Siemens SIMATIC Panel PC 677 Operating Instructions Manual page 49

If the touch screen does not react as expected when touched, repeat the calibration. To do
this, first activate the 9 point calibration and then calibrate the touch screen.
Figure 7-10 Touch defaults, tab "Calibration"
Note
For further information press the "Help" button.
Special features
Warning
Faulty operation
If you touch the touch screen while configuring it or if the screen saver is active, the
SIMATIC process visualization software, e.g. ProTool/Pro, will carry out the functions which
happen to be behind it.
Caution
Only touch one point on the touch screen and not several points at one time. You may
otherwise trigger unintended reactions.
Do not touch the screen in the following situations:
— When the device is booting until the boot process is completed
— When plugging or unplugging USB components
— While Scandisk is running
SIMATIC PC Panel PC 677/877, Control Unit
Operating Instructions, Edition 04/2005, A5E00407724-01
Operating and parametrizing
7.3 Additional drivers and applications
7-11