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NI 9144 User Guide and Specifications
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NI 9234 Example Data Rates
The example data rates use a 12.8 MHz clock source.
NI 9234 Calibration Data
The NI 9234 has four channels with a nominal range of ± 5 V. Each channel
has an associated AC or DC input mode; an optional IEPE excitation; an
associated LSB weight, which is how many volts there are per bit; and an
offset, which is the volts per bit measured with the inputs grounded.
has an associated AC or DC input mode; an optional IEPE excitation; an
associated LSB weight, which is how many volts there are per bit; and an
offset, which is the volts per bit measured with the inputs grounded.
Note
LSB weight is referred to as Gain in the object dictionary.
The calibration data is stored in a U32 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:
Table 48. NI 9234 Example Data Rates
Data Rate
Clock
Divisor
Clock
Source
Rate
Byte
Byte
Oversample
Clock Rate
50.000 kS/s
00001
10
0x06
12.80 MHz
25.000 kS/s
00010
10
0x0A
6.40 MHz
16.667 kS/s
00011
10
0x0E
4.27 MHz
12.500 kS/s
00100
10
0x12
3.20 MHz
10.000 kS/s
00101
10
0x16
2.56 MHz
6.250 kS/s
01000
10
0x22
1.60 MHz
5.000 kS/s
01010
10
0x2A
1.28 MHz
Table 49. NI 9234 Scan List Format
Coefficient
Representation
Units
LSB Weight
Unsigned
pV/LSB
Offset
Signed
nV
V
corrected
V
raw
(
)
V
raw
bits
(
)∗ LSB
weight
pV
bits
---------
⎝
⎠
⎛
⎞∗10
12
–
V
pV
-------
⎝
⎠
⎛
⎞
⎩
⎭
⎨
⎬
⎧
⎫
Offset pV
(
)∗10
9
–
V
nV
-------
⎝
⎠
⎛
⎞
⎭
⎬
⎫
–
=