Command: Download
Function: The command triggers the compile of the active application and download to the controller.
Call: menu
Requirement: The application is in online mode.
When you execute the command, CODESYS performs a syntax check and generates the application code. This code is downloaded to the controller. Furthermore, CODESYS generates the compile protocol <project name>.<device name>.<application ID>.compileinfo in the project directory.
Important
During the download, all variables are re-initialized with the exception of persistent variables.
Important
If a safety controller is inserted below a controller, then this command can temporarily interrupt the communication connections.
Connections of the safety controller to other safety controllers (via safety network variables), to field devices, and to the development system are affected. The safe field devices or other safety controllers can enter the safe state as a reaction. The connection to the development system is affected only when a safety controller that is connected to the main controller via a fieldbus.
For more information, see: Subordinate Safety Controller
The description of the Login command describes the possible situations at login and download.
If you try to download an application when the same version of the application already exists on the controller, then you get the message: "Program is unchanged. Application was not downloaded". CODESYS downloads the application to the controller.
During a download, a protocol of the actions being executed (generation of code, execution of initialization, etc.) is displayed in the message view in the Compile message category. Furthermore, information is displayed regarding the memory ranges, the size of the code, the global data, and the allocated memory. For the purpose of clarity, the modified POUs are no longer listed, which is different from an online change.