I'm using scada to interface to a PLC. Is there a way to create a keyboard hotkey to interact with graphic to toggle switch. Instead of pressing actual switch connected to PLC.

I think MatchKeys is what will help you - I've only used them for playing with... - we had a wireless Xbox controller emulate keystrokes to control VTScada for a demo system. Help file below.

https://www.vtscada.com/help/Content/Pro_Functions/MatchKeys.htm

Tried using Matchkeys. Wanted to see if pressing letter Y would change one of my widget values to = 1.

Receive message: Failed to compile expression. Function not allowed: =

Using Delta PLC to active ladder program output port Y1

Tried all the different possible combinations of expressions:

Matchkeys(2, "Y" )

Not sure of Vtscada syntax.

Copy and pasting C++ expressions do not seem to work. Tried using If, Then, End If

F1 Help file doesn't show detailed examples.

Haven't found any Youtube videos that cover this subject.

Make sure you read the above help page - it states that Matchkeys "should be used in a window or page module to monitor key strokes." Looks like you are trying to assign it to a tag expression.

Below is an example that I have used - when "I<3FCS" is typed in 3 tags are set, first two are string tags and the last one is a trigger tag (the trigger tag resets itself to 0 after a delay). This could be used to set the value of an I/O output tag.

If MatchKeys(2,"I<3FCS");
[
Scope(\VTSDB, "PressureTest\TestInfo\InputPartNumber").Set("P/N Bespoke for you") &&
Scope(\VTSDB, "PressureTest\TestInfo\InputSerialNumber").Set("S/N Linked to your system") &&
Scope(\VTSDB, "Display Controls\LoveMessage").Set("1");
]

Have a read of the help files regarding scripting - it's not C++... there are examples in here.
https://www.vtscada.com/help/Content/Scripting/API/S_Welcome.htm?tocpath=Scripting%7C_____0