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NI 9144 User Guide and Specifications
NI 93
8
1 Calibration Data
The NI 9381 has either input channels or output channels with a nominal range of 0-5 V. Each
channel has an associated LSB weight, which is the number of volts per bit, and an offset, which
is the number of volts per bit measured when the inputs are grounded.
Note
LSB weight is referred to as Gain in the object dictionary.
The NI 9381 EEPROM stores two constants for each channel. The host takes the constants and
adjusts the raw data in calibrated data. The calibration data is stored in a U16 array.
Use the calibration coefficients with the following equation to generate corrected data:
Table 100.
NI 93
8
1 Vendor Configuration Extensions
Index
Sub
Type
R/W
Description
0x2100
0
U32
R/W
Digital Channel Direction
Control, default = 0
0
ARR:U16
—
Calibration = 64
1
R
AI0 Offset
2
R
AI0 Gain
...
—
—
15
R
AI7 Offset
16
R
AI7 Gain
17
R
AO0 Offset
18
R
AO0 Gain
...
—
31
R
AO7 Offset
32
R
AO7 Gain
33
R
External AI0 Offset
...
—
Table 101.
NI 93
8
1 Calibration Coefficients
Coefficient
Representation
Units
LSB Weight
Unsigned
100 nV/LSB
Offset
Signed
10 uV