How To: Wake On LAN (WoL)

Hardware and Linux
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The Edge Computers have a feature that allows them to be powered on over the network. This is a BIOS feature called Wake On LAN (WoL), which allows automating the powering up of edge devices remotely.

It’s quite simple to test this functionality, here are the steps;

Pre-Requisites:

  1. Edge Computer (752-9400, 752-9401, or 752-9800) with Keyboard, Monitor or KVM over IP device
  2. Static IP Address with internet access (to install software)
  3. Another computer on the network running Node-RED (for sending the WoL Magic Packet)

Steps:

  1. Power up the edge computer and press the del key during BIOS post screen.
    On the 752-940x, enable the Wake on Lan Feature. The 752-9800 has WoL enabled by default.

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  2. ssh into the edge device as root and type the following commands

apt update
apt install ethtool
ip addr show

Make note of the ethernet connection in use and record the MAC Address and IP Address.

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  1. Type the following command to ensure Wake on Lan is enabled for the port in use.
    ethtool <interface>
    For example, this might be enp1s0 on the 750-940x or X2 on the 752-9800.
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    You should see Wake-on : g which means supports MagicPacket, here is the table of letters.
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  2. Power down the Edge Computer (either with power button or shutdown command from the CLI)

  3. Test the Wake on LAN feature using another computer on the network. In this tutorial, we will use Node-RED (node-red-contrib-wol), but any properly constructed magic packet will wake up the device.
    Install the node-red-contrib-wol and node-red-contrib-ping palettes in the palette manager.

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  4. Configure the ping node to see when the device is powered on or not.

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  5. Configure the wake on lan node with the MAC and Ip address for the device.
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  6. Click the inject button and watch the LED on the edge computer turn from orange (off) to green (on). The Ping debug will show false when the device is offline and report the ping time when its back online. This can be used as a type of confirmation or heartbeat that the device is on.

WOL Flow.json (1.7 KB)

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I was informed some years ago, the PFC does not support this feature due to WoL hardware requirements.

3

As you may know, you also have the FbWakeOnLAN function block in the WagoAppSocket library, in order to send WOL request from a controller.
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