown in this figure is a method in which a certain station requests data from another station (command issuance), and the other station transmits data in response to the request (response).

[0006]

However, all of these methods have problems. For example, FIG. 7 and FIG.
In the method shown in, the storage space used for communication is P
The problem of having to secure it on the memory in C,
A problem arises in that a separate sequence program must be created for writing data to the storage space and reading data from the storage space. further,
The method of FIG. 8 also has a problem that the storage space becomes enormous because all PCs hold communication data relating to all PCs. Further, in the method shown in FIG. 9, although there is no problem as in the methods shown in FIGS. 7 and 8, there is a problem that the communication time is long and a command for data request is required.

An object of the present invention is to provide a suitable inter-PC data communication system that does not exhibit these problems. Specifically, while securing a continuous storage space necessary for communication with another PC, the storage space in the memory in the PC, the writing of data to the storage space, and the transfer of data from the storage space are performed. It is an object of the present invention to eliminate the creation of a sequence program for reading, an enormous storage space for communication, an increase in communication time, the need for a data request command, and the like.

[0008]

In order to achieve the above object, an inter-PC communication system according to the present invention executes a control of a corresponding device and stores data (for example, a memory in the PC) for storing data relating to the control. ), And a communication control device (for example, a communication module or an integrated PC) that controls communication between the PCs.
PC that communicates a series of data through a communication control device
In the intercommunication system, the communication control device includes an initial processing unit and a communication processing unit.
Here, the initial processing means, by extracting the output address data to be output to another PC is stored for each PC, the first storage space that will be formed by the output address extracted from the corresponding PC PC The first storage space is formed for each system, and the first storage space is integrated in the entire system to form a virtual storage space composed of output addresses extracted from PCs in the system, in which data input from other PCs is stored. by the extracting every PC input address and output the source address for outputting data inputted to the input address, a second storage space that will be formed by the input address extracted from the corresponding PC and output source address PC that It is formed every time . Further, the communication processing means is configured to execute each PC after each storage space is formed by the initial processing means.
, Read the output data from the first storage space, store the data at the corresponding output address in the first storage space, transfer the data in the first storage space to the virtual storage space, and store the data in the virtual storage space in the corresponding second storage space. And stores the data in the second storage space to the corresponding input address of the corresponding PC.

[0009]

In the present invention, prior to the transition to the normal inter-PC communication, the inter-PC data link is initialized by the initial processing means. At this time, the initial processing means first extracts, for each PC, an output address where data to be output to another PC is stored from a storage means such as a memory in the PC. When an output address is extracted for each PC by the initial processing means, a first storage space is formed for each PC using the output address. The first storage space is therefore:
The data output from each PC is formed as a storage space that can continuously store the data. Next, the first storage space is integrated in the entire system by the initial processing means. The resulting virtual storage space is a storage space to which a series of output addresses extracted from PCs in the system are continuously assigned.

On the other hand, a second storage space is formed for each PC by the initial processing means. That is, other P
An input address at which data input from C is stored and an output source address at which data input to this input address are output are extracted for each PC from storage means such as a memory in the PC by the initial processing means. Two storage spaces are formed. The second storage space obtained in this way is a storage space for associating data output from each PC with its output source address and, consequently, an input address that requires the data.

After each storage space has been formed in this way, the processing shifts to normal communication processing by the communication processing means. When performing communication processing, first, output data is read from each PC. The read output data is stored at the corresponding output address of the corresponding first storage space. Further, the data on the first storage space is transferred and stored in the virtual storage space. Then, the data in the virtual storage space is transferred and stored at the corresponding output source address in the corresponding second storage space, and is stored in the second storage space.
Data in the storage space is written to the corresponding input address of the corresponding PC.

As described above, in the present invention, the initial processing is executed prior to the communication. Since the initial processing is performed by extracting the output address and the input address from the storage means such as the memory in the PC, a continuous storage space necessary for communication with another PC is secured in the memory in the PC. You don't have to. Accordingly, it becomes unnecessary to create a sequence program related to data communication (data writing and reading). In addition, no enormous storage space is required, and commands for data request / response are not required.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration of an inter-PC communication system according to an embodiment of the present invention. In the system shown in this figure, PC 10, PC data reading means 1
2 and the PC data writing means 14 constitute a slave station.
N PCs 10 are provided.
Data reading means 12 and PC data writing means 14 are also provided in n pieces. The PC data reading means 12 and the PC data writing means 14 are configured as, for example, a card of the corresponding PC 10 and function as the communication module 16 on the slave station side.

In this embodiment, the master station reads P
It comprises C data storage means 18 and n PC write data extraction means 20. These function as the communication module 22 on the master station side, and normally, P
It is realized as a C card. The aforementioned PC data reading means 12 is connected to the read PC data storage means 18, and the read PC data storage means 18 is connected to each PC write data extraction means 20. The PC writing data extracting means 20 is provided corresponding to each slave station, and is connected to the PC data writing means 14 of the corresponding slave station.

FIG. 2 shows the contents of the initial processing executed prior to normal communication in this embodiment, and FIG. 3 shows the flow of the processing. Next, the initial processing will be described with reference to FIGS.

In this embodiment, input / output identification parameters are associated with each address of a memory mounted on the PC 10, that is, a memory in the PC. As shown in FIG. 2, the input / output identification parameters have "in", "out", and "x" as contents. Among the addresses of the memory in the PC, the address associated with the parameter “ON” is an address to which data is to be input from another PC 10, that is, an input address. The address associated with “out” is an address at which data is to be output to another PC 10, that is, an output address. The address associated with “x” is a non-communication address that is not involved in communication between the PCs 10.

In this embodiment, the output address and the input address are extracted from the memory in the PC using the input / output identification parameter. In the flow of FIG. 3, first, each PC data reading means 14
An output address is extracted from the memory in the PC using input / output identification parameters (100). Next, the PC data reading means 12 sets a parameter indicating the extracted address
It is continuously allocated to a built-in memory, that is, a memory in the PC data reading means (102). For example, as shown in FIG.
When 0, Y001, Y003... Are output addresses,
A storage space to which these are continuously assigned is formed in the corresponding memory in the PC data reading means. At this time, information for specifying the PC 10, "A" or the like is added to each address so that the output address of which PC can be identified when the output address is integrated into the virtual storage space later. Thereafter, the PC data reading means 12 transfers the parameter indicating the output address on the memory in the PC data reading means to the master station (104).

On the master station side, the read PC data storage means 18 receives the output address transferred from each PC data read means 12 (106) and continuously allocates it on the virtual storage space (108). That is, as shown in FIG. 2, by continuously allocating the output addresses transferred from each PC, a virtual storage integrated on the memory in each PC data reading means is integrated in the entire network. Form a space.

Next, each P data is written by each PC data writing means.
The input address is extracted from the memory in C (110).
This extraction is performed using the input / output identification parameters, as in step 100. The PC data writing means 14 continuously allocates the parameter indicating the extracted input address to its own memory, that is, the memory in the PC data writing means (112). For example, as shown in FIG. 2, when addresses X100 and X102 are input addresses on a certain internal PC memory, in the corresponding internal PC data writing unit, the parameters indicating these are continuously input addresses. Assigned. At this time, step 10
As in the case of No. 2, information for specifying the PC 10 is added. The PC data writing means 14 further allocates an output source address corresponding to each input address on the memory in the PC data writing means (114). That is, a parameter indicating from which output address of which PC 10 each input address should input data is assigned to the PC data writing means memory as an output source address. The PC data writing means 14 transfers the output source address on the memory in the PC data writing means to the master station (11).
6).

The PC write data extracting means 20 receives the output source address transferred from the corresponding PC data write means 14 (118), and forms a new storage space based on this. This space is a space in which output source addresses are continuously allocated for each PC (120). For example, "A"
The output source address B is assigned to each input address of the PC represented by
-Y010, C-Y050,...
These output source addresses are
The data is transferred to the C write data extracting means 20 and received at step 118. Thereby, in the following step 120, a storage space to which BY010, CY050,... Are continuously allocated is formed. In this way,
The initial processing ends.

FIG. 4 shows the contents of the communication processing executed after such initial processing, and FIG. 5 shows the flow of the communication processing.

In the process related to normal communication, first,
The output data is read from the corresponding PC memory by each PC data reading means 12 (200). The PC data reading means 12 stores the read output data in the memory in the PC data reading means (202). At this time,
The memory in the PC data reading means has a storage space in which the output addresses of the corresponding PC 10 are continuously allocated. Accordingly, by executing step 202, a series of data to be transmitted to another PC is continuously stored in the memory in the PC data reading means. The PC data reading means 12 transfers the data on the memory in the PC data reading means to the master station (204).

The output data thus transferred is:
The data received by the read PC data storage means 18 (20
6), stored in a virtual storage space for integrating the system (208). Each PC write data extraction means 20 reads the P
Among the output data stored in the C data storage means 18, the data to be input to the corresponding PC 10 is transferred and stored in the memory in the PC write data extraction means (210). PC
The write data extracting means 20 transfers the data on the memory in the PC write data extracting means to the corresponding PC data writing means 14 (212).

The PC data writing means 14 corresponds to the corresponding PC
The data transferred from the write data extracting means 20 is stored in the memory in the PC data writing means (214), and is written into the corresponding memory in the PC (216). At this time,
Since the output source address is associated with the input address on the memory in the PC data writing means, the data transferred from the PC writing data extraction means 20 can be suitably written to the corresponding input address. It is possible.

FIG. 6 conceptually shows a communication method according to this embodiment. As shown in this figure, in the present embodiment, there is no need to secure a continuous storage space for data communication between PCs in the master station and each slave station. Therefore, a sequence program for writing data to be output to the storage space and a sequence program for reading data from the storage space are not required.
Further, there is no need to share an enormous storage space or to issue commands / responses. Therefore, according to the present embodiment, each P
The sequence program to be created for each C10 is simpler than the conventional one, and is easy to design and understand. In addition, addresses related to communication (input address,
The change of the output address) can be executed by changing the input / output identification parameter, which is simpler than the conventional case. Further, the storage capacity is reduced as compared with the conventional case, and the amount of communication data is also reduced.

In the above description, the ratio of the master station to the slave station is 1: n. However, the present invention is not limited to this. For example, you may apply to n: n communication. In this case, a PC number indicating an output destination and an input destination may be added to the input / output identification parameter. Further, the present invention can be applied to a case where a subsystem is provided below a slave station to promote layering. Steps 100 to 108
And the execution order of steps 110 to 120 may be reversed. Then, the PC writing data extracting means 20 may be provided on the slave station side.

[0028]

As described above, according to the present invention,
An output address and an input address are extracted from the addresses of the storage means incorporated in each PC, and based on these, a first storage space composed of continuous output addresses, a virtual storage space obtained by integrating the first storage spaces, A second address composed of an input address and an output source address corresponding to the input address.
Since the storage space is formed and the data link is executed, it is not necessary to secure a continuous storage space required for communication with another PC in each PC, and the sequence program can be simplified. Become. Furthermore, no enormous storage space is required for shared storage of communication data, and commands and procedures such as data requests / responses are not required.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an apparatus configuration of an inter-PC data communication system according to one embodiment of the present invention.

FIG. 2 is a diagram showing the contents of an initial process executed in this embodiment.

FIG. 3 is a flowchart showing a flow of an initial process executed in the embodiment.

FIG. 4 is a diagram showing the contents of normal communication executed in this embodiment.

FIG. 5 is a flowchart showing a flow of normal communication executed in the embodiment.

FIG. 6 is a diagram conceptually showing a communication method in this embodiment.

FIG. 7 is a diagram conceptually showing a communication method in the first conventional example.

FIG. 8 is a diagram conceptually showing a communication method in a second conventional example.

FIG. 9 is a diagram conceptually showing a communication method in a third conventional example.

[Explanation of symbols]

 Reference Signs List 10 Programmable controller (PC) 12 PC data reading means 14 PC data writing means 16 Communication module (slave station) 18 Read PC data storage means 20 PC writing data extraction means 22 Communication module (master station)

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Fuyuhiko Yoshikura 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Co., Ltd. (72) Inventor Kentaro Takasu 1-7 Kitajizoyama Nodacho Kariya City, Aichi Prefecture Toyoda Koki (56) References JP-A-4-39705 (JP, A) JP-A-2-138306 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G05B 19/05

Claims (1)

(57) [Claims] 1. A plurality of programmable controllers for executing control of a corresponding device and storing data relating to the control at a predetermined address of a storage unit containing the same, and a communication control device for controlling communication between the programmable controllers. In a communication system between programmable controllers in which a plurality of programmable controllers communicate a series of data via a communication control device, the communication control device sets an output address at which data to be output to another programmable controller is stored. by extracting each, Ru is constituted by the corresponding output address extracted from the programmable controller
A first storage space is formed for each programmable controller , and the first storage space is integrated in the entire system to form a virtual storage space constituted by output addresses extracted from the programmable controllers in the system. By extracting, for each programmable controller, an input address where data input from the controller is stored and an output source address for outputting data input to this input address, the input address and output source extracted from the corresponding programmable controller are extracted. and initial processing means for forming a second storage space that will be configured by the address in each programmable controller, after each storage space is formed by the initial process unit, pair reads the output data from the programmable controller Storing at a corresponding output address of a corresponding first storage space, transferring and storing data on the first storage space to a virtual storage space, and transferring data on the virtual storage space to a corresponding output source address of the corresponding second storage space; Communication processing means for transferring and storing the data in the second storage space and writing the data in the second storage space to the corresponding input address of the corresponding programmable controller.