Input Parameter
Data Type
EnableIn
BOOL
Source A
REAL
Source B
REAL
Output Parameter
Data Type
EnableOut
BOOL
Dest
REAL
Description:
Arithmetic Status Flags:
Fault Conditions:
Condition
Prescan
Rung-condition-in is false
Rung-condition-in is true
Postscan
Condition
Prescan
Instruction first scan
Instruction first run
EnableIn is cleared
EnableIn is set
Postscan
Compute/Math Instructions (CPT, ADD, SUB, MUL, DIV, MOD, SQR, SQRT, NEG, ABS)
FBD_MATH Structure
Description
Enable input. If cleared, the instruction does not execute and outputs are not updated.
Default is set.
Value of the multiplicand.
Valid = any float
Value of the multiplier.
Valid = any float
Description
The instruction produced a valid result.
Result of the math instruction. Arithmetic status flags are set for this output.
The MUL instruction multiplies Source A with Source B and places the result in
the Destination.
Arithmetic status flags are affected.
None
Execution:
Relay Ladder
Action
The rung-condition-out is set to false.
The rung-condition-out is set to false.
Destination = Source B x Source A
The rung-condition-out is set to true.
The rung-condition-out is set to false.
Function Block
Action
No action taken.
No action taken.
No action taken.
EnableOut is cleared.
The instruction executes.
EnableOut is set.
No action taken.
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Chapter 6
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