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6.3.4 Compact Flash Storage
The compact flash card stores all recorded data. Different size Compact Flash cards are
available. The cards must have a very fast read and write time to be able to record at the fast
sample rates.
The number of records that can be stored depends on the sample rate, number of
channels, and record length.
When the memory is full, the DAQlink III starts over at the beginning and overwrites the
stored data at the beginning of the Flash Card memory.
To estimate number of records, the following guidelines can be used.
• Each sample of data = 3 bytes
• Header information = about 12% of record length ( normally ignored when
estimating). Each record requires additional bytes depending on GPS time and other
peripheral information being recorded.
Example 1: 24 channels at 2msec, 1 second record.
24 channels * 500 samples/sec* 1second* 3 bytes/sample
Equals = 36 K bytes
Or a 32 Megabyte Compact Flash can hold about 800 records
A 1 Gigabyte Compact Flash Card can hold about 27,000 records
.
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