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I have an existing RSView application that I am trying to modify to pop up a verification screen when the operator attempts to start the line with the length counter > 0.

The application works flawlessly until there is an alarm condition that prevents the line from starting. In this case, the calling screen's object, a pushbutton, captures the cursor and that's all she wrote. The computer must be rebooted afterwards.

The pushbutton simply calls the VBA script with the VBAExec command. It also passes an argument so the routine knows which of two buttons were pressed.

The VBA application writes a value to a status register in the PLC depending on the operator response to the popup.

My question is: If the VBA app tried to write a value, does it continue to attempt to write that value until it can successfully read it back. What I think is happening is that the PLC program attempts to write to this same register when the alarm condition occurs. If this is so, then when the VBA app attempts to verify a successful write, it sees that the value is different and writes it again...and again.

Does this assessment sound plausible?

G'day Don,
I would be careful using VBA as a popup, it is not recommended in RSView32. I would use a RSView display/window as a popup instead. From memory if a VBA pop up occurs then RSView stops processing and waits for a result and the pop-up to close. If you can what you need without using VBA then do, either macros or events, and only use VBA if you need to do something that is not otherwise possible. What you have described should be easily done with standard RSView functions.

Cheers,
Trevor.

Trevor,

I had read that somewhere. I only use the VBA script to initiate the pop up (a RSView screen). It is then supposed to terminate. The majority of the functionality is in RSView and not VBA.

VBA script below:

Public Sub productionStart(w_value)

'Subroutine implements poka yoke ensuring that operator is aware of length counter state
'and giving him an opportunity to reset the counter or proceed without resetting.


'local declarations
Dim ctr As Tag

'gets counter value from tag database
Set ctr = gTagDb.GetTag("counter")


'Determines counter state. If zero, exit sub after writing value to state register
'Value written to state register depends on which button was pushed
'Calling function, i.e. RSView passes w_value to subroutine

If ctr = 0 Then
If w_value = "16" Then
gTagDb.GetTag("state").Value = 16
End If
If w_value = "8" Then
gTagDb.GetTag("state").Value = 8
End If
End If


'If not zero, invokes RUSure graphic
If ctr <> 0 Then
gCommand.Execute "display rusure"
End If


End Sub

It is all about focus. The alarm changes focus!
.focus