Hi all

I have wincc ver 5 and one example but i have a problem.
There are many internal and external tags in this example ( e.g. AI C_5011 internal AIC_5011_1 external tag ) and in the graphic pages, only internal tags have been referred. I want to know what is the relation between them. And how these internal tags take a value?

Best regards

donald
[email protected]

 

Hi!
Internal Variables are memory variables which will can be used to store data from scripts etc. No communication with a physical device takes place.

External tags are Device Tags i.e. they are connected to some address location in the PLC or an OPC/DDE Server. Any changes made to the value of an external tags would get reflected in the connected device (PLC).

In WinCC only External Tags are counted for license purposes. You can have as many internal tags as you want.

 

Hello all
See in these case there might be a script written for the property of the respective object in which the value of the external tag is assigned to the internal tag.

Abhimaan

 

internal tags are software generated tags, which are system's specific and external tags are for users. suppose, you want to use the value of any external tag for some manipulation purpose or to display in some other application like excel, you have to use external tags. internal tags are automatically generated by software. suppose internal tag is aic_5011 then external tag will be aic_5011_1.

regards
hitesh madhvani
[email protected]

 

Hi,
External tags are tags that are directly related to the process (e.q. from the PLC).
Internal tags are tags that are used only inside WinCC program (e.q. to store interim result).
Internal tags are unlimited and free where external tags are limited to the number provided by your WinCC program (128/ 512/ 1k/ 8k/ 64k tags).

ck_chen

 

Hello there!
As already told, internal are meant for data locations on your PC. External, refer to memory locations on the PLC. You can assign values to the internal or external tags in many ways. Check the help system for details. Each type of tag (see them as variables in c++, c or some other language) has a different way or command for data assignment and retrieval, all quite simple! Say for a Boolean type: SetTagBit("tag_name", Logic_Satate)....where tag_name is the name of the tag, Logic_Satate is either 1 or 0, what you want. Hint: type "SetTag" in the WinCC help and you will get all the commands necessary. Goodluck!