Fbd_Math Structure - Allen-Bradley Logix5000 Reference Manual

Input Parameter Data Type
EnableIn BOOL
Source X REAL
Source Y REAL
Output Parameter Data Type
EnableOut BOOL
Dest REAL
Description:
Arithmetic Status Flags:
Fault Conditions:

FBD_MATH Structure

Description
Enable input. If cleared, the instruction does not execute and outputs are not updated.
Default is set.
Base value.
Valid = any float
Exponent.
Valid = any float
Description
The instruction produced a valid result.
Result of the math instruction. Arithmetic status flags are set for this output.
If Source X is negative, Source Y must be an integer value or a minor fault will
occur.
The XPY instruction uses this algorithm: Destination = X**Y
The controller evaluates x
Arithmetic status flags are affected.
A Minor Fault Will Occur If
Source X is negative and Source Y is not an integer
value
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Advanced Math Instructions (LN, LOG, XPY)
0 x
=1 and 0 =0.
Fault Type
4
Chapter 15
Fault Code
4
553