Advantech MIC-3396 User Manual page 92

Watchdog Timer Programming Procedure
To program the watchdog timer, you must execute a program that writes a value to I/
O port address 443/444 (hex) for Enable/Disable. This output value represents time
interval. The value range is from 01 (hex) to FF (hex), and the related time interval is
1 to 255 seconds.
Data
01
02
03
04
...
3F
After data entry, your program must refresh the watchdog timer by rewriting the I/O
port 443 and 443 (hex) while simultaneously setting it. When you want to disable the
watchdog timer, your program should read I/O port 444 (hex). The following example
shows how you might program the watchdog timer in BASIC:
10 REM Watchdog timer example program
20 OUT &H443, data REM Start and restart the watchdog
30 GOSUB 1000 REM Your application task #1,
40 OUT &H443, data REM Reset the timer
50 GOSUB 2000 REM Your application task #2,
60 OUT &H443, data REM Reset the timer
70 X=INP (&H444) REM, Disable the watchdog timer
80 END
1000 REM Subroutine #1, your application task
.
1070 RETURN
2000 REM Subroutine #2, your application task
.
2090 RETURN
MIC-3396 User Manual
Time Interval
1 sec
2 sec
3 sec
4 sec
63 sec
82