WatchdogLib

Collaboration diagram for WatchdogLib:

Modules
	Watchdog handling
	Version and Permission
	Structs, Types, ...

Detailed Description

Using the Watchdog library, you can establish a mechanism between your application and the firmware in order to react to exceptions or problems within your client program execution.

The following steps are necessary:

• Setup the watchdog and specify the timeout in milliseconds as well as the action to be taken when the timeout is reached.
• Start the watchdog.
• Reset the watchdog on a cyclic time basis that is lower than the specified timeout. As soon as you do not reset the watchdog in time, it will execute the action as specified during setup, e.g. stop the PLC or restart the device.

Here is some sample code:

// initialization of the watchdog (2 seconds).
// configure that the watchdog will fire a warning if it doesn't get triggered in time.
mlpiWatchdogSetup(connection, 2000, MLPI_WATCHDOG_WARNING);

// starting the Watchdog
mlpiWatchdogStart(connection);

// enter main loop
printf("\nWatchdog active! Press any key to block watchdog reset or 'q' to quit.");
bool done = false;
while(!done)
{
  // you may want to do some work here...
  Sleep(1000);

  // reset watchdog to prevent watchdog from triggering, do this every loop
  mlpiWatchdogReset(connection);

  // print current state of watchdog
  MlpiWatchdogState state;
  mlpiWatchdogGetState(connection, &state);
  switch(state)
  {
  case MLPI_WATCHDOG_DISABLED:
    printf("\nWATCHDOG_DISABLED");
    break;
  case MLPI_WATCHDOG_ENABLED:
    printf("\nWATCHDOG_ENABLED");
    break;
  case MLPI_WATCHDOG_TIMEOUT:
    printf("\nWATCHDOG_TIMEOUT");
    break;
  }

  // on key press by user, delay and block reset of the watchdog --> simulate watchdog timeout
  if (_kbhit())
  {
    char key = _getch();
    if (key=='q'){
      done = true;
    }else{
      printf("\nBlocking reset of Watchdog.");
      Sleep(5000);
    }
  }
}
mlpiWatchdogStop(connection);

Note

The WatchdogLib functions trace their debug information mainly into module the MLPI_WATCHDOG_LIB and in addition into the module MLPI_BASE_MODULES. For further information, see also the detailed description of the library TraceLib.