Campbell CR850, Руководство оператора

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Section 7. Installation
116
7.7.3.4 Single-Line Declarations
Public , Dim , and ReadOnly variables are declared at the beginning of a CRBasic
program, as are Constant s, Units , Alias es, StationName s, DataTable s, and
Subroutine s. Table Rules for Names
(p. 140)
lists declaration names and allowed
lengths.
7.7.3.4.1 Variables
A variable is a packet of memory given an alphanumeric name through which
pass measurements and processing results during program execution. Variables
are declared either as
Public or Dim at the discretion of the programmer. Public
variables can be viewed through the external keyboard / display or software
numeric monitors.
Dim variables cannot.
All user defined variables are initialized once when the program starts.
Additionally, variables that are used in the
Function() or Sub() declaration,or that
are declared within the body of the function or subroutine are local to that
function or subroutine.
Variable names can be up to 39 characters in length, but most variables should be
no more than 35 characters long. This allows for four additional characters that
are added as a suffix to the variable name when it is output to a data table.
Variable names can contain the following characters:
•
A to Z
•
a to z
•
0 to 9
•
_ (underscore)
•
$
Names must start with a letter, underscore, or dollar sign. Spaces and quote
marks are not allowed. Variable names are not case sensitive.
Several variables can be declared on a single line, separated by commas:
Public RefTemp, AirTemp2, Batt_Volt
Variables can also be assigned initial values in the declaration. Following is an
example of declaring a variable and assigning it an initial valued.
Public SetTemp = {35}
In string variables, string size defaults to 24 characters (changed from 16
characters in April 2013, OS 26).
Arrays
When a variable is declared, several variables of the same root name can also be
declared. This is done by placing a suffix of "(x)" on the alphanumeric name,
which creates an array of x number of variables that differ only by the
incrementing number in the suffix. For example, rather than declaring four similar
variables as follows,
Public TempC1
Public TempC2
Public TempC3
Public TempC4