Campbell Scientific CR800 and CR850 Measurement and Control Systems - Manual (Page 319)

Section 8. Operation
319
size of USR: is the total RAM size less 400 kB; i.e., for a CR800 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 using the
external keyboard / display or by loading a program with a different USR: size
entered in a SetStatus() instruction.
Measurement data can be stored on USR: as discrete files by using the
TableFile() instruction. Table TableFile()-Instruction Data-File Formats
(p. 320)
describes available data-file formats.
Note Placing an optional USR: size setting in the user program over-rides manual
changes to USR: size. When USR: size is changed manually, the user 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
(p. 540)
), certain configuration files, files
written for FTP retrieval, HTML files for viewing via web access, and files
created with the TableFile() instruction. Files on USR: can be collected using
support software Retrieve
(p. 431)
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 is used within the CR800 CRBasic program to
remove files. Files also can be removed using support software Delete
(p. 431)
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 support software File Control (p. 431) window.
8.3.1.1.4 USB: Drive
USB: drive uses Flash memory on a Campbell Scientific mass storage device (see
the appendix Mass Storage Devices
). 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. 320)
describes available data-file formats.
Caution When removing mass-storage devices, do so when the LED is not
flashing or lit.
Campbell Scientific mass-storage devices
• should be formatted as FAT32,
• connect to the CR800 via the CS I/O,
• must be removed only when inactive, or data corruption may result.
8.3.1.1.5 Data File Formats
TableFile() instruction data-file formats contain time-series data and may have an
option to include header, time stamp and record number. Table TableFile()-