Enable Watchdog Based on RTC Alarm

Notes

Current Version: A

Revision History

VersionDescriptionDate
AInitial Version2025.03.28

1 Overview

Introducing the Enablement of the Watchdog Functionality on ED-IPC Products.

1.1 Background

In industrial IoT devices, the Watchdog mechanism is a critical component for ensuring long-term stable operation, particularly in scenarios requiring unattended operation, harsh environments, or ultra-high reliability. For ED-IPC products equipped with hardware Watchdog capabilities, our company has developed a software-based Watchdog solution leveraging RTC (Real-Time Clock) Alarms. This innovation significantly enhances system reliability and empowers users to maximize the performance of ED-IPC devices.

1.2 Applicability

This application is compatible with all ED-IPC products equipped with hardware watchdog functionality, provided that the device system is running kernel version 6.6.31 or later. The supported product models include:

  • ED-IPC2100
  • ED-IPC2200
  • ED-IPC2400
  • ED-IPC2600

2 Configuration Guide

The following section uses the ED-IPC2200 device as an example to detail the steps for enabling the Watchdog functionality by installing the DKMS package and updating the initramfs.

2.1 Enable Watchdog

Preparation:

  • One 12V 2A power adapter (with a 3.5mm Phoenix terminal interface) and one Ethernet cable have been prepared.

Steps:

  1. Connect the ED-IPC2200 device to power and the network to ensure it boots up properly.
  2. Run the following commands sequentially in the terminal to add the edatec APT repository.
curl -sS https://apt.edatec.cn/pubkey.gpg | sudo apt-key add -
echo "deb https://apt.edatec.cn/raspbian stable main" | sudo tee /etc/apt/sources.list.d/edatec.list
sudo apt update

WARNING

If line breaks appear when pasting copied commands, remove them and replace with spaces at those positions.

image-20250320151035016
  1. Run the following command to install the DKMS driver package.
sudo apt install ed-pcf8563-dkms ed-rtc-alarm --no-install-recommends -y
image-20250320152004821
  1. Run the following command to update initramfs.
sudo update-initramfs -u
image-20250320152055566
  1. Run the following command to reboot the device.
sudo reboot

2.2 Modify the Watchdog Counter Reset Interval

The default reset interval for the Watchdog counter is set to 2 minutes. Users can adjust this value based on actual requirements.

  1. Run the command below to open the configuration file. The parameter alarm_timeout= specifies the current Watchdog counter reset interval (in minutes).
sudo nano /etc/rtc_alarm.conf
image-20250320152614284

  1. Adjust the numerical value following alarm_timeout= as needed.

  2. Save and Exit the File:

    • Press Ctrl+O to save changes.
    • Press Enter to confirm.
    • Press Ctrl+X to exit the editor.

  3. Run the following command to restart the ed-rtc-alarm.service and apply the configuration.

sudo systemctl restart ed-rtc-alarm.service