Clear (CLR)

This information applies to the CompactLogix 5370, ControlLogix 5570, Compact GuardLogix 5370, GuardLogix 5570, Compact GuardLogix 5380, CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, and GuardLogix 5580 controllers.
The CLR instruction clears all the bits of the Dest.
Available Languages
Ladder Diagram
CLR_LD_avail_v31
Function Block
This instruction is not available in function block.
Structured Text
This instruction is not available in structured text.
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.
The CLR instruction supports elementary data types. See
Elementary
Data Types
.
Ladder Diagram
Operand
Data Type
CompactLogix 5370, ControlLogix 5570, Compact GuardLogix 5370, and GuardLogix 5570 controllers
Data Type
CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers
Format
Description
Dest
SINT
INT
DINT
REAL
SINT
INT
DINT
LINT
USINT
UINT
UDINT
ULINT
REAL
LREAL
LTIME
TIME
TIME32
LDT
DT
tag
Tag to clear.
TIP:
See Time and date data types for a complete description of Relative Time (LTIME, TIME, and TIME32) and Absolute Time (LDT and DT) data types.
Affects Math Status Flags
Controllers
Affects Math Status Flags
CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers
Conditional
CompactLogix 5370, ControlLogix 5570, Compact GuardLogix 5370, and GuardLogix 5570 controllers
Yes
Major/Minor Faults
None specific to this instruction. See Index Through Arrays for array-indexing faults.
Execution
Ladder Diagram
Condition/State
Action Taken
Prescan
N/A
Rung-condition-in is false
Set Rung-condition-out to Rung-condition-in.
Rung-condition-in is true
Set Rung-condition-out to Rung-condition-in.
Clear Dest to 0.
Postscan
N/A
Example
Ladder Diagram
CLR_LD_ex_v31
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