LI-COR LI-6400, Manual

Page: 269 / 846

Data Logging
AutoProgram Descriptions
Using the LI-6400 9-25
When the logging period is over, Buffered AutoLog goes to work on any data
that has accumulated in the buffer (Figure 9-17). During this time, the display
only shows the count of the readings left to process:
The Buffer
As a practical matter, the maximum buffer size that Buffered AutoLog will use
is 500 groups of readings, where each group consists of all the analog inputs
including any spare channels that might be enabled (configuration parameter
UserChan=). If memory becomes sufficiently fragmented so that there are
less than 60 kilobytes available in one contiguous piece, then this maximum
buffer size is reduced.
Typical Performance
The performance of Buffered AutoLog is largely dependent on how fast
OPEN can do the user computations. The following results are based on the
standard equation set (ÒComputeList= DefaultÓ) and log file formats (ÒLog
Format= Std OutputÓ). The optional floating point coprocessor (part number
6400-12) is a big help here, as well.
The number of observations B that will be buffered during logging period T
(s) is,
(9-1)
where f is logging rate (s
-1
), and f
0
is the rate at which observations are com-
puted and stored in the log file (s
-1
). After logging, the time W (s) that it takes
to process the buffered observations is
(63) Doing buffered data...(esc quits)
103
Counts down to 0 as
buffered readings are
processed.
Number of readings that
were processed during
the log period.
Figure 9-17. After Buffered AutoLog is done collecting data, it processes the buffered readings (those it
didnÕt have time to get to during actual data collection).
B f f
0
Ð
( )
T =