NI 5412 Calibration Procedure
|
© National Instruments
|
39
7. Call
niFgen_CalAdjustMainPathPostAmpGainAndOffset
(niFgen Cal Adjust
Main Path Post Amp Gain And Offset VI) using the following parameters:
•
vi
: The session handle returned from
niFgen_InitExtCal
•
channelName
:
"0"
•
configuration
: The
Current Configuration
value for the current iteration from
Table 10.
•
mainDACValues
: An array containing two elements—the values (
0
,
0
) that you set
on the main DAC.
•
gainDACValues
: An array containing one element—the value (
2000
) that you set on
the gain DAC.
•
offsetDACValues
: An array containing two elements—the two values (
50000
,
15000
) that you set on the offset DAC in order.
•
measuredOutputs
: An array containing two elements—the two output voltages
(
measurement 0
,
measurement 1
) that you measured in order.
Adjusting the Oscillator Frequency
Adjusting the oscillator frequency involves generating a sine wave at a desired frequency and
then iteratively measuring the frequency, passing the measured value to NI-FGEN so that the
oscillator can be adjusted, and then remeasuring the resulting frequency. This process is repeated
until the difference between the desired and measured frequency falls within the desired
tolerance, which is 4.5 ppm. This adjustment ensures the frequency accuracy of the onboard
oscillator.
1. Call
niFgen_InitializeOscillatorFrequencyCalibration
(niFgen Initialize
Oscillator Frequency Calibration VI) using the following parameter:
•
vi
: The session handle returned from
niFgen_InitExtCal
2. Call
niFgen_SetAttributeViReal64
to set the sample rate (niFgen property node:
Arbitrary Waveform Output»Sample Rate
) using the following parameters:
•
vi
: The session handle returned from
niFgen_InitExtCal
•
channelName
:
"0"
•
attributeID
:
NIFGEN_ATTR_ARB_SAMPLE_RATE
•
value
:
100000000
3. Call
niFgen_SetAttributeViReal64
to set the gain (niFgen property node:
Arbitrary Waveform Output»Arbitrary Waveform Gain
) using the following
parameters:
•
vi
: The session handle returned from
niFgen_InitExtCal
•
channelName
:
"0"
•
attributeID
:
NIFGEN_ATTR_ARB_GAIN
•
value
:
1
Note
You can adjust this value based on which measuring device you use.
