Chapter 2
Verification
2-8
ni.com
12. Call
niFgen_Close()
to close the instrument I/O session, destroy the
instrument driver session and all of its properties, and release any
memory resources the driver uses. The only parameter required for
this function is
sessionHandle
.
Verifying Total Harmonic Distortion and
Spurious Free Dynamic Range
Using a spectrum analyzer, verify the spectral purity of your NI 54
XX
device by generating a 1 MHz sine wave and a 16 MHz sine wave.
Generate a 1 MHz sine wave with a 10 Vpp amplitude for a 50
Ω
load by
completing the following steps:
1.
Complete the setup steps described in the
section.
2.
Call
niFgen_EnableAnalogFilter()
to select the channel to
enable an analog filter on. Set the following parameters:
•
vi
—The output value
sessionHandle
that you obtained from
the
niFgen_init
function
•
Channel_Name
—
”0”
•
FilterCorrectionFrequency
—
1000000
3.
Call
niFgen_EnableDigitalFilter()
to select the channel to
enable a digital filter on. Set the following parameters:
•
vi
—The output value
sessionHandle
that you obtained from
the
niFgen_init
function
•
Channel_Name
—
”0”
4.
Call
niFgen_ConfigureStandardWaveform()
to select the
channel to output a waveform. Set the following parameters:
•
vi
—The output value
sessionHandle
that you obtained from
the
niFgen_init
function
•
Channel_Name
—
”0”
•
Amplitude
—
10
•
DC_Offset
—
0
•
Frequency
—
1000000
•
Waveform
—
NIFGEN_VAL_WFM_SINE
•
Start_Phase
—
0