Allen-Bradley LOGIX 5000 Reference Manual page 406

Chapter 6 Logical and Move
406
Structured Text
Operand Type
JKFF tag FLIP_FLOP_JK
See Structured Text Syntax for more information on the syntax of expressions
within structured text.
Description
When Clear is set, the instructions clears Q and sets QNot. Otherwise, if Clock is
set and Clockn-1 is cleared, the instruction toggles Q and QNot.
The instruction sets Clockn-1 = Clock state every scan.
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 Action Taken
Prescan EnableIn and EnableOut bits are cleared to false.
Tag.EnableIn is false EnableIn and EnableOut bits are cleared to false.
Tag.EnableIn is true EnableIn and EnableOut bits are set to true.
The instruction executes.
Instruction first run Clockn-1 is set to 1.
Qn-1 is cleared to 0.
Instruction first scan Previous input Clock states is set to True.
Previous output Q state is False.
Postscan EnableIn and EnableOut bits are cleared to false.
Structured Text
Condition/State Action Taken
Prescan See Prescan in the Function Block table.
Normal Execution See Tag.EnableIn is true in the Function Block table.
Postscan See Postscan in the Function Block table.
Rockwell Automation Publication 1756-RM006K-EN-P - November 2018
Format Description
Structure JKFF structure