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NI PXIe-4480//4481 Calibration Procedure
Adjustment (PXIe-4481)
If the PXIe-4481 successfully passed each of the verification procedures within the As Left test
limits
without adjustment
, then an adjustment is recommended, but not required, to warrant the
published specifications for the next calibration interval. If the device was not within the As Left
test limits, you can perform the adjustment procedure to improve the device accuracy and reset
the calibration interval.
In order to update the calibration date without performing adjustment, see the instructions in the
Updating the Calibration Date without Performing Adjustment
section.
The external calibration interval is listed in the
PXIe-4480/4481 Specifications
. An adjustment
is required at least once within this interval. Performing the adjustment procedure automatically
updates the calibration constants, date, and temperature in the device EEPROM.
The following performance adjustment procedures describe the sequence of operation required
to adjust the PXIe-4481.
It is possible to adjust the PXIe-4481 in either of two methods. The Minimum Time method
adjusts the voltage gain of all channels in parallel, utilizing the cable connections shown in
Figure 2. Alternatively, the Minimum Cabling method adjusts the voltage gain of each channel
sequentially, utilizing the cable connections shown in Figure 3. Performance is not affected by
the choice. The trade-off is simply between adjustment time and cabling complexity.
Note
In normal measurement applications, the input configuration of the
PXIe-4481 is controlled using the
range
parameter. However, during adjustment, the
input configuration is controlled using the
gain
parameter. This is a result of
employing an existing adjustment VI that is common across all DSA devices.
Minimum Time Method
Complete the following performance adjustment procedures to adjust the PXIe-4481 using the
“minimum time” method. To view a programming block diagram that provides an overview of
this adjustment procedure, go to
and enter the Info Code
PXIe448x
.
Initialization
1.
Call
DAQmxInitExtCal
(DAQmx Initialize External Calibration VI) to initialize the
calibration, using the following parameters:
deviceName:
Dev_name
password:
NI
calHandle:
&myCalHandle