JPS5995471A - Waveform display device - Google Patents

Abstract

PURPOSE:To display information on a time difference and voltage difference corresponding to the point at an optional time axis in the output waveform on a pipe surface by storing temporarily the data corresponding to the address of a memory by the coincidence output of a digital comparator, and calculating the respective data outputs and the respective numerical outputs of the 1st and 2nd setters. CONSTITUTION:The numerical values equivalent to the two points to be measured on an output waveform are set in setters 11 and 12. The 1st digital comparator 9 generates a coincidence output when the numerical output of the setter 11 coincides with the count output from an address counter 8, that is, the address in the 2nd memory 7. The 1st latch circuit 13 stores temporarily the data for the address transmitted thereto and transmits the outputs thereof to a calculator 15. The 2nd digital comparator 10 produces similarly the coincidence output with the numerical output from the 2nd setter 12 and said output is latched by the 2nd latch circuit 14. The calculator 15 calculates the time difference and voltage difference between the two points of the output waveform in accordance with the output and displays the result thereof in a display device 16.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention converts an input signal of a measured waveform into a digital signal using an A-D converter, stores the output in a memory, and then reads out the stored data as an analog waveform. The present invention relates to a waveform display device that displays information on a cathode ray tube, such as a digital storage scope, that displays information such as time differences and voltage differences corresponding to arbitrary time axis points of a tube output waveform.

Conventionally, the time difference and voltage difference between the tube surface output waveforms on a cathode ray tube have been calculated using values read from a measuring device. However, with this method, reading errors occur and the measured values are inaccurate. In addition, even if an analog comparator is used, direct numerical display requires a sample-and-hold circuit and an arithmetic unit to process the output of the analog comparator, which increases the size and cost of the device. was there.

In view of the above points, the present invention has been made in order to eliminate such conventional drawbacks.The purpose of the present invention is to easily and accurately obtain information such as time differences and voltage differences between arbitrary time axis points of a tube output waveform. The object of the present invention is to provide a waveform display device that can display waveforms.

In order to achieve such an object, the present invention provides a waveform display device in which count outputs of an address counter that counts addresses of a memory storing output waveform data are input to first and second digital comparators, respectively. death,
These first and second digital comparators are provided with separate first and second setters whose set values can be set programmably, and the coincidence output of the first digital comparator corresponds to the address of the memory. At the same time, data corresponding to the address of the memory is temporarily stored based on the matching output of the second digital comparator, and each temporarily stored data output and the first and second setter are By calculating each numerical output of , the time difference corresponding to any time axis point of the tube output waveform is calculated based on the calculation result.

It is designed to display information such as voltage differences.

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

The figure is a basic block diagram showing an embodiment of a waveform display device according to the present invention. In the figure, 1 is an A-D converter that converts an input analog signal A into a digital signal; 2
3 is a first memory that stores the digital signal converted by the A-D converter 1 as data, and 3 is a DA converter that converts the data stored in the first memory 2 into the original analog signal. The analog output is sent as a deflection signal Y to the vertical deflection section of the cathode ray tube 6. 4 is a sweep circuit that generates a time-domain signal X in response to a count output from an address counter 8, which will be described later.
is sent to the horizontal deflection section. 5 is or gate 17 which will be described later.
This is a brightness modulation circuit that controls the brightness of the cathode ray tube 6 in response to the OR output.

Still, T is a second memory similar to the memory 2 that stores the data of the A-D converter 1, and 8 counts the address of the second memory 7 and sends the count output to the memory 7 as a shift pulse. 9 and 10 are first and second digital comparators each inputting the count output of the address counter 8 to one input terminal, and 11 is the other input terminal of the first digital comparator 9. The first one sends out a coded numerical signal as its setting value.
A setter 12 is a second setter 1 that sends an encoded numerical signal as a set value to the other input terminal of the second digital comparator 10;
1.12 consists of a numerical signal corresponding to the address of the second memory 7 that can be set programmably. 13 is a first launch circuit that temporarily stores data corresponding to the address of the second memory 7 based on the coincidence output of the first digital comparator 9; A second launch circuit 15 temporarily stores data corresponding to the address of the memory 7 of No. 2, and 15 receives each data output of the first and second launch circuits 13 and 14 as input, and also sets the first and second settings. This is an arithmetic unit that receives the numerical outputs of the units 11 and 12 as input. This arithmetic unit 15 is composed of an arithmetic element, a decoder, etc., and includes each of the setting units 11.
By performing processing using a well-known arithmetic method based on the respective outputs from 12 and launch circuits 13 and 14, information such as the time difference and voltage difference between two points of the tube output waveform is calculated. The calculation result is sent as a numerical signal to be displayed to a display 16 consisting of a segment element in the shape of a mouth. Reference numeral 17 denotes an OR gate which inputs the coincidence output of the first digital comparator 9 and the coincidence output of the second digital comparator 10, and sends the OR output of t>D to the luminance modulation circuit 5 as a luminance signal. .

Next, the operation of the configuration of the above embodiment will be explained.

Here, when the analog 4g@A of the observed waveform is input to the A-D converter 1, this input signal is converted into a digital signal by the A-D converter 1, and its output is used as data for the first and 2 are stored in memories 2 and 7, respectively.

Thereafter, when the data stored in the first memory 2 is read out for waveform display, this data is input to the D-A converter 3 and converted into the original analog signal, and the analog output is the deflection signal. It is sequentially sent out as Y to the vertical deflection section of the cathode ray tube 6. At the same time, the address counter 8 reads the second memory 8 in synchronization with the read operation of the first memory 2.
The address of 4. is counted, and the count output is sent to the sweep circuit 4. At the same time, it is sent to the second memory 1, and the first
and also sent to a second digital comparator 9.10.

Then, the second memory 7 sequentially reads out the stored data based on the count output from the address counter 8, and the data outputs are sent to the first and second latch circuits 13.
Send on 14th. Further, the sweep circuit 4 generates a time axis signal X upon receiving the count output from the address counter 8, and sends this signal X to the horizontal deflection section of the cathode ray tube 6.

As a result, the cathode ray tube 6 displays on its tube surface an output waveform corresponding to the analog output of the DA converter 3 based on the time axis signal X from the sweep circuit 4.

During this output waveform display, the first and second setting devices 11 and 12 are individually operated to
2, set the numerical value corresponding to the two points to be measured on the output waveform. Then, the first digital comparator 9 generates a match output when the numerical output of the first setter 11 and the count output from the address counter 8 match the address of the second memory 7. Based on this coincidence output, the first launch circuit 13 temporarily stores the data corresponding to the address sent from the second memory T, and sends the output to the arithmetic unit 15. Similarly to the above, the second digital comparator 10 also generates a match output when the numerical output of the second setter 12 and the address of the second memory 7 match, and this match output causes the second lunch to start. The circuit 14 is the second
The data corresponding to the address of the memory 7 is temporarily stored, and the output thereof is sent to the arithmetic unit 15.

Therefore, the numerical output corresponding to the address of the second memory 7 is input from the first and second setter 11.12 to the arithmetic unit 15, and the
Since the data output corresponding to the address of the second memory T is inputted from the launch circuits 13 and 14 of , the arithmetic unit 15 calculates the time difference between two points of the output waveform,
The voltage difference and the like can be calculated and the result of the calculation can be displayed on the display 16. For example, when displaying the time difference between two points of the output waveform, the calculator 15 calculates the time difference from the numerical output of the first setting device 11 and the numerical output of the second setting device. The output can be displayed on display 16. In addition, when displaying the voltage difference between two points of the output waveform, the calculator 15 calculates the voltage difference from the data output of the first launch circuit 13 and the data output of the second launch circuit 14. , the voltage difference output can be displayed on the display 16. At this time, the matching outputs from the digital comparators 9 and 10 are sent to the brightness modulation circuit 5 as the brightness signal B through the OR gate 17, so that the brightness modulation circuit 5 receives the brightness signal and outputs the output from the cathode ray tube 6. A cursor will be displayed between two points on the waveform.

In this way, according to the above embodiment, while displaying the cursor between two time axis points on the tube surface output waveform of the cathode ray tube 6, the time difference corresponding to the two time axis points is determined.

Information such as voltage difference can be displayed. In addition, since the data in the memory that stores the output waveform and the numerical output of each setting device are processed digitally, there is no reading error caused by measuring instruments, unlike in the past, and there are no differences in time or voltage on the output waveform. information can be displayed accurately. Furthermore, since each processing system can be entirely digitalized, the configuration is much simpler than that using conventional analog comparators, which has the advantage of making the device smaller and lower in cost.

Note that the present invention is not limited to the above embodiments,
The arithmetic processing of the arithmetic unit 15 is not limited to the relationship between two points on the output waveform, but may also display the value of one point corresponding to the first and second setters 11 and 12. Further, the calculation results of the calculation unit 15 can be displayed on the cathode ray tube 6 using a separate display 16 or by using a well-known character display means.

As explained above, according to the present invention, it is possible to extract information at any time axis point on the screen output waveform in a waveform storage device such as a digital storage scope, and also to extract the time difference and information corresponding to the time axis point. Information such as voltage differences can be displayed easily and accurately. Moreover,
Miniaturization of equipment.

It has excellent effects such as cost reduction.

[Brief explanation of drawings]

The figure is a basic block diagram showing an embodiment of a waveform display device according to the present invention. 1... AD converter, 2... first memory, 3...
... DA converter, 4 ... sweep circuit, 5 ... brightness modulation circuit, 6 ... cathode ray tube, 7 ... second memory, 8 ... address counter, 9...first digital comparator, 10...second digital comparator,
11...First setter, 12...Second setter, 13...First latch circuit, 14...Second launch circuit, 15...Calculation Device, 16...Display device, 1T...OR gate. Patent applicant: Hitachi Electronics Co., Ltd. Agent: Masaki Yamakawa (1 person)

Claims (1)

[Claims] In a waveform display device that converts an input signal into a digital signal with an AD converter, stores the output in a memory, reads out the stored data, converts it from D to A, and displays it on a cathode ray tube as an analog waveform. first and second digital comparators each receiving a count output of an address counter that counts addresses in the memory;
a first setter capable of programmably setting the set value of the digital comparator; a second setter capable of programmably setting the set value of the second digital comparator; and the first digital comparator. A first launch circuit temporarily stores data corresponding to the memory address, and a second launch circuit temporarily stores data corresponding to the memory address based on the coincidence output of the second digital comparator. a latch circuit, a calculation means that receives as input data outputs temporarily stored in the first and second launch circuits and numerical outputs set in the first and second setters and performs calculations based on these respective outputs; and display means for displaying calculation results obtained from the calculation means, and displaying information such as time differences and voltage differences corresponding to arbitrary time axis points of the tube output waveform. Device.