Allen-Bradley Micro800 General Instructions Manual page 46

Chapter 3
Ladder Diagram (LD) elements
46
Direct Contact
Direct contacts support a Boolean operation between a connection line state and a
Boolean variable.
The state of the connection line on the right of the contact is the logical AND
between the state of the left connection line and the value of the variable
associated with the contact.
Example: Direct Contact
Reverse Contact
Reverse contacts support a Boolean operation between a connection line state and
the Boolean negation of a Boolean variable.
The state of the connection line on the right of the contact is the logical AND
between the state of the left connection line and the Boolean negation of the value
of the variable associated with the contact.
Example: Reverse Contact
Rockwell Automation Publication 2080-RM001D-EN-E - February 2015