Allen-Bradley LOGIX 5000 Reference Manual page 356

Chapter 4 Select_Limit Instructions
356
(2) You can lock the instruction in Program control mode by leaving
ProgProgReq true while ProgOperReq is false.
Affects Math Status Flags
No
Major/Minor Faults
None specific to this instruction. See Common Attributes for operand-related
faults.
Execution
Function Block
Condition/State
Prescan
Tag.EnableIn is false
Tag.EnableIn is true
Instruction first run
Instruction first scan
Postscan
Structured Text
Condition/State
Prescan
Normal Execution
Postscan
Example
This ESEL instruction selects In1, In2, or In3, based on the SelectorMode. In this
example, SelectorMode = 1, which means high select. The instruction determines
which input value is the greatest and sets Out = greatest In.
Rockwell Automation Publication 1756-RM006K-EN-P - November 2018
Action Taken
EnableIn and EnableOut bits are cleared to false.
EnableIn and EnableOut bits are cleared to false.
EnableIn and EnableOut bits are set to true.
The instruction executes
The instruction is set to Operator control.
N/A
EnableIn and EnableOut bits are cleared to false.
Action Taken
See Prescan in the Function Block table.
See Tag.EnableIn is true in the Function Block table.
See Postscan in the Function Block table.