JPH0677975A - Allocating system for communication area - Google Patents

Abstract

PURPOSE:To prevent wrong setting by automatically allocating a transmission/ reception area required for communication. CONSTITUTION:Respective link units 4 are respectively provided with automatic allocation switches. Respective CPU units 2 are provided with the link areas of a fixed length and exchange data with other programmable controllers 11-14 by using the transmission areas and reception areas set to the link areas. As a master station, the programmable controller 11 detects the number of programmable controllers 12-14 which automatic allocation switches are turned on and based on that number, the link areas are divided into equal areas. After the transmission areas and reception areas are successively allocated to the divided areas, the allocation information of areas is transmitted to the other programmable controllers 12-14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention allows data terminals such as programmable controllers to mutually connect data of other data terminals to each other when data terminals such as programmable controllers are mutually connected via a transmission line to build a network. The present invention relates to a communication area allocation method for dividing a link area provided for sharing so as to correspond to each data terminal.

[0002]

2. Description of the Related Art Conventionally, programmable controllers (hereinafter abbreviated as PCs) have been used to control equipment such as factories. When the equipment is installed in a distant place, as shown in Fig. 1, in order to control each equipment with different PCs, maintain the interlocking relationship between them, and manage the operation of each equipment comprehensively. to, each PC1 ₁ ~1 ₄
Is considered to be connected to the transmission line Lc. That is, each PC1 ₁ to 1 by transmitting over the transmission channel Lc and _fourth data, transmission path Lc each PC1 ₁ to 1 ₄ on
During or other computer device it is possible to recognize the operating state of the PC1 ₁ to 1 ₄ and the like. Where each P
C1 ₁ to 1 ₄ are each provided with such a link unit 4 for connecting the power supply unit 3, the CPU unit 2 for feeding the like to the CPU unit 2, the CPU unit 2 to the transmission line Lc. Further, as shown in FIG. 5, the CPU unit 2 is connected to a CPU 11 that performs arithmetic processing, a system memory 12 that stores a program of basic functions as a PC, a program memory 13 that stores a program of the PC, an external device, and the like. And an interface 16 for connecting a support tool and the like, an input / output unit 15 for storing the data, a data memory 14 for storing the operation state of the external device fetched through the input / output unit 15, and the like.

Meanwhile, the link unit 4, there is to be an interface for connecting the PC1 ₁ to 1 ₄ as described above to the transmission line Lc, in order to connect the link unit 4, each PC1 ₁ to 1 ₄ A link area LA is set in the data memory 14, and the input / output relays (memory area for holding the state of relay contacts) and registers (memory area for holding measured values) set in the data memory 14 are set in the data memory 14. As a memory area for the corresponding link unit 4, as shown in FIG. 6, a link relay LY and a link register LR are set in the link area LA. Data is read from and written to the link relay LY and the link register LR as necessary, and the data held in the link relay LY and the link register LR is transferred to other PCs _{1 1} to.
Than it is transmitted through the transmission path Lc with respect to 1 ₄ and the computer device.

By the way, FIG. 6 shows the link area LA of the PC 1 _{2. In} the link relay LY and the link register LR, transmission areas TX ₂₁ and T ₂₁ for holding transmission data are provided.
X _22, and a reception area RX ₁₁ that holds the received data,
RX ₃₁ , RX ₁₂ , and RX ₃₂ are set. here,
Receiving areas RX ₁₁ , RX ₃₁ , RX ₁₂ , RX ₃₂ are provided for each PC 1
It is set individually so as to correspond to _1, 1 _3. Also, each P
C1 ₁ to 1 ₄ in link area LK is set to the same address. Here, the transmission areas TX ₂₁ and TX ₂₂ and the reception areas RX ₁₁ , RX ₃₁ , RX ₁₂ and RX ₃₂ are set so as not to overlap. That is, if you set the (by which shows a single subscript collectively without distinguishing between link relay and link register) each transmission region TX ₁ ~TX ₄ each PC1 ₁ to 1 _4, different PC1 ₁ to 1 ₄ in the address of the transmission region TX ₁ ~TX ₄ is set so as not to overlap. Now, if shed station number No1~No4 each PC1 ₁ to 1 _4, as shown in FIG. 7, the station number No1 PC
1 corresponds to _one of the transmission region TX ₁ in the address area, and than receiving area RX ₁ In other PC1 ₂ to 1 ₄ are set, by such data exchange, each station PC1 ₁ ~
1 ₄ each other will share PC1 ₁ to 1 ₄ of data of other stations.

By the way, as described above, the different PC _{1 1}
In ~ 1 _4, as shown in FIG. 7, the transmission region TX ₁ ~TX
The addresses of ₄ are set so that they do not overlap,
If the addresses are duplicated, the inconvenience that the content of the transmitted data is rewritten by the received data occurs. Therefore, it is necessary to manage the address of the transmission region TX ₁ ~TX _4. Therefore, in each of PC1 ₁ to 1 ₄ sends one another region TX ₁ ~TX ₄ and receiving area RX ₁ to Rx
_{For 4} , it is necessary to hold the start address and the number of occupied words in a specific area of the data memory. At present, such data is written using a support tool or the like when creating a program.

[0006]

As described above, the transmission areas TX _{1 to} TX ₄ and the reception area RX ₁ are manually operated.
When RX ₄ is assigned, the burden on the programmer is increased, and incorrect setting may occur. In order to cope with such an erroneous setting, the allocation duplication error is detected when the addresses of the transmission areas TX _{1 to} TX ₄ are duplicated. However, when an allocation duplication error is detected, it is necessary to correct the program,
The problem of increasing the programmer's burden cannot be solved.

An object of the present invention is to solve the above problems and to automatically assign addresses in the transmission area of a link relay or link register to prevent erroneous setting and reduce the burden on the programmer. It is intended to provide units.

[0008]

According to the invention of claim 1, in order to achieve the above object, a plurality of data terminals are connected to a transmission line via a link unit and one of the data terminals is connected. Build a network as a master station, and each station is set with a transmission area that stores the data to be transmitted to other stations and a reception area that stores the data received from other stations for each other station. Each of the link units has a fixed-length link area whose size matches the transmission area of each other station, and the link unit is equipped with an automatic allocation switch and for the switch that maintains the on / off state of the automatic allocation switch. The data terminal, which is equipped with a data register, detects the setting status of the switch data register and the link unit whose automatic allocation switch is on in the network detects the setting status of the switch data register. Determine the number of units, divide the link area evenly by this number, assign each divided area to each station sequentially, set the transmission area and the reception area in the link area of the master station, and then The setting information of the transmission area and the reception area of the master station is transmitted to the station to set the transmission area and the reception area in the link area of each other station.

According to the invention of claim 2, in addition to the configuration of claim 1, the master station is provided with an interface to which an external device capable of rewriting the contents of the switch data register of the other station is connected.

[0010]

According to the method of claim 1, the link area is evenly divided according to the number of link units whose automatic allocation switches are on in the network, and each divided area is sequentially allocated to each station. Each area of the area will be automatically assigned to each station, resulting in no need to manually assign areas, and the transmission areas of other stations may be set to the same address in duplicate. It can be prevented. Further, since the link area is evenly divided according to the number of data terminal stations transmitting data in the network, the link area can be used to the maximum extent, and there is almost no useless area that is not used in the link area. Of.

According to the method of claim 2, the content of the switch data register of the link unit can be rewritten by connecting an external device to the master station.
Even if the automatic allocation switch is set and already installed, you can remotely rewrite the contents of the switch data register using an external device to join or disconnect from the network. Therefore, maintenance becomes easy.

[0012]

(Embodiment 1) In this embodiment, as shown in FIG. 2, the link unit 4 is provided with an automatic allocation switch SW,
Each programmable controller (PC) 1 provided with the link unit 4 in which the automatic allocation switch SW is turned on
In ₁ to 1 _4, the link area LA provided to the CPU unit 2 is to allocate space in the link relay LY and link register LR automatically. Further, the link unit 4 is provided with a switch data register DR that stores the on / off state of the automatic allocation switch SW.

Here, as shown in FIG. 1, four PCs are used.
1 ₁ to 1 ₄ are ring connection, data token passing scheme shall be transmitted. Also, each PC1 _1-
That power of 1 ₄ is first applied becomes a parent station,
The master station is adapted to exchange data between calling cyclically other slave station in polling selecting system of the PC1 ₁ to 1 _4. Therefore, each PC1 ₁
No. 1 to No. ₄ for identifying each other
Are set individually. In the following description, a case in which the master station calls all the slave stations once to make a round is referred to as one scan. Further, for convenience of explanation, the station number is N
It is assumed that PC1 ₁ which is o1 is the master station.

The PC _{11 serving as the} master station detects the setting state of the switch data register DR of each link unit 4 during the first scan immediately after power-on or immediately after reset. At this time, the setting state of the switch data register DR can know on the a link unit 4 is an attached PC1 ₂ to 1 ₄ of station number. That is,
PC with automatic assignment switch SW turned on 1 to _2
Since the number of ₄ is known, the link relay LY and the link register L of the fixedly set link area LA
The area of the link area LA is secured by equally dividing R based on its number. For example, if data exchange is performed by four units including the master station, as shown in FIG. 3, the link relay LY and the link register LR are four units.
By equally dividing, the areas of the same size corresponding to the respective station numbers No1 to No4 are secured. In this way, in PC1 ₁ in the master station, transmission region TX ₁ and the receiving area RX ₂ ~
RX ₄ can be set. Transmission area T on PC1 ₁
It is determined X ₁ and the reception area RX ₂ ~RX _4, another transmission in the PC1 ₂ to 1 ₄ region TX ₁ is receiving area RX ₁
Next, the receiving area RX ₂ to Rx ₄ would correspond to transmission region TX ₂ ~TX ₄ of the PC1 ₂ to 1 _4. Therefore, in the second scan, the PC that will be the master station
The transmission area TX ₁ and the reception area RX ₂ generated in 1 ₁
Transmitting information about RX ₄ each PC1 ₂ to 1 _4. In this way, it is possible to set the transmission area and receiving area link area of each PC1 ₂ to 1 ₄ that is a slave station. Here, the information to be transmitted from PC1 _1, also good because when it is not possible to transmit in one scan data becomes redundant occurs, corresponding to each PC1 ₁ to 1 ₄ as the start address and the number of occupied words in each area Utilizing that the transmission area and the reception area are evenly divided,
Or transmit only the number of occupied words, or the automatic assignment switch SW of being PC1 ₁ to 1 ₄ that is on the number may be transmitted.

[0015] In the above procedure, in each PC1 ₁ to 1 _4, can be assigned to the link area LA automatically the region of the link relay LY and link register LR, yet different PC1 ₁ to 1 ₄ transmission region for It is possible to prevent the occurrence of trouble without overlapping with each other. In the above embodiment, the PC1 ₁ and the master station other PC1 ₂ to 1 ₄ operates similarly if the parent station. Further, the link unit 4 may be provided with a data register for registering the link area of its own station so that the link area is doubly registered.

(Embodiment 2) In this embodiment, as shown in FIG. 4, the switch data register D of the link unit 4 is used.
The setting state of R can be rewritten by an external device 5 such as a computer device. That is, the switch device data register DR of the link unit 4 can be rewritten by the external device 5 connected to the CPU unit 2 of the PC ₁₁ as a support tool, and the state set by the automatic allocation switch SW can be set to the external device. If the link area is reset after being rewritten by 5, the allocation state of the link area can be changed.

[0017] In this manner, by which to be able to rewrite the allocation status of the link area in the external device 5, even after incorporating the PC1 ₁ to 1 ₄ in a control panel,
It becomes possible to rewrite the contents of the switch data register RG of the link unit 4 from a remote location by connecting the external device 5 to the PC _{11 as the} master station. As a result, maintenance and the like becomes easier. Other configurations are similar to those of the first embodiment.

[0018]

According to the invention of claim 1, the link area is evenly divided according to the number of link units whose automatic allocation switches are turned on in the network, and each divided area is sequentially allocated to each station. Each area of the area will be automatically assigned to each station, resulting in no need to manually assign areas, and the transmission areas of other stations may be set to the same address in duplicate. There is an advantage that it can be prevented. Further, since the link area is evenly divided according to the number of data terminal stations transmitting data in the network, the link area can be used to the maximum extent, and there is almost no useless area that is not used in the link area. There is an advantage.

According to the second aspect of the present invention, since the contents of the switch data register of the link unit can be rewritten by connecting an external device to the master station, the automatic allocation switch is already set and installed. However, it is possible to rewrite the contents of the switch data register from a remote location by using an external device and join or disconnect from the network, which has the effect of facilitating maintenance. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating a first embodiment.

FIG. 2 is a circuit diagram of a main part of a link unit used in the first embodiment.

FIG. 3 is an explanatory diagram showing an example of a state in which a communication area is assigned to a link area according to the first embodiment.

FIG. 4 is a schematic configuration diagram showing a second embodiment.

FIG. 5 is a block diagram of a conventional programmable controller.

FIG. 6 is an explanatory diagram showing a link area allocation state in a conventional example.

FIG. 7 is an explanatory diagram showing a relationship between link areas of respective stations in a conventional example.

[Explanation of symbols]

1 ₁ Programmable Controller 1 ₂ Programmable Controller 1 ₃ Programmable Controller 1 ₄ Programmable Controller 2 CPU Unit 3 Power Supply Unit 4 Link Unit Lc Transmission Line

Claims (2)

[Claims] 1. A data terminal of a plurality of stations is connected to a transmission line via a link unit, and one of the data terminals is connected.
A network with the station as a master station is constructed, and each station is set with a transmission area for storing data to be transmitted to other stations and a reception area for storing data received from other stations for each other station. , Each of which has a fixed-length link area whose reception area matches the transmission area of each other station, and the link unit includes an automatic allocation switch and maintains the on / off state of the automatic allocation switch. The data terminal, which is equipped with a switch data register and serves as the master station, detects the setting status of the switch data register and determines the number of link units in the network for which the automatic allocation switch is on. Divide evenly, allocate each divided area to each station sequentially, set the transmission area and the reception area in the link area of the master station, and then each other station Allocation scheme of the communication area and sets a transmission region and reception region by transmitting a configuration information transmission region and reception region of the parent station in the link area of each other stations for. 2. A communication area allocation system, wherein the master station has an interface to which an external device capable of rewriting the contents of the switch data register of another station is connected.