MTS Series 793 Application - Manual (Page 311)

Cyclic Acquisition Process
MTS MultiPurpose TestWare® Data Acquisition Process Descriptions 311
In this case, the cyclic acquisition process will not trigger until after cycle 100.
So if you specified a logarithmic progression of 1, 2, 5, 10, and so on, the cyclic
acquisition process would skip all of the cycles performed during
preconditioning (1, 2, 5, 10, 20, 50, and 100), and begin acquiring data at cycle
200.
If you had enabled the Relative Cycle (or Segment) Counts, the process would
trigger at cycle 101 of the test. The process would count cycle 101 of the test as
cycle 1 of its logarithmic progression. This is because cycle 101 of the test is the
first cycle performed relative to when the cyclic acquisition process is triggered.
Considerations when
acquiring cycle
clusters
By default, the process stores the data it acquires from each cluster in its buffer,
and then writes the content of its buffer to the data file when it is finished
acquiring data on the cluster.
On a slow test, the process may take a long time to fill its buffer for a given
cluster. As the buffer fills, the data in the buffer will be lost if something
interrupts the progress of the test (for example, power failure, uncontrolled
shutdown, and so on) before the buffer fills completely.
The number of points the process acquires for a given cluster is open-ended and
may become quite large, depending on the test frequency and acquisition
intervals. For optimal results, some systems may require memory upgrades to
accommodate this situation.
When acquiring data, the process fills its buffer by receiving small buffered
chunks of data from the controller. Before the process can write this buffered data
to its data file, the process buffer must fill completely. Because of timing and size
differences between the controller buffer and process buffer, the process may
take up to thirty seconds before it writes data to its data file once its buffer is full.
Note The process will not issue its Process.Buffer Full signal until it has written
data to its data file.