|
Pratik Bilgiler
|
|
| Tips for using the "Tag Prefix" property of picture windows within the faceplate designation. Keywords: WinCC, Tag Prefix, faceplate |
May 2008 |
It is important that the tag prefix of a picture window corresponds to a global definition. This means that the tag prefix of the picture window is valid for all tags that are processed in that picture window or are changed in another way (script).
It thus follows that these tags must be part of the structure whose name you have specified as tag prefix for the picture window.
If, for example, you declare a tag with the name "Status" outside the aforementioned structure and attempt to change it in the picture window, then an attempt is made to change the tag name "MyTagPrefix.Status". This leads to an error, because this tag doesn't exist.
Please also note that the tag prefix of the picture window is also valid when you agree upon another tag prefix in the picture window.
For tags that are processed in the second definition or changed in another way (script), the following interpretation holds:
"TagPrefix1.TagPrefix2.TagName".
Implemented in this example are dynamizations with tag links, dynamic dialog and C script. Dynamic dialog and C script all work with a tag trigger.
The tag prefix works not only in combination with the separation point in WinCC structure tags, but also at any point in the WinCC tag name. The tag prefix can also be used on elementary WinCC tags.
Note on the dynamic dialog
In order to be able to work with the dynamic dialog you must implement two things:
-
The point must be specified with the "Tag prefix" property:
Example:
"MyTagPrefix."
-
The dynamic dialog checks whether the tag exists. Therefore you must create a normal tag once again for each member tag of a structure.
Example:
The structure has three members: "on", "off" and "fault". Then you must create three tags "on", "off" and "fault" in addition.
Advantage of this faceplate technology
You don't need to use any unnecessary C scripts. The tag trigger also ensures good performance.
Note on changing the tag prefix
Please note that changing the tag prefix only becomes effective in a picture window when there is a picture change in the picture window. This has been implemented in this sample project. For this please also refer to the Online Help of the Graphics Designer under the "Tag Prefix" property attribute of the picture window.
Download
There is a WinCC project ready for downloading for the WinCC versions V5 and V6, which each include an example to demonstrate the functionality described above.
Unpack the "ampelv5.zip" using WinCC V5 and the "ampelv6.zip" archive using WinCC V6 respectively in a separate directory.
You can then use WinCC to open and process the extracted project.
|
|
|
