Write a Tag with Visual Basic in FactoryTalk

from visual basic I am trying to write to a variable in factorytalk called alarm, this variable is of binary type, should not be a problem but I try several ways and so far can not,

This is the code that relates to a button,


Private Sub Button1_Release()
Dim alarm as Boolean
If alarm = 1 Then
alarm = 0
Else
alarm = 1
End If
End Sub


as you can see is very basic, the alarm variable already exists in the list tags of plc and lists of factorytalk tags

Thanks for your time,

Best regards,

Since you define the variable 'alarm' in your sub, it is scoped locally so cannot refer to anything outside the sub. You could try not defining it in the sub and see if it compiles OK. If not, then your reference to it must not be proper.
I haven't worked with the VB in FT so maybe the help file can shed some light on how to address a more global variable.

Hello,
Thanks for the answer, try without definition, does not work, I was searching through the help file but did not find an example or a clue to the solution, I will continue searching the web.

Best regards,

Is this a standalone Visual Basic application, or are you trying to write a VBA routine inside the FactoryTalk View application ?

You don't need VBA just to write a value to a FactoryTalk tag on release of a button; that's an ordinary FactoryTalk View Command.

Or you can use an ordinary FactoryTalk View Button object.

The logic you posted will set the tag = 0 if it's already 1, and set it to 1 if it's already 0.

That's how an ordinary Maintained Button works, when it's configured for the next state to be based on the current state.

Hello Ken,

Correct, Im trying to write a VBA routine inside the FactoryTalk View application

Is an existing project, I might add password to the condition before changing to 1, the easiest way to do this without knowing the key is with VBA, maybe I'm wrong,

Thanks for your time

Best regards,