Campbell Scientific CR9000X Measurement and Control System - Manual (Page 74)

Section 2. Data Storage and Retrieval
located in the CPU DRAM and the CardOut instruction's size parameter
sets the actual memory allocated for the Data Table on the PC Card.
See the CardOut topic in Section 6.3 Export Data Instructions for
additional material on the CardOut instruction.
When a card is removed for data retrieval, new data will still be buffered to
the CPU's DRAM, up to the number of records specified by the DataTable
instruction's "Size" parameter. When the same card is reinserted the
buffered records that were not previously written to a card will be written
to the Data Table file located on the card. If a newly formatted card is
inserted, the Data Table structure will be created, and the buffered records
that have not previously been written to a Card will be written to the Card.
See Section 2.3.3 Logger Files Retrieval for additional material on data
retrieval using a PC card.
Using RTDAQ or LoggerNet, data stored on cards can be retrieved through
one of your computer's communication ports tied to the CR9000X, or by
removing the card and inserting it in a PC card slot in a computer. Proper
procedure should be followed when removing the PC card to insure that the
buffered data is flushed to the card and the card is not being accessed when
the card is removed.
If the proper steps are not taken when removing the card, the card
could be corrupted resulting in data loss.
See Section 2.3.4.1: Removing PC Card from CR9000X.
The Data Tables are stored on the card in a TOB3 binary format. CSI's
ViewPro and Split utilities support this format. For all other uses, the data
will need to be converted using CSI's Card Convert utility or the Collect
Data window. Converting the data directly from the PC Card, using the
computer's PC card slot, is usually much faster than retrieving it through
CR9000X using RTDAQ's Collect Data window.
See Section 2.3.5 Converting File Format.
2.2 Internal Data Format
Data are stored internally in a binary format. Variables and calculations are
performed internally in IEEE 4 byte floating point or in 32 bit Long Format
with some operations calculated in double precision. Variables can be
declared using one of four formats. In addition, there are eight data types
(FP2, IEEE4 (float), Long (ULong), UINT2, Bool4 (Boolean), Bool8,
NSEC, and String) used to store data. The output data format is selected
in the instruction that outputs the data. The four byte integer format
(LONG) is used by the CR9000X for storing time (two 4 byte integers) and
record number. Within the CR9000X, time is stored as integer seconds and
nanoseconds into the second since midnight, the start of 1990.
See Table 4.2.4-1 Data Types in Section 4.2.4 Declarations.
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