Naming Convention/ Notation
All names (identifiers) are case sensitive. For path specifications, consider case sensitivity and do not use blanks.
All identifiers have to start with an alphabetic character (letter) or with an underline "_" and may not contain any special characters (:, ., *, #, $, @, ...). Construct the identifiers exclusively using the characters "A...Z", "a...z", "_" and the digits "0...9".
The use of umlauts "ä","ö", "ü" is allowed in many cases but we recommend to avoid the use of them: corresponding keys might not be available during international use and the display might be problematic in case of foreign-language systems.
The length of most of the identifiers in WinCC OA is not strictly limited. Therefore, a unique, well readable and context-oriented naming is possible. We recommend to avoid far too long names because of disk space requirements and processing speed. Use the usual maximum 20 to 30 characters. The correct display of identifiers in the standard interfaces like alarm and event screen also defines meaningful maximum lengths.
| Element | Uniqueness | Miscellaneous |
|---|---|---|
| System names | Within the systems | In addition to special characters, especially the dot "." and colon ":" are forbidden as separator of the complete element address. |
| Data point types | Within the data point types | The use of underline "_" as first character is reserved in the internal data point types of WinCC OA. In addition to the special characters, specially the dot "." and colon ":" are forbidden as separator of the complete element address. |
| Data point name | Within all data point names independent of the data point type | For the allowed characters, see function nameCheck(). |
| Data point element | See data point names (no limitation on element level) | In addition to the special characters, specially the dot "." and colon ":" are forbidden as separator of the complete element address. |
| Configs and Attributes | No predefined | In addition to the special characters, specially the dot "." and colon ":" are forbidden as separator of the complete element address. |
|
Description (Data point element description) |
No |
You can enter descriptions in several languages in case of multilingual projects. For the display, for example, in panels individual fonts/sizes can be used per language. No limitations regarding special characters; blanks are allowed. |
| Alarm texts | No |
You can create alarm texts in several languages in multilingual projects. For the display, for example, in panels individual fonts/sizes can be used per language. No limitations regarding special characters; blanks are allowed. |
| Variable names |
According to the declaration type: - construct local - local - script local - panel global - manager global |
Limitations according to the description convention of the programming language C. Keywords and function names are not permitted as variable names. Also the use of graphic object names is not allowed. |
| Panel names (Panel title) | Within all at a time opened panels |
Since the panel name serves as identification of the panel (for example, for closing), all panels opened at the same time must be unique. Blanks are allowed. It is highly recommended to only use ASCII letters for your panel name to prevent any issues with file related functions. |
| Names of Graphic Objects |
Within the panel, within the reference |
Names of graphic objects must always start with an alphabetic character and must not contain any special characters. We recommend not to use the names of variables as descriptions for graphic objects! |
| Paths | Within the file system of all discs (or in case of UNC paths network-wide). |
You should enter paths independent of the operating system in the following from with slashes "/": //hostname/share/path wincc_oa_path+"panels/vision/dp_monitor.pnl" C:/Siemens/Automation/WinCC_OA/<version> |
| Windows File names |
Windows file names may not contain any special characters like: z.B. / \ : ? * < > | For Windows paths amongst others the following characters are not allowed: ? * < > | |
|
| Binary values | - |
You can specify boolean values in the following way: 0 / 1, true / false, TRUE / FALSE |
| Float values | - |
Float values are specified using a dot as decimal separator as in the international programming standard C: for example: 42.9733 +459.9 -0.0031 You can leave the prefix out for positive values, for negative values prepend a "-". |
| Exponential notation | - |
The exponential notation is similar to that of float values. The small "e" is used as exponential character: for example: 8.859e-12 oder 2.99792e8 (corresponds to 2.99792· 108 or 299792000) |
| Character (char) | - |
Individual characters of data type char are set in single apostrophes: for example: 'a', 'X'. |
| String | - |
Strings are presented through quotation marks: for example: "Valve 17 disturbance", "[Text]" |
