Applies To:
  • CitectSCADA 3.00

Summary:
I ran the Citect example project and selected the shutdown button with the arrow keys. I then pressed return which brought up a form asking me if I want to quit. If I answer no the focus returns to the shutdown button but when I now press return I get an 'Invalid Command' error. Why does this happen and how can I avoid this problem?  

Solution:
The above example outlines a known problem in Citect which will only be noticed by those of us who choose to use the keyboard rather than the mouse to press buttons and change focus. The problem occurs when the focus is switch from citect to a popup. When the popup (genie etc) is shown focus is switched to that window but when the window closes focus isn't correctly restored to the main window. Although the focus rectangle displays at the correct location Citect still thinks that it doesn't have focus. Thus when you press return you get an error. If you use the mouse this problem won't arise because the focus is recalculated every time you move the mouse. As soon as you move the mouse over the button the focus is restored and all commands, including keyboard commands, will work properly. If you don't have a mouse and the button will not respond to keyboard commands the only way to restore the focus is to move the focus off the button onto some other control and then move it back again.

CIT has confirmed this to be a problem in Citect for Windows versions 3.00. We are researching this problem and will post new information here as it becomes available.


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