Updating Application on PLC

CODESYS offers in principle two possibilities to transfer a modified application to the controller: download and online change.

Attention

If you use a device application, please note the restrictions concerning download and online change.

A download leads to a recompilation of the application. In the process, a syntax check is performed and application code is also created and loaded to the controller. This leads to the running program being stopped. A download is the recommended method of data transfer, since a defined starting state is always created due to the program stop and the re-initialization.

In the case of an online change, only the modified parts are reloaded to the controller. A running program is not stopped for this. You should only carry out an online change in the case of minor changes to the application. In the case of extensive changes the behavior of a program cannot be safely predicted. Please read the notes in the description of the Online Change command regarding this.

See also

• Execution of an Online Change
• Execution of a Download
• Command ‘Load’
• Command ‘Online Change’

• Execution of an Online Change
• Execution of a Download