PASCO Xplorer GLX, Руководство пользователя

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82 D a t a F i l e s S c r e e n
RAM and Flash
The GLX has two types of memory for file storage: RAM and Flash, represented
by two folders in the Data Files screen. By default, files are saved in the RAM
folder. Whether it is most appropriate to store a file in RAM or Flash depends on
how you intend to use the file.
Files in the RAM folder are saved in the GLX’s random access memory. With a
capacity of about 12 MB, the RAM folder is large enough to store many files,
including ones containing large data sets. Files can be saved to RAM quickly and
easily.
Files copied to the Flash folder are stored in a special type of programmable
read-only memory. Use the Flash folder to store files that you do not want to be
easily altered, such as configuration files for experiments or sample data files.
When you open a file from the Flash folder and save it again, it does not over-
write the original file; rather, it saves a copy in the RAM folder. This property
prevents users from accidentally saving collected data over a file designed to be
used as an experiment set-up file.
Files saved in either RAM or Flash will remain saved even if the GLX’s battery
runs too low for normal operation. When the battery drains to a critical level, the
GLX shuts down, reserving enough energy to maintain the RAM memory until it
can be connected to AC power. However, if you store the GLX for several days
without power connected after the battery has drained to the critical level, it is
possible for the battery to run so low that RAM is erased.
Flash memory does not require any power to store data permanently. You can
leave the GLX unpowered for any amount of time without losing files saved in
the Flash folder.
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File Size Limits
In order to reserve enough free RAM capacity to save a data file, the GLX limits
a single file to 4 MB. If that size limit is reached, data collection will automati-
cally stop. To collect data after the file-size limit has been reached, delete exist-
ing data or start a new file. Data collection will also stop if the size of the data file
exceeds the free space remaining in RAM. Since a 4-MB file typically contains
over 100000 data points (depending on the sensors used), most users will not be
affected by these limits.
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See page 94 for more information
about battery power and data storage.