Remote Control Properties
What is "Remote Control"?
"Remote Control" allows an PLCVisu UI component to be controlled externally by a PLC. Instead of relying on user input within the UI, the component displays the value it receives from a connected PLC structure (via CODESYS).
When active:
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The user still sees and can interact with the UI component.
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However, the actual selected value comes from the PLC, not from the UI.
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The component behaves as if it were remotely operated — the PLC decides what is shown.
Working Example: Input Select 2
Let’s take Input Select 2 as the concrete example.
Connected CODESYS structure:
TYPE sInputSelect :
STRUCT
value : DINT;
options : ARRAY[1..4] OF PLCVisu.selectOptionsStruct;
END_STRUCT
Example assignment in CODESYS:
Select1.value := 2;
Select1.options[1].id := '1';
Select1.options[1].visible := TRUE;
Select1.options[1].text := 'Option1';
Select1.options[2].id := '2';
Select1.options[2].visible := TRUE;
Select1.options[2].text := 'Option2';
What happens in the UI?
If Remote Control is ON, and Select1.value := 2,
the UI shows Option2 as selected.
The PLC value overwrites any manual user selection.
If Remote Control is OFF,
the UI uses whatever was last selected or configured statically.
No value is fetched from the PLC.
Key Rules (Simple Summary)
| Behavior | Description |
|---|---|
| Control Source | Value always comes from the PLC when Remote Control is active |
| User Input | Still visible, but gets overridden by PLC value |
| Write Direction | PLC → UI only. UI does not write back into the structure |
| Options Limit | Example uses 4 (ARRAY[1..4]), but not limited – you can use more |
| Fallback Handling | If .text is not defined for a visible option, behavior is undefined (TBD) |