JPH03174603A - Communication procedure for programmable controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a programmable controller (hereinafter referred to as rPC).
It is abbreviated as J. ) related to communication procedures.

[Conventional technology]

As a one-to-one communication method between a PC and a programming panel (hereinafter referred to as rPPJ), Japanese Patent Laid-Open No. 62-2
There is a system described in Japanese Patent No. 56152, which enables data to be directly transferred between a PP and a PC.

If this scheme is expanded, communication between a single PP and multiple PCs is also possible. An example is shown in FIG.

In this method, the PP, which is a mask, uses the modem to
Slave PCI, PC2, ... PCn and 1:N
Can communicate.

To explain the communication method, the PP, which is a mask, selects the number of the slave PC by putting a destination address in a command, which is transmission data. The slave PC compares the destination address of the command, which is received data, with its own device address. If the numbers are the same, it accepts the data, processes the command, creates a response, and sends it to the PP. Send the response.

The PC ignores the command if the destination address of the command and its own device address are different.

The PP receives the returned response and processes the response.

[Problem to be solved by the invention]

However, the conventional communication method described above has the following problems.

■ Part 1: Since there is no address of the own station (source address) and the PP which is a mask does not have its own address, the same address as the address of the other station (destination address) added to the command is included in the response data. You must check that it is included.

■ Because a modem is used, the wiring between the mask and multiple slaves are all connected, so if there are multiple masks, the communication control signals issued by each mask will conflict.

■ Due to the reasons for ■ and ■ above, PP and PC are 1:N.
N:N of multiple masks and multiple slaves required for communication such as monitoring and changing large-scale equipment.
Unable to respond to communications.

■ Since a modem had to be used for communication, there were equipment restrictions regarding wiring, installation location, etc.

Therefore, an object of the present invention is to enable communication between multiple masters and multiple slaves without using a modem.

[Means to solve the problem]

To achieve this objective, the programmable controller communication procedure of the present invention includes a communication procedure between a plurality of programming panels and a plurality of programmable controllers, in which the plurality of programmable controllers are connected to the programming panel or are not connected to the programming panel. When communicating data from a programming panel to a specific programmable controller by connecting them with a link between programmable controllers, the programming panel adds a destination address, which is the address of the destination, to the data being sent. The data is sent to the programmable controller connected to the programming panel, and when the address is not the own station, the programmable controller attaches a source address that is the address of the own station and sends the data to the programmable controller-to-controller link. The communication controller of each programmable controller receives the data when the destination address is its own station, performs the requested processing, sets the source address as the destination address, and sets the destination address as the source address. and transmitting the response data to the programmable controller link together with the processing data, and transmitting response data to the programming panel.

[Effect]

The programmable controller of the present invention has an inter-PC link function as shown in FIG.

Then, by adding the command from the PP to the data transmitted and received between the PCs, the command from the PP is sent to the PC having the same device address as the destination address in the command. In addition, the response from the PC that has finished command processing is sent to the PP via the same route.
send it back to

The above operation will be explained using an example.

FIG. 2 is a sequence diagram of data transmission and reception between the PP and the PC and between the PCs.

It is assumed that the PP is connected to a PC with a device address of 1, and a command is created by setting 2 to the destination address. The system is PCI, PC2, PCB
The link system consists of three units. The device address of each PC is the same as each number.

The operation sequence is shown below.

(2) The PP sends a command with destination address 2 to the connected Pct.

(2) Since the destination address of the command received from the PP and its own device address are different, the PCI attaches header 1 to the command and sends it to the link line 20.

(2) Since the destination address in the header of the command received from the link line 20 is the same as its own device address, the PC 2 processes the command.

(2) Since the destination address in the header of the command received from the link line 20 is different from its own device address, the PC 3 ignores the command.

(2) When the command processing is completed, the PC 2 creates a response, attaches a header 2 to the response, and sends it to the link line 20. At this time, the station address is 1.

(2) Since the destination address in the header 2 of the response received from the link line 20 is different from its own device address, the PCB ignores the response.

(2) Since the destination address in header 2 of the response received from the link line 20 is the same as its own device address, the PCI removes the header from the response and sends it to the PP.

■PP receives a response from PCI.

The above sequence allows the PP to communicate with the PC 2 via the PCI and link line 20.

Further, since the link line 20 can perform data communication with each other by controlling the destination address and device address, a plurality of PPs can be connected within the link system.

Therefore, N:N communication can be performed without changing the communication method between the PP and PC and without using a modem.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a block diagram showing an embodiment of the present invention, and FIGS. 4 and 5 are flowcharts showing data processing procedures in the embodiment, respectively.

In Figure 3, PP and programmable controller P
It is connected to the CI via a communication line IO such as R3232C. Furthermore, the programmable controllers PCI and PC2 are connected by a link line 20 (coaxial cable).

Although only two programmable controllers are shown in this example, a link line 20 also connects a plurality of PCs.

PCl and PC2 each include a data processing section 30.50 and a link unit (communication control section) 40.60. The data processing unit 30.50 includes a CPU 31.51 that processes data and a ROM 32 that stores programs.
．． 52 and a RAM 33.53 for storing data. Link line) 40.60 is a communication controller 41 that controls communication with the PP connected via the communication line 10.
61 (However, in this embodiment, the communication controller 61 has a PP
is not connected. 〉, a data format converter 42.62, and a CPU that processes these data.
43.63, and a communication controller 44.64 for controlling data communication to the link line 20.

The operation of this embodiment will be described below with reference to FIGS. 3 to 5.

First, the PP sends a command as shown in step 100 of FIG. This command is sent to the PCI via the communication line 10, and the link unit 40 of the PCI receives this command (step 110) and analyzes the address (step 120). This address is your own station (
PCI), performs step 130 (data format conversion (remove destination address)), sends a command to the data processing unit 30 via the internal bus, and performs data processing based on the command (step 140). and creates a response (step 150).

In step 120, if the address added to the command is not the local station, step 160
Data format conversion (source address,
The destination address and data type are added as a header), and the command is sent to the link line 20 via the communication controller 44 in FIG.
step 170).

The PC 2, which has received the command from the PP via the link line 20 (step 180), compares the station address in the header of the command with its own device address (step 190). No processing is performed as shown in step 200. If it is the own station, the data type is analyzed in step 210, and if it is other than the command type, processing is performed for each type (step -11=220). If it is a command type, data format conversion (header removal) is performed in step 230, the command is sent to the data processing unit 50 via the internal bus, and data processing (step 240) is performed based on the command.
) and create a response (step 250).

Figure 5 shows the response created on PC2.
It shows the process of replying to.

The response created in step 300 is sent to the link unit 60 via the internal bus, and the data format is converted (adding a header) in step 310.
A response is transmitted via the communication controller 64 of FIG. 3 (step 320). The PCI receives the response (step 330) and analyzes the address added to the response (step 340).

If the address is not the local station, no processing is performed (step 350). If the address is your own, step 360
Parse the data type in . If the data type is not a response type, processing for each type is performed in step 370. If it is a response type, step 380
Data formant conversion (\remove ladder,
destination address) and sends a response in step 390. This response is sent to the PP via the communication line 10, and the response is received (step 400).

In this way, the PP can communicate with the PC 2 via the PCI and link line 20.

Further, since the link line 20 can perform data communication with each other by controlling the destination address and device address, a plurality of PPs can be connected within the link system.

With this feature, N:N communication can be performed without changing the communication method between the PP and PC, and without using a modem.

〔Effect of the invention〕

As explained above, according to the present invention, by constructing a PC-to-PC link system, N:N communication is possible without changing the communication method between PP and PC and without using a modem. Become.

[Brief explanation of the drawing]

Figure 1 is a system configuration diagram of the present invention, Figure 2 is PP and PC
A sequence diagram of data transmission and reception between PCs,
FIG. 3 is a block diagram showing an embodiment of the present invention, FIGS. 4 and 5 are flowcharts showing data processing procedures in the embodiment, and FIG. 6 is a system configuration diagram of conventional N communication between PP and PC. It is. PP Niprogramming panel PC, PCl, 2: Programmable controller 10:
Communication line (R3232C) 20 Nilink lines (coaxial cable) 30.50: Data processing section 31.51: CPU 32.52:
R0M33, 53: RAM 4060: Link unit 4161: Communication controller 42.62 + digital format converter 4363: CP
U 44, 64: Communication controller JP-A-3 174603 (6)

Claims (1)

[Claims] 1. In the communication procedure between a plurality of programming panels and a plurality of programmable controllers, the plurality of programmable controllers that are connected to the programming panel or not are connected to each other by an inter-programmable controller link, and a certain programming panel is connected to the programmable controllers. When communicating data to a specific programmable controller, the programming panel adds a destination address, which is the address of the destination, to the data to be sent, and sends the data to the programmable controller connected to the programming panel. In the programmable controller, when the address is not the own station, the data is sent to the link between programmable controllers with a source address that is the address of the own station, and in the communication controller of each programmable controller, the destination address is the own station. When the station is a station, it receives data, performs the requested processing, converts the source address to a destination address, and the destination address to a source address, and sends the processed data to the programmable inter-controller link. , a communication procedure for a programmable controller, characterized in that response data is transmitted to the programming panel.