ADD¶

Returns the sum of two or more inputs.

Signature¶

     ┌─────────┐
IN1 ─┤         │
IN2 ─┤   ADD   ├─ OUT
IN3 ─┤         │
     └─────────┘

FUNCTION ADD : ANY_NUM
  VAR_INPUT
    IN1 : ANY_NUM;
    IN2 : ANY_NUM;
    (* ... additional inputs ... *)
  END_VAR
END_FUNCTION

The return type matches the input type. ADD accepts SINT, INT, DINT, LINT, USINT, UINT, UDINT, ULINT, REAL, LREAL. Inputs of different numeric types widen to the wider one, which is also the return type; see Type Conversions. The time and date types are covered by the overloads below.

Inputs

Name	Type	Description
`IN1`	`ANY_NUM`	The first addend.
`IN2`	`ANY_NUM`	The second addend.

Outputs

Name	Type	Description
Return value	`ANY_NUM`	The sum of all inputs. Same type as the inputs.

Description¶

Returns the sum of all inputs. ADD(a, b) is the functional form of the + operator: a + b. Both forms are equivalent, and ADD(a, b, c) is a + b + c.

For integer types, overflow behavior wraps around (modular arithmetic).

Time and date overloads¶

ADD and the + operator are also defined on the following time and date operands (IEC 61131-3 Table 30). Each combination is the typed function in the last column and computes what it computes.

IN1	IN2	Return value	Same as
`TIME`	`TIME`	`TIME`	ADD_TIME
`TIME_OF_DAY`	`TIME`	`TIME_OF_DAY`	ADD_TOD_TIME
`DATE_AND_TIME`	`TIME`	`DATE_AND_TIME`	ADD_DT_TIME

Folding applies here too: ADD(t1, t2, t3) is t1 + t2 + t3, two ADD_TIME steps.

Each typed function has a long form over LTIME, LDATE, LTIME_OF_DAY and LDATE_AND_TIME (ADD_LTIME, ADD_LTOD_LTIME, ADD_LDT_LTIME), which applies when either operand is of a long type.

Any other combination of types is an error (P4049).

Example¶

Try it

Source

result := ADD(10, 20);      (* result = 30 *)
result := 10 + 20;          (* result = 30, operator form *)
result := ADD(10, 20, 30);  (* result = 60 *)

ADD¶

Signature¶

Description¶

Time and date overloads¶

Example¶

See Also¶

References¶