Campbell CR800 Series - CR800 Memory Allocation

Section 8. Operation
407
Table CR800 Memory Allocation (p. 407) and table CR800 SRAM Memory (p. 408,
http://www.) illustrate the structure of CR800 memory around these media. The
CR800 uses and maintains most memory features automatically. However, users
should periodically review areas of memory wherein data files, CRBasic program
files, and image files reside. See section File Management in CR800 Memory
(p.
416)
for more information.
By default, final-storage memory (memory for stored data) is organized as ring
memory. When the ring is full, oldest data are overwritten by newest data. The
DataTable() instruction, however, has an option to set a data table to Fill and
Stop.
CR800 Memory Allocation
Memory
Sector
Comments
Main
Battery-Backed SRAM1
Status.MemorySize (p. 544)
Status.MemoryFree (p. 544)
• OS variables
• See following table CR800 SRAM Memory (p. 408, http://www.) for detail.
Operating System
Flash Memory
2
• Operating system
• Serial number
• Board revision
• Boot code
• Erased when loading new OS. Boot code erased only if changed.
Internal
Serial Flash3
Status.CPUDriveFree (p. 539)
• Device settings — PakBus address and settings, station name. Rebuilt
when a setting changes.
• CPU:drive — program files, field calibration files, other files not
frequently overwritten. When a program is compiled and run, it is copied
here automatically for loading on subsequent power-ups. Files accumulate
until deleted with File Control (p. 498) or the FilesManage() instruction.
Use USR: drive to store other file types.
• FAT32 file system
• Limited write cycles (100,000)
• Slow serial access
External Flash
(Optional)
USB: drive
USB: drive (p. 571) — SC115: connects to CR800 by CS I/O, connects to
PC by USB port. FAT32. See appendix External Memory – List (p. 571).
Holds program files. Holds a copy of requested final-memory table data
as files when TableFile() instruction is used. USB: data can be
retrieved from the storage device with Windows Explorer. USB: drive
can facilitate the use of Powerup.ini (p. 421).