User`s guide

Universal Library User's Guide Analog Input Boards - PCI-DAS4020 Series
48
For example, to run cbAInScan on one channel at 18 MHz with the CONTINUOUS option set, determine the
minimum sample size from the table to be 262,144 (since the Rate is between 14 and 20 MHz). The minimum
contiguous memory is calculated as:
(262,144 / 512 ) = 512 KB
Number
of
Channels
Rate in MHz
Packet
Size in
Samples
Minimum Sample
Size (two packets)
Contiguous
Memory
Min Contiguous
Memory (based on
Min Sample Size)
1
20 ≥ Rate ≥13.3
131,072
262,144
Required
512 KB
13.3 > Rate > 4
65,536
131,072
Required
256 KB
4 ≥ Rate ≥ 2
4,096
8,192
Not Required
0 KB
2 > Rate
2,048
4,096
Not Required
0 KB
2
20 ≥ Rate ≥ 6.6
131,072
262,144
Required
512 KB
6.6 > Rate ≥ 2
65,536
131,072
Required
256 KB
2 > Rate ≥ 1
4,096
8,192
Not Required
0 KB
1 > Rate
2,048
4,096
Not Required
0 KB
4
10 ≥ Rate ≥ 3.3
131,072
262,144
Required
512 KB
3.3 > Rate ≥ 1
65,536
131,072
Required
256 KB
1 > Rate ≥ 0.5
4,096
8,192
Not Required
0 KB
0.5 > Rate
2,048
4,096
Not Required
0 KB
*Note that the EventData for ON_PRETRIGGER events may not be accurate. In general, this value will be below
the actual number of pretrigger samples available in the buffer.