Relay Ladder; Function Block - Allen-Bradley Logix5000 Reference Manual

Chapter 5 Compare Instructions (CMP, EQU, GEQ, GRT, LEQ, LES, LIM, MEQ, NEQ)
Arithmetic Status Flags:
Fault Conditions:
Condition
Prescan
Rung-condition-in is false
Rung-condition-in is true
Masked Source =
Masked Compare
Rung-condition-out is set
Postscan
Condition
Prescan
Instruction first scan
Instruction first run
EnableIn is cleared
EnableIn is set
Postscan
254
Not affected
None
Execution:

Relay Ladder

Action
The rung-condition-out is set to false.
The rung-condition-out is set to false.
Yes
no
to false.
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 does nothing, and the outputs are not updated.
The instruction executes.
EnableOut is set.
No action taken.
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Rung-condition-out is set
to true.
End