The connection from the CODESYS Development System installed on a PC to the controller is established via the CODESYS Gateway Server, which is installed during setup. The Gateway Server service is started automatically. Typically, you can use the local gateway server on your own PC to connect to the available devices.
You can also connect to any gateway server via its IP address, for example if a device is connected to a remote PC via serial interfaces. In order to do this, simply add a new gateway in the communication settings with Gateway/Add new gateway and specify its IP address and port number. Select this new gateway and scan all devices connected to it with Scan network.
Manufacturers of automation devices can even install the gateway server directly on their devices.