Bitwise operators – Rockwell Automation 1771-DB BASIC MODULE User Manual
Page 117
Chapter
Expressions, Variables and Operators
9
9 -7
The BASIC module contains a complete set of bitwise logical operators.
Bitwise operators perform their operations on a bit-by-bit level. Therefore,
BASIC changes the integers in the expressions to HEX/binary. BASIC can
perform bitwise operations on numbers between 0 (0000H) and 65535
(0FFFFH) inclusive. If the argument is outside this range, then the BASIC
module generates an
ERROR: BAD ARGUMENT
message and returns to
Command mode. All decimal places are truncated, not rounded.
Refer to this truth table when performing bitwise operations.
When X is:
and Y is:
X .AND.Y bit set to:
X .OR. Y bit set to:
X .XOR. Y bit set to:
0
0
0
0
0
0
1
0
1
1
1
0
0
1
1
1
1
1
1
0
Note:
0 = false/off
1 = true/on
X = a bit in the first operand
Y = a bit in the second operand
.AND.
Use the .AND. operator to perform a bitwise AND on two expressions.
The .AND. operator compares the bits of the two expressions and sets the
bit to 1 (true) if both bits being compared are set to 1 (true).
>PRINT 3.AND.2
Result:
2
This example performs a bitwise AND on the integers 3 and 2 and prints
the result. First, BASIC converts 3 and 2 to binary:
3 = 0011
2 = 0010
Then the BASIC module compares each digit of the binary number to
determine if both bits are set to a 1. For example, the first digit of both
numbers is 0 (false) so the result is 0.
0011
0010
0010
BASIC converts the resulting binary number back into an integer and
prints the result.
0010 = 2
Bitwise Operators