Rockwell Automation 2711P Software Development Kit User Manual - Manual (Page 14)

Publication 2711P-UM005A-EN-P - March 2007
14 Introduction to the PanelView Plus CE Terminal
ATMEL Microcontroller
An Atmel 8-bit microcontroller is a coprocessor to provide an 8x8
keypad scanner, 4, 5, and 8-wire touchscreen interface, high-speed
timer, watchdog and to monitor the Celeron die temperature and shut
down the Celeron if the die temperature reaches its maximum
temperature rating. Additionally, the ATMEL plays a role in resetting
the system and controlling the display module backlight.
Watch Dog
The watchdog timer will trigger a system reset in the event the system
or an application loses control. The watchdog hardware is always
enabled and is tagged by the watchdog system service periodically
every 500 ms. One or more applications can register with the
watchdog service wherein the application must periodically tag
(restart) it to prevent it from timing out. If the watchdog times out, a
system reset (warm-boot) is initiated. Once the system has been
restarted, an application can inquire about the event that caused the
restart and learn that the watchdog timed out.
System Timer
A single 50-
μs, high-resolution programmable hardware timer is
available to an application program.
Hardware Monitor
A software accessible hardware monitor provides real-time
temperature, voltage and battery monitoring. Thresholds for warnings
can be established programmatically by application programs.
Applications also have access to the system LED indicators.
Keypad
Certain configurations of the PanelView Plus CE device provide
function keys, a numeric keypad and cursor control keys integrated
into the front bezel. The number of function keys can vary. Some
function keys are relegendable. The keypad handler provides
extended software support. The keypad handler intercepts and
operates on codes produced by the keypad driver before passing
them to the application with current focus. The keypad handler can
optionally re-map keys (assign different virtual key codes) and effect
specialized processing such as the generation of key macros (strings
of virtual key codes) or the launching of a program from a single key
press.