ADLINK PCI-9524 - Manual (Page 77)

Operation Theory 61
ADLINK Technology Inc. PCI-9524
Copyright 2008 User’s Manual
Table 4-3: Default Threshold Values (ADC counts) vs. ADC Sampling Rates
ADC Sampling Rate Threshold Counts
30,000
268
15,000
176
7,500
188
3,750
104
2,000
90
1,000
56
500
46
100
22
60
16
50
14
30
12
25
10
15
8
10
8
5
8
2.5
8
4.2.10 RAW Data Format
To maximize data processing flexibility, it is possible for users to
deal with raw data directly, rather than scaled data. The data for-
mat of the acquired 32-bit raw AI is shown in Table 4-4.
Table 4-4: RAW Data Format
BIT[31..8] BIT[7..4] BIT[3..2] BIT[1] BIT[0]
AD Data Channel No. RSV DSP Flushed Data Refreshed
The 'AD Data' field contains a 2's complement coded AD data, to
manually scale them to physical units; please refer to
Section 4.2.11. To convert the AD data to a decimal count, first
convert it to a signed decimal integer, and divide it by 256; bit 7 to
0 are automatically eliminated during the conversion process.