Codesys network variable list (NVL) generator

Due to recent development of codesys-client Node.js library, I had a need to simplify process to crete network variable list (NVL) declaration files (.GVL).

The codesys-client is a Node.js library to read/write data to Codesys PLCs. It can be found from

I created a simple html page that can be used to create a file that can then be imported to Codesys for receiving data.

The tool can be found online from


Pressing the button creates a NVL_ReceiveTest.GVL file that will be downloaded using browser download window.

<Declarations><![CDATA[{attribute 'qualified_only'}
  DataToReceive : ST_Data;
<NetvarSettings Protocol="UDP">
    <ProtocolSetting Name="Broadcast Adr." Value="" />
    <ProtocolSetting Name="Port" Value="12023" />
Written on July 29, 2022