JPH03204006A - Communication system for programmable controller - Google Patents

Abstract

PURPOSE:To monitor the entire working of a network by pointing the address of the remote side and at the same time performing the communication of data to a slave controller via a master controller. CONSTITUTION:A master controller is provided with an interface unit 6 for connection to a computer equipment. The command given from the computer equipment is decoded by a command decoding part 12 and then converted into the decodable data via a data production part 13. This decodable data is sent to a controller and inputted to a data converting part 15 to be turned into the processable data. This processable data is sent to the computer equipment. Then the addresses of the master controller and each slave controller are designated and at the same time a data transmission line is pointed. Thus a multiple connection is secured just by connecting the computer equipment to the master controller.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a communication system for programmable controllers in which a plurality of programmable controllers are connected to each other via a transmission line to make them work together.

[Conventional technology]

Generally, in order to control one device, it is often sufficient to use one programmable controller, but when multiple devices are to be interlocked, multiple programmable controllers are also required. In this case, if the individual programmable controllers operate independently, the devices will not work together, so it is necessary to make the programmable controllers work together by communicating data between them. To link multiple programmable controllers,
It is necessary to transmit desired data to and from a desired programmable controller by setting a unique address for each programmable controller and specifying the destination using this address. In order to realize such an operation, a communication system has been proposed in which a link unit for data communication is connected to each programmable controller, and the link units are connected via a transmission path. In this communication system, one of the programmable controllers is the master controller, the remaining programmable controllers are slave controllers, and the master controller specifies the address of the slave controller to perform data communication, so that each slave controller can Distributed processing is performed to control each device, and a master controller centrally manages the communication system. As mentioned above, in regular operation, there is no problem because the master controller performs overall management of the communication system, but when you want to change the data of the programmable controller or collect data from the programmable controller, etc. , it is necessary to connect a separate computer device. In order to meet such demands, it has been considered to provide each programmable controller with an interface unit that enables connection with a computer device interface (a general-purpose communication interface such as R8-232C).

[Problem to be solved by the invention]

In the above conventional configuration, if you want to change data or collect data for each programmable controller, it is necessary to connect a computer device to each programmable controller, so each programmable controller has an interface unit for the computer device. The problem arises that the number of interface units increases and the cost becomes high. Furthermore, since the computer device only sends and receives data to and from individual programmable controllers, there is also the problem that the operation of the network of programmable controllers as a whole cannot be monitored using computer equipment. The present invention aims to solve the above-mentioned problems, and allows data to be exchanged between all programmable controllers and computer devices in a network by providing only one interface unit, and also enables data to be exchanged between all programmable controllers and computer devices in a network. The present invention aims to provide a programmable controller communication system in which the entire operation of a network can be monitored by a computer device.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a plurality of programmable controllers each having a unique address, and connects link units for data communication provided in each programmable controller via a transmission path, In a programmable controller communication system in which one of the programmable controllers is the master controller, the remaining programmable controllers are slave controllers, and data communication is performed by specifying the address of the slave controller from the master controller, the master controller is The computer device includes an interface unit that can be connected to a computer device, and the computer device instructs the master controller of the address of the programmable controller with which data should be communicated, and also allows data communication to be performed with the slave controller via the master controller. This is what we are doing.

[Effect]

According to the above configuration, the computer device is connected to the network of programmable controllers only through the interface unit provided in the master controller, and there is no need to provide an interface unit for each programmable controller as in the past. Since there is no interface unit, there is only one interface unit, which reduces costs. Furthermore, since the computer device can perform data communication with all programmable controllers in the network via the master controller, it goes without saying that the computer device can change and collect data from individual programmable controllers. It also becomes possible to monitor the overall operation of the network. In other words, it becomes possible to perform one-to-many data communication instead of one-to-one data communication between a computer device and a programmable controller as in the past.

【Example】

As shown in FIG. 1, one master controller 1,
Multiple (four in this case) slave controllers 21~
24, the master controller 1 and each slave controller 21-2. are each configured by a programmable controller equipped with an arithmetic control section 3 and a link unit 4 for data communication. Each of the slave controllers 21 to 24 is connected to a controlled device to be sequentially controlled. In addition, the master controller 1 and each slave controller 21 to 2. The link units 4 are connected via a transmission path 1 to form a network. Although the network may have either a ring type or a bus type structure, a ring type example is shown here. Master controller 1 and each slave controller 2
Unique addresses are set for 1 to 24; for example, the master controller 1 is set to "O", and the slave controllers 2I to 24 are set to addresses "1" to "4", respectively. By specifying the addresses of the slave controllers 21 to 24, the master controller 1 can individually send and receive data to and from each of the slave controllers 21 to 24. Here, since the network is a ring type, for example, if data is to be exchanged between the master controller 1 and the slave controller 2□, there will be a route passing through the slave controller 21 and a route passing through the slave controllers 24 and 23. Since there are two possible routes, it is necessary to choose which route to take. Therefore, the master controller 1 sends and receives data to the slave controller 2. ~2. address and the destination controller 2
．． ~2. It specifies the route leading to . As described above, the master controller 1 and each slave controller 21-2. data communication between multiple slave controllers 21-2. can be linked together. Master controller 1 and slave controller 2. If a program is set so that each of the arithmetic and control units 3 to 24 operates in conjunction with each other, the network itself will operate independently without any commands being given from outside the network. By the way, the master controller 1 is provided with an interface unit 6 for connecting to a computer device 5. The interface unit 6, as shown in FIG. After being decoded in the data creation unit 13
The data is converted into data that can be interpreted by the master controller 1, and sent to the master controller 1 via the connection section 14.
The data is sent to the arithmetic control section 3 of. On the other hand, data from the arithmetic control section 3 of the master controller 1 is input to the data conversion section 15 through the connection section 14, and after the data in the network is converted into data that can be processed by the computer device 5, it is transmitted through the connection section 11. and sent to the computer device 5. The commands include the master controller l and each slave controller 21-2. There are commands to access individual networks to modify or collect data, and commands to check the operating status of the network. In these commands, the master controller 1 and each slave controller 21-2. Since data will be sent and received individually, the addresses of the master controller 1 and each slave controller 2, to 24 are designated, and the data transmission route is designated. For example, if a command from the computer device 5 specifies "0→4→3→2", data will be exchanged between the slave controller 2□ and the computer device 1 through the master controller 1. be. Here, a path passing through the slave controllers 24 and 23 is selected as the transmission path. In addition, in the ring type, from the master controller 1 to each slave controller 2. ~2. Since there are two routes leading to only(
It is also possible to omit the designation of the transmission route (clockwise or counterclockwise). In the above manner, the computer device 5 is connected to the network.
Although only one interface unit 6 is used to connect the network, the computer device 5 can access the master controller 1 and all slave controllers 21 to 2 in the network. That is,
Conventionally, when changing or collecting data, the master controller 1, slave controller 2. 24, the computer device 5 had to be connected one-to-one, whereas in the present invention, simply connecting the computer device 5 to the master controller 1 constitutes a one-to-many connection. be. Therefore, it becomes possible not only to individually send and receive data to and from the master controller 1 and each of the slave controllers 21 to 24, but also to monitor all data transfers within the network. By the way, as the master controller 1, a program creation device 20 as shown in FIG. 3 may be used. The program creation device 20 includes a system memory 21, a display section 22 consisting of a liquid crystal display, and a keyboard 23 around the arithmetic control section 3, and an interface 2 to an external storage device 24.
5 and slave controllers 21 to 24. In the configuration shown in FIG. 3, the display section 22 is provided with a backlight device 27 using an EL panel. In addition, slave controllers 21 to 2. The interface 26 to the R5-422 standard includes a display control section 22a, a key control section 23a, a backlight device 27, a keyboard 23, a backlight device 27, and a display control section 22a, a key control section 23a, and a A light control section 27a is connected. Furthermore, a volume 22b for adjusting the contrast of the display section 22, a buzzer 28 for notification, a reset input section 29, and the like are provided. As mentioned above, such a program creation device 20 is usually used as the master controller 1, but since a computer device or the like may be connected to the network as a peripheral device, in that case, the program creation device 20 You may also want to configure it as a slave controller. However, as shown in Fig. 4, if a specific key on the keyboard 23 is pressed when the power is turned on or reset, the slave mode in which the controller is set as a slave controller is selected; otherwise, the controller is set as a master controller. The mask mode to be set is selected. Through such processing, the program creation device 20 can be set as either a master controller or a slave controller, so while it normally performs processing as a master controller, it can also be used as a slave controller to interact with a computer device if necessary. Connection can be made.

【Effect of the invention】

As described above, the present invention includes a plurality of 10-gram pull controllers each having a unique address, and connects link units for data communication provided in each programmable controller via a transmission line, In a programmable controller communication system in which one programmable controller is the master controller, the remaining programmable controllers are slave controllers, and data communication is performed by specifying the address of the slave controller from the master controller, the master controller is a computer device. The computer device instructs the master controller of the address of the programmable controller with which data should be communicated, and also communicates data with the slave controller via the master controller. The computer device is connected to the network of programmable controllers only through the interface unit provided in the master controller, and there is no need to provide an interface unit for each programmable controller as in the past. This has the effect of reducing costs since only one is required. Furthermore, since the computer device can perform data communication with all programmable controllers in the network via the master controller, it goes without saying that the computer device can change and collect data from individual programmable controllers. It also becomes possible to monitor the overall operation of the network. That is, there is an advantage that it becomes possible to perform one-to-many data communication instead of one-to-one data communication between a computer device and a programmable controller as in the conventional case.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing an interface used in the above, Fig. 3 is a block diagram of a program creation device used in the same network, and Fig. 4 is a block diagram showing the same as the above. It is an operation explanatory diagram. DESCRIPTION OF SYMBOLS 1... Master controller, 21-24... Slave controller, 3... Arithmetic control unit, 4... Link unit, 5... Computer device, 6... Interface unit.

Claims (1)

[Claims] (1) Equipped with multiple programmable controllers each having a unique address, connecting link units for data communication provided in each programmable controller via a transmission path, and making any one programmable controller the master controller. In a communication system for a programmable controller in which the remaining programmable controllers are slave controllers and data communication is performed by specifying the address of the slave controller from the master controller,
The master controller includes an interface unit connectable to a computer device, and the computer device instructs the master controller the address of the programmable controller with which data communication should be performed, and
A communication system for a programmable controller, characterized in that data communication is performed between a master controller and a slave controller.