CN102109543B - Digital three-dimensional oscilloscope with real-time waveform image zooming function - Google Patents

Abstract

The invention discloses a digital three-dimensional oscilloscope with a real-time zooming function, which combines a three-dimensional image processing technology with a large-capacity data storage technology, and in a screen refreshing period of the digital three-dimensional oscilloscope, all original waveform data before extraction, which are sent to a waveform image processor and correspond to sampling point sample values for drawing a three-dimensional waveform image, are sent to a large-capacity storage device in parallel for synchronous storage. Therefore, after the waveform mapping is finished, the waveform image processor can still flexibly read original waveform data from the large-capacity memory again according to the operation and display requirements of a user, and extract sampling values according to different scaling ratios to rapidly draw a new three-dimensional waveform image, so that the digital three-dimensional oscilloscope realizes image scaling and other operation operations on any captured signal while ensuring high waveform capture rate, and always keeps a three-dimensional waveform image display mode without losing captured signal details.

Description

A digital three-dimensional oscilloscope with real-time scaling function of waveform image

technical field

The invention belongs to the technical field of digital three-dimensional oscilloscopes, and more specifically relates to a digital three-dimensional oscilloscope with a waveform image real-time scaling function.

Background technique

Digital oscilloscope technology has developed from digital storage oscilloscope to digital three-dimensional oscilloscope (defined in Chinese national standard "GB/T 15289-2009 General Specification for Digital Storage Oscilloscope"), and is constantly moving towards high sampling rate, high waveform capture rate and deep storage development in other directions.

Due to the serial processing architecture of traditional digital storage oscilloscopes, the acquisition dead time is long and the waveform capture rate is low, usually within 100wfms/s, which is easy to lose signal details and miss transient events. In addition, digital storage oscilloscopes do not have brightness level changes like analog oscilloscopes in display effect, and can only capture signals in two-dimensional form, that is, amplitude and time.

The digital three-dimensional oscilloscope, represented by the digital phosphor oscilloscope (DPO) launched by Tektronix, adopts a parallel processing architecture, and a new dedicated waveform image processor works in parallel with the system microprocessor, which can effectively shorten the acquisition dead time. , improve the waveform capture rate, the highest waveform capture rate of high-end digital 3D oscilloscope can reach more than 400000wfms/s. At the same time, digital three-dimensional oscilloscopes use three-dimensional arrays to capture signals in the form of amplitude, time, and distribution of amplitude changes over time, displaying brightness levels and even color fluorescent effects similar to analog oscilloscopes. The ultra-high waveform capture rate of the digital 3D oscilloscope combined with the 3D waveform display capability can capture details and abnormal conditions in various complex dynamic signals, increasing the possibility of proving transient events in digital systems.

Fig. 1 is a structural block diagram of a digital three-dimensional oscilloscope in the prior art.

In the prior art, as shown in FIG. 1 , the input analog signal undergoes signal conditioning in the signal conditioning circuit, and then undergoes ADC conversion. Under the control of the trigger and time base circuit, the converted data is stored in the buffer.

As shown in Figure 1, the digital 3D oscilloscope is equipped with a waveform image processor, which is responsible for drawing 3D waveform images at high speed. Complete other tasks such as system control and data calculation.

The mapping process of the waveform image corresponds to the continuous accumulation and update of data in the three-dimensional data storage array. Its essence is to superimpose multiple two-dimensional waveform images together, and to count the distribution of amplitude changes with time, that is, probability information. When a refresh cycle arrives, the waveform mapping terminates, the three-dimensional data storage array device stops updating, and the display window selector selects the corresponding display window area of the three-dimensional waveform image in the three-dimensional data storage array device, and outputs it to the display memory to complete the display. The three-dimensional waveform image superimposed on the two waveforms is displayed on the display screen with different brightness levels or color fluorescent effects according to the probability distribution, so that the user can intuitively observe the three-dimensional signal amplitude, time, and the distribution of amplitude changes over time. information. This is the core and advantage of digital 3D oscilloscope technology.

However, there is a common defect in the existing 3D image processing technology: when the user checks some details in the 3D waveform image captured by the digital 3D oscilloscope, such as one of the multiple waveforms superimposed together or one of them When you are interested in a transient signal, you generally operate the oscilloscope to stop the acquisition, and then perform the following two operations:

1. Directly change the time base position of the digital 3D oscilloscope, zoom in or zoom out the waveform image, and further observe the signal details;

2. Operate the digital 3D oscilloscope to enter the window expansion mode, and compare and observe the waveform images before and after expansion (enlarged) in the dual windows.

However, the results of these two operations will cause the display of the digital 3D oscilloscope to suddenly change from a 3D waveform image effect to a 2D waveform image effect like an ordinary digital storage oscilloscope, that is, the display only retains a part drawn by the last collected data. A two-dimensional waveform image loses the signal details contained in multiple waveforms originally captured in a three-dimensional waveform image. The reason is that the essence of the above-mentioned waveform mapping is to continuously superimpose a series of two-dimensional waveform images into the three-dimensional data storage array. The process does not store the original collected data, and finally displays a pre-superimposed image. The system cannot strip out each waveform before superimposition, so it cannot redraw the 3D waveform image after zooming or window expansion, that is, the image cannot be dynamically zoomed. This defect directly leads to the fact that although most of the current digital 3D oscilloscopes have ultra-high waveform capture rate and can capture various complex transient events, they are weak in zooming and displaying images and analyzing data of transient events.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a digital three-dimensional oscilloscope with a real-time scaling function of waveform images.

In order to achieve the above object, the present invention has a digital three-dimensional oscilloscope with a waveform image real-time zoom function, including: a signal conditioning module, an acquisition and processing module, and a control and display module;

The signal conditioning module adjusts the input analog signal to the input range required for ADC conversion, and then sends it to the acquisition and processing module ADC for analog-to-digital conversion, and at the same time provides a trigger pulse signal to the acquisition and processing module to control the acquisition and processing of waveform data;

The acquisition and processing module includes ADC, waveform image processor, three-dimensional data storage array and display window selector;

The control and display module includes a microprocessor, a display memory and a display screen, and the microprocessor controls the acquisition and processing module and the display memory;

It is characterized by:

The acquisition and processing module also includes a raw value memory, a sample value extractor and a large-capacity memory;

The acquisition and processing module controls the ADC to perform analog-to-digital conversion on the conditioned analog signal according to the higher real-time sampling rate F _max , and outputs the original waveform data to the original value memory; the original value memory converts the original waveform under the control of the trigger pulse signal The data is stored according to the storage depth D, and the D original waveform data is full, and the acquisition of one waveform data is completed.

The acquisition and processing module controls the sample value extractor to extract N snapshot data from the D original waveform data in the original value memory according to the sampling interval of F _max /F, and send it to the waveform image processor to draw a two-dimensional waveform image, and perform waveform mapping, and superimpose this waveform image into the three-dimensional data storage array, where:

There is the following relationship between the number N of snapshot data of a two-dimensional waveform image and the storage depth D:

N＝D·F/ _Fmax

Among them, F is the equivalent sampling rate corresponding to the current time base file;

At the same time, under the control of the acquisition and processing module, the large-capacity memory stores D original waveform data in the original value memory;

After the waveform data is extracted, mapped and stored in the large-capacity memory, under the control of the trigger signal, the acquisition of the next waveform is repeated, and the original waveform data is extracted, mapped and stored in the large-capacity memory. Second, obtain the three-dimensional waveform image after the superimposition of L two-dimensional waveform images in the three-dimensional data storage array device, and obtain the original data of L rows in the large-capacity memory;

During normal 3D waveform display, when a refresh cycle comes, the waveform mapping is terminated, the 3D data storage array stops updating, and the display window selector selects the corresponding display window area of the 3D waveform image in the 3D data storage array, and outputs it to the display The memory completes the display, that is, the three-dimensional waveform image after multiple waveforms are superimposed is displayed on the display screen with different brightness levels or color fluorescent effects according to the probability distribution;

When performing real-time zooming operations, the waveform image processor accesses the large-capacity memory in real time, reads the original waveform data, and extracts them according to the new sampling interval F _max /F' through the sample value extractor, re-maps and displays real-time zooming The three-dimensional waveform image of , where F' is the equivalent sampling rate corresponding to the time base gear under the zoom operation.

The purpose of the invention of the present invention is achieved like this:

With the rapid development of DDR, DDR2 and other storage technologies and the continuous reduction of cost and price, large-capacity storage has been widely used in digital oscilloscope systems. In the digital three-dimensional oscilloscope, the present invention combines a three-dimensional image processing technology with a large-capacity data storage technology. In a screen refresh cycle of the digital three-dimensional oscilloscope, the data sent to the waveform image processor for three-dimensional waveform image drawing All the original waveform data before extraction corresponding to the sampling point sample value are sent in parallel to the large-capacity memory for synchronous storage. In this way, after the waveform mapping is completed, the waveform image processor can still flexibly read the original waveform data from the large-capacity memory according to the user's operation and display needs, and extract sample values according to different scaling ratios to quickly draw new 3D waveforms The image enables the digital 3D oscilloscope to achieve image zooming and other calculation operations on any captured signal while ensuring a high waveform capture rate, and always maintains the display mode of the 3D waveform image without losing the details of the captured signal.

Description of drawings

Fig. 1 is the structural block diagram of prior art digital three-dimensional oscilloscope;

Fig. 2 is a schematic block diagram of a specific embodiment of a digital three-dimensional oscilloscope with a waveform image real-time zoom function in the present invention;

Fig. 3 is the schematic diagram that the large-capacity memory shown in Fig. 2 stores original waveform data;

Fig. 4 is a schematic diagram of waveform positioning before real-time scaling of the waveform image;

Fig. 5 is a schematic diagram of waveform positioning before real-time scaling of the waveform image;

Fig. 6 is a three-dimensional waveform image before real-time zooming;

Fig. 7 is the zoomed two-dimensional waveform image of the prior art digital three-dimensional oscilloscope;

Fig. 8 is a two-dimensional waveform image under the window extension mode of a digital three-dimensional oscilloscope in the prior art;

Fig. 9 is the zoomed three-dimensional waveform image of the digital three-dimensional oscilloscope with waveform image real-time zoom function in the present invention;

Fig. 10 is a three-dimensional waveform image in the window expansion mode of the digital three-dimensional oscilloscope with the waveform image real-time zoom function of the present invention.

Detailed ways

Specific embodiments of the present invention will be described below in conjunction with the accompanying drawings, so that those skilled in the art can better understand the present invention. It should be noted that in the following description, when detailed descriptions of known functions and designs may dilute the main content of the present invention, these descriptions will be omitted here.

Example

Fig. 2 is a functional block diagram of a specific embodiment of a digital three-dimensional oscilloscope with a waveform image real-time zoom function according to the present invention.

In this embodiment, as shown in FIG. 1 , the digital three-dimensional oscilloscope with real-time zooming function of waveform images of the present invention includes three parts: signal conditioning module 1 , acquisition and processing module 2 , and control and display module 3 .

The signal conditioning module 1 includes a signal conditioning channel 101 and a trigger circuit 102 . The signal conditioning channel 101 adjusts the input analog signal to the input range required for ADC conversion, and then sends it to the ADC 201 in the acquisition and processing module 2 for analog-to-digital conversion, while the trigger circuit 102 selects the external trigger signal or the internal trigger signal as the trigger signal, And generate a trigger pulse signal to the acquisition and processing module 2 to control the acquisition and processing of waveform data. The conditioning, analog-to-digital conversion, and acquisition of the input analog signal belong to the prior art, and will not be repeated here.

The acquisition and processing module 2 includes an ADC 201, a waveform image processor 202, a three-dimensional data storage array 203, and a display window selector 204; the control and display module 3 includes a microprocessor 301, a display memory 302, and a display screen 303. The microprocessor 301 adopts a DSP for controlling the acquisition and processing module 2 and the display memory 302 .

As shown in Figure 1, in the present invention, the collection and processing module also includes a raw value memory 205, a sample value extractor 206 and a large capacity memory 207; a waveform image processor 202, a three-dimensional data storage array device 203, a display window selector 204, the original value memory 205 and the sample value extractor 206 are formed by one FPGA. The mass memory 207 is a DDR2 memory.

The acquisition and processing module 2 controls the ADC 201 according to a higher real-time sampling rate F _max , in this embodiment, the highest real-time sampling rate performs analog-to-digital conversion on the conditioned analog signal, and outputs the original waveform data to the original value memory 205 , the original value memory 205 is a FIFO memory; the original value memory 205 stores the original waveform data according to the storage depth D under the control of the trigger pulse signal, and the D original waveform data are full, and the acquisition of one waveform data ends.

The acquisition and processing module 2 controls the sample value extractor 206 to extract N snapshot data from the D original waveform data in the original value memory according to the sampling interval of F _max /F, and send it to the waveform image processor 202 to draw a frame Two-dimensional waveform image, and carry out waveform mapping, this piece of waveform image is superimposed in the three-dimensional data storage array device 203, there is the following relationship between the number of snapshot data N of the two-dimensional waveform image and the storage depth D:

N＝D·F/ _Fmax

Among them, F is the equivalent sampling rate corresponding to the current time base file.

At the same time, under the control of the acquisition and processing module 2 , the large-capacity storage 207 stores D pieces of original waveform data in the original value storage 205 .

After the waveform data is extracted, mapped and stored in the large-capacity memory 207, under the control of the trigger signal, the acquisition of the next waveform is repeated, and the original waveform data is extracted, mapped and stored in the large-capacity memory L times, the three-dimensional waveform image after superposition of L pieces of two-dimensional waveform images is obtained in the three-dimensional data storage array device 203 , and the original data of L rows is obtained in the large-capacity memory 207 .

During normal three-dimensional waveform display, when a refresh cycle arrives, the waveform mapping is terminated, the three-dimensional data storage array 203 stops updating, the window selector 204 selects the corresponding display window area of the three-dimensional waveform image in the three-dimensional data storage array 203, and outputs When the display memory 302 is finished displaying, the three-dimensional waveform image after multiple waveforms are superimposed is displayed on the display screen 303 with different brightness levels or color fluorescent effects according to the probability distribution;

When performing a real-time zoom operation, the waveform image processor 202 accesses the large-capacity memory 207 in real time, reads the original waveform data, and extracts the sample value extractor 206 according to the new sampling interval F _max /F', and re-maps, Displays the real-time zoomed three-dimensional waveform image, where F' is the equivalent sampling rate corresponding to the time base gear under the zoom operation.

Fig. 3 is a schematic diagram of storing original waveform data in the large-capacity memory shown in Fig. 2 .

As shown in Figure 3, in this embodiment, the address space of the large-capacity data memory DDR2 is divided into a table of L rows multiplied by D columns, that is, the total number of address units is L*D: the row address L depends on the digital three-dimensional oscilloscope The waveform capture rate of the oscilloscope, that is, the number of waveforms that are captured within one refresh cycle and need to be stored is L; the column address D depends on the number of original waveform data that stores a waveform, that is, the storage depth D of the oscilloscope. Correspondingly store all the original waveform data from the original value memory 205 in the row and column space of the large-capacity data memory 207 . That is, one row of original data of each waveform is stored correspondingly, a total of L rows are stored, and D pieces of original data are stored in each row.

In this embodiment, when performing real-time zooming operations, the waveform image processor 202 accesses the large-capacity memory 207 in real time, reads the original waveform data, and extracts the data according to the new sampling interval F _max /F' through the sample value extractor 206 , the specific process of re-mapping and displaying the real-time zoomed three-dimensional waveform image is as follows:

1. Clear old images

First according to the address of the three-dimensional waveform image in the screen display window area selected by the display window selector 204 before performing the scaling operation in the three-dimensional data storage array device RAM and the sampling interval of the sample value extractor 206, calculate this section of three-dimensional waveform image The address of the corresponding waveform data in the original value memory 205;

Fig. 4 is a schematic diagram of waveform positioning before real-time zooming of the waveform image. As shown in Figure 4, the address corresponding to the three-dimensional data storage array device 203 on the left side of the display window is u, the address on the right side is u+v, and v is the width of the waveform display window, then the corresponding waveform data is stored in the original value memory 205 The address is u*F _max /F～(u+v)*F _max /F. Then all the old three-dimensional waveform images in the three-dimensional data storage array device 203 are cleared;

2. Read new data and draw new waveform

The waveform image processor 202 accesses _the first line of the large-capacity memory 207, and the sample value extractor 206 extracts N'=D*F'/ F _max data is processed into a two-dimensional waveform image, and this image is superimposed into the three-dimensional data storage array device 203; the operation of the first row is repeated on the second to L rows of the large-capacity memory 207, and finally the obtained A new three-dimensional waveform image after superposition of L waveforms;

3. Determine the display window range

According to the scaling ratio F'/F of the new 3D waveform image after zooming and the old 3D waveform image before zooming, calculate the display window range of the zoomed image: u*F'/F～(u+v)*F'/ F, where u*F'/F is the address corresponding to the left side of the display window in the three-dimensional data storage array device is u, and u+v is the corresponding address on the right side, as shown in FIG. 5 .

example

In this example, the highest real-time sampling rate of the ADC of the digital 3D oscilloscope is 2GS/s, which is taken as the higher real-time sampling rate F _max , the storage depth is D=100Kpts, and the horizontal display direction is 50dot/div. The time base of the digital 3D oscilloscope is 200ns/div, and the equivalent sampling rate F=50dot/div/200ns/div=250MS/s corresponding to the time base. Then the sampling interval F _max /F = 2GS/s/250MS/s = 8, that is, extract 1 from every 8 original collected data, and extract a total of N = D*F/F _max = 100Kpts*250MS/s/ 2GS/s=12.5K pieces of data draw a two-dimensional waveform image and superimpose it into the three-dimensional data storage array 203 . Then, when a refresh cycle comes, the three-dimensional waveform image generated by superimposing multiple two-dimensional waveform images in the three-dimensional data storage array 203 is sent to the display screen for display, as shown in FIG. 6 .

At this time, if the acquisition system of the digital 3D oscilloscope is stopped, and the time base of the digital 3D oscilloscope is changed to 50ns/div, then the equivalent sampling rate F'=50dot/div/50ns/div=1GS/ s.

Then, the digital three-dimensional oscilloscope not using the present invention will be automatically changed to the two-dimensional waveform image display as shown in FIG. 7 .

Or, after the acquisition system of the digital three-dimensional oscilloscope is stopped, the digital three-dimensional oscilloscope is operated to enter the window expansion mode. Similarly, the digital three-dimensional oscilloscope of the present invention will also be automatically changed to a two-dimensional waveform image display as shown in FIG. 8 .

And adopt the digital three-dimensional oscilloscope with waveform image real-time zooming function of the present invention, if the system detects that after the collection stops, there is still switching time base files to zoom or enter the window expansion mode operation, and will read each of the large-capacity storage DDR2 in turn. 1 line, send the read original acquisition data to the sample value extractor, and extract N'=D*F'/F _max according to the sampling interval of F _max /F'=2GS/s/1GS/s=2 =100Kpts*1GS/s/2GS/s=50K collected data are processed into a two-dimensional waveform image, and this image is superimposed into the RAM of the three-dimensional data storage array device, and the above operations are repeated until a refresh cycle arrives, which can be A new three-dimensional waveform image generated by superimposing multiple two-dimensional waveform images is obtained. Then, according to the zoom ratio F'/F of the new image after zooming and the old image before zooming, calculate the display window range of the zoomed image: u*F'/F～(u+v)*F'/F, namely 4u ~4(u+v). Finally, under the control of the trigger circuit, the finally displayed three-dimensional waveform image can be obtained, as shown in Fig. 9 and Fig. 10 .

Although the illustrative specific embodiments of the present invention have been described above, so that those skilled in the art can understand the present invention, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, As long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present invention are included in the protection list.

Claims (3)

1. the digital three-dimensional oscillograph with the real-time zoom function of waveform image comprises: signal condition module, collection and processing module and control and display module;

The signal condition module is changed the required input scope with the analog signal conditioner of input to ADC, then send among collection and the processing module ADC and carry out analog to digital conversion, provide simultaneously start pulse signal to gathering with processing module the acquisition and processing of Wave data to be controlled;

Gather with processing module and comprise ADC, waveform image processor, three-dimensional data storage array device and display window selector switch;

Control comprises microprocessor, display-memory and display screen with display module, and microprocessor is controlled collection and processing module, display-memory;

It is characterized in that:

Gather with processing module and also comprise original value storer, sample value withdrawal device and mass storage;

Gather with processing module control ADC according to higher real-time sampling rate F _MaxSimulating signal after the conditioning is carried out analog to digital conversion, and the output original waveform data is in the original value storer; The original value storer is stored according to storage depth D original waveform data under the control of start pulse signal, and original waveform data is filled with, and 1 amplitude wave graphic data collection finishes,

Gather with processing module control sample value withdrawal device according to F _MaxThe interval of taking out of/F extracts the individual data of taking out of N from the original waveform data of original value storer, send into the waveform image processor and be plotted as 1 width of cloth dimensional waveform image, and carry out waveform mapping, this amplitude wave shape image is added in the three-dimensional data storage array device, wherein:

Taking out of 1 width of cloth dimensional waveform image has following relation between a data number N and the storage depth D:

N＝D·F/F _max

Equivalent sampling rate corresponding to base shelves when wherein, F is current;

Simultaneously, under collection and processing module were controlled, mass storage was stored the original waveform data in the original value storer;

Wave data is extracted, shines upon and in mass storage the storage complete after, under the control of trigger pip, repeat next amplitude wave shape is gathered, original waveform data is extracted, shines upon and stores L time in mass storage, in the three-dimensional data storage array device, obtain the three-dimensional waveform image after L width of cloth dimensional waveform image superposes, in mass storage, obtain the capable original waveform data of L;

When normal three-dimensional waveform shows, arrive when a brush screen cycle, the waveform mapping stops, the three-dimensional data storage array device stops to upgrade, the display window selector switch is chosen the corresponding display window zone of the three-dimensional waveform image in the three-dimensional data storage array device, output to display-memory and finish demonstration, soon the three-dimensional waveform image after several waveforms stacks adopts different briliancy grades or color fluorescence effect to show at display screen according to probability distribution;

When carrying out real-time zoom operations, waveform image processor real time access mass storage reads original waveform data, and process sample value withdrawal device is according to a new interval F that takes out _Max/ F ' extracts, and re-starts the three-dimensional waveform image of mapping, the real-time convergent-divergent of demonstration, and wherein, F ' is equivalent sampling rate corresponding to zoom operations base gear of lower time.

2. the digital three-dimensional oscillograph with the real-time zoom function of waveform image according to claim 1, it is characterized in that, described when carrying out real-time zoom operations, waveform image processor real time access mass storage, read original waveform data, and process sample value withdrawal device is according to a new interval F that takes out _Max/ F ' extracts, and re-starts mapping, shows that the idiographic flow of the three-dimensional waveform image of real-time convergent-divergent is:

A, remove old image

At first according to carry out three-dimensional waveform image in the screen display window area that the display window selector switch is chosen before the zoom operations in the three-dimensional data storage array device the address and the sample value withdrawal device take out an interval, calculate the address of Wave data in the original value storer corresponding to this section three-dimensional waveform image;

The display window left side is u corresponding to the address of three-dimensional data storage array device, and the address, right side is u+v, and v is the waveform display window width, and then the corresponding address of Wave data in the original value storer is u*F _MaxThe * F of/F～(u+v) _Max/ F is then with three-dimensional waveform image full scale clearance old in the three-dimensional data storage array device;

B, read new data, draw new waveform

The 1st row of waveform image processor access mass storage, the sample value withdrawal device is according to F _MaxThe interval of taking out of/F ' extracts N '=D*F '/F from the 1st row original waveform data _MaxIndividual data are treated to 1 width of cloth dimensional waveform image, and this width of cloth image is added in the three-dimensional data storage array device; To the capable operation that repeats such as the 1st row of the 2nd～L of mass storage, finally obtain the new three-dimensional waveform image after L amplitude wave shape superposes;

C, determine the display window scope

According to three-dimensional waveform imagezoom old before three-dimensional waveform image new behind the convergent-divergent and the convergent-divergent than F '/F, calculate the display window scope of image behind the convergent-divergent: * the F '/F of u*F '/F～(u+v), wherein, u*F '/F is that address corresponding to display window left side is u in the three-dimensional data storage array device, and u+v is address corresponding to right side.

3. the digital three-dimensional oscillograph with the real-time zoom function of waveform image according to claim 1 is characterized in that, described higher real-time sampling rate F _MaxBe digital three-dimensional the highest oscillographic real-time sampling rate.

Images