Vibrations and Data Acquisition Devices

NI Deice Information

  • Cotrol DX
    • Network information
      • ip = 10.0.0.10
      • netmask = 255.0.0.0
    • Runing labview runtime 10.0
  • Cotrol SX
    • Network information
      • ip = 10.0.0.11
      • netmask = 255.0.0.0
    • Runing labview runtime 10.0
  • Development laptop
    • Network information
      • ip = 10.0.0.9
      • netmask = 255.0.0.0
    • Running labview 9.0

NI Noise and Performance Tests

Noise Tests

Input card parameters:
  • Sampling frequency [Hz] = 5000
  • Voltage range [v] = -10 to 10
  • Samples to read = 50000 (10 seconds at 5 kHz)
  • Signal voltage [v] = 10 Vpp
  • Signal type = Sine
  • Signal frequency
Preliminary signal-to-noise results (M. Brix). More details in Signal.pdf

ni_pxi_spectral_2hz.jpg

Figure : Spectral representation of Signal-to-Noise measurement and ENOB value at 2 Hz signal frequency

ni_pxi_spectral_10hz.jpg

Figure : Spectral representation of Signal-to-Noise measurement and ENOB value at 10 Hz signal frequency

ni_pxi_spectral_300hz.jpg

Figure : Spectral representation of Signal-to-Noise measurement and ENOB value at 300 Hz signal frequency

Preliminary conclusions

  • "There are small differences at different frequencies but it seems in comparison to tested UEI and datatranslation devices the NI is the best solution (ENOB about 20). Unfortunately the expected sensitivity to see displacements (<100nm) at low frequencies (<3 Hz) probably is not achievable. ICP tests are necessary to confirm this hypothesis." M. Brix.

Noise Tests with ICP

This second part of analyzes describes the "real behavior" of the data logging device with 24-AD-resolution cards connected to accelerometers of PCB (393B05) and WILCOXON (731-207) with the use of the NI-internal ICP signal path to drive the accelerometers of PCB . Preconditions and measurement parameters noise tests:

  • Input card parameters:
    • Sampling frequency [Hz] = 5000
    • Voltage range [v] = -10 to 10
    • Samples to read = 25000 (5 seconds at 5 kHz)
    • Signal voltage range [V] = -0.1...0.1
    • Signal type = Sine
    • Signal frequencies: 1, 1.3, 1.6, 1.9, 2.2, 2.5, 2.8, 3.1, 3.4, 3.7, 4 Hz
Results The following figures demonstrate the different results of signal spectra for the 2 different accelerometers for the signal frequencies 4, 3.4, 2.8 and 2.5 Hz. The point beside the signal lines denotes the "real" value referred to the moved stage (discrete sine wave) and is suitable for a rough comparison. The values for frequencies below 2.8 Hz are very difficult to extract for an excitation at about 90nm.

ni_pxi_spectral_4hz_icp.jpg

Figure : Spectral representation of signal measurements at 4 Hz; 90nm sine-wave movement

ni_pxi_spectral_3point4hz_icp.jpg

Figure : Spectral representation of signal measurements at 3.4 Hz; 90nm sine-wave movement

ni_pxi_spectral_2point8hz_icp.jpg

Figure : Spectral representation of signal measurements at 2.8 Hz; 90nm sine-wave movement

ni_pxi_spectral_2point5hz_icp.jpg

Figure : Spectral representation of signal measurements at 2.5 Hz; 90nm sine-wave movement

Setup of the Accelerometers over the LN Bench

NI_test_LN_bench1.JPG

NI_test_LN_bench2.JPG

Performance Tests

The performance test was done using the following LabView application:

labview_app.jpg

The application samples the channel 1 at maximum speed (100khz). We use a buffer to store 10 samples and makes an average which is sent to the output channel 1. The NI expert believes that this mechanism reduces the noise and improves the performance of the system.

The following plots show the measured latency of the system. The time needed to read a signal with the analog input card and send it to the output card was about 500 us.

ni_pxi_performance_sinus.jpg

ni_pxi_performance_sinus_1.jpg

ni_pxi_performance_step.jpg

National Instrument: Vibration and Sound measurements

National Instrument Trial Software

United Electronic Independent ADC Cards

Measuring Dynamic Specifications
I Attachment Action Size Date Who Comment
NI_test_LN_bench1.JPGJPG NI_test_LN_bench1.JPG manage 1 MB 31 Jul 2018 - 22:56 AndrewColson  
NI_test_LN_bench2.JPGJPG NI_test_LN_bench2.JPG manage 1 MB 31 Jul 2018 - 22:56 AndrewColson  
Signal.pdfpdf Signal.pdf manage 1 MB 01 Jun 2018 - 18:07 AndrewColson  
labview_app.jpgjpg labview_app.jpg manage 189 K 31 Jul 2018 - 22:57 AndrewColson  
ni_100hz.csvcsv ni_100hz.csv manage 1 MB 01 Jun 2018 - 18:03 AndrewColson  
ni_10hz.csvcsv ni_10hz.csv manage 1 MB 01 Jun 2018 - 18:02 AndrewColson  
ni_2hz.csvcsv ni_2hz.csv manage 1 MB 01 Jun 2018 - 18:02 AndrewColson  
ni_300hz.csvcsv ni_300hz.csv manage 1 MB 01 Jun 2018 - 18:04 AndrewColson  
ni_pxi_performance_sinus.jpgjpg ni_pxi_performance_sinus.jpg manage 134 K 31 Jul 2018 - 22:57 AndrewColson  
ni_pxi_performance_sinus_1.jpgjpg ni_pxi_performance_sinus_1.jpg manage 145 K 31 Jul 2018 - 22:58 AndrewColson  
ni_pxi_performance_step.jpgjpg ni_pxi_performance_step.jpg manage 128 K 31 Jul 2018 - 22:58 AndrewColson  
ni_pxi_spectral_10hz.jpgjpg ni_pxi_spectral_10hz.jpg manage 491 K 31 Jul 2018 - 22:42 AndrewColson  
ni_pxi_spectral_2hz.jpgjpg ni_pxi_spectral_2hz.jpg manage 477 K 31 Jul 2018 - 22:40 AndrewColson  
ni_pxi_spectral_2point5hz_icp.jpgjpg ni_pxi_spectral_2point5hz_icp.jpg manage 377 K 31 Jul 2018 - 22:55 AndrewColson  
ni_pxi_spectral_2point8hz_icp.jpgjpg ni_pxi_spectral_2point8hz_icp.jpg manage 368 K 31 Jul 2018 - 22:52 AndrewColson  
ni_pxi_spectral_300hz.jpgjpg ni_pxi_spectral_300hz.jpg manage 371 K 31 Jul 2018 - 22:47 AndrewColson  
ni_pxi_spectral_3point4hz_icp.jpgjpg ni_pxi_spectral_3point4hz_icp.jpg manage 370 K 31 Jul 2018 - 22:49 AndrewColson  
ni_pxi_spectral_4hz_icp.jpgjpg ni_pxi_spectral_4hz_icp.jpg manage 352 K 31 Jul 2018 - 22:48 AndrewColson  
Topic revision: r2 - 31 Jul 2018, AndrewColson
This site is powered by FoswikiCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding Foswiki? Send feedback