3 ai data format, Ai data format, Table 3-2: ai data format – ADLINK PCI-9846 User Manual
Page 40: Figure 3-4: basic acquisition timing of digitizer

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Operation Theory
Figure 3-4: Basic Acquisition Timing Of Digitizer
3.2.3 AI Data Format
The following table illustrates the idea transfer characteristics of
various input ranges of the PCI/PXI-9816/26/46. The data format
of the PCI/PXI-9816/26/46 is straight binary.
Description
Analog Input Range
Digital Code (HEX)
Full-scale Range
±1 V
±0.2 V
Least significant bit
30.52 μV
6.10 μV
FSR – 1LSB
0.999969 V 0.199993 V
FFFF
Midscale + 1LSB
30.5 μV
6.10 μV
8001
Midscale
0.0 V
0.0 V
8000
Midscale - 1LSB
-30.5 μV
-6.10 μV
7FFF
-FSR
-1.000 V
-0.200 V
0000
Table 3-2: AI Data Format
TIMEBASE
DATA
D1
D253 D254
Acquisition
In Progress
Trigger
Acquisition starts right after this clock edge
D2
D3
D4
D255
D256
Analog
signal
Trigger mode = post-trigger, DataCnt = 256, ScanIntrv = 1