JP2002341906A - Program formula display device and data communication system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily connect a plurality of program formula display devices 12 and computers 38 without using additional devices, to reduce a wiring cost and to stably perform an exact data communication processing operation. SOLUTION: A loop-like communication network simultaneously provided with a switching hub function and a traffic control function inside each of the program formula display device 12 and simultaneously provided with a main computer 38a and a sub-computer 38b, is constituted, the sub-computer 38b is used as backup for the main computer 38a and on the other hand, the respective program formula display devices 12 are enabled to individually control traffic quantity with other parties of data communication.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable display device capable of performing a display operation corresponding to a change in a control state in a PLC, and a data communication system using the display device.

[0002]

2. Description of the Related Art Conventionally, this type of program type display device is
When a LAN is connected in combination with another program type display device or computer device, a necessary data communication network is constructed by separately providing a hub and connecting a plurality of devices in a tree or loop. ing.

[0003]

However, since a normal hub is configured to connect a plurality of devices in a tree shape, the devices are concentrated in the same place as in an office. Wiring can be done efficiently, but if it is often distributed and arranged, as in the case of a programmable display device, wiring is required, such as requiring long wiring or providing a large number of hubs. It is complicated and wasteful.

The inventor of the present invention has studied the above disadvantages, and as a result, has provided a hub function in a programmable display device.
It has been found that the above problem can be solved at once by enabling a plurality of display devices and computer devices to be connected in series.

[0005] The present invention provides a programmable display device suitable for operating a plurality of programmable display devices and computer devices in coordination by simultaneously providing a switching hub function and a traffic control function therein. The purpose is to:

The present invention further comprises a loop communication network having a main computer device and a sub-computer device at the same time, wherein the sub-computer device is used as a backup for the main computer device, while each of the programmable display devices performs data communication. It is an object of the present invention to provide a data communication system capable of performing a stable and accurate data communication processing operation by individually controlling the traffic volume with the other party.

[0007]

The programmable display device 12 according to the present invention is connectable to a PLC 10 through a dedicated communication line 27, as schematically shown in FIG. , A computer device or a computer application device can be connected via a common communication line 34.

The programmable display device 12 has a switching hub function of enabling connection with a plurality of devices via a common communication line 34 and a traffic control function on the common communication line 34. It is characterized by having.

In this traffic control function, when there is a data transmission request on the dedicated communication line 27 and the common communication line 34 at the same time, the priority of the data is determined and the data transmission timing and It includes a function to control the amount of transmission.

In the data communication system according to the present invention, the programmable display device 12 having the above-described configuration in which the PLC 10 is connected to the dedicated communication line 27 is connected in series through a common communication line 34, and The main and sub-computer devices 38a and 38b are connected to both ends of a common communication line 34 connected to.

Further, the two computer devices 38a and 38b are connected one-to-one by an arbitrary communication line 39 in a wired or wireless state, and control for matching the two data is performed through the communication line 39. , Constitute a loop communication network as a whole.

The main computer device 38a enables control of the entire system, and the sub computer device 38b has a function as a backup for the main computer device 38a. Mirroring of data between 38b is attempted.

Each of the programmable display devices 12 normally performs a data communication operation with the main computer device 38a. However, any trouble in data communication with the main computer device 38a, for example, a disconnection of a communication line or traffic. When a situation such as an abnormal increase in communication becomes difficult, the destination of data communication is switched to the sub-computer device 38b to enable data communication to be continued.

[0014]

According to the present invention, as described above, the switching function and the traffic control function are simultaneously provided inside the programmable display device 12, so that a plurality of the programmable display devices 12 and the computer device 38 can be used as additional devices. Connection can be made easily without wiring, and wiring costs can be reduced.

Further, a loop communication network having a main computer device 38a and a sub-computer device 38b at the same time is constructed, and the sub-computer device 38b is used as a backup for the main computer device 38a. By making it possible to individually control the traffic amount with the partner of data communication, a stable and accurate data communication processing operation via the programmable display device 12 can be performed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG.
The PLC 10 enables sequence control of devices of a controlled system provided in the target system 11 such as a belt conveyor type automatic assembling machine.
A description will be given based on an example in which a program type display device 12 is provided as a control panel for C and a computer device 38 is used for controlling the entire system.

In the PLC 10, a circuit is formed for each required function, such as the CPU unit 13 and the memory unit 16, and each unit is appropriately added via a bus line as needed, so that the entire PLC is formed. The configuration is substantially the same as that of the related art, so that the functions to be achieved can be increased or decreased.

In this embodiment, a CPU unit 13 that controls the entire PLC 10, an input unit 14 that enables direct capture of a detection signal sent from the target system 11, Output unit 1 capable of outputting a predetermined control signal
5, a memory unit 16 for storing various data, and a computer link unit 17 for enabling predetermined data communication with the programmable display device 12 as basic units. Then, the CPU unit 13 constantly monitors the change state of the input / output means, and when a data change such as a new data input is recognized, necessary arithmetic processing is performed, and then the corresponding address on the memory unit 16 is accessed. To read / write the contents or send data to the output unit 15.

The storage location of status data which is directly input / output to / from the target system 11 or used for control thereof is controlled by a passive level such as a level gauge or limit switch provided on the target system 11 to be controlled or displayed. Parts, active parts such as relays and motors, or data setting parts such as counters and printers are secured in the memory unit 16 and input / output data is a word device for word data such as numerical values. However, for bit data such as on / off information, a bit device
The storage location is set in the memory unit 16 so that the storage location can be specified by designating a device name or address such as “X001” specific to the model.

Therefore, only by specifying and accessing an arbitrary word device or bit device in the memory unit 16 from inside or outside the PLC 10,
The corresponding position of the target system 11 can be controlled or information on the operation state can be individually extracted.

The PLC 10 receives a command sent from another data processing device, and writes or reads data corresponding to the command to or from the memory unit 16 or returns the sent command or data as it is. In general, it has a general data transmission function. However, it is needless to say that the present invention can be implemented in substantially the same manner even when it has an active data transmission function.

The programmable display device 12 includes a PLC 10
Together with the console of the target system 11 or the like, or is provided independently, and is used as a control panel for the target system 11. For example, the front side of a substantially rectangular main body case In addition, a screen using a liquid crystal display device as a display 18 is arranged, and a touch panel 19 is arranged in close contact with the screen, and a display control circuit 20 is housed inside a main body case.

With this configuration, a display corresponding to the control state of the target system 11 in the PLC 10 is displayed on the screen, and at the same time, data input by a fingertip via the touch panel 19 and the touch panel controller 21 and a display on the target system 11 side via the PLC 10 are performed. Enables indirect control.

It should be noted that, as a data input means of the program type display device 12, instead of or in addition to the touch panel 19, various manual data input means such as a pointing device such as a mouse or a keyboard can be used. .

The basic configuration of the display control circuit 20 is substantially the same as that of a general-purpose personal computer device.
A PU 22, a ROM 23, various memories including a RAM 24, or a graphic controller 25 is connected, and the CPU 22 performs a predetermined arithmetic operation according to a system program stored in the ROM 23, while the RAM 22
The various calculation results appropriately stored in 24 are developed as bit images by the graphic controller 25 using various display data, and the display corresponding to the contents is performed on the screen of the display 18.

Further, a communication controller 26 which can exchange various data with a dedicated protocol specialized for the circuit configuration of the PLC 10 and a computer link unit 17 on the PLC side are connected through a dedicated communication line 27 in a serial state. Have been.

The communication controller 26 is provided with one or a plurality of communication ports so that one PLC 10 can be connected to each communication port, and data communication is performed with each other according to a communication procedure specific to each model. I have.

The programmable display device 12 and the PLC
The dedicated communication line 27 that connects between the 10
The connection target and method are not limited to those connected to the computer link unit 17 on the C side, but may be connected to the bus line in the PLC 10 or the CPU unit 13 in the PLC 10.

Here, in the programmable display device 12, a stationary figure 28 such as a name plate shown in FIG. 3 which does not require a change in display contents, or a part figure 29 such as a switch shape for changing shape, blinking or changing color. Are displayed on the base screen 30 as a unit screen. Further, one programmable display device 12
A plurality of unit screens are provided for the data processing, and a different file number F is designated for each unit screen, so that a display screen displaying necessary operation contents can be obtained simply by switching the unit screens. I have to.

Furthermore, when one unit screen is selected, a processing instruction word W related to the selected unit screen as illustrated in FIG. 4A is stored in the event data memory 31 in advance. In addition, the processing instruction word W is read out intermittently every minute time, and the operation of the content specified by the event name N of each processing instruction word W is performed from the PLC 10 side to the display device 1.
By sequentially executing the data while referring to the data taken out to the second side, the display operation in which the component graphic 29 and the display data change in response to the change in the content of the bit device or the word device of the PLC 10 is performed on the display screen. Will be

That is, the basic structure of the processing instruction word W is substantially the same, and the base screen 3 on which the display control operation is to be performed is performed.
0, a file number F, an event name N for specifying an operation content to be executed on the base screen 30, and reference information r including one or a plurality of data referred to for each execution event.
We have as a set.

For example, the processing instruction word WT shown in FIG.
The bit device that is set at a predetermined address position in the state data memory 32 can be inverted in conjunction with a pressing instruction operation on the touch panel 19. That is, the file number F1 of the unit screen, the touch panel 1
Event name N starting with "T", for example, specifying operation 9
1. An input coordinate range X / Y in which an input operation from the touch panel 19 is valid, and an address A at which data is to be rewritten in conjunction with a pressing operation on the touch panel 19.

Further, the processing instruction word WL shown in FIG.
In conjunction with the operation of the touch panel 19, a predetermined figure can be displayed at a corresponding position on the display screen. That is, the file number F of the base screen 30
1. An event name N2 starting with, for example, "L" for specifying the display of the part graphic 29, a display coordinate range XY of the part graphic 29,
It is composed of a file number FL for specifying the part graphic 29 to be called, and an address A for referring to the part graphic 29 at the time of display.

Therefore, as shown in FIG.
The two processing instruction words WL1 and WT1 having the same address and the reference address A are set in the event data memory 31. The state data memory 3 provided on the PLC 10 side
If the bit device at address A of No. 2 is "0", it is made to correspond to the off state of the switch in advance, and the PLC 10 performs the off operation on the actual switch contact of the target system 11 to be controlled. At the same time, the part graphic 29 corresponding to the switch off state
Is read from the graphic memory 33, and is developed and displayed in the designated coordinate range XY on the corresponding base screen 30.

When the display location of the component figure 29 having the switch shape on the touch panel 19 is pressed, the processing instruction word WT for the touch panel is searched, and the touch panel 19 is searched.
It is determined whether or not there is a processing instruction word WT having a range including the corresponding coordinates as coordinate information from the instruction coordinates made via the.

For example, when one point in the coordinate range XY is pressed, the processing instruction word WT1 constructed as described above is pressed.
Therefore, as shown in FIG. 3B, by writing data to the corresponding address A in the PLC 10 and inverting the data value from “0” to “1”, the PLC 10
Control to turn on the corresponding switch contact. At the same time, the processing instruction word WL1 reads the data at the reference address A and determines that the data has changed to “1”. Then, the graphic data FL2 corresponding to the ON state of the switch
Is read out from the graphic memory 33 and displayed in the corresponding coordinate range XY, the switch-shaped component graphic 29 displayed on the base screen 30 is also changed from the off state to the on state. .

According to the present invention, a hub mechanism is integrally provided in the above-mentioned programmable display device 12, and the programmable display device 12 and the computer device 38 can be connected in series to connect the Ethernet between them. (Registered trademark) through a general-purpose common communication line 34
N connections can be made.

That is, the hub mechanism provided in the programmable display device 12 includes a plurality of (two in this embodiment) transceivers 35 for data input / output, a hub function and a traffic control function. The transceiver 35 is connected to a communication control circuit 36 having the following. Further, each of the transceivers 35 has one data input / output end on the back side of the main body case of the display device, for example, in which a plug provided at the tip of the communication line 37 is detachably fitted.

Then, a plurality of programmable display devices 1
2 are connected in series by a communication line 37, and the remaining transceivers 35 in the programmable display device 12 provided at both ends are connected to a computer device 38.
a and 38b are connected one by one. Finally, a communication line 3 in a wired or wireless state different from the common communication line 34 between the two computer devices 38a and 38b.
By making a one-to-one connection at 9, one or more programmable display devices 12 and two computer devices 38a and 38b form a loop-shaped data transmission path.

The programmable display device 1 having the above-described configuration and further connected via a common communication line 34
2 and the computer device 38 can exchange various data with each other by using a general-purpose common communication protocol, which will be described in detail later.

On the other hand, even when the data communication protocol is dedicated to each PLC and is different from one PLC to another, even if the PLC 10 and the computer 3
Various data such as state data MD corresponding to the control state in the PLC 10 can be exchanged between the program display devices 12 through the programmable display device 12.

For example, as shown in FIG. 5, a computer 38 performs predetermined data processing and displays the processing result on a screen, while data to be transmitted is transmitted via a common communication line 34 using a common protocol. Sent out.

The PLC 10 performs input / output operations of various signals with the controlled system device 40 in the target system 11 according to a preset program, and stores data having contents corresponding to the control state in the memory unit 16 as shown in FIG. The address is specified and stored in the state data memory 32 set in (1).

The updated state data MD is stored in the display device 1.
In response to a data read request from the two sides, the data is sent from the PLC 10 to the display device 12 via the PLC dedicated communication line 27 using a dedicated protocol specific to the model. Also, in response to a data write request from the display device 12, a dedicated communication line 2 using a dedicated protocol.
When data for changing the state data MD in the PLC 10 is input through the CPU 7, a control operation for the controlled system device 40 corresponding to the data change is performed.

Here, the TCP / TCP is connected between the programmable display device 12 connected via the common communication line 34 and all the data processing devices including the computer device 38.
Data is transferred in a common data transfer format using a general-purpose communication protocol such as IP.

For example, the programmable display device 12 and the PL
Information is exchanged with C10 using data created based on a dedicated data transfer format defined by a model-specific communication protocol.

The common data transfer format is shown in FIG.
As illustrated in (a), a process ID to be processed in the programmable display device 12, an address specifying a data source, an address specifying a data destination, and data specified by the process ID described above. And first data for defining processing details in detail. Note that this is an example, and the format can be arbitrarily set as long as it can be used in common.

In this embodiment, the computer 3
8, the data processing contents requested from the programmable display device 12 include data access to the internal memory, screen processing operation in the display device 12, and the PLC 1.
Data communication for 0 is assumed. Therefore, a correspondence table is provided for specific processing contents and an ID code for uniquely specifying the contents, and a specific ID according to the correspondence table is provided.
The designation is performed, and the device to which the data is to be transferred is specified by the source and destination addresses.

For each data sent using the common protocol and the common data format described above, each PL
The communication protocol defined by the C10 maker generally specifies not only the command system, but also the data contents included in the data transfer format and the transfer information, or the order in which the data is arranged in a different order, and the use thereof is generally forced. is there.

Therefore, in a data transfer format defined by each dedicated communication protocol, a skeleton state format in which a data portion to be actually transferred is undetermined is extracted and held as format information.

Further, a conversion table is formed in which an intermediate code used in the above-mentioned common communication protocol and a command unique to each model are formed as a pair. By providing on the internal memory in the display device 12, only by switching the model-dependent protocol information and applying specific data to it, the connected PLC
Data communication can be performed by a protocol that depends on ten models.

At the time of initial setting of the programmable display device 12 or when the connected PLC 10 is changed, communication protocol information corresponding to the PLC 10 which may be connected to itself is stored in the computer device 38, for example. Selected from the protocol database
The data is downloaded onto the memory of each programmable display device 12 via a common communication line 34 using a common communication protocol.

The present invention is constructed as described above, and further comprises one computer device 38a as a main and the other computer device 38b as a sub. In a normal state, the main computer device 38a comprises the entire system. Control and data management. Further, when there is a change in the management data in either the main computer device 38a or the sub-computer device 38b, the change is transmitted to the other through the communication line 39, and the data contents of the two are not delayed without a time delay. It is configured to match.

Here, not only when the main computer device 38a goes down, but also when data communication with the main computer device 38a becomes impossible due to disconnection of a part of the common communication line 34 or the like. In addition to this, even when the traffic in the main computer device 38a becomes large, the sub computer device 38b operates instead of or in addition to the main computer device 38a to distribute the traffic.

Further, in each of the programmable display devices 12, when a data communication request with the PLC 10 via the dedicated communication line 27 and a data communication request with the computer device 38 via the common communication line 34 conflict, It exerts a traffic control function of adjusting the data communication amount and data communication time of both. Normally, data communication between the PLCs 10 should be given the highest priority.
Control for limiting the amount of data communication toward 4 is performed, but the priority order is not limited, and it goes without saying that conditions can be set in detail and a traffic control operation based on the conditions can be performed. .

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically showing a basic configuration of the present invention.

FIG. 2 is a block diagram illustrating an electrical configuration of a PLC and a programmable display device.

FIG. 3 is an explanatory diagram illustrating an example of a control operation using a processing instruction word.

FIG. 4 is an explanatory diagram showing a configuration of a processing instruction word.

FIG. 5 is an explanatory diagram showing a data transmission procedure via a display device.

FIG. 6 is an explanatory diagram showing an example of a data transfer format used in a common communication protocol.

[Explanation of symbols]

 Reference Signs List 10 PLC 11 Target system 12 Program display device 16 Memory unit 17 Computer link unit 18 Display 19 Touch panel 20 Display control circuit 24 RAM 26 Communication controller 27 Dedicated communication line 31 Event data memory 32 State data memory 33 Graphics memory 34 Common communication line 35 Transceiver 36 Communication control circuit 37 Communication line 38 Computer device 39 Communication line

Claims (5)

[Claims] 1. A programmable display device which is connectable to a PLC via a dedicated communication line while being connectable to a computer device or a computer application device via a common communication line. A programmable display device comprising: a switching hub function of enabling connection to a plurality of devices via a communication line; and a traffic control function on the common communication line. 2. The traffic control function according to claim 1, further comprising: determining a priority of data when the dedicated communication line and a common communication line are requested to transmit data at the same time; 2. The programmable display device according to claim 1, further comprising a function of controlling a transmission amount. 3. The programmable display device according to claim 1, wherein a PLC is connected to said dedicated communication line, wherein said programmable display device is connected in series through said common communication line, and said common connection device is connected in series. One computer device is connected to each of the two ends of the communication line, and the two computer devices are connected by a communication line, and control is performed to match the data of the two via the communication line. Data communication system. 4. The above-mentioned one computer device is a main computer device capable of controlling the entire system, and the other computer device is a sub-computer device having a function as a backup of the main computer device. The data communication system according to claim 3. 5. The program display device normally performs a data communication operation with the main computer device. If a trouble in data communication with the main computer device is detected, the program display device determines a destination of the data communication. 5. The data communication system according to claim 4, wherein the data communication system can be switched to the sub-computer device.