Use bitwise operators, Determine the order of execution – Rockwell Automation Logix5000 Controllers Structured Text Programming Manual User Manual

Page 19

Advertising
background image

Publication 1756-PM007D-EN-P - November 2012

19

Program Structured Text Chapter 1

Use Bitwise Operators

Bitwise operators manipulate the bits within a value based on two values.

For example:

Determine the Order of Execution

The operations you write into an expression are performed in a prescribed
order, not necessarily from left to right.

Operations of equal order are performed from left to right.

If an expression contains multiple operators or functions, group the
conditions in parenthesis “( )”. This ensures the correct order of
execution and makes it easier to read the expression.

For

Use this operator

Optimal Data Type

Bitwise AND

&, AND

DINT

Bitwise OR

OR

DINT

Bitwise exclusive OR

XOR

DINT

Bitwise complement

NOT

DINT

Use this format

Example

For this situation

You’d write

value1 operator value2

If input1, input2, and result1 are DINT tags and your
specification says: “Calculate the bitwise result of
input1 and input2. Store the result in result1.”

result1 := input1 AND input2;

Order

Operation

1.

( )

2.

function (…)

3.

**

4.

- (negate)

5.

NOT

6.

*, /, MOD

7.

+, - (subtract)

8.

<, <=, >, >=

9.

=, <>

10.

&, AND

11.

XOR

12.

OR

Advertising