JP3400315B2 - Profibus data transmission system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is based on data transferred between various coordinate positions on a display screen of a display and various network connection devices of a programmable controller such as a PLC (programmable logic controller). In addition, the present invention relates to a programmable display device that displays a screen for operating an external device, which is composed of drawings, graphs, numbers, characters, and the like.

[0002]

2. Description of the Related Art PLC has various field networks depending on each manufacturer, and the PLC of the manufacturer is used.
The hardware configuration and characteristics differ depending on C. Conventionally,
For this kind of network, a given address in the PLC
(Hereinafter, referred to as device) because the need to access high speed, the device only network connection device of limited range (e.g., a programmable display device) not be accessed from. Therefore, devices outside the access range
When accessing the chair, it has been stored in the PLC in the past.
Connected device is desired by the created program
Devices that are out of the access range
Access by copying to the device area of
The method was adopted. Thus, to change the device to be accessed, the access range programmable display device
Every time I try to display an external device, the PLC
It was necessary to change the program inside, and it took time to debug.

[0003]

However, the PLC
It is necessary to stop the working machine and work even if it is a simple modification in the case where the application is built into the machine,
It cannot be changed easily. As a result of the inventors' consideration of such inconvenience, the PL prepared in advance
Program in PLC of C (hereinafter referred to as execution program
Is included in the PLC, and the programmable display
The information of the device you want to access from the PLC
Stored in a fixed memory and based on the execution of the above execution program.
And interpret that information as a run command and run that
You can access the device in the PLC by the command.
As a result, they realized that all devices can be accessed, and completed the present invention.

[0004]

A method according to the invention of claim 1
The Rofibus data transmission method solves the above problems.
A programmable controller that acts as a master
And as a slave to the programmable controller
A function programmable display device which are connected with each other through the interface unit, the said programmable control unit and the interface unit, Ru communicable der each other via a Profibus Network Temporary
On the other hand, the programmable controller is
Stored information in a predetermined memory
Based on the execution of the pre-stored execution program ,
Interpret the information stored in the above memory as an execution command
Then, based on the execution command, the programmable control
It is characterized in that a predetermined address in the control device is accessed .

Profibus data according to the invention of claim 2
The transmission method is the Profibus data transmission method according to claim 1.
In the expression, the contents of the specified address accessed above
Via the Profibus network
Characterized by displaying on the display screen of a ramable display device
It

[0006]

According to the Profibus data transmission method type according to the present invention, the actual programmable controller previously prepared
By incorporating the row program into the programmable controller, all subsequent devices can be accessed by making subsequent changes on the programmable display device.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 represents the normal operation of the programmable display device (1), the commands sent from the programmable display device (1) to the programmable control device (2) being outlined by the manufacturer of the master programmable display device (1). Performs the read and write operations by mimicking the commands defined by. The programmable controller (2) returns the information requested by the programmable display device (1). In contrast, FIG. 2 represents the operation of the Profibus network according to the present invention. The commands from the master programmable controller (2) follow the Profibus standard of operation . Programmable table of slave
The indicating device (1) returns the requested information to the programmable control device (2).

The communication protocol adopted in the data transmission system according to the present invention is a programmable display device (1).
To enable communication with the Profibus network. Although Profibus network is complex, executing operating on the interface unit and the master programmable controller (2)
With the help of programs (eg, assembly language programs that are understandable by the CPU ) , many complex problems with networks such as the present invention can be solved.

[0009] Typically, the programmable display device (1),
It operates as a master, as shown in FIG. 1, and controls the command sent to the programmable display device (1) controls. On the Profibus network according to the present invention , these roles are reversed, and the programmable controller (2) as the master sends a command to the programmable display device (1) as shown in FIG. Responds to these commands.

On such a network, the programmable display device (1) is allowed to function normally, and for example, different types of memories (access points) in the programmable control device (2) are accessed.
An execution program is stored in advance in the programmable control device (2) in order to enable normal writing and reading with respect to devices outside the access range) . Su
The Reve programmable display (1) is the master
That responds to commands from the programmable controller (2), the information sent to the programmable controller (2) is the master by a programmable display device of the slave (1) is given in the programmable controller (2)
It is stored in the memory of and programmable control is possible in advance.
Based on the execution of the execution program stored in the device (2)
The information stored in that memory as an execution command
Interpret.

In order to make the programmable display device (1) function on the Profibus network according to the present invention ,
An interface unit (4) is required. A Profibus network to which the programmable display device (1) is connected is shown in FIG. As shown, the programmable controller (2) and the interface unit (4) communicate with each other via a Profibus network.

In order to operate the programmable display device (1) as described above, the following structure is required. 1) Interface unit 2) Protocol specifications 3) Execution program

[0013] 1) interface unit (4) interface unit (4), depending porting suitable Seiryo (porting), is the intelligent unit for enabling communication over the Profibus network to the programmable display device (1) . Programmable display device (1) simply performs a write to the DPRAM (Dual Port RAM) of the interface unit (4), the interface unit (4) adjusts the processing required by the Profibus network. The control operation of the interface unit (4) is shown in FIG.
Shown in.

2) Protocol Specifications Protocol specifications are shown in FIGS. 5 shows specifications of packet transmission from the programmable display device (1) to the programmable control device (2), and FIG. 6 shows specifications of packet transmission from the programmable control device (2) to the programmable display device (1). It represents. Further, FIG. 7 shows a handshake operation between the programmable display device (1) and the programmable control device (2).

[0015] 3) executing a program execution program makes use of the fact that it has the programmable control unit (2) is distributed to each slave under management memory a certain amount within that "peripheral memory area". There can be three different types of slaves: 1) Input only 2) Output only 3) Both input and output

FIG. 8 shows an input only case, FIG. 9 shows an output only case, and FIG. 10 shows both an input case and an output case.
Thus, depending on how the slaves are formed (input only, output only, or both input and output)
The programmable controller (2) writes any data as long as the data exists in the output area distributed to the slaves in the question. Similarly, the data sent by the slave to the memory assigned to the slave in the input area of the programmable controller (2) is read and stored.

[0017] The programmable control device (2), programming
Predetermined memory in the programmable controller (2) and a programmable
Predetermined memory (slave memo) in the mable display device (1)
Adjusting the data exchange between the Li). The slave information from the programmable display device (1) is, (following the specification of the protocol) when read out in a predetermined memory in the programmable controller (2), programmer
Interprets previously stored execution program information to the table control unit (2) as the execution command, its execution command
A predetermined value in the programmable controller (2) based on
To access the address . The flow of this program is shown in FIG.

Further , as shown in FIG. 12 , the interface unit (4) has an interrupt line (interruput) of the programmable display device (1) on the GMU bus.
programmable display device (1)
Notify new data to. This one line is connected to a new data register on the interface side.

13 to 15 show the basic flow of the execution program of the programmable controller (2). FIG. 13 shows the first flow of the program,
A check is performed to ensure that all processing of the previous command is complete and that the accessed range is valid. FIG. 14 shows the main flow of this program. Also, FIG.
Indicates the flow when an error occurs during command processing.

According to the above-mentioned Profibus data transmission system of the present invention, the execution program prepared in advance is incorporated into the programmable controller (2) and the programmable table
The information of the device desired to be accessed from the display device (1)
Stored in a predetermined memory of the programmable controller (2)
Then, based on the execution of the above execution program,
Interpret as an execution command, and by the execution command,
Access devices in programmable controller (2)
By doing so, all devices can be accessed. Therefore, either programmable display device (1)
Although outside Luo access range, when it is intended to display the required devices, as in the prior art, each time there is no need to change the program in the programmable controller (2).

[Brief description of drawings]

FIG. 1 is a diagram illustrating a normal operation of a programmable display device.

FIG. 2 is a diagram illustrating an operation of a Profibus network.

FIG. 3 is a diagram illustrating an operation of a Profibus network including a programmable display device.

FIG. 4 is a flowchart showing the operation of the interface unit.

FIG. 5 is a diagram showing specifications of packet transmission from a programmable display device to a programmable control device.

FIG. 6 is a diagram showing specifications of packet transmission from a programmable control device to a programmable display device.

FIG. 7 is a diagram showing a handshake operation between a programmable display device and a programmable controller.

FIG. 8 is a diagram illustrating a correspondence relationship between memory areas when a slave has only inputs.

FIG. 9 is a diagram illustrating a correspondence relationship between memory areas when a slave has only an output.

FIG. 10 is a diagram illustrating a correspondence relationship between memory areas when slaves are both input and output.

FIG. 11 is a flowchart showing the overall flow of an execution program.

FIG. 12 is a block diagram showing a hardware configuration.

FIG. 13 is a flowchart showing a first flow of an execution program of the programmable controller.

FIG. 14 is a flowchart showing a main flow of the program.

FIG. 15 is a flowchart showing a flow when an error occurs.

[Explanation of symbols]

(1) Programmable display device (2) Programmable controller (4) Interface unit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-36372 (JP, A) JP-A-6-216969 (JP, A) JP-A-6-125371 (JP, A) JP-A-5- 298221 (JP, A) JP-A-8-65764 (JP, A) JP-A-4-288798 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G05B 15/00-15 / 02 G05B 19/04-19/05

Claims (2)

(57) [Claims] 1. A programmable that functions as a master.
A controller and a sled for the programmable controller.
A programmable display device which functions as a blanking are connected with each other through the interface unit, the said programmable control unit and the interface unit, while Ru communicable der each other via a Profibus network, the programmable controller, the Programmable table
The information from the display device is stored in a predetermined memory and
Based on the execution of the stored execution program,
The information stored in the memory is interpreted as an execution command, and based on the execution command, the programmable control device
A Profibus data transmission method characterized by accessing a predetermined address in the storage. 2. Among the predetermined addresses accessed,
Content via the Profibus network.
It is characterized by displaying on the display screen of the programmable display device.
The Profibus data transmission method according to claim 1.