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

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

Provide Feedback

Have questions or feedback about this documentation? Please submit your feedback here.