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)
If you negate a negative value, the result is positive. If you negate a positive value,
the result is negative.
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 = 0 − Source
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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