Campbell CR9000, Инструкция по эксплуатации

Страница: 33 / 218

2-1
Section 2. Data Storage and Retrieval
The CR9000 can store individual measurements or it may use its extensive processing
capabilities to calculate averages, maxima, minima, histograms, FFTs, etc., on periodic or
conditional intervals. Data are stored in tables. For simplicity, the PC9000 program
generator allows a maximum of six data tables (in the native language the limit on the
number of data tables depends on where the tables are stored). The number of tables and
the values to output in each table are selected when running the program generator
(Overview) or when writing a datalogger program directly (Sections 4 – 9).
2.1 Data Storage in CR9000
There are three possible areas for data storage on the CR9000:
Internal Static Ram –avaliable storage the only limit on the number of tables
Internal Flash Memory –6 data tables maximum
PCMCIA PC Card –30 data tables maximum
Internal Ram is used as either the sole storage area for a data table or as a
buffer area when data are sent to the PC card or to internal flash memory.
When PC9000 requests data from a table that is stored in Flash memory or a
PC card, the CR9000 only looks for the data in flash memory or in the PC card
when the oldest data are requested or if the data are not available in CPU
memory.
In the CRBASIC program, the DataTable instruction sets the size of the data
table or buffer area. A data table can be stored in a PC card by including the
PAMOut instruction within the data table declaration. A data table can be
stored in internal flash memory by including the FlashOut instruction within
the data table declaration. A data table cannot be sent to both a PC card and to
internal flash memory; the CR9000 will flag an error if both PAMOut and
FlashOut are in a data table declaration.
2.1.1 Internal Static Ram
Internal Ram is used as either the sole storage area for a data table or as a
buffer area when data are sent to PC card or to internal flash memory. The
only limit on the number of tables is the available memory. Data in RAM are
lost if the CR9000 is powered down either by switching off the power switch
or with the PowerOff instruction.
2.1.2 Internal Flash Memory
There are 1.5 M bytes of flash memory available for data storage. No more than
six data tables can be stored in flash memory. Flash Memory is always fill and
stop, that is, once the space allocated for the data table is full, no more data are
stored until the table is reset.