Symbol Configuration: CODESYS creates symbols with specific access rights for the variables in an application. With these symbols, you can access the variables from outside, for example from an OPC server.

Data Source Manager: Manages the connection settings and the data transmission to remote devices (data sources)

The transmitted data is mapped in data source variables that are accessed in the visualization or local application. An example of this is a control panel that controls remote devices and displays the state of the device as an HMI application.

Network Variables: Network variables are variables whose values are accessible to different controllers in the network. The variables have to be defined in rigid, identical lists in both the transmitter device and the receiver device. These lists are assigned to applications, but can be located in different projects.