Description
You can use the "Decrement" instruction to change the value of the operand at parameter IN/OUT to the next lower value and query the result.
The enable output ENO has the signal state "0" if one of the following conditions applies:
-
Enable input EN has the signal state "0".
-
A floating-point number has an invalid value.
Parameters
The following table shows the parameters of the instruction "Decrement":
|
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 |
|
IN/OUT |
InOut |
Integers |
I, Q, M, D, L |
I, Q, M, D, L |
Value to be decremented. |
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 operands "TagIn_1" and "TagIn_2" have the signal state "1", the value of the operand "Tag_InOut" is decremented by one and the output "TagOut" is set.