JP2000242315A - Setting display unit, programmable controller, programmable controller system and device with display part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lighten the burden on a screen designer of the setting display unit and to evade parameter misalteration by an operator by eliminating the need of screen generation on a setting display unit side. SOLUTION: The programmable controller system is equipped with the programmable controller 12 where the I/O comment for the maintenance of a program is written to a memory in combination by a support tool and the setting display unit 10 equipped with a display part 13 which is connected to the programmable controller 12 and sets data regarding a control state and an operation state in association with its control contents; and the setting display unit 10 inputs the character string of the I/O command from the programmable controller 12 and displays it at the display part 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a setting display, a programmable controller, a programmable controller system, and a device with a display unit.

[0002]

2. Description of the Related Art A setting display is also abbreviated as a programmable terminal or PT, and communicates with a programmable controller (PLC) to connect to a machine.
It displays the operating status of the device, work instructions to the site, and other information.

A conventional programmable controller system using such a setting display and a programmable controller will be described below with reference to FIG. 1
Is a screen creation support tool, 2 is a setting display, 3 is an upper link I / F unit, 4 is a PLC, and 5 is a PLC support tool.

The screen creation support tool 1 is composed of a personal computer, a floppy disk provided with software, or the like, and is used by a screen creation designer to create a screen displayed on the setting display 2. .

The setting display 2 functions as an operation panel for monitoring the operation of a line controlled by the PLC 4, for instructing a site worker on the line, and as a control panel for machinery and equipment arranged in the line. For example, a screen created by using the screen creation support tool 1 is a screen for monitoring the operation status of a line, a screen for instructing an FA site worker, A screen as an operation panel such as touch keys or numeric keys can be displayed.

The upper link I / F unit 3 mediates between the setting display 2 and the PLC 4 to display status data of a line controlled by the PLC 4 or setting status data on the setting display 2. PLC
4, and transmits the contents of the touch switches and numerical values input to the setting display 2 to the setting display 2 by the PLC 4.
To the setting display 2 and the PLC.
And a unit for communication with the setting display 2
Attached to.

The PLC 4 includes a plurality of input contacts to which input devices such as sensors are connected, an input circuit for processing a signal output from the input device via each input contact, and a CPU.
An internal circuit section mainly constituted by a microprocessor section including an output circuit section for processing and outputting a signal from the internal circuit section, an output device such as a relay is connected and outputting a signal from the output circuit section to them. It is configured to have a plurality of output contacts for outputting to devices.

The PLC support tool 5 is constituted by a personal computer, and is for creating, adding, and changing a program of the PLC 4. The data of this program is transmitted from the PLC support tool 5 to the PLC 4 and stored in a memory in the PLC 4.

[0009]

In the setting display device described above, it is necessary to create each of the above-mentioned screens using a screen creation support tool.
It is necessary to input character strings and numerical values, and to set display contents such as lamps and touch switches. Therefore, it is required that the creator of such a screen is considerably proficient in operating a personal computer as a screen creation support tool. You can hardly do. Further, even if the user is familiar with the operation of a personal computer, considerable effort and time are required until screen creation. In this case, since the PLC program is created by a completely different support tool from the screen creation support tool, it is necessary to learn the knowledge of the setting display, the knowledge of the PLC, and the operation method of both support tools. This makes it difficult to create a screen for the setting display.

Therefore, in the present invention, by utilizing the character string of the I / O comment written in the memory of the control device such as a programmable controller, the screen on the setting display side can be displayed by using the support tool as in the prior art. It is an object of the present invention to eliminate the necessity of creating the setting display and to make the setting display screen or reduce the burden on the designer.

Another object of the present invention is to prevent the operator of the setting display from changing parameters such as numerical values with respect to the control state without fail.

[0012]

According to the present invention, it is possible to connect to a control device for controlling an apparatus, a machine, etc., and to set data relating to the control contents to the control device, A setting display having a display unit for displaying data, a first display unit for displaying a control state of the control device, a second display unit for displaying an operation state of the control device, and the first display And an operation key for data displayed on the control unit, and directly or indirectly inputs an I / O comment written in a memory of the control device from the control device, and
The above-described problem is solved by configuring at least a part of the character string included in the comment to be displayed on the display unit.

[0013]

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

Referring to FIG. 1, a PLC system according to the present embodiment will be described. In this case, the illustration of the PLC support tool is omitted in FIG. Reference numeral 10 denotes a setting display as an example of a device with a display unit, 11 denotes an upper link I / F unit, and 12 denotes a PLC. The setting display 10 and the PLC 12 are connected by wire or wirelessly. The setting display 10 shown in FIG. 1 includes a display unit 13 and a touch key 14 as an example of an operation unit on a front panel.
And The display unit 13 further includes a control state display unit 13a as an example of a first display unit that displays a control state by the PLC 12 that is a control device, and a PLC that is a control device.
An operation state display unit 13b is provided as an example of the second display unit that displays the operation state by the operation unit 12. Control status display 1
3a displays “current temperature 120 ° C.” and “set temperature 130 ° C.” as an example of a display, and the operating state display section 13b shows that the system is “in normal operation” as an example of displaying the operating state. It is displayed that there is.
Here, “130” at the set temperature can also be called a parameter. The touch keys 14 include a power operation key 14a, a mode key 14b for switching a display mode of the display unit 13, and a setting displayed in the mode, as operation units for data displayed on the control state display unit 13a. An up key 14c for increasing data such as a value and a down key 14d for decreasing data are displayed. The mode key 14b can be switched to a desired display content by, for example, every single operation or a plurality of operations, an operation that is continued for a predetermined time, or according to a specific operation procedure. In this case, the numerical value of the current temperature is PL
Updated with numerical data from C side. The display of "normal operation" on the control state display section 13b is switched to the display of "stop" when the system is abnormal. P
One or more input devices 15 and one or more output devices 16 are connected to the LC 12.

Referring to FIG. 2, setting display 10 and PLC 1
2 will be described. Upper link I / F
The unit 11 is for communication and is not shown. Depending on the communication method, this unit 11 is not necessarily required. The setting display 10 is a setting display 10
CPU 17 for controlling the entire operation, memory 18 having at least the area shown in FIG. 3, at least PLC 1
1, a communication unit 19 for communicating with the display unit 2, a display unit 13 in FIG.
Touch keys 14 are provided. The PLC 12 includes a memory 20 having at least the area shown in FIG. 3, a communication unit 21 that performs communication with at least the setting display 10,
A CPU 22 for controlling the operation of the entire system 12, an input / output interface 23 for connection to a PLC support tool, an input unit 24 to which one or more input devices 15 are connected, and an output to which one or more output devices 16 are connected A section 25 is provided.

Referring to FIG. 3, memory 1 of setting display 10
8, an example of data stored in the PLC 12 and the memory 22 will be described. The data area shown in FIG. 3 is merely an example, and other data areas may of course be used. Also, it does not show all of the data area. The memory 18 of the setting display 10 includes, for example, a CPU as shown in FIG.
A program data area (referred to as a program data area) 18a that defines the operation of 17 and a numerical value such as a current temperature or a set temperature exclusively (not limited to a numerical value but data other than a numerical value if a control state can be specified) ), An area (referred to as a control state data area) 18b of an I / O comment consisting of a character string corresponding to the control state, data indicating the operation state by bits, and bit data (An operation state data area) 18c with an I / O comment composed of a character string corresponding to. The bit indicating this operation state is one bit, that is, "1" or "0". For example, if the bit is "1", it means normal operation, and if the bit is "0", it means that operation is stopped. In this case, the bit is one bit in the embodiment, but the present invention is not limited to this. The definition of bits is not limited to the embodiment. Similarly, as shown in FIG. 3B, the memory 22 of the PLC 12 also stores a program data area 22a, a control state data area 22b, and an operation state data area 22c.
And

The control status data area 20b in the memory 20 of the PLC 12 is configured as follows, for example.

Address I / O comment Numerical data indicating control state a1 current temperature 120 a2 set temperature 130 a3 current time 30 a4 set time 65 a5 current production quantity 250 ::: a7 set production quantity 3000 Operating state in memory 20 of PLC 12 The data area 20c is configured as follows, for example.

Address I / O comment Bit data b1 indicating the operating state b1 Temperature sensor disconnection 1 b2 Heater disconnection 1 b3 Normal operation / stopping 1: Setting display 10 is stored in control status data area 20b of memory 20 of PLC 12 Both the stored I / O comment and the numerical data, and the I / O comment and the bit data stored in the operation state data area 20c are read out by communication with the PLC 12 and read out by the display unit 1.
3 displays the I / O comment, and performs a required corresponding operation. Further, in this case, the data stored in the memory 20 of the PLC 12 is read and transferred to the memory 18 of the setting display 10, but the present invention is not limited to this, and the transfer form is not limited.

Further, in this case, when defining each address of the control state data area 20b of the memory 20 of the PLC 12 using the PLC support tool, the I / O comment data and the operation state data area which are meant by the numerical data written to the address. 20c is a character string composed of one character or a combination of a plurality of characters and I / O comment data meaning bit data written to the address when defining each address (characters here are Japanese characters , Not only ordinary characters such as foreign language characters, but also all forms such as coined words, numbers, symbols, figures, etc., and one or more combinations thereof.) Such an I / O comment enables the maintenance person to easily know what numerical data or bit data is written in each address when performing maintenance of the program. Memory 20 when creating a program
Are written together with numerical data indicating the control state or bit data indicating the operation state.

In the present embodiment, I / O comment data written for such maintenance is used,
The I / O comment data is fetched on the setting display 10 side, and can be displayed as a character string.
As a result, on the setting display 10 side, the character strings are displayed on the display unit together with the numerical data indicating the corresponding control state or the character string of the I / O comment according to the content of the bit data indicating the operation state. It is not necessary to create the screen of the setting display 10 using the screen creation support tool as in the related art.

Referring to FIG. 4, temperature control will be described as an example of control using the PLC system of the present embodiment having such a configuration. The temperature control here is performed on the temperature in the electric furnace 30 as an example. A belt conveyor 31 is arranged in the electric furnace 30 from the furnace inlet to the furnace outlet. The heating object 32 to be heated in the electric furnace 30 is conveyed by the belt conveyor 31.
A heater 33 for heating an object to be heated 32 is provided in an electric furnace 30.
And a temperature sensor 15a in the electric furnace.
The PLC 12 has a temperature sensor 15a, a production quantity (the number of objects to be heated carried out from the outlet of the electric furnace), a production time and set temperature setting device 15b, a production quantity counter 15c,
The disconnection sensor 15d is connected as an input device, and the heater drive switch 16a and the heater stop switch 16b are connected as output devices. The operator operates the setting device 15b to produce, for example, 3,000 pieces of production quantity, for example, three production times.
For 0 hour, a set temperature, for example, 130 ° C. is input. These numerical data are input to the PLC 12 and written to the corresponding addresses of the control status data area 20b of the memory 20 of the PLC 12. When an appropriate start switch is turned on, P
The heater drive switch 16a is turned ON from the LC 12,
The belt conveyor 31 is moved by a belt conveyor 31 drive mechanism (not shown), and the object to be heated 32 is conveyed into the electric furnace 30. The object to be heated 32 is heated in the electric furnace 30 and then transferred to the outside of the electric furnace 30.

The current heating temperature of the object 32 is detected by the temperature sensor 15a. The numerical data of this current temperature is PL
The data is written to the address a1 of the memory 20 of C12, and the numerical value of the current temperature is sequentially updated as the current temperature increases. The number of heated objects 32 to be heated is counted by the counter 15c as the number of products to be produced.
The data is written to the address a5 of the memory 20, and the numerical data of the production quantity is sequentially updated as the production quantity increases.

The memory 18 of the setting display 10 also has a PLC
In communication with the controller 12, the numerical data of the set production quantity, the set time, and the set temperature set by the setter 15b and the counter 15c are written in the corresponding address of the memory 18 together with the I / O comment data. The set value is displayed on the setting display 10
Can be changed on the side. Then, the setting display 10 writes the numerical data of the current temperature and the production quantity together with the I / O comment data to the corresponding addresses of the memory 16 by communication from the PLC 12 and displays them on the control state display section 13a. Therefore, in the present embodiment, in the setting display 10 shown in FIG. 1 as a display example, the character string of the I / O comment of “current temperature” and the numerical data 120 corresponding thereto, and the I / O comment of “setting temperature” O
The comment character string and the corresponding numerical data 130 are displayed.

In this case, the setting display 10 displays "normal operation" on the operation state display section 13b based on the bit data indicating the operation state from the corresponding address in the memory 20 of the PLC 12 and the corresponding I / O comment data. Is displayed.

Thus, in the present embodiment, the setting display 1
The operator of the number 0 does not need to create a screen for displaying the current temperature and the set temperature using the screen creation support tool, and can obtain the screen only by communication with the PLC 12 side.

In this embodiment, the indication of "normal operation" on the operation state display section 13b of the display section 13 of the setting display 10 indicates that the contact (bit) of the PLC 12 is ON.
This is (1), which indicates that the switch is ON, and when the contact (bit) is OFF (0), "Stopped" is displayed. In this case, in the present embodiment, the I / O comment of the character string in this case includes a character string of “normal operation” and a character string of “stopping”. Special or specific (this is a broad concept including special) symbols (symbols are not limited to this, as long as the CPU can determine the front and rear delimiters by software).
In this case, a character string or a character string group is selected and displayed depending on whether the bit data indicating the contact state is "1" or "0". It does not matter. Here, FIG. 1 shows an example in which “normal operation”, which is a character string before the special symbol, is displayed on the operation state display unit 13b.

In this embodiment, when the backlight is monochrome, the display can be viewed more accurately by blinking and turning on the backlight.

In the present embodiment, the character color and / or the backlight color of the control state display section 13a and the operation state display section 13b can be set appropriately on the display section 13 of the setting display 10. Although it does not matter, a character string that can specify the character color and / or the backlight color is inserted into the character string of the I / O comment,
For example, if "normal operation", the backlight color is green, and the character string "normal operation" is white, and if "stop", the backlight color may be red. Then, it may be possible to operate according to this character string.

In the present embodiment, the size of a character string can be specified in the I / O comment by a character string, and the setting display 10 changes the size of the character string in accordance with the character string. You may be able to do it.

In this embodiment, when an alarm is issued, a character string for driving the buzzer is inserted into the I / O comment, and the buzzer provided in the setting display 10 is displayed according to the character string. Driving may be performed.

In the present embodiment, the display section 13 and the touch keys 14 of the setting display 10 may be constituted by a color liquid crystal display.

In this embodiment, as shown in FIG. 5, when the mode key 14b is operated, the screen of the control state display section 13a is changed from screen 1 → screen 2 → screen 3 → screen 4 →
Screen 1 may be repeated. Screen 1 is a display screen of the current temperature and the set temperature, screen 2 is a display screen of the current time and the set time, screen 3 is a display screen of the current production quantity, and screen 4 is a display screen of the set production quantity. Screen.

In this embodiment, as shown in FIG. 6, the screen of the operating state display section 13b is displayed on the display screen 1b.
If there is a disconnection in the sensor while "Normal operation" is displayed as shown in the above example, the character string "Sensor disconnection alarm is generated" is displayed in this example from the display screen 1 to the display screens 2 to 3. When the sensor and battery status are abnormal, the sensor disconnection and battery abnormality are simultaneously displayed as shown on the display screens 4 and 5, "sensor disconnection alarm generation" and "battery abnormality". May be displayed as if they flow from the right to the left in the illustrated example.

In this embodiment, as shown in FIGS. 7 and 8, the setting display 10 is integrally or removably attached to the PLC 12, and the setting display 10 has a peripheral connector 40 and an analog volume control. If a peripheral device connector is attached to the peripheral connector 40, a communication between the peripheral device and the PLC 12 via the communication unit 19 of the setting display 10 and the communication unit 21 of the PLC 12 may be possible. Alternatively, the set value may be changed in an analog manner by the analog volume 41.

In the present embodiment, the setting display 10 has been described as an example of a device with a display unit, but a device without a setting function may be used.

Although the setting display 10 of the present embodiment has a control state display section as the first display section and an operation state display section as the second display section, the operation state display section is not necessarily required. A setting display having only a control state display unit may be used.

In the present embodiment, it is not limited to displaying all the character strings constituting the I / O comment on the display unit 13 of the setting display 10.
Part of the character string may be displayed.

In the above embodiment, whether or not the numerical data of the control state can be changed may be specified by a character string of an I / O comment input from the control device. In such a case, key protection can be performed. Specifically, this key protection may mean that the operator of the setting display 10 does not want the operator to change the setting, but wants to display only the setting value. In such a case, the setting change may be prohibited, and a character string for displaying only the setting value may be designated.

[0040]

As described above, according to the present invention, the following effects can be obtained.

According to the setting display according to the first aspect of the present invention, the setting display is connected to a control device for controlling an apparatus, a machine, and the like, and can set data relating to the control content to the control device. A setting display having a display for displaying required data together with a first display for displaying a control state of the control device; and an operation unit for data displayed on the first display. And directly or indirectly inputs an I / O comment written in a memory of the control device from the control device, and replaces at least a part of a character string included in the I / O comment with the first Since it is configured to be displayed on the display unit,
On the setting display side, it is no longer necessary to use a screen creation support tool to create a screen including characters for displaying the control status of the control device, which increases the burden on the designer of the setting display. It can be reduced. Further, since it is not necessary to provide an MMI program (screen transition, key sequence, etc.) on the setting display side as in the related art, one setting display can be attached to and detached from a plurality of control devices, and only when necessary. The control device can be attached to a specific control device to display the control state of the control device and change the setting or to display the operation state, and can be used as a handy pro setting display. In addition, in the present invention, a designer who programs a control device selects a parameter to be displayed on a setting display and selects a key sequence by using a key sequence. Therefore, the above problem can be solved.

According to a second aspect of the present invention, the apparatus further comprises a second display section for displaying an operation state of the control device, and an I / O written in a memory of the control device.
When the O comment is directly or indirectly input from the control device and at least a part of the character string included in the I / O comment is configured to be displayed on the second display unit, not only the control state but also the , Moreover, there is no need to create a screen that includes text to display driving status,
The burden on the operator of the setting display can be greatly reduced.

As in the setting display of claim 3, claim 2
When the form of the I / O comment input from the control device for displaying the operating state on the second display unit has a character string before and after the specific symbol, one of the character strings before and after the specific symbol is displayed. When the data is selected and displayed in accordance with the operation state data, the number of I / O contacts and I / O comments can be reduced, so that the memory capacity of the setting display and the programmable controller can be reduced.

[0044] Like the setting display of claim 4, claim 1
If the character color and / or the backlight color displayed on at least one of the display units is specified by the character string of the I / O comment input from the control device, it can be seen at a glance Can determine the control state, that is, the process state.

[0045] Like the setting display of claim 5, claim 1
Further, if any of the numerical values in the control state can be specified by the character string of the I / O comment input from the control device, the key can be protected.

According to a sixth aspect of the present invention, there is provided a programmable controller which operates in accordance with a program and in which an I / O comment for maintenance of the program is written in a memory by a support tool. Since an I / O comment having a character string indicating the operation state of the programmable controller is written before and after the specific symbol,
If one of the character strings before and after that is selected and displayed in accordance with the data of the operating state, the memory capacity of the programmable controller can be reduced by reducing the number of I / O comments.

According to a seventh aspect of the present invention, there is provided a programmable controller which operates in accordance with a program and in which an I / O comment for maintenance of the program is written in a memory by a support tool. Since an I / O comment including a character string specifying a character color and / or a backlight color displayed on a display unit of a device connected to the programmable controller is also described, a setting display connected to the I / O comment includes In the setting display unit, a character color or a backlight color can be designated by an I / O comment from the programmable controller to make it easier to see the display unit without doing anything, and the burden on the CPU can be reduced.

According to the programmable controller system of the present invention, the programmable controller operates according to a program, and an I / O comment for maintenance of the program is written in a memory by a support tool. Connected, and comprises a setting display with a display unit for setting required data in connection with the control content of the programmable controller and displaying the data, and the setting display, Since the character string of the I / O comment is directly or indirectly input from the programmable controller and the character string can be displayed on the display unit, the setting display in this system creates a screen as in the related art. Use the support tool to attach the control State needs to create a screen including a character for displaying a control eliminates, becomes capable of significantly reduced the burden on the operator side of the setting indicator.

According to the ninth aspect of the present invention, there is provided a display having a display connected to a control device which operates according to a required program and displaying required data in relation to the control device. In a part-equipped device, an I / O comment written in a memory of the control device is directly or indirectly input from the control device, and
Since at least a part of the character string included in the O comment is configured to be displayed on the display unit, the setting display in the programmable controller system controls the control device using a screen creation support tool as in the related art. There is no need to create a screen including characters for displaying the state, and the burden on the operator of the setting display can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a programmable controller system according to an embodiment of the present invention.

FIG. 2 is an internal circuit diagram of a setting display and a programmable controller of FIG. 1;

FIG. 3 is a diagram showing a memory configuration of each of a setting display and a programmable controller in FIG. 1;

FIG. 4 is a diagram showing a configuration of a temperature control system using the system of FIG. 1;

FIG. 5 is a diagram showing a screen on a display unit of the setting display in FIG. 1;

FIG. 6 is a diagram showing a screen displayed by a display unit of the setting display of FIG. 1;

FIG. 7 is a diagram showing a configuration of a programmable controller system according to another embodiment of the present invention.

8 is an internal circuit diagram of a main part of each of the setting display and the programmable controller in FIG. 7;

FIG. 9 is a diagram showing a configuration of a conventional programmable controller.

[Explanation of symbols]

 Reference Signs List 10 setting display 12 PLC 13 display 13a control status display (first display) 13b operation status display (second display) 14 touch key 15 input device 16 output device

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) DD13 JJ46 LL09

Claims (11)

[Claims] A display unit connected to a control device for controlling an apparatus, a machine, and the like, capable of setting data relating to the control content to the control device and displaying required data; A setting display, comprising: a first display unit for displaying a control state of the control device; and an operation unit for data displayed on the first display unit, which is written in a memory of the control device. Input directly or indirectly from the control device the I / O comment that has been entered, and
A setting display configured to display at least a part of a character string included in the I / O comment on the first display unit. 2. The setting display according to claim 1, further comprising a second display unit for displaying an operation state of the control device, wherein the I / O comment written in a memory of the control device is displayed. Input directly or indirectly from the control device, and
A setting display, wherein at least a part of a character string included in the I / O comment is configured to be displayed on the second display unit. 3. The setting display according to claim 2, wherein a form of the I / O comment input from the control device for displaying an operation state on the second display unit is a character string before and after a specific symbol. A setting display, wherein one of the character strings before and after the setting is selected and displayed in accordance with the operation state data. 4. The setting display according to claim 1, wherein a character color and / or a backlight color displayed on at least one of the display units is an I / O comment input from the control device. A setting display characterized by being specified by a character string. 5. The setting display according to claim 1, wherein whether the numerical data of the control state can be changed or not can be designated by a character string of an I / O comment input from the control device. , A setting indicator. 6. A programmable controller which operates in accordance with a program and in which an I / O comment for maintenance of the program is written in a memory by a support tool, wherein the memory is provided before and after a specific symbol in the memory. A I / O comment having a character string representing the operating state of the I / O is also described. 7. A programmable controller which operates in accordance with a program and in which I / O comments for maintenance of the program are written in a memory by a support tool, wherein the memory has a device connected to the programmable controller. A I / O comment including a character string designating a character color and / or a backlight color displayed on the display unit of (1). 8. A programmable controller which operates in accordance with a program, wherein an I / O comment for maintenance of the program is written in a memory by a support tool, wherein the programmable controller is connected to the programmable controller, and And a setting display having a display unit for setting required data and displaying the data in relation to the control content. The setting display displays a character string of the I / O comment. A programmable controller system configured to be able to directly or indirectly input from the programmable controller and display the character string on the display unit. 9. A device with a display unit connected to a control device that operates according to a required program and having a display unit for displaying required data in relation to the control device, wherein a memory of the control device is provided. Input directly or indirectly from the control device the I / O comment written in the
A device with a display unit, wherein at least a part of a character string included in the I / O comment is configured to be displayed on the display unit. 10. The device with a display unit according to claim 9, wherein a character string of the I / O comment is configured to be flow-displayed by a key operation on a screen displayed on the display unit. Characteristic device with display. 11. The device with a display unit according to claim 9, wherein a character string of a plurality of I / O comments can be displayed by a key operation on a screen displayed on said display unit. A device with a display unit, characterized in that: