Description
You can use the "Add" instruction to add the value at input IN1 to the value at input IN2 and query the sum at output OUT (OUT := IN1+IN2).
In its initial state the instruction box contains at least 2 inputs (IN1 and IN2). The number of inputs can be extended. The inserted inputs are numbered in ascending order in the box. During the execution of the instruction, the values of all available input parameters are added. The sum is stored at output OUT.
The enable output ENO has the signal state "0" if one of the following conditions applies:
-
Enable input EN has the signal state "0".
-
The result of the instruction is outside the range permitted for the data type specified at output OUT.
-
A floating-point number has an invalid value.
Parameters
The following table shows the parameters of the instruction "Add":
|
Parameters |
Declaration |
Data type |
Memory area |
Description |
|
|---|---|---|---|---|---|
|
S7-1200 |
S7-1500 |
||||
|
EN |
Input |
BOOL |
I, Q, M, D, L or constant |
I, Q, M, D, L, T, C or constant |
Enable input |
|
ENO |
Output |
BOOL |
I, Q, M, D, L |
I, Q, M, D, L |
Enable output |
|
IN1 |
Input |
Integers, floating-point numbers |
I, Q, M, D, L, P or constant |
I, Q, M, D, L, P or constant |
First number to be added |
|
IN2 |
Input |
Integers, floating-point numbers |
I, Q, M, D, L, P or constant |
I, Q, M, D, L, P or constant |
Second number to be added |
|
INn |
Input |
Integers, floating-point numbers |
I, Q, M, D, L, P or constant |
I, Q, M, D, L, P or constant |
Optional input values, which are added. |
|
OUT |
Output |
Integers, floating-point numbers |
I, Q, M, D, L, P |
I, Q, M, D, L, P |
Sum |
You can select the data type of the instruction from the "???" drop-down list of the instruction box.
For additional information on valid data types, refer to "See also":
Example
The following example shows how the instruction works:
If the "TagIn" operand has signal state "1", the instruction is executed. The value of operand "Tag_Value1" is added to the value of operand "Tag_Value2". The result of the addition is stored in the operand "Tag_Result". If the instruction is executed without errors, the enable output ENO has the signal state "1" and the "TagOut" output is set.