Specifications

CARROLL TOUCH Chapter 2 - Introduction to Guided Wave Touch Systems
Touch System Programmer’s Guide 2-3
When a stylus enters the touch active area, acoustic waves are attenuated
at that location on the overlay. The touch screen then transmits to the
controller information indicating the location of the attenuated waves.
The controller converts this information to an x, y coordinate that
identifies the location of the touch. The x, y coordinate data is
transmitted to the host processor via the controller and is then processed
and used by the application program.
EEPROM File and Parameters
Guided wave touch screens use an electrically erasable programmable
read-only memory (EEPROM) chip. An associated file stores the values
of the EEPROM parameters that control many features of the touch
screen. The following EEPROM values may be displayed, modified,
saved, and restored:
• Touch sensitivity.
• Touch active region.
• Transducer corner.
• Coordinate origin corner.
• Transducer orientation.
• Touch refresh time.
• No touch refresh time.
• Temporal filter space.
• Temporal filter time.