JPH05281938A - Man-machine interface device and its display screen updating method - Google Patents

Abstract

PURPOSE:To prevent the operability of interactive processing from being spoiled by selectively outputting an optional screen on an optional display device at a high speed. CONSTITUTION:A man-machine interface consists of a display controller 30 which generates data for screen display with data from a computer for device control, a display device which displays a screen with data for screen display, and an external input device, the display controller 30 is provided with plural memories 308 for display screens which stores the generated display data and plural frame memories 309 for the display device, and a display data bus 313 is provided between them. Then, data transfer from the optional display screen memory to the optional frame memory can be performed with a command from an external input device. Consequently, the display data as much as necessary screens are transmitted from the computer for control to the display controller in advance and then the display screens can freely be selected in a short time corresponding to the external input device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a man-machine interface device connected to a control computer such as a plant and capable of selecting and displaying an arbitrary screen on its display device, and further updating the display screen at high speed. The present invention relates to a method for updating a display screen of a man-machine interface device that makes it possible.

[0002]

2. Description of the Related Art Conventional man-machine interface devices generally connect one display device to one display control device and display a screen on the display device. Then, for example, in a configuration including two display control devices and two display devices connected to each, when it is desired to switch the screens from each other, the display data is sent to the display control device again from the host control computer. However, the screen was switched by redrawing. Therefore, with such a conventional configuration, it is difficult to switch screens at high speed.

Further, in the conventional man-machine interface device, when it is desired to switch screens at high speed, video signals from a plurality of display control devices are input to a multiplexer for obtaining one output from a plurality of inputs. The output is input to one display device, but in this case, the horizontal and vertical simultaneous signals are interrupted when the screen is switched, so that the screen displayed on the display device is disturbed. There was a problem. Also, with this configuration,
Distributors for distributing video signals and multiplexers for each display device must be prepared for each display control installation, and a large number of cables must be connected, which causes a problem of high cost. ..

Further, as described in, for example, Japanese Patent Application Laid-Open No. 1-276196, a single display control device displays a plurality of types of screens on a plurality of display devices and a display device predesignated by application software. Although there are examples in which output is displayed respectively, however, the device according to the conventional technique is not one in which an operator who views the display screen can freely select a desired screen. That is, also in this conventional device, when switching or updating the screen on the display device, all the data of the screen to be displayed is newly transmitted from the host control computer, and the drawing data is displayed in the display control device. However, it was difficult to switch or update the display screen at high speed, and it was impossible to display the monitoring data of the plant in real time. Furthermore, in this conventional technique, which is important as a man-machine interface device,
That is, no consideration is given to the correspondence between the display screen and the input device, and even if the display screen is arbitrarily selected,
It is pointed out that the input device corresponding to the selected screen cannot be determined.

Further, according to Japanese Patent Application Laid-Open No. 2-157909, in order to provide an operation device excellent in responsiveness of operation of a plant, a table having a predetermined order of importance is provided, and a plant state at that time is provided. Alternatively, it is known that a calculation is performed by selecting a keyboard to preferentially display a highly important display screen. According to such a conventional driving device, the operator can display the screen required for monitoring.
The images can be viewed simultaneously on one CRT device, and the size of the display screen can be freely changed as needed, so that quick operation corresponding to the control state of the plant is possible. However, although this prior art is provided with a plurality of frame memories, the information of the split screens stored in these frame memories is automatically selected according to its importance and is displayed preferentially. It does not allow screen selection by operator operation. That is,
The operator did not arbitrarily select the display screen required and switch or update the display screen at high speed.

In addition, according to Japanese Patent Laid-Open No. 63-267993, the memory for accumulating the data to be displayed on the CRT can be effectively controlled by one CRT so that the storage means can be selectively operated. Storage means for controlling
2. Description of the Related Art There is known a display control method including a display selection unit that selectively outputs display data to an image display device. According to this conventional technique, the display data stored in a plurality of arbitrary frame memories can be displayed on a desired CRT, and the output destination of the display data output from the plurality of frame memories can be switched. Although the means is disclosed, however, the structure does not mean that the display screen is switched or updated at high speed.

[0007]

That is, the conventional man-machine interface device described above has the following problems. (1) The display screen required by the operator cannot be freely selected in a short time. (2) When updating the screen, even if it is a partial update, the display data of the entire screen is transmitted from the host control computer and the screen is regenerated, so the updated screen cannot be displayed in a short time. .. (3) The display screen is intended only for switching the display screen, and the input device at the operator's hand is not associated with the display screen. This considers the operability as a man-machine interface device. Not not.

Therefore, the present invention has been made in view of the above problems in the prior art, and it is an object of the present invention to provide a man-machine interface device and a display screen updating method therefor capable of achieving the following objects. It is intended. (1) A plurality of display screen memories and a plurality of frame memories can be mutually switched by an external screen switching command, and the display screen required by the operator can be freely selected in a short time. (2) When updating the screen, it is not necessary to transmit all the data of the screen to be updated from the host computer, and the screen can be updated in a short time. (3) Based on a screen switching command from the outside, the display screen is switched and the input device and the display screen are associated with each other.
Enable screen operation from the input device at the operator's hand.

[0009]

According to the present invention, the following technical means are adopted in order to achieve the above object. (1) A plurality of display screen memories and a plurality of frame memories are provided, and between these display screen memories and frame memories,
Combined with a dedicated bus interface, the display screen selection control unit enables any display screen to be selected and output on any display screen. (2) Which display screen memory the data from the external input device corresponds to, and to which frame memory the microprocessor that manages the correspondence between the plurality of display screen memories and the plurality of frame memories. Then, the data from the external input device is output to the display device viewed by the operator who is performing the input operation. (3) The display screen is divided into the fixed screen data for displaying the fixed screen and the changing screen data for displaying the changing screen. Only the changing screen is drawn when the screen is updated, and the fixed screen is stored in the display screen memory. It is displayed by combining with the data.

[0010]

The display screens used in the control system of a plant or the like can be divided into groups according to their uses. Therefore, according to the man-machine interface device of the present invention, a display screen memory is prepared in advance for each screen that can be grouped. From the upper-level control computer, data is sequentially transmitted to the display screen memory group divided into groups, and the display data is stored, while the operator displays the required screen from the display screen memory group. It can be selected and output to the display device.

According to the man-machine interface device of the present invention, the display screen is stored in the display screen memory so that the screen data required by the operator can be received in response to the screen switching request from the operator. Is transferred from the display screen memory to the corresponding frame memory for the display device via a dedicated bus interface, whereby the screen is switched. The drawing processing to the display screen memory is performed by the drawing processor by performing the data transfer from the display screen memory to the frame memory and the display screen selection control unit by reading the data from the frame memory in a distributed manner. , Reduce load on both sides and improve processing efficiency. As a result, drawing processing to the display screen memory can be performed without being affected by data reading processing from the frame memory, and data transfer from the display screen memory to the frame memory can be performed by using a dedicated bus interface. It enables high-speed data transfer between memories. However, this data transfer does not necessarily have to be performed regularly, and is executed when the contents of the display screen memory are updated or when a screen switching instruction is issued, reducing the load on the dedicated bus interface. You can do it.

Further, since the microprocessor manages the switching state of the screen and the external input device and the display screen are always associated with each other, the data from the external input device is processed by the drawing processor and the corresponding display screen is displayed. Since the data is stored in the memory and then transferred to the frame memory, the input data from the external input device is always displayed on the corresponding display device.

Further, when the display screen is updated, by rewriting only the changing screen data without rewriting the fixed screen data stored in the display screen memory,
It is possible to increase the processing speed in updating the display screen.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. First, FIG. 2 is a block diagram showing an overall system configuration of a monitoring / control system for a plant, for example, to which the man-machine interface device of the present invention is applied. In this figure, a higher-order control computer 1 is a computer. It is connected to the input / output device 2 via the network 6. The man-machine interface device 3 is also connected to the host computer 1 for control via the computer network 6.

This man-machine interface device 3
Has a display control device 30, a display device 40, an external input device 50, and
It is composed of a screen switching selection switch 70. Note that FIG.
, A plurality of display devices (for example, CRT) 40,
The external input device 50 and the screen selection switch 70 are shown by adding a serial number following a dash (-) after each symbol. In this embodiment, for example, four display devices 4 are provided for one display control device 30.
0-1, 40-2, 40-3, 40-4, external input devices 50-1, 50-2, 50-3, 50-4, and screen switching selection switches 70-1, 70-2, 70. -3, 70
-4 is shown, however, the present invention is not limited to this, and it is also possible to configure by connecting one or a plurality of things, for example. Further, the man-machine interface device 3 is not limited to one for one system or network as shown in FIG. 2 described above, but a plurality of man-machine interface devices 3 can be provided.

In the configuration of the man-machine interface device 3 described above, the display control device 30 sends and receives data to and from the host control computer 1 via the computer network 6 to transfer data from the control computer 1. Screen data is generated based on the above, and this is displayed on the display screen of the display device 40. Further, when the display control device 30 receives the input data from the external input device 50, the display control device 30 outputs a display screen corresponding to the received input data, for example, a picture or a character, to the display device 40, and if necessary. ,
Data is transmitted to the host computer 1 for control.

Next, FIG. 1 shows the display control device 3 described above.
The detailed circuit configuration of is shown. This display control device 30
In the block diagram showing one embodiment, the system bus 305 includes a microprocessor 301, a computer network interface 302, an external input device interface 303, a screen changeover selection switch interface 304, a screen processor 306, and a display screen selection. The control unit 307 is connected. This system bus 3
Reference numeral 05 denotes an address bus, a data bus, status signals and control signals for the above-mentioned respective parts, and further, the drawing microprocessor 3
06 interrupt signal to the microprocessor 30
It is used for inputting / outputting data between 1 and each of the above parts.

The microprocessor 301 has a plurality (three in this embodiment) of display screen memories 308-1, 3 for storing screen data whose display is predicted in advance.
08-2, 308-3 and the above four display devices 40-
1, 40-2, 40-3, 40-4 and one-to-one correspondence with the frame memories 309-1, 309-2 (however, in FIG. 1, for simplification of description, among the four frame memories, (Only two of which are shown) are managed. That is, the microprocessor 301 receives a processing request interrupt signal from the computer network interface 302, the external input device interface 303, and the screen changeover selection switch interface 304, and inputs data from the host control computer 1. , Its input data is the display screen memory 30
8-1, 308-2, 308-3 to which memory, and the frame memories 309-1, 309-.
2) to which frame memory the data should be transferred, and based on the input data, a drawing instruction is given to the screen processor 306, and the display screen selection control unit 3
A display data transfer instruction is sent to 07, so that input / output of data in the display control device 3 is efficiently controlled.

Further, in FIG. 1, the display screen selection control unit 307 is provided with display screen memories 308-1, 308-2, 3 and 3.
08-3 is connected via a drawing data bus 311 and a display screen memory address bus 312. Further, to the frame memories 309-1 and 309-2, a display data bus 313 and a frame memory are used. It is connected via an address bus 314. The display screen memories 308-1, 308-2, and 308-3 are connected to the frame memory 309-1 via the display data bus 313.
309-2 is connected. Further, the frame memories 309-1 and 309-2 are connected to the D / A converters 310-1 and 310-2, respectively, and the outputs thereof are connected to the display devices 40-1 and 40-2, respectively. ..

Next, the operation of the display control device 30 of the man-machine interface device 3 in the present embodiment having the above-described configuration will be described in detail below with reference to the flow chart of FIG. First, the processing is started by the initial setting interruption, and the display screen memories 308-1, 308-
2, 308-3 and frame memories 309-1 and 309
A correspondence table that defines the correspondence relationship with -2 is created (step S10).

Subsequently, the display control device 30 selects the display data of the screen predicted to be displayed in advance from the display data transmitted from the host control computer 1 to the computer network 6 by the computer network interface 302. The data is received by the microprocessor 301 via (step S20). This microprocessor 3
01 instructs the drawing processor 306 to create so-called drawing data based on the received display data. Upon receiving this instruction, the drawing processor 306 generates a drawing address and a timing signal, controls the display screen memory address bus 312 and the drawing data bus 311, and draws drawing data in the display screen memory 308 (step S30). .. At this time, the microprocessor 301
Is a predetermined display screen memory 308 every time the drawing process on one display screen memory 308 is completed.
In accordance with the correspondence between the display screen memory 308 and the frame memory 309, the display screen selection control unit 30 transfers the data from the display screen memory 308 whose drawing has been completed to the frame memory 309.
Instruct to 7. After that, the display screen selection control unit 307 that receives this instruction controls the display screen address bus 312, the frame memory address bus 314, and the timing signal, and the display screen memory 308 changes the frame memory from the display screen memory 308 via the display data bus 313. Data is transferred to 309 (step S40).

Further, it is judged whether or not this data transfer is completed for all the display screen memories 308-1, 308-2, 308-3 (step S50), and as a result, it is completed for all, that is, " If it is determined to be “yes”, the above processing is ended. On the other hand, if it is determined to be "no" because it has not been completed yet, the process returns to step S20, and then step S20.
30 and S40 for all display screen memories 308-
It will be repeated until 1, 308-2, 308-3 are completed.

FIG. 5 attached herewith shows the display data of the screen predicted to be displayed in advance, as described above.
08-1, 308-2, 308-3 are drawn, and operation waveforms for sequentially transferring data to the corresponding frame memories 309-1, 309-2 are shown. That is, as shown in the figure, in the present embodiment, the operation in which the display data stored in the display screen memory 308-1 is transferred to the frame memory 309-1 is shown.

Further, the display screen selection control unit 307 periodically reads out the data stored in the frame memory 309 and causes the D / A converter 310 to output the data. This D / A
The converter 310 converts the display data periodically read from the frame memory 309 into a video analog signal and outputs it to the display device 4.

After the data transfer to all the frame memories 309-1 and 309-2 is completed by the above-described processing, when a drawing request is made, for example, the display data is sent from the control computer 1 to the computer network. When 302 receives and sends an interrupt signal to the microprocessor 301, and when the external input device interface 303 receives display data from the external input device 50 and sends an interrupt signal to the microprocessor 301. , The screen is updated based on the input data. This screen update is
The microprocessor 301 determines which display screen memory 308 and frame memory 309 the input data corresponds to, instructs the drawing processor 306 to create drawing data for screen update, and receives the instruction. Generates a drawing address and a timing signal, controls the display screen memory address bus 312 and the drawing data bus 311, and draws the updated drawing data in the display screen memory 308. The updated data in the display screen memory 308 is transferred to the corresponding frame memory 309 according to the above-described processing.

At this time, as shown in FIG. 6, the processing started based on the drawing request is performed after it is confirmed that the display screen memory 308 to be drawn is not being accessed (step S60). And write drawing data in the display screen memory (step S70).
After that, the display data bus 313 is further "Busy".
After confirming that it is not in the state (step S80), the data is transferred from the display screen memory 308 to the frame memory 309 (step S90).

FIG. 7 is a time chart showing operation waveforms for drawing display data in the display screen memory 308-1 and transferring the data to the frame memory 309-1.

Further, FIG. 8 shows a display screen memory 308-1.
In the state corresponding to the frame memory 309-1 from the display screen memory 308-1 to the frame memory 3
09-2 is a time chart when a drawing request is generated in the display screen memory 308-1 during the switching operation, and shows that the drawing operation is started after the switching operation is completed. Further, when the microprocessor 301 determines that the processing of the control computer 1 is necessary, the input data from the external input device 50 is transmitted by the microprocessor 301 to the control computer 1 via the computer network 6.

Next, the screen switching request operation will be described. The screen switching selection switch interface 304
Receives a signal from the screen switching selection switch 70 prepared for each display device 40 and sends an interrupt signal (that is, a screen switching request) to the microprocessor 301, the microprocessor 301 sends the interrupt signal. Upon receiving the signal, the display screen selection control unit 307 is instructed to transfer the data from the selected display screen memory 308 to the frame memory 309 for the display device 40 corresponding to the screen changeover switch. On the other hand, the display screen selection control unit 307 that receives this command controls the display screen address bus 312, the frame memory address bus 314, and the timing signal, and the microprocessor 301 specifies them via the display data bus 313. Data is transferred between the display screen memory 308 and the frame memory 309, and the display screen is switched. When this data transfer is completed, the display screen selection control unit 307 causes the microprocessor 301 to
Upon receiving the data transfer end report signal, the microprocessor 301 receives the signal and rewrites the contents of the management table for managing the correspondence between the display screen memory 308 and the frame memory 309 to the new correspondence after the screen switching.

The flowchart at this time is shown in FIG. 9, and the processing started based on the screen switching request confirms that the display screen memory 308 which is the transfer source is not being accessed (step S100), and further displays. Data bus 3
Confirm that 13 is not in the "Busy" state (step S
110), the data is read from the display screen memory 308 that is the transfer source, and the frame memory 30 that is the transfer destination is read.
The data is transferred to 9 (step S120). afterwards,
The contents of the management table that manages the correspondence between the display screen memory 308 and the frame memory 309 are rewritten (step S130) as described above.

FIG. 10 shows that the display screen memory 308-1 corresponds to the frame memory 309-1.
Display screen memory 308-1 to frame memory 309-
6 is a time chart showing operation waveforms when switching to 2.

Further, FIG. 11 shows a display screen memory 308-
1 corresponds to the frame memory 309-1, a time indicating an operation waveform when a switching request is generated from the display screen memory 308-1 to the frame memory 309-2 during drawing on the display screen memory 308-1. It is a chart showing that the switching operation is started after the drawing operation is completed.

That is, according to the above embodiment of the present invention, a plurality of display screen memories 308 and a plurality of frame memories 309 are provided, and a dedicated bus interface (display data bus 313) is provided between the display screen memories 308 and 309. ) And transfer data at high speed, it is possible to freely display any display screen required by the operator in a short time. Further, by associating the plurality of display screen memories 308 with the plurality of frame memories 309 by the dedicated microprocessor 301 at all times, which display screen memory 308 the data from the external input device 50 corresponds to. Further, it is possible to determine in a short time which frame memory 309 the frame memory 309 is transferred to, and the display device 50 viewed by the operator who is performing the input operation.
Allows for immediate output display on top.

In general, the display screens used in the control system can be grouped according to their uses. Therefore, as for the display screen memory 308, a required number of display screen memories are prepared in advance for each screen that can be grouped. As a result, in the above-described embodiment, the data transmitted from the host control computer 1 is sequentially subjected to drawing processing and stored as display data in the plurality of display screen memories 308 divided into these groups. On the other hand, the operator can select a required screen from these display screen memory groups and output and display it on the display device 40.

Further, referring to FIG. 12, a display screen updating method applied in the man-machine interface device 3 according to the present invention will be described. This figure shows an example of a graphic screen used for monitoring and controlling the plant, for example, and a fixed screen A showing the form of the plant and a change screen B showing the changing part are combined and displayed. A display screen C output to the device 40 is configured.

Therefore, if the display data for the fixed screen A is stored in the display screen memory 308 in advance, the display data for the fixed screen A is again displayed when the display of the display screen C is updated. It is not necessary to draw on the screen, and only the update data of the changed screen need be drawn. That is, the display screen memory 308 in this embodiment can store the display data in a form in which the fixed screen A and the change screen B are combined, so that the frame memory 309 can be stored.
By adopting the same data storage form as above, the data of the fixed screen A stored in the display screen memory 308 can be transferred without being processed and can be transferred to the frame memory 309 at high speed, and the data transfer speed can be further increased. It is possible to transform.

[0037]

As is apparent from the above detailed description,
According to the man-machine interface device and the display screen updating method thereof of the present invention, display data for a required screen is stored in advance in a plurality of display screen memories, and an arbitrary frame is displayed from any display screen memory by the data transfer means. By transferring data to the memory, it becomes possible for an operator to freely select an arbitrary screen and output it on an arbitrary display device in a short time. In addition, data transfer is performed via a dedicated bus interface, and the drawing process and data transfer process are distributed respectively to improve processing efficiency, and when the display screen is updated, all It is possible to execute the screen in a short time without regenerating the screen.

Further, by always associating the display screen with the external input device corresponding thereto, the display screen can be freely and arbitrarily switched without impairing the operability of interactive data input / output.

[Brief description of drawings]

FIG. 1 is a block diagram showing a detailed circuit configuration of a display control device which is a characteristic part of a man-machine interface device of the present invention.

FIG. 2 is a block diagram showing an overall schematic configuration of a plant monitoring / control system to which the man-machine interface device of the present invention is applied.

FIG. 3 is a diagram showing an example of an external configuration of a man-machine interface device of the present invention.

FIG. 4 is a flowchart illustrating a data processing operation in the man-machine interface device.

FIG. 5 is a time chart showing operation waveforms in the man-machine interface device.

FIG. 6 is a flowchart illustrating another processing operation in the man-machine interface device.

7 is a time chart showing operation waveforms in the man-machine interface device in relation to FIG.

FIG. 8 is a time chart showing operation waveforms when a drawing request is made in the man-machine interface device.

FIG. 9 is a flowchart illustrating an operation when a screen switching request is made in the man-machine interface device.

FIG. 10 is a time chart showing operation waveforms in the man-machine interface device when the screen switching is requested.

FIG. 11 is a time chart showing operation waveforms in the man-machine interface device when a switching request is made.

FIG. 12 is a diagram illustrating a display screen updating method of the man-machine interface device of the present invention.

[Explanation of symbols]

 1 control computer 2 input / output device 3 man-machine interface device 6 computer network 30 display control device 40 display device 50 external input device 70 screen switching selection switch 301 microprocessor 302 computer network interface 303 external input device interface 304 screen switching selection switch Interface 305 system bus 306 drawing processor 307 display screen selection control unit 308-1 to 3 display screen memory 309-1 to 2 frame memory 310-1 to 2 D / A converter 311 drawing data bus 312 display screen memory address bus 313 Display data bus 314 Frame memory address bus

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kyora Kato 52-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Process Computer Engineering Co., Ltd. 2-2-1 Niitsu Process Computer Engineering Co., Ltd. (72) Inventor Kazuyuki Takano 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitec Process Computer Engineering Co., Ltd. (72) Inventor Takayuki Morioka Ibaraki Prefecture 5-2-1 Omika-cho, Hitachi City, Ltd. Omika Factory, Hitachi Ltd.

Claims (10)

[Claims] 1. A display control device that creates screen display data based on transfer data from a host control computer, a display device that outputs and displays a screen based on the screen display data, and a screen that is output and displayed. In a man-machine interface device consisting of an external input device for inputting commands, data, etc. in response to: a display control device having a plurality of display screens for storing screen display data created by the display control device. Memory and a plurality of display device frame memories, the external input device is provided with a screen changeover selection switch, and the display control device is further instructed by the screen changeover selection switch. , From one selected memory of the plurality of display screen memories to one selected memory of the plurality of display device frame memories. A man-machine interface characterized by comprising means for performing data transfer, and by freely transferring a desired screen by transferring data from an arbitrary display screen memory to an arbitrary frame memory. apparatus. 2. The man-machine interface device according to claim 1, wherein a dedicated bus interface for enabling high-speed data transfer between the plurality of display screen memories and the display device frame memory. A man-machine interface device characterized by being provided with. 3. The man-machine interface device according to claim 1, wherein data is periodically transferred from the plurality of display screen memories to the plurality of display device frame memories in a predetermined order. ,
Therefore, the display device is a man-machine interface device in which the screen is periodically updated. 4. The man-machine interface device according to claim 1, wherein when the data in the display screen memory is updated, the updated part of the data is transferred to the display device frame memory. Man-machine interface device. 5. The man-machine interface device according to claim 1, further comprising a management table for managing the association between the plurality of display screen memories and the plurality of display device frame memories. Man-machine interface equipment. 6. The man-machine interface device according to claim 1, wherein a processor for managing the association between the plurality of display screen memories and the plurality of display device frame memories, and the plurality of display screens A man-machine interface device comprising: a memory and a processor for controlling data transfer between the plurality of display device frame memories. 7. The man-machine interface device according to claim 1, wherein the corresponding screen display in the display screen memory is displayed based on the data input from the external input device corresponding to the selected display screen memory. The input data from the external input device while changing the input data from the external input device by changing the input data on the display device, and transmitting the input data from the external input device to a host control computer to which the man-machine interface device is connected. Man-machine interface device. 8. A display control device for creating screen display data based on transfer data from a host control computer, a display device for outputting and displaying the screen based on the screen display data, and the output and displayed screen. And an external input device for inputting commands, data, etc. in response to: a plurality of display screen memories for storing screen display data created by the display control device; A frame memory for a display device, the external input device is provided with a screen switching selection switch, and the display control device is further configured to display the plurality of displays according to a command from the screen switching selection switch. A man provided with means for transferring data from a selected one of the screen memories to a selected one of the plurality of display device frame memories. In the machine interface device, when the data in the display screen memory is updated,
A method for updating a display screen of a man-machine interface device, characterized in that the updated part of the data is transferred to the corresponding frame memory for the display device. 9. A display control device for creating screen display data based on transfer data from a host control computer, a display device for outputting and displaying a screen based on the screen display data, and the output and displayed screen. And an external input device for inputting commands, data, etc. in response to: a plurality of display screen memories for storing screen display data created by the display control device; A frame memory for a display device, the external input device is provided with a screen switching selection switch, and the display control device is further configured to display the plurality of displays according to a command from the screen switching selection switch. A man provided with means for transferring data from a selected one of the screen memories to a selected one of the plurality of display device frame memories. In a machine interface device, data to be displayed on the display device is separated into fixed screen data and change screen data, and these are combined and output as display screen data. Display screen update method. 10. The display screen updating method for a man-machine interface device according to claim 9, wherein only the change screen data is changed when the screen is updated.