One Shot Rising (OSR)

The OSR instruction sets the output bit for one scan when rung-condition-in transitions from false to true.
RSL5K_OSR Description
Available Languages
Ladder Diagram
Ladder Diagram_One Shot Rising (OSR)_v1
Operands
IMPORTANT: Unexpected operation may occur if:
  • Output tag operands are overwritten
  • Members of a structure operand are overwritten
  • Except when specified, structure operands are shared by multiple instructions.
Ladder Diagram
Operand
Data Type
Format
Description
Storage Bit
BOOL
tag
Stores the rung-condition-in from when the instruction was last executed.
There are various operand addressing modes possible for the storage bit, see Bit Addressing for examples.
Output Bit
BOOL
tag
Bit to be modified.
Affects Math Status Flags
No
Major/Minor Faults
None specific to this instruction. See Index through arrays for array-indexing faults.
Execution
Ladder Diagram
Condition/State
Action Taken
Prescan
The storage bit is set to true to prevent an invalid trigger during the first program scan.
The output bit is cleared to false.
Rung-condition-in is false
Set Rung-condition-out to Rung-condition-in
The storage bit is cleared to false.
The output bit is cleared to false.
Rung-condition-in is true
Set Rung-condition-out to Rung-condition-in
See OSR Flow Chart (True).
Postscan
N/A
OSR Flow Chart (True)
OSR Flow Chart True
Example
Ladder Diagram
FTStudio-OSR-LD-EX-V1
This example shows how an OSR can be used to make one or more instructions edge-triggered. Each time Limit_Switch_01 transitions from false to true the OSR will set Output_bit_02 to true. Any instruction conditioned by Output_bit_02 will be enabled and, since Output_bit_02 is only true for one scan, will execute once per transition.
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