Command ‘Load’¶

Function: This command causes a compilation of the active application with subsequent download to the controller.

Call: Menu bar: Online .

Requirement: The application is in online mode.

When you execute this command, CODESYS performs a syntax check and generates the application code. This code is downloaded to the PLC. Furthermore, CODESYS generates the build log <project name>.<device name>.<application ID>.compile info in the project directory.

Hint

During loading all variables are re-initialized with the exception of persistent variables.

Hint

If a safety controller is inserted below a PLC, then this command can temporarily interrupt the communication links of the safety controller to other safety controllers (via safety network variables), to field devices, and to the development system. The safe field devices and the other safety controller can enter the safe state as a reaction. The connection to the development system is affected only in the case of a safety controller that is connected to the main controller via a fieldbus. For more information, refer to the section “Subordinate Safety Controllers”.

The description of the Login command describes the possible situations when logging in and loading.

If you attempt to download an application when the same version of the application is already on the PLC, then you get the message: “Program is unchanged. Application was not downloaded”. CODESYS downloads the application to the PLC.

During loading a record of the actions being executed (generation of code, execution of initialization, etc.) appears in the Message window in the message category Compile. 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, as opposed to the online change, the modified function blocks are no longer listed.