Campbell CR3000 Micrologger, Руководство оператора

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Section 7. Installation
138
Data Types in Variable Memory
Name
Comman
d
Description
Word
Size
(Bytes)
Notes Resolution / Range
String As String ASCII string
Minimum
: 3 (4
with null
terminato
r)
Default:
24
Maximu
m:
limited
only to
the size of
available
CR3000
memory.
See caution.
1
String size is defined by the
CR3000 operating system and
CRBasic program.
When converting from
STRING to FLOAT,
numerics at the beginning of a
string convert, but conversion
stops when a non-numeric is
encountered. If the string
begins with a non-numeric,
the FLOAT will be NAN. If
the string contains multiple
numeric values separated by
non-numeric characters, the
SplitStr() instruction can be
used to parse out the numeric
values. See the sections String
Operations
(p. 327)
and Serial
I/O
(p. 303).
Unless declared otherwise, string size is 24
bytes or characters. String size is allocated
in multiples of four bytes; for example,
String * 25, String * 26, String * 27, and
String * 28 allocate 28 bytes (27 usable).
Minimum string size is 4 (3 usable). See
CRBasic Editor Help for more information.
Maximum length is limited only by
available CR3000 memory. As a special
case, a string can be declared as String * 1.
This allows the efficient storage of a single
character. The string will take up 4 bytes in
memory and when stored in a data table,
but it will hold only one character.
1
CAUTION When using a very long string in a variable declared Public, the operations of datalogger support software
(p. 615)
will
frequently transmit the entire string over the communication link. If communication bandwidth is limited, or if communications are
paid for by they byte, declaring the variable Dim may be preferred.
Data Types in Final-Storage Memory
Name Argument Description
Word
Size
(Bytes)
Notes Resolution / Range
FP2
FP2
Campbell
Scientific
floating point
2
Default final-memory data type.
Use FP2 for stored data requiring
3 or 4 significant digits. If more
significant digits are needed, use
IEEE4 or an offset.
Absolute Value
Decimal
Location
0 – 7.999 X.XXX
8 – 79.99 XX.XX
80 – 799.9 XXX.X
800 – 7999. XXXX.
Zero Minimum Maximum
0.000 ±0.001 ±7999.
IEEE4
IEEE4 or
Float
IEEE floating
point
4 IEEE Standard 754
±
1.4E–45 to
±
3.4E38