8.3.1.1.3 USR: Drive
SRAM can be partitioned to create a FAT32 USR: drive, analogous to partitioning
a second drive on a PC hard disk. Certain types of files are stored to USR: to
reserve limited CPU: memory for datalogger programs and calibration files.
Partitioning also helps prevent interference from data table SRAM. USR: is
configured using DevConfig settings or SetStatus() instruction in a CRBasic
program. Partition USR: drive to at least 11264 bytes in 512-byte increments. If
the value entered is not a multiple of 512 bytes, the size is rounded up. Maximum
size of USR: is the total RAM size less 400 kB; i.e., for a CR1000 with 4 MB
memory, the maximum size of USR: is about 3.6 MB.
USR: is not affected by program recompilation or formatting of other drives. It
will only be reset if the USR: drive is formatted, a new operating system is
loaded, or the size of USR: is changed. USR: size is changed manually by
accessing it in the Status table or by loading a CRBasic program with a different
USR: drive size entered in a SetStatus() or SetSetting() instruction. See section
Configuration with CRBasic Program
(p. 115).
Measurement data can be stored on USR: as discrete files by using the
TableFile() instruction. Table TableFile()-Instruction Data-File Formats
(p. 378)
describes available data-file formats.
Note Placing an optional USR: size setting in the CRBasic program over-rides
manual changes to USR: size. When USR: size is changed manually, the
CRBasic program restarts and the programmed size for USR: takes immediate
effect.
The USR: drive holds any file type within the constraints of the size of the drive
and the limitations on filenames. Files typically stored include image files from
cameras (see the appendix Cameras
), certain configuration files, files written for
FTP retrieval, HTML files for viewing with web access, and files created with the
TableFile() instruction. Files on USR: can be collected using datalogger support
software
(p. 95) Retrieve (p. 515) command, or automatically using the datalogger
support software Setup File Retrieval tab functions.
Monitor use of available USR: memory to ensure adequate space to store new
files. FileManage() command can be used in the CRBasic program to remove
files. Files also can be removed using datalogger support software Delete
(p. 515)
command.
Two Status table registers monitor use and size of the USR: drive. Bytes
remaining are indicated in register USRDriveFree. Total size is indicated in
register USRDriveSize. Memory allocated to USR: drive, less overhead for
directory use, is shown in datalogger support software File Control
(p. 515)
window.
8.3.1.1.4 USB: Drive
USB: drive uses Flash (p. 516) memory on a Campbell Scientific mass storage
device (see the appendix Mass Storage Devices
(p. 653) ). Its primary purpose is the
storage of ASCII data files. Measurement data can be stored on USB: as discrete
files by using the TableFile() instruction. Table
TableFile()-Instruction Data-File Formats (p.
378)T
erm. Flash (p. 516)describes available data-file formats.
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