WinCC tag problem


Thread Starter

Mark Vyshkin

Dear sirs.
We have a problem when working with WinCC tags:

We are working with:
WinCC v5.0 SP2
TCP/IP or Industrial Ethernet connection

We have made several operations:
1. Created a tag 'D30024_Status', Unsigned 16-bit, DB30, DW108
2. Created a structure 'DTest' with 1 WORD tag.
3. Created a tag 'D30024' of type 'DTest'
(As a result we have a tag 'D30024.Status', Unsigned 16-bit, DB30,

Now we have 2 tags , both connected to the same address.
The first one we can read and write properly, but the second (in the structure) doesn't refresh its value:
If we write into 'D30024.Status', then we see the value in 'D30024_Status',
If we write into 'D30024_Status', the value in PLC changes, but the 'D30024.Status' stays unchanged.

We have tryed the situation on several PCs and the result is the same.
Can anybody help ?

Mark Vyshkin
Project Manager
Biotechnical Center
Riga, Latvia
[email protected]

Ronald Nijssen


You have not explained how your tags are used, did you use them both in a Graphic?
When you go into WinCC Explorer, you can see the tags under the Channel, a tooltip text will indicate the tags status, are both requested from the PLC? What is the status of both tags? This information is in the tooltip.
Did you run channel diagnostics, this is available with WinCC V5.0, also under tools in the menu you will find status information about the connections that you are using.