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NI 5412 Calibration Procedure
18. Repeat steps 9 through 17 for each iteration in Table 7.
19. If any of the errors are greater than the test limits, perform an external adjustment.
Note
To verify the flatness for the High-Gain Amplifier path, repeat
steps 1 through 18, but set the Gain to 3 in step 10.
Adjusting the NI 5412
If the NI 5412 successfully passes all verification within the calibration test limits, adjustment
is recommended, but not required, to guarantee its published specifications for the next
two years. If the NI 5412 was not within the calibration test limits for each verification
procedure, perform the adjustment procedure to improve the accuracy of the NI 5412. Refer
section to determine which procedures to perform.
An adjustment is required only once every two years. The adjustment procedure automatically
updates the calibration date and temperature in the EEPROM of the NI 5412.
If the NI 5412 passed verification within the calibration test limits and you do not want to do an
adjustment, you can update the calibration date and onboard calibration temperature without
making any adjustments by completing the following steps:
1. Call
niFgen_InitExtCal
(niFgen Init Ext Cal VI) to open an NI-FGEN external
calibration session using the following parameters:
•
resourceName
: The name of the device you want to calibrate. You can find this name
under Devices and Interfaces in MAX.
•
password
: The password required to open an external calibration session. If this
password has not been changed since manufacturing, the password is
"NI"
.
•
vi
: A pointer to a ViSession. The variable passed by reference through this parameter
receives the value that identifies the external calibration session created by this
function. This value acts as the session handle and is passed as the first parameter to
all subsequent NI-FGEN functions.
2. Call
niFgen_CloseExtCal
(niFgen Close Ext Cal VI) using the following parameters:
•
vi
: The session handle returned from
niFgen_InitExtCal
•
action
:
NIFGEN_VAL_EXT_CAL_COMMIT
The external calibration procedure adjusts the analog output, the oscillator frequency, and the
calibration ADC. Analog output adjustment characterizes the DC gains and the offsets of the
analog path to ensure the analog output voltage accuracy. Adjusting the oscillator frequency
adjusts the onboard oscillator to ensure frequency accuracy. Calibration ADC adjustment
characterizes the onboard ADC gain and offset so that self-calibration results in an accurately
calibrated device.
You cannot perform an external calibration using a standard NI-FGEN session. You must create
an external calibration session using
niFgen_Init
ExtCal
(niFgen Init Ext Cal VI). An
external calibration session allows you to use NI-FGEN functions and attributes that are
specifically for external calibration, while still allowing you to use all the standard NI-FGEN
functions and attributes with the external calibration session.
