When people think of hardware Watchdog Timers OS, they think of a device used to automatically restart a computer down. This article discusses some ideas for alternative applications.
1. Beep or security patch panel
There are some applications where a computer can have multiple programs running critical and can not be reset because only one program fails. Most computer watchdogs are equipped with additional auxiliary relays dry type of closure which can be set to pulse or crashes during a timeout touch. Once activated, the security panel would call a central monitoring station for them to call a technician.
2. Duration external trigger signal
Some watchdogs are equipped with an external digital input type that can be activated by an external signal or a type of dry closure of the ignition switch. Normally this input is used to "please" the dog so that custody does not count and restart the computer. In some applications, you may want to just monitor an external trigger signal to see if it stops or if there are large time gaps.
The watchdog must have a programmable method for you to load an initial countdown timer value and a method for counting the number of external signal switches. With this information, you can expect a certain amount of time, then read the hound guard time countdown and the number of external trigger to see if the number of switches per second are within tolerance. If the external input signal should fail completely, the end of the monitoring and reset increment a counter that you can read with a user program, or use the auxiliary relay as described in the first section.
Hopefully this article has shown that there are other useful functions as an OS Watchdog timer hardware can provide other than a restart (reset) a private or defective computer.