User guide

30 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 μV6.10 μV
FSR – 1LSB 0.999969 V 0.199993 V FFFF
Midscale + 1LSB 30.5 μV6.10 μV 8001
Midscale 0.0 V 0.0 V 8000
Midscale - 1LSB -30.5 μV -6.10 μV7FFF
-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