Rockwell Automation 1775-KA PLC-3 Communication Adapter Module User Manual User Manual

Page 72

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Addressing Rules and Examples

Chapter 4

4Ć16

The result of a logical complement is 1 (true) if the expression following
the .NOT. is a value of 0 (zero). Otherwise, the result is 0 (false). For
example, consider the command

$I12:24=.NOT.SYMBOL_A

If the value of SYMBOL_A is 0 (zero), then a 1 is stored in word 24 of
input file 12. If the value of SYMBOL_A IS anything other than 0, then a
0 (zero) is stored in word 24 of input file 12.

The result of a logical AND is 1 (true) if the expression preceding the
.AND. and the expression following the .AND. are both non–zero.
Otherwise, the result is 0 (false).

The result of a logical OR is 1 (true) if either the expression preceding the
.OR., the expression following the .OR., or both expressions are
non–zero. Otherwise, the result is 0 (false).

Bitwise 32–Bit Operators

Bitwise 32–bit operators manipulate the individual bits in a 32–bit
operand.

The bitwise 32–bit complement (.BNOT.) inverts the state of each bit in
the 32– bit expression. That is, bits set to 1 are inverted to 0, and bits set
to 0 are inverted to 1.

The bitwise 32–bit AND (.BAND.) forms a bit–by–bit logical AND of
two 32–bit operands. There is no carry from one bit position to the next
within the operand. For example, if

A contains the bit pattern
10101010010011110010101010101011

B contains the bit pattern
01110101011100100010101110001010

then the assignment C=A.BAND.B yields

C contains the bit pattern
00100000010000100010101010001010

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