©
National Instruments Corporation
2-1
2
Verification
This chapter provides detailed step-by-step instructions for verifying
the specifications of your signal source. Verification determines whether
your device is performing within its specifications prior to adjustment.
Verification and adjustment together comprise a complete calibration.
To verify that your NI 54
XX
still meets its specifications, you must use
the NI-FGEN device driver to control the NI 54
XX
device. The following
steps describe the code you use to generate the appropriate signals and the
NI-FGEN function calls you make to verify specifications. The code varies
depending on which programming application you use: LabVIEW, CVI/C,
or Visual Basic. The examples shown in this section use CVI/C code,
but LabVIEW has a corresponding VI for each function.
You can verify the following specifications for NI 54
XX
devices:
•
DC offset
•
Amplitude accuracy
•
Amplitude flatness over frequency
•
Total harmonic distortion (THD)
•
Spurious free dynamic range (SFDR)
•
Device oscillator frequency accuracy
Table 2-1.
Specifications Table
Characteristic
Value
DC Offset Accuracy
±5
mV
Amplitude Accuracy
±.1 dB
Amplitude Flatness Over Frequency
±2 dB
Sine Spectral Purity (Harmonic and Spurious)
Up to 1 MHz
Up to 16 MHz
–60 dBc
–35 dBc
Oscillator Frequency Accuracy
±15 ppm, 20 to 30 °C
ambient temperature
