Advantech A120-X5X, User Manual

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122 PPC-A84/A120 User's Manual
A.1 Programming the Watchdog Timer
To program the watchdog timer, you must write a program which
writes I/O port address 443 (hex). The output data is a time interval
value. The value range is from 01 (hex) to 3E (hex), and the related
time interval is from 1 sec. to 62 sec.
Data Time Interval
01 1 sec.
02 2 sec.
03 3 sec.
04 4 sec.
• •
• •
• •
3E 62 sec.
After data entry, your program must refresh the watchdog timer by
rewriting the I/O port 443 (hex) while simultaneously setting it. When
you want to disable the watchdog timer, your program should read I/O
port 443 (hex).