554 Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Chapter 15 Advanced Math Instructions (LN, LOG, XPY)
Execution:
Relay Ladder
Function Block
Condition Action
Prescan The rung-condition-out is set to false.
Rung-condition-in is false The rung-condition-out is set to false.
Rung-condition-in is true The controller takes Source X to the power of Source Y and places the result in the Destination.
The rung-condition-out is set to true.
Postscan The rung-condition-out is set to false.
Condition Action
Prescan No action taken.
Instruction first scan No action taken.
Instruction first run No action taken.
EnableIn is cleared EnableOut is cleared.
EnableIn is set The instruction executes.
EnableOut is set.
Postscan No action taken.