NEG (Negate) Ladder Logic Instruction

Definition

The Negate instruction is a ladder logic rung output instruction that changes the sign of the Source value and places the result in the Destination tag. The instruction is enabled when the preceding logic is true and disabled otherwise. The values can be constants, tags or any combination.

To negate values is to change the sign. Negate will change a positive value to a negative or a negative to a positive.

List of possible arguments

SOURCE and DESTINATION can be any combination of the following data types.

  • CONSTANT             Can’t be the DESTINATION obviously
  • SINT              
  • INT
  • DINT
  • REAL

Note: Arithmetic status flags are affected (S:V, S:Z, S:N, S:C). Overflow, Zero, Negative, and Carry.