5. Data memory
The data logger includes three types of memory: SRAM, Flash, and Serial Flash. A memory card
slot is also available for an optional microSD card. Note that the data logger USB port does not
support USB flash or thumb drives (see
(p. 12) for more information).
5.1 Data tables
Measurement data is primarily stored in data tables within SRAM. Data is usually erased from this
area when a program is sent to the data logger.
During data table initialization, memory sectors are assigned to each data table according to the
parameters set in the program. Program options that affect the allocation of memory include the
Size
parameter of the
DataTable()
instruction, the
Interval
and
Units
parameters of
the
DataInterval()
instruction. The data logger uses those parameters to assign sectors in a
way that maximizes the life of its memory. See the CRBasic Editor help for detailed instruction
information and program examples:
https://help.campbellsci.com/crbasic/cr6/.
By default, data memory sectors are organized as ring memory. When the ring is full, oldest data
is overwritten by newest data. Using the
FillStop
statement sets a program to stop writing to
the data table when it is full, and no more data is stored until the table is reset. To see the total
number of records that can be stored before the oldest data is overwritten, or to reset tables, go
to Station Status > Table Fill Times in your data logger support software.
Data concerning the data logger memory are posted in the Status and DataTableInfo tables. For
additional information on these tables, see
Information tables and settings (advanced)
For additional information on data logger memory, visit the Campbell Scientific blog
article, "
How to Know when Your Datalogger Memory is Getting Full
."
5.2 Memory allocation
Data table SRAM and the CPU drive are automatically partitioned by the data logger. The USR
drive can be partitioned as needed. The CRD drive is automatically partitioned when a memory
card is installed.
The CPU and USR drives use the FAT file system. There is no limit, beyond practicality and
available memory, to the number of files that can be stored. While a FAT file system is subject to
fragmentation, performance degradation is not likely to be noticed since the drive has a relatively
small amount of solid state RAM and is accessed very quickly.
5. Data memory
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