National Instruments Deterministic Ethernet Expansion Chassis NI..., User Manual

Page: 61 / 65

© National Instruments Corporation 61 NI 9144 User Guide and Specifications
NI 9264
NI 9264 Calibration Data
The NI 9263 has four channels with a nominal range of ±10.5 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 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.
Use the calibration coefficients with the following equation to generate
corrected data:
Table 58. NI 9264 Vendor Configuration Extensions
Index Sub Type R/W Description
0x2100 1 ARR:U32 — Calibration = 16
2 R Ch0 Gain
3 R Ch1 Offset
... ... ...
8 R Ch3 Gain
9 R External Ch0
Offset
... ... ...
Table 59. NI 9264 Scan List Format
Coefficient Representation Units
LSB Weight Unsigned pV/LSB
Offset Signed nV
V
desired
Code
( )
Code LSB
weight
•
nV
bits
---------
⎝ ⎠
⎛ ⎞
10
9
–
•
V
nV
-------
⎝ ⎠
⎛ ⎞
Offset nV
( )
10
9
–
V
nV
-------
⎝ ⎠
⎛ ⎞
•
+ =