E
thernet
P
anel
Hardware EthernetPanel
© 2010 by Grossenbacher Systeme AG DVS 48961 V3.0
37
8 Notes on the touch-screen
8.1 B
ASIC TOUCH
-
SCREEN FUNCTION
Devices with infrared
touch-screen
The touch-screen operates on the active light matrix principle in the infra-
red range. Interrupting this light matrix at any point will initiate an operation
if a touch activated screen element was touched (e.g. a button).
A timeout is initiated if the light matrix is interrupted for longer than
approx.
15s.
The touch panel then switches to the “non-actuated” state, and further
operations cannot be initiated until the initial touch actuation has stopped
(e.g. button released) or the touch is actuated again. Several simultaneous
touch actuations at different points cannot be evaluated.
Devices with resistive
touch-screen
The resistive touch-screen operates on an analog principle. Pressing the
touch-screen at any point results in an electrical resistance which is
measured and will be calculated into a position by the touch controller. This
initiates an operation if a touch activated screen element was touched (e.g.
a button).
Because of this function principle the resistive touch-screen has to be
calibrated. The first calibration is already done when delivered. A
recalibration of the touch-screen is necessary when the touch position is
different to the screen, e.g. because of ageing, temperature, etc.
For further details about the touch-calibration see manual system
description WindowsCE or EPAM manual (Button-Action „Touch_calibrate”).
For an optimal operation of the resistive touch-screen it
is recommended to use a touch-pen for the calibration.
DVS 48961-V4.0
Summary of Contents for 50 81 332
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