Statement List (STL) - DCE FEL ČVUT v Praze

1 Bit Logic Instructions
1.1 Overview of Bit Logic Instructions
Description
Bit logic instructions work with two digits, 1 and 0. These two digits form the base of
a number system called the binary system. The two digits 1 and 0 are called binary
digits or bits. In the world of contacts and coils, a 1 indicates activated or energized,
and a 0 indicates not activated or not energized.
The bit logic instructions interpret signal states of 1 and 0 and combine them
according to Boolean logic. These combinations produce a result of 1 or 0 that is
called the ”result of logic operation” (RLO).
Boolean bit logic applies to the following basic instructions:
• A And
• AN And Not
• O Or
• ON Or Not
• X Exclusive Or
• XN Exclusive Or Not
• O And before Or
You can use the following instructions to perform nesting expressions:
• A( And with Nesting Open
• AN( And Not with Nesting Open
• O( Or with Nesting Open
• ON( Or Not with Nesting Open
• X( Exclusive Or with Nesting Open
• XN( Exclusive Or Not with Nesting Open
• ) Nesting Closed
Statement List (STL) for S7-300 and S7-400 Programming
A5E00706960-01 1-1