Intersolo

Is it possible to get LUD (local user data) with STEP7 or with OPC tag?  

We need more details of what devices & software you are using, and what user management system you are already using in order to help.  If user management is implemented, HMI's may know what user has logged in.  In some cases, PLC's may know who is using the controlled system (this is usually implemented in the application with a card reader or RFID system).  If Step 7 has opened a protected project, then Step 7 will know which user is active.  If SIMATIC Logon or UMC is being used, there may be ways of obtaining user information from them. 

i want to get GUD and LUD using OPC DA (SINUMERIK HMI Advanced).

I think this won't be available as LUDs are declared in the part program and as such could be wildly different depending on which program is running. you would need to know the structure of the variables (bool, int, real etc) and they are re initialised when the program changes ie running different subroutines in a part program the LUDs will change and be redefined

could you not use GUDs for the data you want to look at? you can definitely get to them