JPH03217905A - Data transfer method between programmable controllers - Google Patents

Abstract

PURPOSE:To transmit information to different kinds of programmable controllers with simple processing by generating a frame in which different kinds of header parts are positioned at the forefront of a data part. CONSTITUTION:When data is transmitted from a first program controller (PC) 20 coupled with a network bus 10 to a second PC 20, the CPU 102 of a control arithmetic part 101 decides whether or not the second PC 20 is the same kind by referring to file information stored in a station number registration file 103, and when it is the different kind of PC, a transmission frame for second PC 20 is generated based on the head format information of the second PC 20, and it is added on the forefront of the data part 3 as second header information, then, it is transferred. The link control part 22 of the second PC 20 reads the second header information, and performs the reception of the data according to the information. Communication between the different kinds of PCs can be performed as usual.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a data transfer method between programmable controllers, and more specifically, the present invention relates to a data transfer method between programmable controllers that are connected to a common network bus and have different frame configurations of transfer data. Regarding the transfer method.

[Prior Art] Conventionally, a system is known in which a plurality of programmable controllers are connected to a network bus, information processing is shared among the plurality of programmable controllers, and electronic equipment is automatically controlled.

When data is transferred using a network bus, a programmable controller on the sending side creates one frame of transmission data and sends it to the network bus at a predetermined timing. Usually, an l frame is composed of a header section and a data section, and the header section is composed of header information for calling the other station, such as an identification code assigned to the receiving station and the data length of the transferred data. The data part consists of the information to be transferred.

When the receiving station side synchronously receives the transfer data on the network bus and confirms that the above identification code for calling the other station, which is included in the above header section, specifies the own station, One frame of data designated for the local station is taken into the device.

[Problem to be solved by the invention]

However, in the conventional data transfer method between programmable controllers of this type, the format of the header part constituting the frame may differ depending on the model, as shown in FIG. In this case, the programmable controller of the receiving station of a different model could not recognize the contents of the header section and could not receive information from the transmitting station.

SUMMARY OF THE INVENTION In view of the above-mentioned points, an object of the present invention is to provide a data transfer method that allows data transfer even between programmable controllers with different header formats.

[Means to solve the problem]

In order to achieve such an object, the present invention receives frame information from a programmable controller on the transmitting side, which is composed of a header section containing header information for calling a receiving station and a data section containing data to be transmitted. In a data transfer method between programmable controllers that transfers data to a side programmable controller via a network bus, when transmitting data to a programmable controller with a different format of front header information, a header section that matches the format of the different programmable controller is used. is positioned at the beginning of the data section, the created frame information is transmitted from the transmitting programmable controller to the network bus, and on the different programmable controller side, the frame information is positioned at the beginning of the data section. The frame information on the network bus is received by regarding the header part of the frame information as the beginning of the frame information.

[For production]

In the present invention, when information is transmitted to a programmable controller of a different model, information in the normal header section is not received, but information in the header section at the beginning of the data section is accepted. Therefore, information can be transmitted to a programmable controller of a different model without replacing the transmitting/receiving circuit of the conventional programmable controller in accordance with the model.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows a system configuration of a programmable controller to which the present invention is applied.

In FIG. 2, a plurality of programmable controllers 2
0 is connected to the network bus 10.

The programmable controller 20 is the interface section 1
00 and control calculation 101.

In the interface section 100, the link control section 22 uses a dedicated LSI, transfers the transmission information from the control calculation section 101 to the network bus via the transmission/reception circuit 21, identifies the frame signal for the own station on the network bus, The frame signal is transferred to the control calculation section 101.

Specifically, it performs serial-to-parallel conversion and modulation/demodulation of transmission data. Transceiver circuit 2l has hybrid I for transceiver.
A C (integrated circuit) is used to send and receive signals to and from the network bus IO according to instructions from the link control unit 22.

The control calculation unit 101 has a central processing unit (CPU) 102 that executes a sequence program, a station number registration file 103 using a random access memory (RAM), and performs calculation processing and processing for automatically controlling equipment to be controlled. Executes frame generation/decomposition processing for transmission and reception.

In this example, the information signal from the controlled object-like device 30 is
It is transmitted to the first programmable controller via the programmable controller, and the sequence calculation results of the first programmable controller are transmitted to the controlled device 30 in the reverse order.

As shown in FIG. 3, the station number registration file 103 related to the present invention includes the station number (identification code) of the programmable controller connected to the network bus IO and its model number.

The procedure for transferring data from the first programmable controller to the second programmable controller of a different model in such a system configuration will be explained with reference to the flowchart of FIG.

When transmitting information, the CPU 102 of the control calculation unit 101
By referring to the file information stored in the station number registration file 103, the second programmable controller to which the transmission is to be made determines whether or not its own station is of the same model (Steps St-S2→ in FIG. 4). S3).

When the model of the second programmable controller is determined to be a different model by this determination, the CPU 102 uses the head format information for the second programmable controller inputted from the keyboard input device (not shown) to
Create a transmission frame for the programmable controller. As shown in FIG. 1, this transmission frame is created by copying the input header information corresponding to the model of the second programmable controller to the beginning position of the data section 3 of the transmission frame. The remaining area of the data section 3 is used for information to be transmitted. Further, in the first header section, various information for transmission is set in the same manner as in the conventional example (step S4 in FIG. 4).

The transmission format created in this way is used in the control calculation unit 1.
01 to the link control unit 22, modulated, and then transferred onto the network bus 10 via the transmitting/receiving circuit 21 (step S in FIG. 4).

On the other hand, in the link control unit 22 of the second programmable controller, the second
Transmission to the own station is detected based on the header information, and information from the second header information to the information end end code is captured as one frame of information.

In addition, when the first programmable controller transmits information to another programmable controller of the same model, a transmission request of the same model is detected by referring to the station number registration file 103, and the header information is stored in the first header section as in the past. and sets the information to be transmitted from the beginning of the data section 3 (steps S1 to S3→S5→S6 in FIG. 4).

As explained above, in this embodiment, the header section of a different model is positioned at the beginning of the data section in the frame information, so the programmable controller that receives this frame information moves the beginning of the data section of the frame to the header section of the different model. It can be regarded as the beginning and can be received.

In addition to this example, the following nine examples can be cited.

In this embodiment, an example is shown in which a frame is created in the control calculation unit 101, but the same process as described above is performed in the link control unit 101.
2 may be executed.

In this case, it is preferable to store information indicating the header format in association with each model of the programmable controller in the station number registration file.

It goes without saying that the registered file information can be registered and modified using a programmable input device.

[Effect of the invention 1] As explained above, according to the present invention, information can be sent to a programmable controller of a different type by a simple process of creating a frame in which the header section of the different model is positioned at the beginning of the data section. You can add a new programmable controller to an existing system, or
This has the effect of enabling data communication between a plurality of systems using different programmable controllers.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the format contents of transmission data according to the embodiment of the present invention, Fig. 2 is a block diagram showing the system configuration of the embodiment of the present invention, and Fig. 3 is the contents of the station number registration file according to the embodiment of the present invention. FIG. 4 is a flowchart showing the frame creation procedure according to the embodiment of the present invention, and FIG. 5 is an explanatory diagram showing the format contents of transmission data in a conventional example. 1...Transmission frame, 2...Header section, 3...Data section, 20...Programmable controller, 2l...Transmission/reception circuit, 102...CPU. Figure 1 Transfer Heaven 14-'f v1 Rika No. 3 Figure Service January tip] Request example's Flow Naito Figure 4 Inside'J- and Ne1
Yumeien Garden Figure 5

Claims (1)

[Claims] 1) Frame information composed of a header section containing header information for calling a receiving station and a data section containing data to be transmitted is transferred from a transmitting-side programmable controller to a receiving-side programmable controller over a network. In a method for transferring data between programmable controllers via a bus, when transmitting data to a programmable controller having a different format of the header information, a header section matching the format of the different programmable controller is positioned at the beginning of the data section. and transmitting the created frame information from the sending-side programmable controller to the network bus, and on the different programmable controller side, the header section at the beginning of the data section is replaced with the beginning of the frame information. A data transfer method between programmable controllers, characterized in that frame information on the network bus is received by regarding the frame information as being.