- Studio 5000 Logix Designer
- Tasks, programs, and routines
- Add-On Instructions
- Controller Organizer
- Logical Organizer
- Alarms
- Tag-based alarms
- Tag Editor and Data Monitor
- Configure settings for Tag Editor and Data Monitor
- Equipment phases
- Equipment Sequences
- Equipment Sequence Diagrams
- Ladder Editor
- Structured Text Editor
- Sequential Function Chart Editor
- Define the steps of an SFC process
- PlantPAx instruction properties
- Controller Properties
- Editing Controller Properties
- Controller Security
- Source Protection
- License Source Protection for Routines and Add-On Instructions
- Module Information
- 1756 ControlLogix I/O Modules
- Instruction Set
Is Infinity (IsINF)
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 Infinity (IsINF) instruction tests whether the Source is infinity.
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 +INF or -INF. Set Rung-condition-out to true else Clear Rung-condition-out to false. |
Postscan | N/A |
Examples
Ladder Diagram

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