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National Instruments Corporation
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Introduction—Document Scope
This chapter discusses what calibration is, why you should do it, and how
often. You will also learn about the necessary equipment for calibrating
your signal source.
Use the following procedure to calibrate the NI 54
XX
device series of
function generators, arbitrary waveform generators, and video signal
generators. This series includes NI 5401, 5411, and 5431 devices on PCI
or PXI buses.
What Is Calibration?
Calibration consists of verifying the accuracy of a device and adjusting for
any error. To calibrate the NI 54
XX
devices, you need to initiate a sequence
of signal outputs and measure these signals to calculate calibration
constants that are stored in non-volatile memory on the device. When
you use the device to generate signals, the driver software retrieves these
constants and uses them to determine the fine adjustments needed to
achieve optimal signal characteristics.
You have two options for calibrating your NI 54
XX
devices: internal
adjustment and external adjustment.
Internal Adjustment
You can do internal adjustment, or self-calibration, with the software
command
ni54xx_CalSelfCalibrate
. The NI 54
XX
device
automatically calculates and stores certain constants. It is faster than
external adjustment because the device does everything automatically,
and no external measurement devices are needed.
External Adjustment
External adjustment involves measuring device output under different
configurations using high-precision external measurement devices.
Calibrate externally when you want to do a complete calibration of all
constants to a high degree of accuracy.