Calibration
This chapter discusses the calibration of the PXIe-6674T.
Calibration consists of verifying the measurement accuracy of a device and correcting for any
measurement error. The PXIe-6674T is factory calibrated before shipment at approximately
25 °C to the levels indicated in the PXIe-6674T Specifications. The associated calibration
constants—the corrections that were needed to meet specifications—are stored in the onboard
nonvolatile memory (EEPROM). The driver software uses these stored values.
Factory Calibration
The factory calibration of the PXIe-6674T involves calculating and storing four calibration
constants. These values control the accuracy of two features of the device, which are discussed
in the following sections.
OCXO Frequency
The OCXO frequency can be varied over a small range. The output frequency of the OCXO is
adjusted using this constant to meet the specification listed in the PXIe-6674T Specifications.
PXI_CLK10 Phase
When using the PLL to lock PXI_CLK10 to an external reference clock, the phase between the
clocks can be adjusted. The time between rising edges of PXI_CLK10 and the input clock is
minimized using this constant.
Note
The PXI_CLK10 phase is set during manufacturing and does not need to be
recalibrated.
Additional Information
Refer to
ni.com/calibration
for additional information on NI calibration services.
Compliance
Electromagnetic Compatibility Information
This hardware has been tested and found to comply with the applicable regulatory
requirements and limits for electromagnetic compatibility (EMC) as indicated in the
hardware's Declaration of Conformity (DoC)
4
. These requirements and limits are designed to
provide reasonable protection against harmful interference when the hardware is operated in
the intended electromagnetic environment. In special cases, for example when either highly
4
The Declaration of Conformity (DoC) contains important EMC compliance information an
dinstructions for the user or installer. To obtain the DoC for this product, visit
ni.com/
certification
, search by model number or product line, and click the appropriate link in the
Certification column.
PXIe-6674T User Manual
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© National Instruments
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