JPH10303991A - Display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the display unit which informs a user that noise is mixed with communication data sent to or received from an external device or electric power. SOLUTION: An interface part 14 sends and receives communication data to and from a sequencer 2. A CPU 11 displays the control state of a sequencer 2 at a liquid crystal display part 13 according to the communication data received through the interface part 14. A noise detecting circuit 16 once detecting noise exceeding a specific value being mixed with the communication data between the display unit 1 and sequencer 2 and the electric power supplied from a power source part 15 indicates the mixture of the noise by using a noise display means 17 such as an LED and a buzzer and also outputs a detection signal to the CPU 11. The CPU 11 once receiving the detection signal from the noise detecting circuit 16 displays a mark indicating the mixture of the noise at a liquid crystal 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 display for displaying the status of an external device on a screen based on communication data received from an external device such as a sequencer.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, communication data transmitted from a sequencer 2 as an external device via a wiring 4 is received, and a control state of the sequencer 2 is displayed on a liquid crystal display unit 13 as a screen display unit. There was an indicator 1 to display.

[0003]

SUMMARY OF THE INVENTION A display 1 having the above-described structure.
A wiring 4 for connecting between the display 1 and the sequencer 2 and between the display 1 and a power supply 3 for supplying power to the display 1
In addition, the noise 7 from the peripheral device 6 is used without much consideration. For example, when the display 1 is used in a factory, even if a new facility is introduced around the installation location of the display 1 and the noise environment surrounding the display 1 changes, the noise generated by the peripheral device 6 is changed. The user rarely confirms the extent to which the display 7 affects the display 1, and as a result, there is a problem that the display 1 malfunctions due to the noise 7 mixed in from the wiring 4. Further, it was not possible to specify that the cause of the malfunction of the display 1 was caused by noise. Further, the malfunction of the display 1 may cause a malfunction in an external device such as the sequencer 2 connected to the display 1.

In order to prevent the display 1 from malfunctioning due to noise 7 from the peripheral device 6, the display 1
It is conceivable to improve the noise resistance performance of the display 1, but the noise existing around the display 1 varies depending on the environment in which the display 1 is used. Although improving noise immunity uniformly is beneficial for some users, it is unnecessary performance for other users and simply increases costs.

The present invention has been made in view of the above problems, and an object of the present invention is to detect that noise has been mixed in communication data with an external device or a power supply. An object of the present invention is to provide a display for notifying a user.

[0006]

According to the first aspect of the present invention, in order to achieve the above object, an interface unit for exchanging communication data with an external device, a screen display unit having a display screen, and an interface unit And an arithmetic control unit that displays the status of the external device on the screen display unit based on the communication data received via the PC, and detects noise mixed in communication data with the external device and power supplied from the power supply device And a noise display unit that displays the detection result of the noise detection unit, so that the user can be notified that noise has entered the communication data or the power supply.

According to a second aspect of the present invention, in the first aspect of the present invention, the screen display unit also serves as a noise display unit, and the detection result of the noise detection unit is displayed on the screen. In the first or second aspect of the present invention, the noise display section includes a light emitting diode that emits light in accordance with the detection result of the noise detection section. Since it is composed of a buzzer that sounds, the user can be notified of the entry of noise by screen display, light, sound, or the like.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the noise detecting section includes a first variable resistor for dividing a reference voltage applied between both ends at a predetermined voltage dividing ratio, and a communication data or power supply. A first and second resistor connected in series between an input terminal to which a voltage is input and an intermediate terminal of the first variable resistor, and a non-inverting input terminal is a connection point of the first and second resistors. And a comparator whose inverting input terminal is connected to the ground, wherein the noise detection unit includes a second variable resistor for dividing communication data and a power supply voltage. And a voltage detection IC for comparing the magnitude relationship between the divided voltage divided by the second variable resistor and a predetermined threshold value, so that the noise detection unit can be configured with a simple circuit configuration. can do.

According to a seventh aspect of the present invention, in the first to sixth aspects of the present invention, a sequencer is used as an external device, and when the noise detection unit detects the entry of noise, the arithmetic control unit sends the noise to the sequencer via the interface unit. The detection result is sent out, and the sequencer shifts from the normal operation mode to the safety mode in which the control target is stopped or controlled to a safer state by this detection result. It is possible to prevent the sequencer from malfunctioning due to the malfunction of the display.

According to an eighth aspect of the present invention, in the seventh aspect of the invention, when the non-detection state of the noise detection section continues for a predetermined time, the signal indicating that the arithmetic control section is in the non-detection state to the sequencer via the interface section. And the signal returns the sequencer from the safe mode to the normal operation mode. Therefore, when the influence of the noise is eliminated, the sequencer can be immediately returned to the normal operation mode.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of a display device according to the present embodiment, FIG. 2 is an external perspective view, and FIG. 3 is a circuit diagram of a noise detector. The display 1 includes a CPU 11 as an arithmetic and control unit for controlling the operation of each unit described later, a memory unit 12 including a ROM for storing an operation program of the CPU 11 and a RAM for storing data, and a sequencer 2 as an external device.
Liquid crystal display unit 13 as a screen display unit for displaying the control state of the display on the screen, CPU 11, sequencer 2 and liquid crystal display unit 1.
3, an interface unit 14 for transmitting signals between the
A power supply unit 15 serving as a power supply device for supplying operation power to each unit;
A noise detection unit, which is a noise detection unit that detects that noise of a predetermined voltage or more is mixed in the wiring 4 connecting the sequencer 2 and the interface unit 14 and the power supply line 18 connecting the circuit unit such as the CPU 11 and the power supply unit 15. Circuit 16
And a noise display unit 17 for displaying the detection result of the noise detection circuit 16 with light or sound.

As shown in FIG. 2, the display 1 comprises a substantially box-shaped casing 10, and a liquid crystal display 13
Liquid crystal screen 13a is provided. The noise display unit 17
The light emitting diode 17a emits light in response to the detection result of the noise detection circuit 16, and a buzzer 17b sounds in response to the detection result of the noise detection circuit 16. The light emitting diode 17a is located at the upper left corner in FIG. The buzzer 17b is provided inside the lower left corner of the housing 10 in FIG.

On the other hand, as shown in FIG. 1, the sequencer 2 has an input / output unit 24 for inputting and outputting signals to and from an external device 5 such as an inverter, and an interface for transmitting and receiving communication data to and from the display 1. A unit 23, a CPU unit 21 for controlling or monitoring the external device 5 via the input / output unit 24, and outputting a control state to the display 1 via the interface unit 23, and a power supply unit for supplying operating power to each unit 22.

Here, when the noise detection circuit 16 detects noise of a predetermined voltage or more, the noise detection circuit 16 outputs a noise detection signal to the CPU 11, turns on or blinks the light emitting diode 17a, and sounds the buzzer 17b. . When a detection signal is input from the noise detection circuit 16, the CPU 11 causes the liquid crystal display unit 13 to display, for example, a noise signal in the upper left corner of the liquid crystal screen 13 a in FIG. 2 according to the operation program for noise detection stored in the memory unit 12. A mark 13b indicating the mixture is displayed. As described above, when the noise detection circuit 16 detects noise, the mark 13b is displayed on the liquid crystal screen 13a of the liquid crystal display unit 13, the light emitting diode 17a is turned on or blinks, the buzzer 17b
By sounding, it is possible to notify the user that noise has entered the communication data or the power supply of the display 1 and the user can take appropriate measures against this noise.

The noise display section is a liquid crystal display section.
13, a predetermined mark 13b may be displayed,
Using the display of the liquid crystal display unit 13 and the light emitting diode 17a together
Or the display on the liquid crystal display unit 13 and the buzzer 17b.
May be used together. By the way, the noise detection circuit 16
It may be provided for each communication line or power line, as shown in FIG.
As described above, the reference voltage Vr applied between both ends is divided into a predetermined voltage dividing ratio.
Variable resistor VR dividing the voltage by₁And wiring 4 or
A voltage signal such as communication data or a power supply is
Input terminal t to be input₁And the first variable resistor VR₁End of
Child t _ThreeAnd a second resistor R connected between₁, R
_TwoAnd a non-inverting input terminal is composed of first and second resistors.
R₁, R_TwoAnd the inverting input terminal
Comparator COMP connected to ground₁And from
Compose and Comparator COMP₁Between both input terminals
Diode D₁, D_TwoAre connected in anti-parallel. here
And the comparator COMP₁Is the terminal t₁Voltage and terminals
t_ThreeAnd the first and second resistors R₁, R_TwoWith pressure
Voltage and the ground level are compared.₁Given
When a voltage exceeding the threshold is applied, the noise detection signal
Output a signal. At this time, the first and second resistors R₁, R_Two
And the reference voltage Vr are set in advance to predetermined values,
Variable resistor VR₁By adjusting the
Data COMP₁Can be adjusted.

The noise detection circuit 16 has a commercially available voltage detection circuit.
An intelligent IC may be used, as shown in FIGS.
In addition, the noise detection circuit 16 can be realized with a simple circuit configuration.
Can be. The noise detection circuit 16 is shown in FIG.
As shown in the terminal t_Four, T_FivePower such as communication data or power
The second variable resistor VR to which the pressure signal is applied_TwoAnd the input end
Is a second variable resistor VR_TwoTerminal t₆City connected to
And a voltage detecting IC 16a for sale. FIG.
(B) shows an internal circuit of the IC 16a, and an input terminal
P₁And ground terminal P_ThreeBetween the resistance R_Three, R_FourFrom
And a reference voltage source V_refAnd between gates and
P-channel MOSFET Q connected between the rains
₁And n-channel MOSFET Q_TwoAnd the series circuit of
Each is connected in parallel. In addition, the comparator COM
P_TwoThe inverting input terminal of_Three, R _FourNon-anti
Input terminal is the reference voltage source V_refAnd the output terminal is FETQ
₁, Q_TwoAre connected to the respective gates. And IC16
Output terminal P of a_TwoIs FETQ ₁, Q_TwoConnected to the drain of
Is done.

Here, the second variable resistor VR_TwoIs the terminal
t_Four, T_FiveThe voltage signal input between the IC 16a
Divide the voltage to the voltage range and set the input terminal P of the IC 16a.₁Mark on
Add. Input terminal P₁Is further applied to the resistor R
_Three, R_FourAnd the divided voltage V_ThreeIs a comparison
TA COMP_TwoIs input to the inverting input terminal. Comparing
TA COMP_TwoIs the divided voltage V_ThreeAnd reference voltage V_refBig and small
Are compared, and the terminal t_Four, T_FiveMixed with the voltage signal applied between
When the input noise is less than a predetermined voltage value and the divided voltage V_ThreeIs based
Reference voltage V_refIf less than the comparator COMP
_TwoIs at a high level. At this time, FET Q₁Ha
F, FETQ_TwoTurns on and the output terminal P_TwoSignal level
Becomes low level. On the other hand, terminal t_Four, T_FiveApply between
Noise mixed into the output voltage signal exceeds a predetermined voltage value.
And the divided voltage V_ThreeIs the reference voltage V _refWill be larger than
And the comparator COMP_TwoOutput goes low.
You. At this time, FET Q₁Is on, FET Q_TwoIs off
Output terminal P_TwoBecomes high level.

Here, a system including the sequencer 2 using the display 1 of the present embodiment will be described with reference to FIG. The system includes a sequencer 2 for controlling a plurality of external devices 5 and a wiring 4 ′ from an external power supply 3 as a power supply device.
And a display 1 for displaying the control state of the sequencer 2 on the liquid crystal display unit 13 based on the communication data transmitted from the sequencer 2 via the wiring 4.

Wiring 4 connecting display 1 and sequencer 2 and wiring 4 'connecting display 1 and external power supply 3
When the noise 7 having a predetermined voltage level or more is mixed in from the peripheral device 6 and the above-described noise detection circuit 16 detects the mixing of the noise, the display 1 displays a mark indicating the mixing of the noise on the liquid crystal screen of the liquid crystal display unit 13. Is displayed, a light emitting diode emits light, and a buzzer sounds to inform the user that noise has entered.
Sends a noise detection signal to the sequencer 2 via the wiring 4. When the sequencer 2 receives the noise detection signal from the display 1, the sequencer 2 shifts from the normal operation mode to the safe mode. Here, the safety mode refers to the sequencer 2
In order to prevent the external device 5 controlled by the erroneous operation from causing a fatal accident or an accident that causes serious damage, the operation of the external device 5 is stopped or a safer operation is performed. It refers to a mode in which the state is controlled.

FIGS. 6A and 6B show a specific system using the display 1 of this embodiment. In this system, the saw 55 is rotated and the wood 56 is moved in one direction. A woodworking machine 53 having a motor 54 that cuts the wood 56 by using a motor, an inverter 52 that controls the rotation of the motor 54 to control the amount and speed of movement of the wood 56,
A rotary encoder 51 for detecting a moving amount and a moving speed of the wood 56, a sequencer 2 for feeding back a detected value of the rotary encoder 51 to control an output of the inverter 52, and a sequencer based on communication data received from the sequencer 2. The control state of the liquid crystal display unit 13
And a display 1 for displaying the information. Sequencer 2
Is an interface unit 23 for transmitting and receiving communication data to and from the display 1, an output unit 24a for outputting a control signal to the inverter 52, and a rotary encoder 5.
1 and a CPU unit 21 that outputs a control signal to the inverter 52 via the output unit 24a based on the detection value of the rotary encoder 51 input via the input unit 24b.
And a power supply unit 22 that supplies operation power to each unit.

If the display 1 malfunctions due to noise generated by another peripheral device (not shown), the sequencer 2 is affected by the malfunction of the display 1 and the motor 54
Is rotated at a rotation speed equal to or higher than the set value, and when the rotation speed of the saw 55 or the moving speed of the wood 56 increases rapidly,
A worker operating the woodworking machine 53 may be at risk. Therefore, in the display 1 of the present embodiment, when noise of a predetermined voltage level or more is mixed into communication data or a power supply from a peripheral device, the noise detection circuit 16 detects the mixing of noise as described above, and At the same time as displaying a mark indicating noise contamination, turning on or blinking a light emitting diode, and sounding a buzzer on the liquid crystal screen 13a of the LCD, the operator is informed of the noise contamination, and at the same time, the sequencer is displayed from the display 1. 2 sends a noise detection signal. At this time, in the sequencer 2, the CPU unit 21 shifts from the normal control mode to the safety mode based on the noise detection signal received via the interface unit 23, changes the output of the inverter 52, and Since the rotation speed of the woodworking machine 53 is reduced or stopped, it is possible to prevent the occurrence of a serious accident that may pose a danger to the operator operating the woodworking machine 53.

Further, if the noise detection circuit 16 of the display 1 detects noise contamination and the noise detection circuit 16 keeps detecting the noise for a certain period of time, the display 1 shows the sequencer 2 the noise non-detection state. Output a signal. In the sequencer 2, when the CPU unit 21 receives the noise non-detection signal via the interface unit 23, the CPU unit 21 returns from the above-described safety mode to the normal control mode,
Since the output of the inverter 52 is changed via the output unit 24a and the motor 54 is rotated at the normal rotation speed, the sequencer 2 can be immediately returned to the normal control mode when the influence from the noise from the peripheral device disappears. Can be.

As described above, the noise detection circuit 1 of the display 1
When the noise detector 6 detects the noise, the display 1 sends a noise detection signal to the sequencer 2 to shift the sequencer 2 from the normal operation mode to the safe mode. Is not detected, the display 1 sends a noise non-detection signal to the sequencer 2 to return the sequencer 2 from the safe mode to the normal operation mode. Even in this case, a serious accident can be prevented from occurring in the woodworking machine 53, and the worker can perform the operation with peace of mind.

[0024]

According to the first aspect of the present invention, as described above, an interface for transmitting and receiving communication data to and from an external device, a screen display having a display screen, and communication data received via the interface are provided. A noise control unit for displaying a state of the external device on the screen display unit based on the noise detection unit for detecting communication data between the external device and noise mixed in the power supplied from the power supply device; Since the noise display unit that displays the detection result of the detection unit is provided, the user can be notified that noise has entered the communication data or the power supply, and the user can take appropriate measures against the noise. effective. In addition, there is an effect that the user can be notified that the external device connected to the display is also affected by the noise.

According to a second aspect of the present invention, the screen display section also serves as a noise display section, and the detection result of the noise detection section is displayed on the screen. The noise display unit comprises a buzzer that sounds according to the detection result of the noise detection unit. The noise display unit includes a buzzer that sounds according to the detection result of the noise detection unit. There is an effect that the user can be notified by light, sound or sound.

According to a fifth aspect of the present invention, the noise detecting section divides the reference voltage applied between both ends at a predetermined voltage dividing ratio.
A variable resistor, a first resistor and a second resistor connected in series between an input terminal to which communication data and a power supply voltage are input, and an intermediate terminal of the first variable resistor, and a non-inverting input terminal. First
And a comparator connected to the connection point of the second resistor and having an inverting input terminal connected to the ground. The noise detecting section according to claim 6, wherein the noise detecting section separates communication data and power supply voltage. A second variable resistor for compressing;
And a voltage detection IC that compares the magnitude relationship between the divided voltage divided by the variable resistor and a predetermined threshold value, so that the noise detection unit can be configured with a simple circuit configuration. There is.

According to a seventh aspect of the present invention, a sequencer is used as an external device, and when the noise detector detects noise contamination, the arithmetic and control unit sends a noise detection result to the sequencer via the interface unit. The sequencer shifts from the normal operation mode to the safe mode in which the control target is stopped or controlled to a safer state. Therefore, when noise is mixed in the display, the sequencer malfunctions due to the malfunction of the display. And the occurrence of an accident due to a malfunction of the sequencer can be prevented.

According to the present invention, when the non-detection state of the noise detection unit continues for a predetermined time, the arithmetic control unit sends a signal indicating that the noise detection unit is in the non-detection state to the sequencer via the interface unit. Since the sequencer returns from the safety mode to the normal operation mode, there is an effect that the sequencer can be immediately returned to the normal operation mode when there is no influence of noise.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a display device of the present embodiment.

FIG. 2 is an external perspective view illustrating the noise detection unit according to the first embodiment.

FIG. 3 is a circuit diagram of the same.

FIG. 4A is a circuit diagram illustrating another noise detection unit according to the first embodiment. (B) It is an equivalent circuit diagram showing the voltage detection IC used in the above.

FIG. 5 is a schematic configuration diagram of a system using the same display device.

FIG. 6 shows another system using the same indicator.
(A) is a block diagram, (b) is an explanatory view showing a load.

FIG. 7 is a schematic configuration diagram of a system using a conventional display.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display 2 Sequencer 11 CPU 13 Liquid crystal display part 14 Interface part 15 Power supply part 16 Noise detection circuit 17 Noise display part

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI G09G 3/20 G05B 19/05 D

Claims (8)

[Claims] An interface unit for transmitting and receiving communication data to and from an external device; a screen display unit having a display screen;
An arithmetic control unit for displaying the status of the external device on the screen display unit based on the communication data received via the interface unit, and noise mixed in communication data with the external device and power supplied from the power supply device And a noise display unit for displaying a detection result of the noise detection unit. 2. The display according to claim 1, wherein the screen display unit also serves as a noise display unit, and displays a detection result of the noise detection unit on a screen. 3. The display according to claim 1, wherein the noise display section comprises a light emitting diode which emits light in accordance with a detection result of the noise detection section. 4. The display according to claim 1, wherein the noise display section comprises a buzzer that sounds according to the detection result of the noise detection section. 5. A first variable resistor for dividing a reference voltage applied across both terminals by a predetermined voltage dividing ratio, an input terminal for inputting communication data and a power supply voltage, and a first variable resistor. The first and second resistors connected in series between the resistor and the intermediate terminal, the non-inverting input terminal is connected to the connection point of the first and second resistors, and the inverting input terminal is connected to ground. 2. The display according to claim 1, further comprising a comparator connected thereto. 6. A second variable resistor for dividing a communication data or a power supply voltage by a noise detector, and a magnitude relationship between a divided voltage divided by the second variable resistor and a predetermined threshold value. 2. The display according to claim 1, further comprising a voltage detection IC for comparing. 7. A sequencer is used as an external device, and when a noise detector detects noise contamination, an arithmetic control unit sends a noise detection result to the sequencer via an interface unit. 7. The display device according to claim 1, wherein the operation mode is shifted from the operation mode to a safety mode in which a controlled object is stopped or controlled to a safer state. 8. When the non-detection state of the noise detection unit continues for a predetermined time, the arithmetic control unit sends a signal indicating that the noise detection unit is in the non-detection state to the sequencer via the interface unit. 8. The display according to claim 7, wherein the display returns to a normal operation mode.