The import-db command generates a SIMATIC AX library which allows access to "coupling DBs" (Data Blocks) defined in a TIA Portal project. With this command technology object data block (TO-DBs) are not considered, but every other data block. Information about accessing TO-DBs (also called technology objects) can be found in the IMPORT command.
Use cases of "coupling DBs" while using the TIAX Direct Loading workflow:
- Access to additional data blocks for Motion Control as an open interface for drives and encoders for reading and writing data of PROFIdrive telegrams.
Examples:- Connecting ext. encoder of Startdrive to the TO_ExternalEncoder,
- Connecting non PROFIdrive drives/encoders with technology objects.
- Access to HMI data blocks configured in a TIA Portal project.
Notes
WARNING: This command is only preliminary for an initial evaluation!
This workflow is only compatible with the TIAX Direct Loading workflow if the
sldcommands LOAD and STORE are used with the option--non-overwriting!Currently,
AX Codedoes not offer intellisense support for a "coupling DB". For this reason, all usages of the library are marked as erroneous in the IDE. However, the build process works without errors.
If you're unfamiliar with the naming and structure, it's recommended to refer to the TIA Portal project.
Caution
Starting with SLD v2.5.10, during download, it is verified that the data block loaded from the TIA project and the AX code reference the same structure. This prevents the PLC from accidentally going to STOP when accessing a couple data block.
If you want to modify your couple block afterwards, it must be downloaded from TIA Portal in offline mode while the PLC is in STOP mode. This ensures that the AX code is removed by the download, preventing access to a different structure.
Unfortunately, this is not guaranteed if you download the structural change from TIA Portal in online mode.
Therefore, always load a couple data block in offline mode!