Subtract (SUB)
When enabled, the SUB instruction and the operator '-' subtracts Source B from Source A.
Available Languages
Ladder Diagram
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.
There are data conversion rules for mixing numeric data types within an instruction. See Data conversions.
Ladder Diagram
Operand | Data Type | Format | Description |
---|---|---|---|
Source A | SINT INT DINT LINT USINT UINT UDINT ULINT REAL LREAL | immediate tag | Value from which to subtract Source B. |
Source B | SINT INT DINT LINT USINT UINT UDINT ULINT REAL LREAL | immediate tag | Value to subtract from Source A. |
Dest | SINT INT DINT LINT USINT UINT UDINT ULINT REAL LREAL | tag | Tag to store result of the instruction. |
Affects Math Status Flags
See Math status flags.
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 Dest = Source A - Source B |
Postscan | N/A |
Examples
Ladder Diagram
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