Negate (Neg); Relay Ladder; Structured Text; Function Block - Allen-Bradley Logix5000 Reference Manual

Chapter 6 Compute/Math Instructions (CPT, ADD, SUB, MUL, DIV, MOD, SQR, SQRT, NEG, ABS)

Negate (NEG)

dest := -source;
Input Parameter Data Type
EnableIn BOOL
Source REAL
Output Parameter Data Type
EnableOut BOOL
Dest REAL
286
The NEG instruction changes the sign of the Source and places the result in the
Destination.
Operands:

Relay Ladder

Operand
Source
Destination

Structured Text

Use the minus sign '−' as an operator in an expression. This expression changes
the sign of source and stores the result in dest.
See Structured Text Programming
within structured text.

Function Block

Operand
NEG tag

FBD_MATH Structure

Description
Enable input. If cleared, the instruction does not execute and outputs are not updated.
Default is set.
Value to negate.
Valid = any float
Description
The instruction produced a valid result.
Result of the math instruction. Arithmetic status flags are set for this output.
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Type Format
SINT Immediate Tag
INT
DINT
REAL
A SINT or INT tag converts to a DINT value by sign-extension.
SINT Tag
INT
DINT
REAL
for information on the syntax of expressions
Type
FBD_MATH_ADVANCED
Description
Value to negate
Tag to store the result
Format Description
Structure NEG structure