on page 16 for an illustration of how the
PXIe-6674 performs synchronous routing operations.
Calibration
This chapter discusses the calibration of the PXIe-6674.
Calibration consists of verifying the measurement accuracy of a device and correcting for any
measurement error. The PXIe-6674 is factory calibrated before shipment at approximately
25 °C to the levels indicated in the device's specifications. The associated calibration constants
—the corrections that were needed to meet specifications—are stored in the onboard non-
volatile memory (EEPROM). The driver software uses these stored values.
Factory Calibration
The factory calibration of the PXIe-6674 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.
OXCO 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-6674 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.
Compliance
Electromagnetic Compatibility Information
This hardware has been tested and found to comply with the regulatory requirements and
limits for electromagnetic compatibility (EMC) as indicated in the hardware's Declaration of
Conformity (DoC).
4
The Declaration of Conformity (DoC) contains important EMC compliance information and
instructions for the user and 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-6674 User Manual
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© National Instruments
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