Applies To:
  • CitectSCADA 5.xx

I want to find an easy way to connect to a LON network. What should I use and how should I use it? 

A company called Gesytec in Germany has a software package called EasyLon. This is an OPC Server that connects to a number of different LON devices. You can download an evaluation copy of EasyLon from the company's homepage (

As EasyLon is an OPC Server, you have to configure the OPC Client driver in Citect. This is explained later in this article. (For more information about OPC, also see article Q2536.)

Once you have installed EasyLon, you should have two programs in the Start menu: EasyLon OPC Server (config) and EasyLon OPC Server. The first time you should start the "config" version. You have to select a project where all the LON I/O's are configured; in the evaluation version you'll get a demo project called Demo.tdb. In "File/Open"; you can select this project. To start this project go to the Control menu and click Start - you should now see a tree structure looking something like this:

        -Domain: "
                    -Subnet: 1
                                -LDM44 [  ]

".1.4.0" is the OPC Item name that has to be used as the Tag address in Citect. If you do not want to use ".1.4.0" as the address you can double click the item and enter a description. This description can also be used as the Tag Address in Citect.

See below for Citect configuration.

I/O Server Form

Name: IOServer

Boards Form

Board Name: Board1
Board Type: OPC
Address: 0

Ports Form

Port Name: Port1
Port Number: 1
Board Name: Board1