9 Memory mode
So that the acquisition of a periodic signal is convenient, you should select a sampling period that is compatible with the frequency of the signals at the input terminals of the recorder.
A
9.3.Internal memory, blocks
You can divide the available memory of the recorder into blocks that will be filled one after the other at each acquisition.
The amount of data of acquisition is worth N / (B * V)
N = total memory
B = number of blocks
V = number of channels to collect
Example: memory: 32 Mbytes, 16 blocks and 3 channels "ON"; you will have N = 32,554,432 / (16 * 3) = 699,050 bytes/channel
Any new acquisition will be placed automatically into the first free block available (in increasing sense).
When every blocks are full, a new acquisition will shift the previous block N into the block
The new acquisition will then take the place of the last block.
9.4.Triggering position
The acquisition into a memory block is based on the system of the 
rotary memory 
:
-the memory starts filling from the start condition
-the memory keeps on filling as long as the stop condition is not valid; if the memory is full, the filling restarts from the beginning of the memory zone (block)
Thus, the memory block always contains the N last samples.
The user can choose the moment when the samples in the memory will be frozen: to do so, he will define a delay between the triggering moment and the beginning of the effective transfer into memory.
This delay can be positive or negative. The samples in memory can thus be either before or after or on both sides of the triggering moment.
We can also not inhibit the trigger during the pre trigger phase : this allow to test the trigger condition during the pre trigger phase and make the trigger function even if the pre trigger time isn
t passed.
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