NI 5922 Calibration Procedure
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© National Instruments
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17
Timing Accuracy
Complete the following steps to verify the timing accuracy for the NI 5922.
Note
The same time source is used for both channel 0 and channel 1, so you only
need to verify the timing accuracy on one channel.
1.
Call
niScope_ConfigureChanCharacteristics
(niScope Configure Chan
Characteristics VI) with the following parameters:
•
channelList
:
"0"
•
inputImpedance
:
NISCOPE_VAL_50_OHM
•
maxInputFrequency
:
0
2.
Call
niScope_ConfigureVertical
(niScope Configure Vertical VI) with the
following parameters:
•
channelList
:
"0"
•
range
:
10
•
offset
:
0.0
•
coupling
:
NISCOPE_VAL_DC
•
probeAttenuation
:
1.0
•
enabled
:
NISCOPE_VAL_TRUE
3.
Call
niScope_ConfigureHorizontalTiming
(niScope Configure Horizontal
Timing VI) with the following parameters:
•
minSampleRate
:
15,000,000
•
minNumPts
:
1,000,000
•
refPosition
:
50.0
•
numRecords
:
1
•
enforceRealtime
:
NISCOPE_VAL_TRUE
4.
Call
niScope_Commit
(niScope Commit VI) with the following parameter:
•
vi
: The instrument handle you obtained from
niScope_init
5.
Connect the scope calibrator to the channel 0 input of the oscilloscope. Configure the
calibrator to output an exact 2 MHz sine wave with 1 V peak-to-peak amplitude and 50
Ω
load impedance.
6.
Wait 1,000 ms for the impedance matching and frequency of the calibrator to settle.
7.
Call
niScope_InitiateAcquisition
(niScope Initiate Acquisition VI) with the
following parameter:
•
vi
: The instrument handle you obtained from
niScope_init
8.
Call
niScope_FetchMeasurement
(niScope Fetch Measurement VI) with the
following parameters:
•
channelList
:
"0"
•
timeout
:
1.0
•
scalarMeasFunction
:
NISCOPE_VAL_FFT_FREQUENCY
