When using a programmable (T30/T40) Compax three there are two different methods for selecting a Codesys project to use in the drive. The two options are LINK and IMPORT. Following is an explanation of the behavior of these two options
SELECTING PROJECT ATTACHMENT TYPE
The two different methods of attaching a Codesys project to a configuration are selected in the C3 Manager under the "IEC61131-3 Programming (Codesys)" menu. The type of project attachment made will depend on which menu item the user is active in when the project is selected.
LINK A CODESYS PROJECT
When a project is linked to a C3 configuration file a connection is made between the configuration and the project selected. The main behavior of this method is that the latest compiled project file will be downloaded to the drive each time a project download is performed in C3 manager (or debugger). This is useful when a single project will be used in multiple drives, or when frequent changes will be made to the project.
IMPORT A CODESYS PROJECT
When a project is imported to a C3 configuration a separate copy is made of the project and stored with the configuration. Whenever a download of the configuration (Complete or Project only) is performed on a drive then the copy of the project in the configuration will be used in the drive. Essentially, a snapshot of the Codesys project at that point in time is taken and will be used with the configuration. Even if the project that was selected for importation is modified and recompiled there would be no effect on the project that is in the configuration or used in the drive.
EXAMPLES OF BEHAVIOR
The architecture shown below will be used for the examples. A user has a Codesys project to be used with a C3 configuration in a C3 servo drive. Two identical systems will be used in the example.
For the first step in the example, Version 1 of the Codesys project is used. In the identical systems below, Version 1 of the project is LINKED to the configuration of the system shown on the left. Version 1 of the project is then IMPORTED to the configuration of the system shown on the right. The result of which Codesys project the drive will actually be executing is shown below each diagram.
For the next step in the example the Codesys project has been modified and is now at Version 2. A download has been performed on each C3 servo drive (this could be a Complete download or a project download only). Referring to the diagram below it can be seen that the C3 Servo drive with the LINKED project will be running Version 2. However, the C3 Servo drive using the IMPORTED project will still be using Version 1. As stated earlier, when the IMPORT option is selected, a copy of the project is taken and stored in the configuration file. Regardless of how the external Codesys project file is modified, if the LINKED configuration is downloaded then Version 1 of the project will be used in the C3 Servo drive.