• Home
• Function/Function Block Reference
• IEC 61131-3 Functions and Function Blocks
• Arithmetic
• ADD / ADD_S

ADD / ADD_S

Type	Function Available as standard (non-safety-related) and safety-related type (*_S). For the safety-related type, the safety-related data types (SAFE*) are expected at the formal parameters.
Description	Adds the values connected to the inputs and writes the result (sum) to the output.
Notes	When the addition result exceeds the permissible range of the output value, an overflow occurs. Overloaded function. The function can operate on various input data types (see description of the function parameters for the supported data types). Further inputs can be added. The function provides implicit data type conversion at its input and output parameters according to the rules defined by the IEC 61131 standard.
Parameters	Inputs IN1 Data type: Integers: (SAFE)SINT, (SAFE)INT, (SAFE)DINT, LINT, (SAFE)USINT, (SAFE)UINT, (SAFE)UDINT, ULINT Floating point numbers: REAL, LREAL TIME, LTIME Description: Summand IN2 Data type: Integers: (SAFE)SINT, (SAFE)INT, (SAFE)DINT, LINT, (SAFE)USINT, (SAFE)UINT, (SAFE)UDINT, ULINT Floating point numbers: REAL, LREAL TIME, LTIME Description: Summand Output Out Data type: Integers: (SAFE)SINT, (SAFE)INT, (SAFE)DINT, LINT, (SAFE)USINT, (SAFE)UINT, (SAFE)UDINT, ULINT Floating point numbers: REAL, LREAL TIME, LTIME Description: Sum
Error behavior	Error behavior The following table shows the errors which may occur while executing the function and the value returned by the function in the corresponding error case. As described, the value returned by the function in the error case depends on the value of the input (for example, if any of the input values is not a legal number (NaN), the function returns NaN). Error case Output value Numeric or time overflow Overflow value Real overflow Inf+ or Inf- (depends on input values) Any input = NaN NaN Mix of Inf+ and Inf- NaN Any input = Inf+ but not Inf- Inf+ Any input = Inf- but not Inf+ Inf-
Additional information	EN/ENO behavior The POU is only executed if TRUE is applied to the EN input. If EN = FALSE, the POU is not executed and ENO = FALSE indicates the inactivity. If any of the errors listed under "Error behavior" occurs while executing the function, ENO is set to FALSE. Further Info See the topic "General information on execution control with EN/ENO" for further details.