Справочник Пользователя для National Instruments NI 9144
NI 9144 User Guide and Specifications
58
ni.com
NI 9237 Calibration Data
The NI 9237 has four channels. 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.
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 calibration data is stored in a U16 array, though each Offset field
(subindex 1, 3, 5, and so on) should be interpreted as a signed value.
(subindex 1, 3, 5, and so on) should be interpreted as a signed value.
Use the calibration coefficients with the following equation to generate
corrected data:
corrected data:
NI 9229/9239
Table 53. NI 9237 Scan List Format
Coefficient
Representation
Units
LSB Weight
Unsigned
pV/LSB
Offset
Signed
nV
Table 54. NI 9229/9239 Vendor Configuration Extensions
Index
Sub
Type
R/W
Description
0x2002
0
U32
R/W
Configure ADC,
default = 0x06
default = 0x06
0x2100
0
ARR:U32
Calibration = 16
1
R
Ch0 Offset
2
R
Ch0 Gain
3
R
Ch1 Offset
...
...
8
R
Ch3 Gain
9
R
External Ch0
Offset
Offset
...
...
V
corrected
V
raw
(
)
V
raw
bits
(
)∗ LSB
weight
pV
bits
---------
⎝
⎠
⎛
⎞∗10
13
–
V
pV
-------
⎝
⎠
⎛
⎞
⎩
⎭
⎨
⎬
⎧
⎫
Offset pV
(
)∗10
8
–
V
nV
-------
⎝
⎠
⎛
⎞
⎭
⎬
⎫
–
=