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Entry type: FAQ, Entry ID: 26460337, Entry date: 09/21/2007

What does the compile OS error message "302:3018 - There are process variables whose names are not unique within the project after replacing special characters..." mean?

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Configuration notes:
The following error message can appear during OS compilation:

"Compile OS (302:3018) - There are process variables whose names are not unique within the project after replacing special characters..."

Fig. 01


In the "TRANSFER.log" file on the compilation process, the error text is followed by the names of the process variables which are used more than once.

Fig. 02


If the Make dialog ("Compile and Download Objects") is used to compile/download multiple stations, the compilation process is interrupted with a general error message. However, the separate window with the error message (Fig. 01) doesn't appear. In this case, you will only find the actual error message in the "TRANSFER.log" file for the compilation process (see Fig. 02).

During OS compilation, the process objects from the AS programs (SIMATIC Manager) are transferred into the specified OS projects (WinCC project). The names of the process objects must be unique within an AS and within an OS. Two reasons why the names of the process objects lose their uniqueness within the OS are described below.

  • Process objects from a number of AS programs can be transferred (compiled) into the same OS. If multiple AS programs with process objects of the same name are compiled into the same OS, this error message occurs because the process objects no longer have unique names within the OS. On the other hand, identically named process objects from multiple AS programs can be transferred to different OSs.
  • During OS compilation, certain special characters in the name of the configured process objects are replaced by other characters. Situations can arise where different special characters are replaced by the same character. If process objects from one or more AS program(s) are transferred into the same OS and are only distinguished from one another by certain special characters, the special characters which are different in the AS may be replaced by identical characters in the OS. As a result, the name ceases to be unique in the OS. You can obtain information about separators and special characters
    • in the PCS 7 Online Help under "Configuration - Engineering System > Implementing the PCS 7 Configuration > Hierarchy (PH) > Rules for Naming in the PH"
    • in Entry ID 7000709 - Which special characters/separators may not be used in PCS7 V4, V5, and how are they replaced during AS/OS transfer?

The figure below illustrates these two causes of this error taking a plant hierarchy (PH) configuration as an example.

Fig. 03



  • In this example, only the chart name is used as part of the higher level designation (HID). The name of a block within a chart always forms part of the HID.
  • Charts with the same names cannot be created in the SIMATIC Manager's plant hierarchy if they are assigned to the same AS, even if they have different HIDs (different hierarchy folders).

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