Campbell Scientific CR800 and CR850 Measurement and Control Systems User Manual

Page 316

Section 8. Operation

316

Table 70. CR800 Memory Allocation

Memory

Sector

Comments

Internal

battery-backed

SRAM

4 MB*

See

table

CR800 SRAM Memory

(p. 317)

for detail.

Internal Flash

2 MB

Operating

system

Internal Serial Flash

12 kB: Device Settings

500 kB: CPU: drive

Device Settings — A backup of settings such as PakBus address, station name, beacon
intervals, neighbor lists, etc. Rebuilt when a setting changes.
CPU: drive — Holds program files, field calibration files, and other files not frequently
overwritten. Slower than SRAM. 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 or the FilesManage() instruction. Use USR: drive to store other file types.
Available CPU: memory is reported in Status table field CPUDriveFree.

External Flash

(Optional)

2 GB: USB: drive

USB: drive

— Holds program files. Holds a copy of requested final-storage 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.

SRAM

·CR800 series changed from 2- to 4-MB SRAM in Sept 2007. SNs ≥ 3605 are 4 MB.

2Flash is rated for > 1 million overwrites.

Serial flash is rated for 100,000 overwrites (50,000 overwrites on 128-kB units). Care should be taken in programs that

overwrite memory to use the CRD: or USR: drives so as not to wear-out the CPU: drive.

·The CR800 series changed from 128- to 512-kB serial flash in May 2007. SNs ≥ 2787 are 512
kB.