Allen-Bradley Logix5000 Reference Manual

Rockwell Automation Publication 1756-RM003N-EN-P - October 2011 553
Advanced Math Instructions (LN, LOG, XPY) Chapter 15
FBD_MATH Structure
Description: If Source X is negative, SourceY must be an integer value or a minor fault will
occur.
The XPY instruction uses this algorithm: Destination = X**Y
The controller evaluates x
0
=1 and 0
x
=0.
Arithmetic Status Flags: Arithmetic status flags are affected.
Fault Conditions:
Input Parameter Data Type Description
EnableIn BOOL Enable input. If cleared, the instruction does not execute and outputs are not updated.
Default is set.
Source X REAL Base value.
Valid = any float
Source Y REAL Exponent.
Valid = any float
Output Parameter Data Type Description
EnableOut BOOL The instruction produced a valid result.
Dest REAL Result of the math instruction. Arithmetic status flags are set for this output.
A Minor Fault Will Occur If Fault Type Fault Code
Source X is negative and Source Y is not an integer
value
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Allen-Bradley Logix5000 Specifications

General

Brand	Allen-Bradley
Model	Logix5000
Category	Controller
Language	English