Is Not a Number (IsNAN)

Is Not a Number (IsNAN)

This table lists the controllers and applications that support this instruction.
Architecture
Standard applications
Safety applications
CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers
Yes
Yes
When enabled, the Is Not a Number (IsNAN) instruction tests whether the source is not a number.
Available Languages
Ladder Diagram
Function Block Diagram
This instruction is not available in Function Block Diagram.
Structured Text
This instruction is not available in structured text.
Operands
Ladder Diagram
Operand
CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers
Data Type
Format
Description
Source
REAL
LREAL
tag
Value to test against Infinity
Affects Math Status Flags
No
Major/Minor Faults
This instruction does not generate any major/minor 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 Source is NAN.
Set Rung-condition-out to true
else
Clear Rung-condition-out to false.
Postscan
N/A
Examples
Ladder Diagram
IsNAN_example_ladder
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