SCADA/HMI Workstations Screen Saver
Frequently Asked Questions
Q: Why screen saver blanks the whole screen instead of just one part if "On resume, password protect" option is turned on in the Control Panel's applet?
It does not - Windows does that. Normally, if a screen saver is password protected it means that one wants to hide one's data and block access to the computer. In that case, Windows automatically blanks the entire desktop before starting a screen saver and there is nothing that can be done about it without messing up security settings.
Since the idea of SCADA/HMI Workstation Screen Saver is to protect monitors while operators are doing their job, password protection is meaningless and should not be used.
Q: Why there is no option for smooth scrolling of the blank area?
Although graphic output is mostly static, a typical SCADA/HMI Workstation is quite busy all the time, synchronizing and archiving many variables (so called "Tags") each second and often doing complex calculations at the same time.
Therefore a screen saver with smooth transitions like scrolling and fading would not be a good idea as it would consume too much system resources. Industrial automation requires it to be as simple as possible and it is the same if you use it on a server system or a rendering computer: "Save the screen but do not slow the computer down!"...
Q: How efficient is this partial screen saving?
It is efficient. Although it is hard to give an exact answer since it actually depends on various factors, like the screen type, brightness and contrast settings, color intensity of displayed graphics and the level of graphic steadiness.
Think of it this way: if you wish to burn a piece of paper with a sunlight and a lens, you need to hold the lens in a certain position for some 15 seconds. If you hold it for just ten seconds and then remove it for five seconds and repeat that procedure during a whole day - paper just won't burn.
We have been experimenting with some old monitors in a period of nine months and SCADA/HMI Workstation Screen Saver did prevent the display damage while unprotected monitors got ghosting effect.
However, we cannot guarantee that every monitor, no matter how old and configured, will be saved forever. And we leave statements like "83% less damage and 11% brighter colors" for imbecile detergents and cosmetics advertisements and commercials...