Application Monitor
The application monitor is graphically represented by a state-device as follows:
Application monitor block diagram
The application monitor cannot memorize its state when power is switched off. During Power On, it always starts in the OFF state. The application monitor becomes active, and goes in the CNT DOWN state under the software application control by simply setting the ApplicationTimeout element to a desired value.
The application monitor can be in two states: OFF, or CNT DOWN.
OFF
In the OFF state, the application monitor is disabled.
CNT DOWN
Once in the CNT DOWN state, the application monitor waits for a new setting of the ApplicationTimeout element. Two situations may occur in the CNT DOWN state:
- The software application is alive, and sets the ApplicationTimeout element before the time-out expiration. The application monitor concludes that the application is correctly running. The application monitor stays in the CNT DOWN state, and waits for the next ApplicationTimeout element setting during the time-out period.
- A malfunction occurs, and the application does not run the appropriate code which sets the ApplicationTimeout element. Time-out expiration occurs, and the application monitor concludes that the application is no longer running. The application monitor goes in the OFF state, and closes the PC reset relay during about 1 second.