JPH1020807A - Display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of wiring by displaying data while discriminating a serial data signal to be inputted from the same signal line and also performing display control in accordance with display control data. SOLUTION: A display controller 3 performs the display of displaying data and display control based on displaying data and display control data transmitted via a signal line from a control part. That is, when a signal is inputted, the controller judges whether the signal is the displaying data or not, and when it is the displaying data, the controller decodes the data to output them to first and second driver circuits 10, 11 and performs a display corresponding to the displaying data on a display part 13 by outputting a display digit specifying signal and 7 segment signals. When it is not the displaying data, that is, it is the display control data, the controller 3 performs display control such as decimal point, a zero suppression and so forth according to the display control data by controlling the first and second driver circuits 10, 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for performing display according to digital input data, and more particularly, to a display device capable of controlling display such as decimal point display and blinking display.

[0002]

2. Description of the Related Art Conventionally, for example, when digital display data such as a current value and a voltage value is displayed on a multi-digit display device, the display data corresponding to each digit is converted into a parallel signal. The number of wires to send as
Further, in the case of performing display control such as decimal point display and +,-sign display, the number of wirings must be further increased, and the wiring configuration becomes complicated, and the wiring work is troublesome. There are drawbacks such as high costs.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and is intended to reduce the number of wires in a display device which performs display and display control according to digital input data. The purpose is to reduce wiring.

[0004]

In order to achieve the above-mentioned object, the present invention is configured as follows.

That is, the display device of the present invention determines whether a serial data signal input from the same signal line is display data or display control data, and displays the display data. To perform display control according to the display control data, and a conversion unit that converts the serial data signal into a parallel data signal; and a display unit that determines whether the display data is the display data based on the data signal. A configuration may be provided that includes a determination unit that determines whether the data is the display control data.

In the display device of the present invention, the display data may be a binary code signal, and the display control data may be a hex code signal, or the display control data may be based on predetermined bit data of the data signal. Thus, it may be determined whether the data is display data or display control data.

Further, the display device of the present invention has at least two types of reception modes in which the reception speed of the input data signal is different, and whether or not the data signal is correctly received in the set reception mode. If it is determined that the data is not correctly received, the setting of the reception mode is automatically switched.

According to the display device of the present invention, it is determined whether a serial data signal input from the same signal line is display data or display control data, and the display data is displayed. In addition, since the display control according to the display control data is performed, the display data can be displayed with one signal line, and the display control can be performed. Wiring can be reduced.

According to the display device of the present invention, at least two types of reception modes having different reception speeds are provided, and when an input data signal is not correctly received,
Since the reception mode is automatically switched, there is no need to manually switch the reception mode.

[0010]

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

FIG. 1 is a configuration diagram of an inspection system provided with a display device according to one embodiment of the present invention. This inspection system measures the current and voltage of an inspection object 1 and measures the measurement. The data is stored in the P
This is transmitted to the display device 3 according to the present invention via the control unit 2 such as an LC (program logic controller) and displayed on the display panel of the display device 3.

The display device 3 of this embodiment is a digital display for displaying a four-digit numerical value, and is connected by three lines, that is, plus and minus power lines 4 and 5 and a signal line 6. The display device 3 displays display data based on display data and display control data transmitted from the control unit 2 via the signal line 6 as described later, and displays decimal points and unnecessary “ This is to perform display control such as zero suppression to erase "0" for easy viewing.

FIG. 2 is a circuit block diagram of the display device 3 of FIG.

The display device 3 includes a control unit 2 on the transmitting side.
And a serial input circuit 7 to which a serial data signal is input from the controller 3. The serial input circuit 7 converts the serial signal from the serial input circuit 7 into a parallel data signal. A parallel conversion circuit 8 that outputs an error signal when the transmission speed does not match the transmission speed of the unit 2, a switching power supply circuit 9 that supplies a power supply input to each unit as a stabilized power supply of 5 VDC, and a data signal from the parallel conversion circuit 8 Based on the first and second
In addition to controlling the driver circuits 10 and 11 to perform display and display control, when the error signal is input, the serial input circuit 7 is used to match the reception speed of the serial input circuit 7 with the transmission speed of the transmission side. MPU 12 for switching the receiving speed of the display, a display unit 13 including a 7-segment LED and a sign LED, and data for designating a display digit of the display unit 13 and data of a display content to perform dynamic lighting. Second driver circuits 10 and 11 are provided.

Here, a data signal input to the display device 3 will be described. There are two types of data signals, display data for displaying a 4-digit numerical value and display control data for performing display control such as decimal point display and zero suppression. Either of the data is input, and neither is input at the same time.

The display data is binary (BCD)
Code signal, that is, one digit of decimal number "1" with 4 bits
In this embodiment, which is a binary-coded decimal number representing "~ 9" and displays a 4-digit numerical value, on the transmitting side, Table 1
As shown in, A ₀ to A 4 bits each of 16-bit inputs up to _{15 (digits) A 0 ~A 3, A 4} ~A 7, A 8
To A ₁₁ and A _{12 to} A ₁₅ are represented by the first digit (first place) of the display unit 13,
2nd digit (10th digit), 3rd digit (100th digit) and 4th digit (1000th digit)
, And each of the four bits A _{0 to} A ₃ , A ₄ to
_{A 7, A 8 ~A 11,} A 12 of the display data of the to A ₁₅ '000
0 "to" 1001 ", as shown in Table 2,
"1" to "9" in decimal notation are displayed in each digit.

[0017]

[Table 1]

[0018]

[Table 2]

On the other hand, display control data such as decimal point display and zero suppression is a hexadecimal code representing a hexadecimal code signal, that is, a 4-digit binary number as one digit. As shown, display control contents are assigned to the 16 bits A _{0 to} A ₁₅ of display control data. For example, the display control data “F
F00 ”is a display start command, and the display control data“ FF10 ”is a decimal point (decimal point display).
Of the display control data "FF1
"1" is a command for displaying the decimal point of the second digit.

[0020]

[Table 3]

As shown in Table 3, in this embodiment, decimal point display, zero suppression, + and-sign display, all digits blinking (blinking), and two-step luminance switching display are performed. .

FIGS. 3 and 4 show an example of the display of the third digit of the decimal point and an example of the zero suppression display, respectively, as an example of the display control. In FIGS. The segments are hatched, and indicate “00.01” and “0.01”, respectively.

On the transmitting side, the above 16-bit display data or display control data is converted into a serial signal and transmitted to the display device 3. The display device 3 converts the serial signal into The MPU 12 having a function as a discriminating means is received by the serial input circuit 7 shown in FIG.
The device performs display of display data based on the parallel signal and performs display control according to the display control data.

FIG. 5 is a flowchart for explaining the display operation. FIG. 5 shows the display operation after the display control data for starting the display is inputted in advance.

First, when there is a signal input, it is determined whether or not it is display data, that is, whether or not it is a binary code signal (step n1). If it is display data, it is decoded. To the first and second driver circuits 10 and 11 (step n2).
The driver circuits 10 and 11 provide a display digit designation signal and 7
A segment signal is output, a display corresponding to the display data is performed on the display unit 13, and the process returns to step n1.

If it is determined in step n1 that the data is not display data, that is, it is display control data of a hexa-code signal, the first and second driver circuits 1
By controlling 0 and 11, display control such as decimal point display and zero seperation is performed according to the display control data (step n4), and the process returns to step n1.

When the signal input has not been continued for a certain period, an error display may be performed.

As described above, display and display control are performed by serial display data and display control data input through the same signal line 6, so that the number of wirings is smaller than that of the conventional display device. As a result, the wiring work is simplified, and the cost can be reduced.

In this embodiment, since the display data is a binary code signal and the display control data is a hex code signal, 4-digit decimal display and display control are performed by 16-bit data. Can be.

Conventionally, there is a transmission system in which a transmitting side converts a parallel signal into a serial signal and transmits the signal, and a receiving side converts a received serial signal into a parallel signal and processes the signal. There are two types of transmission modes having different transmission speeds, that is, a standard mode and a high-speed mode, and the mode can be switched by operating a changeover switch.

However, in the conventional configuration, every time the mode on the transmitting side is switched, the mode on the receiving side must be switched to match the transmission speed. Therefore, the device on the transmitting side and the device on the receiving side must be switched. When they are arranged apart from each other, the switching operation is very troublesome.

Therefore, in the display device 3 of this embodiment, when the mode on the transmitting side is switched, the mode on the receiving side is automatically switched to match the mode on the transmitting side. .

That is, the parallel conversion circuit 8 shown in FIG. 2 outputs an error signal to the MPU 12 based on the output of the serial input circuit 7 when the data signal is not correctly received, and the MPU 12 Upon receiving the signal, it is determined that the reception speed does not match the transmission speed on the transmission side, and a reception speed switching signal is output to the serial input circuit 7, and the serial input circuit 7 changes the reception speed by switching the sampling frequency. Is switched to match.

FIG. 6 is a flowchart of the switching operation of the receiving speed.

First, the reception speed is initialized to either the standard mode or the high-speed mode (step n1).
0) Next, whether or not the data is correctly received, that is, ON / OFF of a prescribed waveform width corresponding to a set reception mode in which data input is a prescribed signal form.
Is determined (step n1).
1) When it is determined that the input is made in the prescribed signal form, it is determined that the reception speed and the transmission speed are the same, and the data input is taken in and the display process is performed as shown in FIG. 5 (step n12). ), And return to step n11.

When it is determined in step n11 that the signal is not input in the prescribed signal form, the receiving speed is
Assuming that the transmission speed does not match the transmission speed on the transmission side, the currently set reception mode is switched to another reception mode, for example, if it is the standard mode, it is switched to the high-speed mode, and if it is the high-speed mode, it is switched to the standard mode (step n13). ), Step n1
Return to 1.

As described above, when the reception mode of the display device 3 does not match the transmission mode of the transmission side, the currently set reception mode is automatically switched to another reception mode and the transmission mode of the transmission side is changed. Since the transmission mode can be made coincident with each other, the reception mode of the reception-side device located at a position distant from the transmission-side device is manually switched each time the transmission mode of the transmission-side device is switched, as in the conventional example. This eliminates the need for such troublesome work.

In the above-described embodiment, the display data is a binary code signal and the display control data is a hexacode signal. However, in another embodiment of the present invention, a predetermined bit is "0". The display data or the display control data may be determined depending on whether the data is present or “1”. For example, in the above-described embodiment, hexadecimal display may be performed by adding a predetermined bit for discrimination.

In the above-described embodiment, although data is input from a control unit such as a PLC, the transmission-side equipment is not limited to the PLC, but a transmission terminal for converting a parallel input into a serial output and transmitting the serial output. Of course, other devices may be used.

In the above-described embodiment, the display control is only the external control performed by external display control data. However, as another embodiment of the present invention, in addition to the above-described external control, a display control is performed. A setting switch for display control is added to the device, and the display control can also perform internal control by setting the setting switch. When the internal control is selected, only display data is transmitted from the outside. Good.

In the above-described embodiment, the receiving speed can be switched between the standard mode and the high-speed mode. However, as another embodiment of the present invention, there are two types of receiving modes. The present invention is not limited to this, and three or more types may be used. In another embodiment of the present invention, the reception speed may be only one type of mode.

In the above embodiment, the display is made by using the LED. However, as another embodiment of the present invention, the display may be made by using an LCD or a fluorescent display tube.

[0043]

As described above, according to the present invention, it is determined whether a serial data signal input from the same signal line is display data or display control data. Since data is displayed and display control is performed in accordance with the display control data, display data can be displayed by one signal line, and display control can be performed. It is possible to reduce the number of wires and reduce wiring.

According to the present invention, there are at least two types of reception modes having different reception speeds. When an input data signal is not correctly received, the reception mode is automatically switched. There is no need to switch modes.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of the display device of FIG.

FIG. 3 is a diagram showing a display example.

FIG. 4 is a diagram showing a display example.

FIG. 5 is a flowchart for explaining a display operation.

FIG. 6 is a flowchart for explaining a reception speed switching operation.

[Explanation of symbols]

 Reference Signs List 3 display device 6 signal line 7 serial input circuit 8 parallel conversion circuit 12 MPU 13 display unit

Claims (5)

[Claims] 1. A method for determining whether a serial data signal input from the same signal line is display data or display control data, displaying the display data, and displaying the display control data. A display device for performing display control according to data. 2. A conversion unit for converting the serial data signal into a parallel data signal, and a determination unit for determining whether the data is the display data or the display control data based on the data signal. The display device according to claim 1, further comprising: 3. The display device according to claim 1, wherein the display data is a binary code signal, and the display control data is a hex code signal. 4. The display device according to claim 1, wherein it is determined whether the data is display data or display control data based on predetermined bit data of the data signal. 5. It has at least two types of reception modes in which the reception speed of the input data signal is different, and determines whether or not the data signal is correctly received in a set reception mode. 5. The display device according to claim 1, wherein when it is determined that no reception is made, the setting of the reception mode is automatically switched.