Campbell Scientific CR1000KD CR1000 Measurement and Control System - Page 494

Appendix A. CRBasic Programming Instructions The result of these operators is the value of the left hand operand with all of its bits moved by the specified number of positions. The resulting "holes" are filled with zeroes. Consider a sensor or protocol that produces an integer value that is a composite of various "packed" fields. This approach is quite common to conserve bandwidth and/or storage space. Consider the following example of an eight-byte value: • bits 7-6: value_1 • bits 5-4: value_2 • bits 3-0: value_3 Code to extract these values is shown in CRBasic example Using Bit-Shift Operators (p. 494). With unsigned integers, shifting left is equivalent to multiplying by two. Shifting right is equivalent to dividing by two. > Amount >> Bitwise right shift Syntax Variable = Numeric Expression >> Amount & Bitwise AND assignment ‐‐ Performs a bitwise AND of a variable with an expression and assigns the result back to the variable. A.6.4 Compound-assignment operators Table 117. Compound-Assignment Operators Symbo l Name Function ^= Exponent assignment Raises the value of a variable to the power of an expression and assigns the result back to the variable. *= Multiplication assignment Multiplies the value of a variable by the value of an expression and assigns the result to the variable. += Addition assignment Adds the value of an expression to the value of a variable and assigns the result to the variable. Also concatenates a String expression to a String variable and assigns the result to the variable. -= Subtraction assignment Subtracts the value of an expression from the value of a variable and assigns the result to the variable. /= Division assignment Divides the value of a variable by the value of an expression and assigns the result to the variable. \= Division integer Divides the value of a variable by the value of an expression and assignment assigns the integer result to the variable. 494