Examine If Open (XIO)

Examine If Open (XIO)

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 Examine If Open (XIO) instruction examines the data bit to set or clear the rung condition.
Available Languages
Ladder Diagram
Operands
Ladder Diagram
Operand
Data Type
Format
Description
Data bit
BOOL
tag
Bit to be tested. There are various operand addressing modes possible for the data bit, see Bit Addressingfor examples.
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
N/A
Rung-condition-in is false
Set Rung-condition-out to Rung-condition-in
Rung-condition-in is true
If Data Bit is true, rung-condition-out is cleared to false.
If Data Bit is false, rung-condition-out is set to true.
Postscan
N/A
Examples
Example 1
Ladder Diagram
If Limit_Switch_01 is false, the next instruction is enabled.
Example 2
Ladder Diagram
If S:V is false, this enables the next instruction.
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