Phase difference test and amplitude-frequency characteristic frequency sweep measurement system design method based on LabVIEW and PXI

Abstract

The invention discloses a phase difference test and amplitude-frequency characteristic frequency sweep measurement system design method based on LabVIEW and PXI. The method comprises the following steps: controlling PXI hardware by using LabVIEW programming to realize cooperative control of signal generation and acquisition, phase difference dynamic measurement, frequency sweep signal generation and amplitude-frequency characteristic analysis, and multi-dimensional data recording and verification functions. The system generates an elliptical image and automatically calculates a phase difference through a multi-dimensional technology fusion architecture based on a Lissajous graphic method, supports formulated analysis and multi-band phase difference verification, and solves the problems of low efficiency and large error of traditional manual measurement. And the frequency range is verified through a self-defined algorithm by using a sweep-frequency amplitude-frequency characteristic analysis technology, the cut-off frequency is quickly positioned, and an amplitude-frequency characteristic curve is generated, so that the test efficiency and precision are remarkably improved. The limitation of point-by-point measurement and manual operation of a traditional instrument is broken through, and integration, automation and digitization of phase difference testing and amplitude-frequency characteristic analysis are achieved through deep fusion of LabVIEW and PXI.

Description

Technical Field

[0001] The present invention discloses a design method for a phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI, which relates to the technical field of the development of automated measurement and control systems. Specifically, this method innovatively integrates the Lissajous figure phase analysis algorithm and the swept-frequency frequency domain response measurement technology, breaks through the limitations of traditional instrument discrete measurement, significantly improves the measurement accuracy of the phase difference of high-frequency signals and the sweep test efficiency of wide frequency bands, and can be widely applied to scenarios such as filter characteristic analysis, harmonic detection in communication systems, and impedance characteristic testing of power electronic devices that require joint debugging of time-frequency domain multi-dimensional parameters. Background Art

[0002] Traditional signal test systems have long faced the inherent defects of the discrete measurement mode in phase difference detection and amplitude-frequency characteristic analysis: the time-domain phase characteristics and frequency-domain amplitude response data are fragmented, resulting in systematic error risks in scenarios such as filter group delay and communication harmonic analysis; manual sweep operation relies on the oscilloscope to trigger and adjust point by point, with poor sweep step accuracy and easy loss of accuracy of high-frequency signals; there are timing deviations in the multi-device collaborative control of LabVIEW, leading to timing misalignment between phase difference measurement and sweep signal timing, and it is difficult to meet the high-frequency and high-precision test requirements of 5G communication millimeter waves, radar pulses, etc. In response to the above bottlenecks, the present invention constructs a comprehensive measurement system for time-frequency domain signal characteristics based on the LabVIEW and PXI architectures, innovatively integrates the Lissajous figure phase analysis algorithm and the swept-frequency spectrum analysis technology, synchronously outputs sweep / reference signals through the dual channels of the PXIe-5402 function generator, and combines multi-channel hardware synchronization acquisition of the PXIe-5114 oscilloscope to achieve dynamic correlation measurement of phase-frequency and amplitude-frequency characteristics.

[0003] Compared with the prior art, the technical differences are as follows:

[0004] Technical comparison with the patent CN107907892A "A navigation signal simulator, a closed-loop controller and a closed-loop test method based on the PXI architecture"

[0005] 1. The navigation signal simulator of the patent CN107907892A is based on a dedicated PXI architecture and is designed specifically for the closed-loop test of satellite navigation receivers. Its core functions are the generation of high-dynamic navigation signals (carrier frequency, code phase) and interaction with real-time dynamic models. The hardware is highly customized, emphasizing aerospace-level real-time performance. While this patent adopts a general PXI modular architecture (signal generator + oscilloscope), combines LabVIEW to achieve multi-dimensional signal analysis, supports waveform generation and time-frequency domain cross-verification, has flexible hardware configuration, adapts to the test requirements of multiple scenarios such as communication, education, and industry, and significantly improves the scalability.

[0006] Second, Patent CN107907892A focuses on the aerospace field, specifically for the navigation receiver test of the satellite attitude control subsystem, with its function bound to space environment simulation. This patent breaks through the field limitations, covering three scenarios: educational experiments, electronic R & D, and industrial inspection. It generates complex waveforms through parametric configuration, supports the replacement of high-risk / high-cost tests, and solves cross-field problems such as filter group delay and communication link distortion, with stronger horizontal technical penetration.

[0007] Third, Patent CN107907892A relies on a local hardware closed-loop (direct connection of the upper computer and the lower computer via network cable), and data interaction is limited within the LabVIEW RT system, without remote operation or cloud interaction functions. This patent constructs a distributed test network, integrating VISA remote control, LabVIEW Web services, and cloud data upload, supporting multi-user collaborative operation, and achieving hardware-level synchronization through the PXI backplane trigger bus, with a significant improvement in efficiency compared to traditional solutions and a significant technological generation gap. Summary of the Invention

[0008] Aiming at the problems in traditional phase difference measurement and amplitude-frequency characteristic analysis, such as discrete testing, low manual efficiency, and large hardware collaboration errors, the present invention realizes the automatic joint test of phase-frequency characteristics and amplitude-frequency characteristics by deeply integrating the PXIe-5402 function generator and the PXIe-5114 oscilloscope. The system adopts a modular hardware architecture, relying on the high-speed bus interconnection of the PXI backplane, supporting synchronous triggering and data closed-loop interaction between the signal generator and the oscilloscope, eliminating the complexity of cable connection and timing misalignment problems of traditional bench instruments, and significantly improving the reliability of high-frequency signal testing.

[0009] The present invention synchronously collects the input / output signals of the system under test, synchronously generates the amplitude-frequency attenuation curve and the phase difference change curve during a single sweep frequency process, and based on the theoretical correlation between the two, dynamic mutual verification can be achieved: for example, when the amplitude-frequency curve shows the cut-off frequency point, we can verify whether the phase difference reaches the expected value. If the deviation exceeds the limit, hardware self-check or local retesting is triggered, thereby improving the test accuracy through two-dimensional data cross-verification and solving the problems of error isolation and low efficiency in traditional independent measurements, and being applicable to fast and highly reliable frequency-domain analysis in scenarios such as filters and communication links.

[0010] To achieve the above object, the technical solution adopted by the present invention is:

[0011] A design method for a phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI, characterized by including the following steps:

[0012] Step 1: Construct a signal processing hardware closed-loop and a unified analysis architecture;

[0013] Establish a hardware closed-loop link through a signal generator and an oscilloscope. Use BNC-BNC connecting wires to directly connect the signal generation and acquisition channels, and synchronize the clock and trigger signal based on the PXI backplane bus to achieve unified measurement of time, frequency, and phase characteristics;

[0014] Design parallel threads in LabVIEW to separately control the signal generator to output a swept-frequency signal and a fixed-frequency signal, and collect data through the oscilloscope to generate an amplitude-frequency characteristic curve and calculate the phase difference by the Lissajous figure method. Cross-verify the signal integrity with the two sets of data;

[0015] Step 2: Signal characteristic fusion verification and dynamic correction;

[0016] Integrate a spectrum analysis module and an ellipse image analysis module in the LabVIEW program block diagram. When there is a deviation in the cut-off frequency of the amplitude-frequency test and the phase difference result of the phase-frequency test within the time-frequency correlation range, dynamically adjust the output parameters of the signal generator to ensure the system consistency of time interval, frequency, and phase characteristics;

[0017] Step 3: Multidimensional characteristic output under a unified system scope;

[0018] Based on the same hardware architecture, synchronously output the amplitude-frequency characteristic curve and the phase-frequency characteristic parameters, and centrally display the time-domain waveform, spectrum diagram, and XY-mode image through the LabVIEW front panel to verify the correlation of time, frequency, and phase as the core indicators of signal integrity in electronic measurement.

[0019] As a further improvement of the present invention, the following specific steps are required to calculate the phase difference by the Lissajous figure method in Step 1:

[0020] The steps to configure FGEN are as follows:

[0021] 1) Open PXI FGEN Generator and Acquisition.vi, and save it as Lissajous with FGEN&SCOPE.vi to the Exercises folder;

[0022] 2) Open Lissajous with FGEN&SCOPE.vi and convert some parameters into constants;

[0023] 3) Configure FGEN;

[0024] 4) Use local variables and property nodes to change the output waveform of FGEN;

[0025] The steps of the main vi function of FGEN are as follows:

[0026] 1) Start the session control module of the PXI signal generator through the device driver function to establish a hardware communication link;

[0027] 2) Execute the driver function instruction to complete the operation mode switch of the signal generator from the pre-configured standby state to the real-time waveform output;

[0028] 3) Set the output mode to custom waveform or predefined sequence type through the waveform generation function;

[0029] 4) Call the parameterized waveform configuration function to define the core parameters of the standard waveform, including signal type, fundamental frequency, and amplitude;

[0030] 5) Transmit the logic control instruction to activate the output enable state of the specified channel of the signal generator;

[0031] 6) Execute the waveform generation driver function to achieve the complete link trigger from parameterized configuration to physical signal output;

[0032] 7) Add a conditional loop and add a conditional structure for changing the frequency in the conditional loop;

[0033] 8) Execute the synchronous trigger instruction function to send a hardware cascade trigger or timing synchronization signal to an external device;

[0034] 9) Call the session termination function to destroy the FGEN device session handle and its configuration attributes, and release all memory resources occupied during the operation of FGEN.

[0035] As a further improvement of the present invention, the Lissajous figure method phase difference calculation in step 1 requires configuring the SCOPE and SCOPE main vi functions. The specific steps are as follows:

[0036] The steps for configuring SCOPE are as follows:

[0037] 1) Call the SCOPE device initialization function outside the loop structure to create a global session control module to establish an oscilloscope hardware communication link;

[0038] 2) Execute the parameter configuration function inside the loop logic to dynamically load the core parameters of the oscilloscope's sampling rate, record length, and vertical range;

[0039] 3) Set the edge trigger mode, trigger source, and reference position threshold of the oscilloscope through the trigger condition configuration function;

[0040] 4) Call the hardware resource release function to destroy the SCOPE session handle and clear the memory and bus resources it occupies;

[0041] The steps of the SCOPE main vi function are as follows:

[0042] 1) Call the hardware session management module to complete the establishment of device communication connections, resource allocation, and initialization of default parameters;

[0043] 2) Execute the channel vertical range configuration function to dynamically adjust the voltage measurement range of a single or dual channels of the oscilloscope;

[0044] 3) Call the signal integrity configuration function to define the impedance matching parameters and bandwidth limit thresholds of the oscilloscope channels;

[0045] 4) Through the horizontal timing parameter configuration module, set the sampling rate, record length, and trigger delay of the oscilloscope to achieve time-domain synchronization calibration;

[0046] 5) Modify the trigger mode property node to switch the trigger type of the oscilloscope;

[0047] 6) Call the auto-trigger logic instruction to force the oscilloscope to perform data capture at a preset period without a trigger signal;

[0048] 7) Call the data acquisition control function to start the multi-channel synchronous capture engine of the oscilloscope;

[0049] 8) Extract the original acquisition data stream, complete waveform rendering and display through the data visualization interface, and change the data type of the acquired data to a one-dimensional array of 32-bit integer data;

[0050] 9) Convert the coupling mode DC and attenuation coefficient 1.0 into constants.

[0051] As a further improvement of the present invention, the steps for calculating the phase difference by the Lissajous figure method in step 1 require configuring a simulation signal, and the steps for configuring the simulation signal are as follows:

[0052] 1) Find the simulation signal function from the function palette as the waveform in the X-axis direction of the XY graph;

[0053] 2) Create an Express XY graph on the front panel;

[0054] 3) Connect the output terminal of the simulation signal to the connection terminal collected by the SCOPE;

[0055] 4) Merge the error cluster wires through a simple error handler;

[0056] 5) Set the frequencies of the FGEN and the X-axis simulation signal;

[0057] 6) Observe the Lissajous image in the XY graph, judge and record the phase difference.

[0058] 5. According to the method for designing a phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI as described in claim 1, characterized in that;

[0059] In the step 1 of calculating the phase difference of the Lissajous figure method, the steps of measuring the phase difference of the test signal are as follows:

[0060] 1) Run LabVIEW, create a new VI file, and name it Measure Phase Distance with LABVIEW.vi;

[0061] 2) Add the required controls on the front panel interface;

[0062] 3) Create an event structure in the block diagram;

[0063] 4) Add events, including connecting the instrument, write operation, read operation, and exit;

[0064] 5) Add the program for the oscilloscope to collect data in the while loop;

[0065] 6) Run the program, input the instructions and make records.

[0066] 6. According to the method for designing a phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI described in claim 1, wherein;

[0067] In the step 2 of signal characteristic fusion verification and dynamic correction, the specific steps are as follows:

[0068] Call the PXI-FGEN and PXI-SCOPE drivers through LabVIEW to control the signal generator and the oscilloscope, use the PXI backplane trigger bus to achieve hardware clock synchronization, combine the Lissajous figure method to input the signal into the X / Y channels of the oscilloscope to generate an elliptical image, automatically analyze the phase difference through the ratio of the major and minor axes of the ellipse or the intersection coordinates, and form a closed-loop calibration link on the basis of dynamically correcting the phase parameters of the signal generator by real-time data comparison in LabVIEW to achieve microsecond-level dynamic measurement and error compensation of the phase difference.

[0069] As a further improvement of the present invention, the steps of the block diagram of the amplitude-frequency characteristic curve generation design program and the main vi function of the block diagram are as follows:

[0070] The steps of designing the block diagram are as follows:

[0071] 1) Connect CH0 of PXI-5402 to CH0 of the oscilloscope PXIe-5114;

[0072] 2) Write a program, create a numerical control, and adjust the starting frequency of the swept-frequency signal through this control;

[0073] 3) In the block diagram, initialize the FGEN, terminate the waveform output, and configure the parameters;

[0074] 4) Create a For loop;

[0075] 5) Create an Oscilloscope Express VI to acquire a sine wave signal;

[0076] 6) Add a Spectrum Analysis Express VI and connect it to the Oscilloscope Express VI;

[0077] 7) Create a Waveform Graph to display the time-domain signal and spectrum;

[0078] 8) Connect the error cluster, close the hardware session, save and run the VI;

[0079] 9) Modify the VI, add code to the VI to verify whether the signal frequency received by the oscilloscope is within the swept frequency range;

[0080] 10) Adjust the front panel layout, run the program and test;

[0081] The steps of the main vi function of the program block diagram are as follows:

[0082] 1) Call the instrument driver API interface to initialize the PXI signal generator control session and establish a device communication channel;

[0083] 2) Implement the conversion of the signal generator from the standby parameter preloading state to the dynamic waveform output mode through the driver interface command;

[0084] 3) Use the waveform mode selection interface to set the output type to user-defined waveform or standard sequence template;

[0085] 4) Run the waveform parameter configuration module and load the defined parameters of the standard waveform (including basic parameters such as waveform shape, fundamental frequency, amplitude threshold, etc.);

[0086] 5) Send a channel enable instruction to the signal generator to enable the physical output function of the target channel;

[0087] 6) Trigger the waveform generation engine to complete the full-process signal output from digital parameter configuration to analog signal output;

[0088] 7) Place the PXI-SCOPE Express VI to the right of the FGEN Frenquency property node;

[0089] 8) Place the Spectrum Measurement Express VI to the right of the PXI-Scope Express VI;

[0090] 9) Call the multi-device trigger synchronization interface to send a timing alignment pulse or a hardware-level trigger interlock signal to an external instrument;

[0091] 10) Execute the device session closing protocol, release the device control handle, and clear its configuration attributes as well as the occupied bus and memory resources.

[0092] The specific function implementation is as follows:

[0093] 1. Dual-channel synchronous triggering and data closed-loop: Through LabVIEW programming, control the PXIe-5402 to synchronously output a swept-frequency signal and a reference signal, and combine with the PXIe-5114 dual-channel synchronous acquisition to achieve the full-process automation test of "swept-frequency signal generation → dynamic phase difference detection → amplitude-frequency characteristic analysis → time-frequency domain data mutual verification".

[0094] 2. Dynamic parameter joint regulation: Support the real-time reconstruction of parameters such as the swept-frequency range, step interval, and phase difference detection sensitivity to meet the diverse requirements of scenarios such as filter group delay and communication harmonic analysis.

[0095] 3. Time-frequency domain cross-validation algorithm: Integrate the analysis of the elliptical parameters of the Lissajous figure (phase difference calculation) and the swept-frequency spectrum analysis technology, establish a correlation model between the time-domain phase shift and the frequency-domain amplitude attenuation, and can generate a comprehensive characteristic curve and an error calibration report.

[0096] The beneficial effects of the present invention;

[0097] 1. Double improvement in test efficiency and accuracy: Through the collaborative control of automated swept-frequency and dynamic phase difference detection, the wide-band scanning speed is greatly improved, the phase difference measurement accuracy is significantly higher than that of the traditional manual method, and at the same time, it supports the real-time mutual verification of time-frequency domain data to eliminate one-dimensional measurement errors.

[0098] 2. Deep integration of hardware resources: Utilize the PXI modular architecture and LabVIEW graphical programming to achieve centralized control and dynamic matching of the hardware parameters (frequency, amplitude, trigger conditions) of multiple devices, avoiding the operation redundancy and collaborative misalignment problems of traditional discrete instruments.

[0099] 3. Enhanced adaptability to complex scenarios: For the requirements of harmonic analysis of nonlinear systems and group delay testing of high-frequency filters, through the joint calculation of the time-frequency domain parameter matrix, the correlation characteristics of harmonic amplitude attenuation and phase distortion can be synchronously captured, providing high-confidence data support for multi-dimensional diagnosis of electronic systems. Description of the drawings

[0100] Figure 1 It is the front panel for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture for phase difference testing by the Lissajous figure method;

[0101] Figure 2 It is the program block diagram for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture for phase difference testing by the Lissajous figure method;

[0102] Figure 3 The front panel for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase difference of RIGOL signals;

[0103] Figure 4 The sub - vi for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase difference of RIGOL signals;

[0104] Figure 5 The block diagram for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase difference of RIGOL signals;

[0105] Figure 6 The connection of instruments and error handling of the sub - vi for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase difference of RIGOL signals;

[0106] Figure 7 The write operation and error judgment of the sub - vi for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase difference of RIGOL signals;

[0107] Figure 8 The read operation and error handling of the sub - vi for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase difference of RIGOL signals;

[0108] Figure 9 The exit situation of the sub - vi for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase difference of RIGOL signals;

[0109] Figure 10 The front panel for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to perform amplitude - frequency characteristic sweep measurement test;

[0110] Figure 11 The block diagrams of two sub - vis for function call and spectrum measurement of the amplitude - frequency characteristic sweep measurement system by using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture;

[0111] Figure 12 The block diagram for using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to implement the amplitude - frequency characteristic sweep measurement system;

[0112] Figure 13The front panel of the function call sub - VI for realizing the sweep measurement system of amplitude - frequency characteristics by using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture;

[0113] Figure 14 The block diagram of the function call sub - VI for realizing the sweep measurement system of amplitude - frequency characteristics by using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture;

[0114] Figure 15 An example of using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture for phase - difference testing by the Lissajous - figure method;

[0115] Figure 16 An example of using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase - difference of RIGOL signals;

[0116] Figure 17 An example of using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to realize the sweep measurement system of amplitude - frequency characteristics. Specific implementation manners

[0117] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners:

[0118] Design of the front panel:

[0119] The front panel designed in the present invention is constructed based on LabVIEW graphical programming. As the interaction interface between the user and the phase - difference testing and amplitude - frequency characteristic sweep measurement system, its core functions include signal parameter configuration, hardware collaborative control, and multi - dimensional data display. As shown in Figure 1 , Figure 3 and Figure 10 , the front panel is divided into the following functional modules:

[0120] Front panel for phase - difference testing:

[0121] 1. Waveform parameter setting area: Realize dual - channel independent regulation. The FGEN frequency control defines the actual signal frequency output by the PXIe - 5402. The X - axis simulation signal frequency generates a reference waveform through the built - in simulation function of LabVIEW. The two support asynchronous adjustment to simulate the frequency - mismatch scenario. Among the phase - difference parameters, the initial phase of CH1 and the initial phase of CH2 are set through the angle input control. The user can manually input or fine - tune by dragging the slider to observe the real - time deformation of the Lissajous figure.

[0122] 2. Hardware Channel and Trigger Setting Area: The device name dropdown menu binds the PXIe-5402 signal generator and the PXIe-5114 oscilloscope at the same time. The VISA addresses of them can be selected respectively to achieve multi-chassis expansion. The oscilloscope channels are specified as Channel 0 and Channel 1 through a multi-selection control, and the trigger mode is set to auto trigger to ensure distortion-free acquisition of high-frequency signals.

[0123] 3. Real-time Waveform Display Area: Integrating graphics and quantitative analysis, the Express XY graph dynamically renders the Lissajous figure synthesized by the CH0 and CH1 input signals. Users can zoom in on the image to observe the details of the ellipse. The ellipse parameter measurement module calculates the pixel lengths of the major and minor axes in real time, and at the same time marks the intersection points of the ellipse and the coordinate axes to assist users in cross-verifying the reliability of the phase difference calculation results.

[0124] Front Panel of the Amplitude-frequency Characteristic Sweep Measurement System:

[0125] 1. Waveform Parameter Setting Area: As the core input unit, it covers the full parameter configuration of the sweep signal. The start frequency and end frequency are set through high-precision numerical controls, supporting users to quickly define the sweep range. The sweep step number cooperates with the formula calculation module to dynamically generate the frequency increment:

[0126] Ensure that the sweep process is linear and without omission.

[0127] 2. Hardware Channel and Trigger Setting Area: Deeply integrating the PXI hardware characteristics, the device name dropdown menu is directly associated with the VISA resource identifier of the PXIe-5402 signal generator to achieve immediate selection and connection. The oscilloscope channel is fixed to Channel0, and the trigger mode uses Edge trigger. The hardware-level cascade trigger is used to ensure strict synchronization between the sweep signal and the acquisition timing.

[0128] 3. Real-time Waveform Display Area: Providing two-dimensional data verification, users can analyze signal amplitude, period, and distortion rate through the cursor measurement tool. The spectrum analysis graph dynamically draws the amplitude-frequency response curve within the frequency band based on the power spectral density algorithm, automatically marks the cut-off frequency points, and superimposes a red tolerance band to assist users in quickly judging the flatness of the passband.

[0129] Design of the Program Block Diagram:

[0130] As the core logic carrier of the method of this patent, the program block diagram is based on the virtual-real fusion architecture of LabVIEW, and realizes a closed-loop verification mechanism of time-frequency domain joint calibration, dynamic parameter correction, and hardware collaborative trigger through modular PXI. The specific structure is as Figure 2 , Figure 5 and Figure 12 shown, and its design is closely related to the technical solution of the patent claim. The program block diagram is divided into the following main VIs and sub-VIs, which are specifically as follows:

[0131] 1. Phase Difference Test of Lissajous Figure Method - FGEN Main VI Function Setting

[0132] As Figure 2 shown, it includes using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to implement the main VI of the phase difference test of Lissajous figure method for FGEN

[0133] The main VI is designed based on the LabVIEW platform. It generates a standard sine wave through the PXIe - 5402 signal generator, and uses the PXIe - 5114 oscilloscope to collect the actual signal as the Y - axis input. At the same time, it combines with the built - in simulation signal function of LabVIEW to generate the X - axis reference waveform. The two generate the Lissajous figure dynamically through the Express XY Graph. The program automatically calculates the phase difference by analyzing the ratio of the major and minor axes of the ellipse, avoiding the measurement error of the traditional intersection method at nearly 90° phase.

[0134] The steps of the main VI function are as follows:

[0135] Step 1: Create a session instance through the Fgen Initialize function to build the communication link between the signal generator and the host application program, laying the channel foundation for subsequent data transmission;

[0136] Step 2: Execute the Fgen Abort Generation function to forcibly interrupt the waveform output function of the signal generator;

[0137] Step 3: Use the Configure Output Mode function to set the output mode of the signal generator to the conventional function generator mode;

[0138] Step 4: Set the waveform characteristic parameters through the Configure Standard Waveform function and bind the front - panel control parameters to the corresponding interface terminals;

[0139] Step 5: Call the Output Enable function to activate the output function of the specified physical channel;

[0140] Step 6: Execute the Initiate Generation function to trigger the FGEN board to start signal output, and convert the channel name (0), waveform type (Sine), peak - to - peak voltage (5V), initial phase (0°), and DC offset (0V) into constants;

[0141] Step 7: Add a conditional structure;

[0142] Step 8: Create a corresponding local variable for the frequency on the front - panel, and at the same time create an attribute node using the attribute node function in the FGEN function palette

[0143] Step 9: Run the Fgen Abort Generation function to forcibly terminate the waveform output process of the signal generator and reset the hardware system to the initial standby state;

[0144] Step 10: Enable the Fgen Close function to complete the resource cleaning process and recycle all dynamic memory spaces occupied by FGEN;

[0145] 2. Settings of the main vi function for phase difference testing by Lissajous figure method in SCOPE

[0146] As Figure 2 shown, it includes using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to implement the main vi of the phase difference testing by Lissajous figure method in SCOPE

[0147] The main VI is built based on the PXIe-5114 oscilloscope, and its core functions are multi-channel synchronous acquisition and signal processing. In the phase difference measurement, the SCOPE module inputs the actual signal into the Y-axis of the XY graph, dynamically superimposes it with the X-axis simulation signal to generate a Lissajous figure, and analyzes the phase relationship through the elliptical shape. The program also supports dual-channel parallel configuration, combines with the PXI-SCOPE driver to achieve high-precision synchronous sampling, uses the error cluster mechanism to ensure the reliability of hardware communication, and finally calculates the phase difference through the major axis / minor axis ratio Avoid the critical errors of traditional methods and provide stable and scalable data support for multi-band phase analysis.

[0148] The steps of the main vi function are as follows:

[0149] Step 1: Run the ScopeInitialize function to initialize the instrument communication link, create a control session with the PXI oscilloscope and complete the hardware readiness detection;

[0150] Step 2: Enable the Scope Configure Vertical function to define the channel vertical system parameters;

[0151] Step 3: Call the Configure Chan Characteristics function to set the channel electrical characteristics;

[0152] Step 4: Execute the Configure Horizontal Timing function to configure the time base system, set the minimum sampling rate, trigger reference point position and waveform recording depth to ensure the high-fidelity capture of time-domain signals (such as frequency components, transient responses);

[0153] Step 5: Activate the free-running acquisition strategy through the trigger mode property node;

[0154] Step 6: Call the Configure Trigger(poly) function to enable the intelligent trigger mode;

[0155] Step 7: Run the Initiate Acquisition function to trigger the hardware to execute the signal capture task, and drive the oscilloscope to start the real-time data stream acquisition process according to the preset vertical / time base / trigger parameters.

[0156] Step 8: Call the Fetch(poly) function to read the acquired waveform data from the on-board memory of the oscilloscope, and change the data type of the acquired data by Fetch(poly) to a one-dimensional array of 32-bit integer data (1D I32);

[0157] Step 9: Configure the simulation signal and make connections;

[0158] Step 10: Set the frequencies of the FGEN and X-axis simulation signals;

[0159] Step 11: Observe the Lissajous figure in the XY graph, judge and record the phase difference;

[0160] 3. Main vi function settings for testing the phase difference of RIGOL signals

[0161] As Figure 5 shown, it includes the main vi for testing the phase difference of RIGOL signals by using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture

[0162] The main VI realizes automatic measurement by integrating instrument control, data acquisition and signal analysis functions. The user selects the VISA resource address and enters the SCPI instruction through the front panel, and triggers the event-driven structure to complete instrument connection, dual-channel signal source configuration and output control. The program calls the oscilloscope to collect the waveform data of two channels in real time through a While loop, generates a graph with the help of an XY graph, and automatically deduces the phase difference by analyzing the graph morphology or calculating the zero-crossing time difference. The event structure synchronously responds to instruction writing, data reading and exit operations, and combines the error cluster transfer mechanism to ensure communication stability.

[0163] The steps of the main vi function are as follows:

[0164] Step 1: Run LabVIEW, create a new VI file, and name it Measure Phase Distance with LABVIEW.vi;

[0165] Step 2: Add controls to the front panel interface, including an address bar, a command bar, a return value bar, and connection, write, read, and exit buttons;

[0166] Step 3: Switch to the block diagram and create an event structure;

[0167] Step 4: Add events, including connecting the instrument, write operation, read operation, and exit;

[0168] Step 5: Add the program for oscilloscope acquisition in the while loop. Channels CH0 and CH1 need to be used simultaneously, and both channels are configured simultaneously;

[0169] Step 6: Run the program;

[0170] 4. Sub - VI function settings for testing the phase difference of RIGOL signals

[0171] As Figure 4 shown is the sub - VI for testing the phase difference of RIGOL signals by using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture

[0172] This sub - VI is a LabVIEW functional module for controlling the connection status of RIGOL devices and error handling. Its core logic revolves around the event - driven process triggered by the "Connect" button: When the user clicks the button (value change event), the program uses the "TF" judgment module to verify whether the current connection status is "false" (not connected). If the condition is met, it enters the "Address" module, calls the VISA function to parse the instrument address input by the user, and attempts to establish a communication link. If the address is invalid (such as incorrect format or the device does not respond), the program triggers a pink warning box through the "error" cluster transfer mechanism, prompting "Connect failed! The address is invalid!", and terminates subsequent operations; if the address is valid, it normally returns the VISA session handle.

[0173] The steps of the sub - VI function are as follows:

[0174] Step 1: Connect the instrument (including error handling);

[0175] As Figure 6 shown is the connection of the instrument and error handling of the sub - VI for testing the phase difference of RIGOL signals by using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture

[0176] Trigger connection: Click the "Connect" button to trigger the value change event and start the connection process.

[0177] Address validity check: The "TF" module detects the input address format: Valid (false): Enter the "Address" module to parse the VISA address, and the purple data line activates the "NoError" status (green box); Invalid (true): Trigger the "Error" module to display "Connect failed! The address is invalid!".

[0178] Step 2: Write operation (including error judgment);

[0179] As Figure 7 shown is the write operation and error judgment of the sub-vi that uses the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase difference of the RIGOL signal

[0180] Trigger writing: Click the "Write" button (value change event) to start the process.

[0181] Connection check: The "TF" module detects the instrument session: Not connected (true): Trigger the purple error line and pop up a prompt box "Please connect to instrument first!"; Connected (false): Enter the "Command" module to generate instructions (such as "ab + address").

[0182] Step 3: Read operation (including error handling);

[0183] As Figure 8 shown is the read operation and error handling of the sub-vi that uses the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase difference of the RIGOL signal

[0184] Trigger reading: Click the "Read" button (value change event) to start the reading process.

[0185] Connection status check: The "TF" module detects the instrument session: Not connected (true): Trigger the purple error line and pop up a prompt box "Please connect to instrument first!"; Connected (false): Enter the "FIFO" buffer to read data.

[0186] Step 4: Exit operation;

[0187] As Figure 9 shown is the exit operation of the sub-vi that uses the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to test the phase difference of the RIGOL signal

[0188] Trigger exit: The "Source" module initiates an exit instruction (yellow solid line).

[0189] Condition judgment: Detect the status of the "true" flag: When the condition is met (true): Jump to "Exit" along the yellow solid line; In case of abnormal status: Return to the "T" node along the purple dotted line to release resources.

[0190] 5. Main VI settings of the amplitude-frequency characteristic sweep measurement system

[0191] As Figure 12 shown, it includes using the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to implement the main VI of the amplitude-frequency characteristic sweep measurement system

[0192] The main VI implements an automatic measurement system for amplitude-frequency characteristics based on the sweep method. The system generates a sinusoidal sweep signal with linearly increasing frequency through the PXIe-5402 function generator. After being collected by the PXIe-5114 oscilloscope, the power spectrum curve is plotted in real time using the spectrum analysis module. The main program adopts a modular design: the start frequency, end frequency, and sweep step number are set on the front panel. The frequency increment is dynamically calculated through a For loop, and the signal frequency is updated successively.

[0193] The steps of the main VI are as follows:

[0194] Step 1: Execute the Fgen Initialize function to initialize the instrument communication protocol, build a control channel between the signal generator and the host computer software, and realize two-way data interaction after the session is established;

[0195] Step 2: Run the Fgen Abort Generation function to forcibly interrupt the waveform generation process. Typical application scenarios include:

[0196] Step 3: Enable the Configure Output Mode function to set the output mode of the signal generator to the conventional function generator mode;

[0197] Step 4: Call the Configure Standard Waveform function to define the waveform characteristic parameters (amplitude / frequency / phase), and dynamically bind the front panel control parameters to the target interface terminals;

[0198] Step 5: Execute the Output Enable function to activate the output enable signal of the specified physical channel;

[0199] Step 6: Trigger the Initiate Generation function to drive the FGEN board to start the waveform output task according to the pre-configured parameters;

[0200] Step 7: Create a For loop, and inside the loop, use the Frequency property node of FGEN to adjust the frequency of the signal generated by FGEN;

[0201] Step 8: Add code to calculate the input frequency for each loop;

[0202] Step 9: Create an Oscilloscope Express VI to acquire the sine wave signal;

[0203] Step 10: Add a Spectrum Analysis Express VI and connect it to the Oscilloscope Express VI;

[0204] Step 11: Create a waveform graph to display the time-domain signal and spectrum;

[0205] Step 12: Connect the error cluster, close the hardware session, save and run the VI;

[0206] Step 13: Modify the VI, add code to the VI to verify whether the signal frequency received by the oscilloscope is within the swept frequency range;

[0207] Step 14: Adjust the front panel layout, run the program and test;

[0208] 6. Settings of Two Sub VIs in the Swept Frequency Measurement System for Amplitude-Frequency Characteristics

[0209] As Figure 11 shown are two sub VIs that utilize the LabVIEW graphical system design programming platform to control the PXI modular hardware architecture to implement the swept frequency measurement system for amplitude-frequency characteristics

[0210] These two sub VIs interact with each other and jointly demonstrate the common working process of two core modules in the LabVIEW signal processing chain. The "PXI-SCOPE Express" sub VI on the left is the hardware interaction layer, which acquires the original time-domain signal in real time by calling the oscilloscope driver interface. The "Spectrum Measurement" sub VI on the right undertakes the signal analysis task. After receiving the time-domain signal input from the left, it internally generates data representing the frequency component distribution through FFT transformation and windowing processing.

[0211] As Figure 13 shown are the front panel and block diagram of the first sub VI respectively. Figure 14

[0212] The steps of the two sub VIs cooperate as follows:

[0213] Step 1: Right-click on the block diagram and select Express >> Input >> PXI-SCOPE Express;

[0214] Step 2: Place the PXI-SCOPE Express VI to the right of the FGEN Frenquency property node;

[0215] ​Step 3: Configure the PXI-SCOPE Express VI dialog box, select Channel 0 for the channel, set the record length to 20000, and keep other values at their default settings;

[0216] Step 4: Select the Trigger tab and configure the dialog box;

[0217] Step 5: First change the type to Edge, and then change the source, ref position, and :maxtime according to the following figure;

[0218] Step 6: Click OK to save the Express VI configuration;

[0219] Step 7: Connect the error out output terminal of the FGEN Frenquency property node to the error in input terminal of the oscilloscope Express VI;

[0220] Step 8: Right-click on the block diagram and select Express » Signal Analysis » Spectrum Measurement;

[0221] Step 9: Place the Spectrum Measurement Express VI to the right of the PXI-Scope Express VI;

[0222] Step 10: Configure the dialog box, select Power Spectrum in the Selected Measurements column, keep other values at their default settings, click OK, and save the configuration;

[0223] Step 11: Connect the Spectrum Measurement Express VI to the PXI-SCOPE Express VI;

[0224] Step 12: Right-click on the signal output terminal of the PXI-Scope Express VI, and in the pop-up menu, select Create » Graph Display Control to create a waveform graph display control;

[0225] Step 13: Right-click on the waveform graph display control, select Properties in the shortcut menu, and in the Properties dialog box, select the Scale tab and set the minimum value to -1 and the maximum value to 1;

[0226] Step 14: Create a waveform graph display control at the Power Spectrum output terminal of the Spectrum Analysis Express VI, rename it to Power Spectrum to display the spectrum, and modify the properties;

[0227] Step 15: Set the scale name to Frequency (X-axis), the minimum value to 0, and the maximum value to 60000;

[0228] Step 16: Set Number of Steps to 25, Start Frequency to 500, and Stop Frequency to 50000. Click the button to run the program. The Power Spectrum waveform will display the frequencies at which the signal is scanned from low to high;

[0229] Step 17: Right-click on the block diagram of the program and click to select the vi;

[0230] Step 18: In the Support Files directory, select: limit test.vi, place it on the right side of the For loop, and connect the input terminals of limit test.vi to the Start Frequency and Stop Frequency controls respectively;

[0231] Step 19: Right-click on the three output terminals of limit test.vi, select Creat » Indicator (create display control), create three display controls: max frequency, Boolean, and min frequency, and rename the Boolean control to Test Passed;

[0232] Step 20: Connect the output terminal of the signal of PXI-SCOPE EXPRESS to the array input terminal at the bottom of limit test.vi;

[0233] Example

[0234] To help those skilled in the relevant arts deeply understand the technical solutions of the present invention, the following will be explained through three specific embodiments.

[0235] Example 1

[0236] When the user starts the application program, the system will directly jump to Figure 1 the displayed operation interface, and at this time, the user can follow the interface instructions to gradually complete the operations of each link.

[0237] Step 1: Set the X-axis simulation signal to 10K;

[0238] Step 2: Set the FGEN frequency to 10K;

[0239] Step 3: Run the program to achieve the effect as Figure 15 shown;

[0240] Example 2

[0241] When the user starts the application program, the system will directly jump to Figure 6The displayed operation interface, at this time the user can follow the interface guidance to gradually complete the operations of each link.

[0242] Step 1: Click the "Address" drop-down box to select the VISA resource name; click the "Connect" button to connect the instrument; enter a command in the "Command" text box; click the "Write" button to write to the instrument;

[0243] Step 2: Enter the following content in sequence; enter *IDN?; enter :SOUR1:APPL:SIN 500,2.5,0,90; enter :OUTP1ON;

[0244] Step 3: Enter :SOUR2:APPL:SIN 500,2.5,0,0; enter :OUTP2ON; enter :SOUR1:PHAS:INIT;

[0245] Step 4: Set CH1 to 1K; set CH2 to 2K;

[0246] Step 5: Run the program to achieve the effect as Figure 16 shown;

[0247] Example 3

[0248] When the user starts the application program, the system will directly jump to Figure 17 The displayed operation interface, at this time the user can follow the interface guidance to gradually complete the operations of each link.

[0249] Step 1: Set the number of steps to 25;

[0250] Step 2: Set the starting frequency to 500;

[0251] Step 3: Set the termination frequency to 50000;

[0252] Step 4: Run the program to achieve the effect as Figure 17 shown.

[0253] The above are only the preferred embodiments of the present invention, and are not any other form of limitation to the present invention. Any modification or equivalent change made according to the technical essence of the present invention still belongs to the scope protected by the present invention.

Claims

1. Design method of phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI, characterized in that It includes the following steps: Step 1: Construct a signal processing hardware closed-loop and unified analysis architecture; Establish a hardware closed-loop link through a signal generator and an oscilloscope. Use BNC-BNC connecting wires to directly connect the signal generation and acquisition channels, and synchronize the clock and trigger signal based on the PXI backplane bus to achieve unified measurement of time, frequency, and phase characteristics; Design parallel threads in LabVIEW to separately control the signal generator to output a swept-frequency signal and a fixed-frequency signal, and collect data through the oscilloscope to generate an amplitude-frequency characteristic curve and calculate the phase difference by the Lissajous figure method. Cross-verify the signal integrity with the two sets of data; Step 2: Signal characteristic fusion verification and dynamic correction; Integrate a spectrum analysis module and an elliptical image analysis module in the LabVIEW program block diagram. When there is a deviation in the cut-off frequency of the amplitude-frequency test and the phase difference result of the phase-frequency test within the time-frequency correlation range, dynamically adjust the output parameters of the signal generator to ensure the systematic consistency of time interval, frequency, and phase characteristics; Step 3: Multidimensional characteristic output under a unified system scope; Based on the same hardware architecture, synchronously output the amplitude-frequency characteristic curve and phase-frequency characteristic parameters, and centrally display the time-domain waveform, spectrogram, and XY-mode image through the LabVIEW front panel to verify the correlation of time, frequency, and phase, which are all core indicators of signal integrity in electronic measurement.

2. The design method of the phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI according to claim 1, It is characterized in that; For the phase difference calculation by the Lissajous figure method in Step 1, it is necessary to configure the FGEN and FGEN main vi functions. The specific steps are as follows: The steps for configuring FGEN are as follows: 1) Open PXI FGEN Generator and Acquisition.vi, and save it as Lissajous with FGEN&SCOPE.vi to the Exercises folder; 2) Open Lissajous with FGEN&SCOPE.vi and convert some parameters into constants; 3) Configure FGEN; 4) Use local variables and property nodes to change the output waveform of FGEN; The steps of the FGEN main vi function are as follows: 1) Start the session control module of the PXI signal generator through the device driver function to establish a hardware communication link; 2) Execute the driver function instruction to complete the operation mode switch of the signal generator from the pre-configured standby state to the real-time waveform output; 3) Set the output mode to custom waveform or predefined sequence type through the waveform generation function; 4) Call the parameterized waveform configuration function to define the core parameters of the standard waveform, including signal type, fundamental frequency, and amplitude; 5) Transmit logic control instructions to activate the output enable state of the specified channel of the signal generator; 6) Execute the waveform generation driver function to achieve the complete link trigger from parameterized configuration to physical signal output; 7) Add a conditional loop and add a condition structure for changing the frequency in the conditional loop; 8) Execute the synchronous trigger instruction function to send a hardware cascade trigger or timing synchronization signal to an external device; 9) Call the session termination function to destroy the FGEN device session handle and its configuration attributes, and release all memory resources occupied during the operation of FGEN.

3. The design method of the phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI according to claim 1, It is characterized in that; The steps for calculating the phase difference by the Lissajous figure method in step 1 require configuring the SCOPE and the SCOPE main vi function. The specific steps are as follows: The steps for configuring SCOPE are as follows: 1) Call the SCOPE device initialization function outside the loop structure to create a global session control module to establish the oscilloscope hardware communication link; 2) Execute the parameter configuration function inside the loop logic to dynamically load the core parameters of the oscilloscope's sampling rate, record length, and vertical range; 3) Set the edge trigger mode, trigger source, and reference position threshold of the oscilloscope through the trigger condition configuration function; 4) Call the hardware resource release function to destroy the SCOPE session handle and clear the memory and bus resources it occupies; The steps of the SCOPE main vi function are as follows: 1) Call the hardware session management module to complete the establishment of device communication connections, resource allocation, and initialization of default parameters; 2) Execute the channel vertical range configuration function to dynamically adjust the voltage measurement range of single or dual channels of the oscilloscope; 3) Call the signal integrity configuration function to define the impedance matching parameters and bandwidth limit threshold of the oscilloscope channel; 4) Set the oscilloscope sampling rate, record length, and trigger delay through the horizontal timing parameter configuration module to achieve time-domain synchronization calibration; 5) Modify the trigger mode property node to switch the trigger type of the oscilloscope; 6) Call the auto-trigger logic instruction to force the oscilloscope to perform data capture at a preset period without a trigger signal; 7) Call the data acquisition control function to start the multi-channel synchronous capture engine of the oscilloscope; 8) Extract the original acquisition data stream, complete waveform rendering and display through the data visualization interface, and change the data type of the acquired data to a one-dimensional array of 32-bit integer data; 9) Convert the coupling mode DC and the attenuation coefficient 1.0 into constants.

4. The design method of the phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI according to claim 1, It is characterized in that; The steps for calculating the phase difference by the Lissajous figure method in step 1 require configuring the simulation signal. The steps for configuring the simulation signal are as follows: 1) Find the simulation signal function from the function palette as the waveform in the X-axis direction of the XY graph; 2) Create an Express XY graph on the front panel; 3) Connect the output terminal of the simulation signal to the connection terminal collected by SCOPE; 4) Merge the error cluster wires through the simple error handler; 5) Set the frequencies of the FGEN and the X-axis simulation signal; 6) Observe the Lissajous figure in the XY graph, judge and record the phase difference.

5. The design method of the phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI according to claim 1, It is characterized in that; The steps for testing the phase difference of the test signal in the phase difference calculation by the Lissajous figure method in step 1 are as follows: 1) Run LabVIEW, create a new VI file, and name it Measure Phase Distance with LABVIEW.vi; 2) Add the required controls on the front panel interface; 3) Create an event structure in the program block diagram; 4) Add events, including connecting instruments, write operations, read operations, and exit; 5) Add the program for oscilloscope acquisition in the while loop; 6) Run the program, input instructions and make records.

6. The design method of the phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI according to claim 1, characterized in that; The specific steps of the signal characteristic fusion verification and dynamic correction in step 2 are as follows: Call the PXI-FGEN and PXI-SCOPE drivers through LabVIEW to control the signal generator and oscilloscope, use the PXI backplane trigger bus to achieve hardware clock synchronization, combine the Lissajous figure method to input the signal into the X / Y channels of the oscilloscope to generate an elliptical image, automatically analyze the phase difference through the ratio of the major and minor axes of the ellipse or the intersection coordinates, and form a closed-loop calibration link on the basis of dynamically correcting the phase parameters of the signal generator by real-time data comparison in LabVIEW to achieve microsecond-level dynamic measurement and error compensation of the phase difference.

7. The design method of the phase difference test and amplitude-frequency characteristic sweep measurement system based on LabVIEW and PXI according to claim 1, Characterized in that; The steps of the amplitude-frequency characteristic curve generation design program block diagram and the main vi function of the program block diagram in step 1 are as follows: The steps of designing the program block diagram are as follows: 1) Connect CH0 of PXI-5402 to CH0 of the oscilloscope PXIe-5114; 2) Write a program to create a numerical control, and adjust the starting frequency of the swept-frequency signal through this control; 3) In the program block diagram, initialize the FGEN, terminate the waveform output, and configure the parameters; 4) Create a For loop; 5) Create an oscilloscope Express VI to collect sine wave signals; 6) Add a spectrum analysis Express VI and connect it to the oscilloscope Express VI; 7) Create a waveform graph to display the time-domain signal and spectrum; 8) Connect the error cluster, close the hardware session, save and run the VI; 9) Modify the VI, add code to the VI to verify whether the signal frequency received by the oscilloscope is within the swept-frequency range; 10) Adjust the front panel layout, run the program and test; The steps of the main vi function of the program block diagram are as follows: 1) Call the instrument driver API interface to initialize the PXI signal generator control session and establish a device communication channel; 2) Implement the conversion of the signal generator from the standby parameter preloading state to the dynamic waveform output mode through the driver interface command; 3) Use the waveform mode selection interface to set the output type to user-defined waveform or standard sequence template; 4) Run the waveform parameter configuration module and load the defined parameters of the standard waveform (including basic parameters such as waveform shape, fundamental frequency, amplitude threshold, etc.); 5) Send a channel enable instruction to the signal generator to enable the physical output function of the target channel; 6) Trigger the waveform generation engine to complete the full-process signal output from digital parameter configuration to analog signal output; 7) Place the PXI-SCOPE Express VI on the right side of the FGEN Frenquency property node; 8) Place the spectrum measurement Express VI on the right side of the PXI-Scope Express VI; 9) Call the multi-device trigger synchronization interface to send a timing alignment pulse or a hardware-level trigger interlock signal to an external instrument; 10) Execute the device session closing protocol to release the device control handle and clear its configuration attributes and the occupied bus and memory resources.

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