Campbell Scientific CR800 and CR850 Measurement and Control Systems - Manual (Page 317)

Section 8. Operation
317
Table 71. CR800 SRAM Memory
Use Comments
Static Memory Operational memory used by the operating system regardless of the user
program. This sector is rebuilt at power-up, program re-compile, and watchdog
events.
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Operating Settings and Properties
"Keep"
memory. Stores settings such as PakBus address, station name, beacon
intervals, neighbor lists, etc. Also stores dynamic properties such as the routing
table, communications timeouts, etc.
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CRBasic Program
Operating Memory
Stores the currently compiled and running user program. This sector is rebuilt on
power-up, recompile, and watchdog events.
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Variables & Constants
Stores variables in the user program. These values may persist through power-
up, recompile, and watchdog events if the PreserveVariables instruction is in
the running program.
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Final-Storage Data Tables
Final Storage is given lowest
priority in SRAM memory
allocation.
Stores data resulting from CR800 measurements. This memory is termed "Final
Storage." Fills memory remaining after all other demands are satisfied.
Configurable as ring or fill-and-stop memory. Compile error occurs if
insufficient memory is available for user-allocated data tables.
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Communications Memory 1
Construction and temporary storage of PakBus® packets.
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Communications Memory 2
Constructed Routing Table: list of known nodes and routes to nodes. Routers use
more space than leaf nodes because routes to neighbors must be remembered.
Increasing the PakBusNodes field in the Status table will increase this allocation.
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USR: drive
<= 3.6 MB (4 MB Mem)
<= 1.5 MB (2 MB Mem)
Less on older units with more
limited memory.
Optionally allocated. Holds image files. Holds a copy of Final Storage when
TableFile() instruction used. Provides memory for FileRead() and FileWrite()
operations. Managed in File Control. Status reported in Status table fields
"USRDriveSize" and "USRDriveFree."