Ever wondered how to setup an online service to read an IP Address from a PLC? This example shows both the Automation Platform code and the code on the PLC.

CODESYS Addresses vs. IP Addresses

PLCs in the CODESYS network use their own addressing mechanism (e.g. [053D.0001]) which is independent from the actual physical connection. These CODESYS addresses were necessary to allow communication between PLCs with different physical connections (e.g. USB, COM, Ethernet, etc). If you want to learn more about CODESYS addresses, they are explained in the documentation of the runtime system. To get an idea on how the CODESYS Address is related to the IP Address, check out the attached PDF.

As there is no way to reverse-engineer the IP address from the CODESYS address, there is no way to know the IP address of a PLC that responded in a network scan via UDP. However, by building a custom component in the runtime system and creating a matching online service in a plugin, an OEM can read the IP address directly from the PLC. This example contains both the code needed in the Automation Platform as well as the code for the runtime system.

Preparations

• Open the file "Example_ReadIpFromCmpTemplate.cs" and add the code to one of your plugins.
• Add a button or command that lets you trigger the code later on
• Browse to your local directory for the CODESYS Control Soft PLC (e.g. C:\Program Files (x86)\3S CODESYS\GatewayPLC)
• Right-click on the attachment "CmpTemplate.dll" and save it to this directory.
• Open the file "CODESYSControl.cfg" and add the component "Component.xxx=CmpTemplate" ("xxx" is the next unused component number!).
• Save the configuration file.
• Right-click on the file "CODESYSControlService.exe" and create a shortcut
• Right-click on the shortcut and add "-d" behind the target:
  "C:\Program Files (x86)\3S CODESYS\GatewayPLC\CODESYSControlService.exe" -d

Executing the example

• Start your patched PLC by double-clicking on the shortcut created above
• Open or create a project in CODESYS with a device matching the CODESYS Control PLC.
• Scan for your patched PLC and set the active path.
• Select the PLC in the navigator tree
• Trigger the method

⇒ There will be a popup showing the example address "192.168.101.72" (or an error message).

Note

The returned IP address is just an example and not the actual one. If you want to get the real IP address, use the attached code "RtsServiceHandler.c" for the runtime project "CmpTemplate" (part of the runtime delivery). You can use this as a starting point to dynamically read the IP address from your system (e.g. by calling "SysSockGetFirstAdapterInfo"). But this is not in the scope of the Automation Platform anymore.