Question: If in a PLC project a containing library is to be exchanged by another one (e. g. in case of an update), the user has to delete the previous status in the library and insert the requested library. What are the single steps for exchanging a library in a DDS project by another one?
Answer:
The following instructions describe the procedure of how to exchange a library in DDS:
Open your project with DDS. For control make your project being rebuilt in its old version in order to ensure that it is faultless. In the library manager mark the library you want to remove and press the button <Delete>. A security check will ask you to confirm the removal which is to be done by <Yes>. When the window of the library manager is in the foreground (active window), you can open a selection window by means of menu <Insert> => <Additional Library …>. In this window you can select the required library. Confirm this added library with <Open>. Select the menu <Project> => <Clean all>. By means of this function the generated binary file (BIN-File = compiler of the project) is deleted. You will be informed that after cleaning a log-in to the target system is not possible anymore without download. As due to the modified library a download is required anyway, you can confirm with <Yes>. Make the complete project being rebuilt by means of menu <Project> => <Rebuild all>. If the message window does not show any errors, the elements (functions, function blocks, variables…) of the newly inserted library are presented like the elements of the eliminated (original) one. In this case the library exchange is finished successfully and the project can be processed, adjusted and stored as usual. If after rebuilding the message window still shows errors, the cause of the error messages is to be eliminated.
Generally the library exchange can lead to errors when …
… the quantity or sequence of inputs / outputs of functions or function blocks has changed. … the name of inputs / outputs of functions or function blocks has changed. … the names of data types of global variables in the library have changed. … data structures, if existing, were modified or their name was changed. …variables of function blocks, that have been assigned to codes via the instance parameter manager, have changed. Consequently, libraries can only be exchanged, when their contents are generally the same. In the attached document the library exchange is explained by means of screenshots.
