Applies To:
  • CitectSCADA 5.xx
  • CitectHMI 5.xx

When I restart my computer and CitectSCADA attempts to run automatically on startup (either as a service, or by a shortcut in the startup folder) CitectSCADA fails to start, and displays the error "Software Protection Failure" or "Cannot Find Serial Drivers".

I have checked my license key and my serial ports, and they seem to be working correctly. If I wait for a few minutes and then try to start CitectSCADA, it works correctly. What is wrong?


When Windows XP first boots up, it attempts to speed up the boot process by delaying the start of "non-essential" drivers and services so that it can display the desktop faster. These drivers are later loaded in the background once the desktop is displayed.

Unfortunately, if CitectSCADA is started before the Sentinel driver or Serial Port drivers are loaded, the above errors can occur. This was not a problem with earlier versions of Windows as these drivers were always loaded before CitectSCADA was started.

To work around this limitation in Windows XP, you can delay the startup of CitectSCADA by setting the following parameter in the Citect.ini file:

StartDelay=120 ! Delay Citect startup by 2 minutes

The exact value required may vary from computer to computer, but normally 2 to 3 minutes is sufficient to allow the drivers to load.

See also Q3963 for a way to start Sentinel immediately on Windows startup so a Citect start delay is not needed.


Protection, Serial, XP