Rockwell Automation 6182 SDK - Manual (Page 25)

Introduction to the RAC6182 1–19
Publication 6182-UM002B-EN-P
The current contrast and brightness values are individual user
preferences rather than traits of the panel, so are stored in registry rather
than in the bezel EEPROM. However, if the registry contrast or
brightness value is not present or not in the min/max range specified for
the panel by the bezel EEPROM data, a default value is used from the
bezel EEPROM.
Touch screen data
The touch screen driver uses a 16 bit value in the bezel EEPROM to
identify the model of touch screen. This is used to determine what type
of touch screen interface and decoding logic to use. Also, the bezel
EEPROM is used to store touch calibration data, since calibration data
will be specific to particular touch screens even of the same model.
Keypad data
The keypad driver uses a 16 bit value in the bezel EEPROM to identify
the model of the keypad. This ID is used to determine what keypad scan
code to virtual key mapping information is obtained from the keypad
handler for the driver to use in decoding keys.
Layout of the Bezel EEPROM
The following table shows the layout of the bezel EEPROM.
Assignments within the lower 128 bytes (system area) are subject to
change. However, the upper 128 bytes (beginning at offset 0x80) are
guaranteed to be available for use by applications needing non-volatile
storage.