Feedback
In some controls, a so-called feedback is used.
The feedback should help to be able to give the user a feedback, if a BV is written, but the confirmation (feedback) of the PLC is still pending, for example.
Accordingly, the controls always display only the feedback value (e.g. StateFeedback of the checkbox), which ensures that the current value is always displayed in the HMI.
![]() | Changing the value of State has no effect on the display in the HMI, as only the value of StateFeedback is displayed. |
Procedure
The procedure using the example of the checkbox is as follows:
![Feedback 2:](Images/png/10512015371__Web.png)
- Write value by marking the checkbox
- Value is written to the State symbol
- Display of the loading animation
- Response of the PLC:
Hiding the loading animation
There are only two possible outputs.
a. Value of symbol linked to StateFeedback changes to the same value written to State.
b. Value of StateFeedback does not change.