Data memory

The data logger includes three types of memory: RAM, Flash, and Serial Flash.

CPU Drive: 80 MB serial flash
Data Storage: 30 MB serial flash
Operating System: 2 MB flash
Settings, Calibration, TLS Certificates and Key, System Information: 3 MB serial flash
Background Tasks and Table Information, Buffers, System Memory, Program Variables: 756 KB RAM

Data tables

Measurement data is primarily stored in data tables within serial flash. Data is usually erased from this area when a program is sent to the data logger. Final-data memory for the CR300 series is organized in 4 KB sectors. Each sector is rated for 100,000 serial flash erases.

During data table initialization, memory sectors are assigned to each data table according to the parameters set in the program. Program options that affect the allocation of memory include the Size parameter of the DataTable() instruction, the Interval and Units parameters of the DataInterval() instruction. The data logger uses those parameters to assign sectors in a way that maximizes the life of its memory. See the CRBasic Editor help for detailed instruction information and program examples: https://help.campbellsci.com/crbasic/cr300/ .

By default, data memory sectors are organized as ring memory. When the ring is full, oldest data is overwritten by newest data. Using the FillStop statement sets a program to stop writing to the data table when it is full, and no more data is stored until the table is reset. To see the total number of records that can be stored before the oldest data is overwritten, or to reset tables, go to Station Status > Table Fill Times in your data logger support software.

Data concerning the data logger memory are posted in the Status and DataTableInfo tables. For additional information on these tables, see Information tables and settings (advanced).

For additional information on data logger memory, visit the Campbell Scientific blog article, How to Know when Your Datalogger Memory is Getting Full .

Flash memory

The data logger operating system is stored in a separate section of flash memory. To update the operating system, see Updating the operating system.

Serial flash memory holds the CPU drive, web page, and data logger settings. Because flash memory has a limited number of write/erase cycles, care must be taken to avoid continuously writing to files on the CPU drive.

CPU drive

The serial flash memory CPU drive contains data logger programs and other files. This memory is managed in File Control File Control is a feature of LoggerNet, PC400, Device Configuration Utility, and RTDAQ data logger support software. It provides a view of the data logger file system and a menu of file management commands..

NOTE:

When writing to files under program control, take care to write infrequently to prevent premature failure of serial flash memory. Internal chip manufacturers specify the flash technology used in Campbell Scientific CPU: drives at about 100,000 write/erase cycles. While Campbell Scientific's in-house testing has found the manufacturers' specifications to be very conservative, it is prudent to note the risk associated with repeated file writes via program control.