Campbell CR800 Series, Operator'S Manual

Page: 409 / 598

Section 8. Operation
409
CR800 Memory Drives
Drive Recommended File Types
CPU:
1
cr8, .CAL
USR:
1
cr8, .CAL, images
USB: .DAT
1
The CPU: and USR: drives use the FAT32 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 so is accessed very quickly.
2
8.8.1.1 Memory Drives — On-Board
Data-storage drives are listed in table CR800 Memory Drives
(p. 409).
Data-table
SRAM and the CPU: drive are automatically partitioned for use in the CR800.
The USR: drive can be partitioned as needed. The USB: drive is automatically
partitioned when a Campbell Scientific mass-storage device
(p. 571)
is connected.
8.8.1.1.1 Data Table SRAM
Primary storage for measurement data are those areas in SRAM allocated to data
tables as detailed in table
CR800 SRAM Memory
(p. 408,
http://www.
).
Measurement data can be also be stored as discrete files on USR: or USB: by
using TableFile() instruction.
The CR800 can be programmed to store each measurement or, more commonly,
to store processed values such as averages, maxima, minima, histograms, FFTs,
etc. Data are stored periodically or conditionally in data tables in SRAM as
directed by the CRBasic program (see Program Structure
(p. 119)
). The
DataTable() instruction allows the size of a data table to be programmed.
Discrete data files are normally created only on a PC when data are retrieved
using datalogger support software
(p. 86).
Data are usually erased from this area when a program is sent to the CR800.
However, when using support software File Control menu Send
(p. 498)
command
or
CRBasic Editor
Compile, Save and Send
(p. 494)
command, options are
available to preserve data when downloading programs.
8.8.1.1.2 CPU: Drive
CPU: is the default drive on which programs and calibration files are stored. It is
formatted as FAT32. Do not store data on CPU: or premature failure of memory
will probably result.