User’s Manual
WIN Enterprises, Inc.
Feb., 2010
57
Appendix A: Programming the Watchdog Timer
The PL-80120 provides a watchdog timer that resets the CPU or enables LAN bypass
mode. This function ensures greater system reliability in industrial stand-alone and
unmanned environments.
In order to enable the watchdog timer, you have to output the value of the watchdog
timer interval to the controller. The value range is from 01H to FFH, and the related
time watchdog timer interval is 1 sec to 255 sec.
Data Timer
interval
00 Disabled
01 1
sec
02 2
sec
* *
* *
FF 255
sec
If you want to disable the watchdog timer, just set the timer interval value to 00H.
After setting the timer interval value, the watchdog timer begins to count down. You
have to refresh the watchdog timer, so that the watchdog timer will return to its initial
value, otherwise, your system will reset after a time-out. The following program
shows how to set the watchdog timer:
