Chapter 3
Adjustment
©
National Instruments Corporation
3-29
If you have exited the loop, the VCXO is adjusted within the tolerance or
as close as possible.
You have completed adjusting the M-PAL Video Mode.
Calibrating the NTSC Video Mode for NI 5431
To calibrate the NTSC video mode for NI 5431 devices only, complete the
following steps:
1.
Enable the analog filter by calling the function
ni54xx_SetAnalogFilter
. Set the following parameters:
•
sessionHandle
—The handle of the calibration session for the
device
•
filterState
—
NI5XX_ENABLE
2.
Generate a full scale (10 V) sine wave at 1 MHz in NTSC video mode
by calling the function
ni54xx_GenerateVideoWaveform
. Set the
following parameters:
•
sessionHandle
—The handle of the calibration session for the
device
•
waveType
—
NI54XX_SINE
•
amplitudeInVolts
—
10
•
frequencyInHz
—
1000000
•
videoMode
—
NI54XX_NTSC_M
3.
Set the gain and offset by calling the function
ni54xx_SetAdjustedGainAndOffset
with 0 offset and
0 attenuation, in the unterminated case using the following parameters:
•
sessionHandle
—The handle of the calibration session for the
device
•
offsetInVolts
—
0
•
attenuationInDb
—
0
•
terminationState
—
NI54XX_UNTERMINATED
4.
Initialize the VCXO calibration for NTSC mode by calling the
function
ni54xx_InitializeVCXOCalibration
. Set the
following parameters:
•
sessionHandle
—The handle of the calibration session for the
device
•
type
—
NI54XX_SET_VCXO
_
NTSC_M