Software

You should use the Watchdog library  “#include <avr/wdt.h>” provided by Arduino in order to program our own Watchdog.

Functions:

IMPORTANT: The Ardbox PLC watchdog cannot work under 500ms. There are not limitations for M-Duino PLC.

Below you will find an example about how to use it:the Watchdog lib

/*
   Copyright (c) 2017 Boot&Work Corp., S.L. All rights reserved

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <avr/wdt.h>

//////////////////////////////////////////////////////////////////////////////////////////////
void setup() {
	Serial.begin(9600L);
  // Set the watchdog on 500 ms 
  wdt_enable(WDTO_500MS);
}

//////////////////////////////////////////////////////////////////////////////////////////////
void loop() {
  // Refresh the watchdog
  wdt_reset();

  // WORK HERE, but faster than 500ms
  
  Serial.println("Watchdog is working if you don't see the points");
  delay(550);
  
  

  Serial.println("...");
}