UPC-F12C-ULT3 Panel PC
Page 96
NOTE:
The following discussion applies to DOS. Contact IEI support or visit the IEI
website for drivers for other operating systems.
The Watchdog Timer is a hardware-based timer that attempts to restart the system when it
stops working. The system may stop working because of external EMI or software bugs.
The Watchdog Timer ensures that standalone systems like ATMs will automatically
attempt to restart in the case of system problems.
A BIOS function call (INT 15H) is used to control the Watchdog Timer.
INT 15H:
AH – 6FH Sub-function:
AL – 2:
Sets the Watchdog Timer’s period.
BL:
Time-out value (Its unit-second is dependent on the item “Watchdog
Timer unit select” in CMOS setup).
Table D-1: AH-6FH Sub-function
Call sub-function 2 to set the time-out period of Watchdog Timer first. If the time-out value
is not zero, the Watchdog Timer starts counting down. When the timer value reaches zero,
the system resets. To ensure that this reset condition does not occur, calling sub-function
2 must periodically refresh the Watchdog Timer. However, the watchdog timer is disabled
if the time-out value is set to zero.
A tolerance of at least 10% must be maintained to avoid unknown routines within the
operating system (DOS), such as disk I/O that can be very time-consuming.
Summary of Contents for UPC-F12C-ULT3
Page 15: ...UPC F12C ULT3 Panel PC Page 1 1 Introduction Chapter 1 ...
Page 23: ...UPC F12C ULT3 Panel PC Page 9 2 Unpacking Chapter 2 ...
Page 27: ...UPC F12C ULT3 Panel PC Page 13 3 Installation Chapter 3 ...
Page 43: ...UPC F12C ULT3 Panel PC Page 29 4 BIOS Setup Chapter 4 ...
Page 75: ...UPC F12C ULT3 Panel PC Page 61 Chapter 5 5 Interface Connectors ...
Page 95: ...UPC F12C ULT3 Panel PC Page 81 Appendix A A Regulatory Compliance ...
Page 100: ...UPC F12C ULT3 Panel PC Page 86 B Safety Precautions Appendix B ...
Page 106: ...UPC F12C ULT3 Panel PC Page 92 C BIOS Menu Options Appendix C ...
Page 109: ...UPC F12C ULT3 Panel PC Page 95 Appendix D D Watchdog Timer ...
Page 112: ...UPC F12C ULT3 Panel PC Page 98 Appendix E E Hazardous Materials Disclosure ...