Campbell Scientific CR6 CR6 Measurement and Control System - Page 131

Section 7. Installation CRBasic Example 5. Load binary information into a variable ' how binary data are loaded into a variable. The binary 'format (1 = high, 0 = low) is useful when loading the status of multiple flags 'or ports into a single variable. For example, storing the binary number &B11100000 'preserves the status of flags 8 through 1: flags 1 to 5 are low, 6 to 8 are high. 'This example demonstrates an algorithm that loads binary status of flags into a LONG 'integer variable. Public FlagInt As Long Public Flag(8) As Boolean Public I DataTable(FlagOut,True,-1) Sample(1,FlagInt,UINT2) EndTable BeginProg Scan(1,Sec,3,0) FlagInt = 0 For I = 1 To 8 If Flag(I) = true Then FlagInt = FlagInt + 2 ^ (I - 1) EndIf Next I CallTable FlagOut NextScan EndProg 7.8.3.2 Program Structure Essential elements of a CRBasic program are listed in the table CRBasic Program Structure (p. 131) and demonstrated in CRBasic example Program Structure (p. 132). Table 18. CRBasic Program Structure Declarations Define CR6 memory usage. Declare constants, variables, aliases, units, and data tables. Declare constants List fixed constants. Declare Public variables List / dimension variables viewable during program execution. Dimension variables List / dimension variables not viewable during program execution. Define Aliases Assign aliases to variables. Define Units Assign engineering units to variable (optional). Units are strictly for documentation. The CR6 makes no use of Units nor checks Unit accuracy. Define data tables. Define stored data tables. Process / store trigger Set triggers when data should be stored. Triggers may be a fixed interval, a condition, or both. Table size Set the size of a data table. 131