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plc st - 19.9<br />

• Functions for Boolean algebra <strong>and</strong> logic include,<br />

AND(A,B)<br />

OR(A,B)<br />

XOR(A,B)<br />

NOT(A)<br />

!<br />

logical <strong>and</strong><br />

logical or<br />

exclusive or<br />

logical not<br />

logical not<br />

Figure 19.12<br />

Boolean Functions<br />

• The precedence of operations are listed below from highest to lowest. As normal<br />

expressions that are the most deeply nested between brackets will be solved first. (Note:<br />

when in doubt use brackets to ensure you get the sequence you expect.)<br />

highest priority<br />

!<br />

()<br />

XPY, **<br />

SQR, TOD, FRD, NOT, NEG, LN, LOG, DEG, RAD, SIN, COS, TAN, ASN, ACS, ATN<br />

*, /, MOD<br />

+, -<br />

AND (for word)<br />

XOR (for word)<br />

OR (for word)<br />

>, >=, =,

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