SUB

Subtract

The content of the accumulator is subtracted from the operand defined in the operand field. The result is transferred to the accumulator.

Parameters

Input

Unnamed input (INT, DINT, UINT, UDINT, REAL, LREAL): 1st input: minuend
Unnamed input (INT, DINT, UINT, UDINT, REAL, LREAL): 2nd input: subtrahend

Output

Unnamed output (INT, DINT, UINT, UDINT, REAL, LREAL): Output as input: result

Remarks

All operands must be of the same data type.

Example

POU header

All input and output variables used for programming this function have been declared in the POU header. The same POU header is used for all programming languages.

	VAR
		bStart: BOOL:=FALSE;
		iMinuend: INT:=0;
		iSubtrahend: INT:=0;
		iResult: INT:=0;
	END_VAR

In this example the input variables (iMinuend, iSubtrahend and bStart) have been declared. Instead, you may enter constants directly into the function (enable input e.g. for tests).

LD body

If bStart is set, iSubtrahend (data type INT) is subracted from iMinuend. The result will be written into iResult (data type INT).

BODY
    WORKSPACE
        NETWORK_LIST_TYPE := NWTYPELD ;
        ACTIVE_NETWORK := 0 ;
    END_WORKSPACE
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 8 ;
        NETWORK_BODY
B(B_VARIN,,minuend,6,3,8,5,);
B(B_VARIN,,subtrahend,6,4,8,6,);
B(B_VAROUT,,result,14,3,16,5,);
B(B_CONTACT,,enable,3,2,5,4,);
B(B_F,E_SUB!,Instance,8,1,14,6,,?DEN?D?D?AENO?C);
L(1,3,3,3);
L(5,3,8,3);
L(1,0,1,8);
        END_NETWORK_BODY
    END_NET_WORK
END_BODY

ST body

IF bStart then
    iResult:=iMinuend-iSubtrahend;
END_IF;