Adding OPC Items with the DSC Module

[mo.mant]

Hello,

I'm working on my bachelor thesis and discovered a problem. I Need to connect from my LabView Project to an SIMATIC NET OPC Server. The connection between the LabView environment and SIMATIC NET is working and i can access all tags wich are created on my SIMATIC NET OPC Server.

My task is to write a programm wich can create/remove tags(during runtime) on/from the OPC Server and read and write this tags.

first attemp

When I'am using a Datasocket I can access the OPC Server tags with the IP Adress the ProgID and an specific AccessPath of the OPC Server. The AccessPath is SIMATIC specific and allows to request OPC Tags wich are not createt on the OPC Server. The Access Path gives the Server the Information where he has to look for the value of the tag.

For example:

\\192.168.2.20\OPC.SimaticNet\S7:[PLC-Connection]I8.2 --> This would read the Input 8.2 of a specific S7-PLC

OPC Server IP + ProgID           +  AccessPath

This is my favorite way, because i can access all tags i need without an add / remove tag function, by simply creating a string and using a Datasocket. The Problem: I can not use the Datasockets because they are to slow. The average access/update time of the datasockets is for my configuration about 800ms, but i need 100ms or less.

second attemp

My second attemp is a I/O-Server configured as OPC-Client wich connects to the SIMATIC OPC Server. The connection works and i can acces the SIMTIC OPC Server over the LabView I/O Server. I can read and wirte the values by using LabView Bound Variables. I also figured out how to create the Bound Variables during runtime. But I didn't figure out how to create OPC Tags in the SIMATIC NET OPC Server in the runtime. I experimented with the AccessPath while creating bound variables to access the data i need, but it didn't work.

If I'am able to create tags during the runtime on the SIMATIC OPC Server i can use the AccessPath to configure this tag and then use this tag in LabView via I/O-Server and bound Variables. If anybody could help me that would be realy nice because im totally stuck.

LabView is working with the DA3.0 Interface  and I know it is possible to create, remove and configure tags over the DA3.0 Interface, but i'm not able to find the functions and methods in LabView.

[Julien_De_Freitas]

Hi,

First, thank you for using the National Instruments discussion forum.

Please, have a look at this document:

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000x0MPCAY&l=en-US

Hope it helps,

Regards,

[mo.mant]

Yeah, i know this paper. Thats not the Problem i have, the Problem is that when my application is running, i need to access the SIMATIC NET OPC Server and add OPC Tags in it. But Anyway i didn't found the Funktions i need for this. I know its possible because this function is specified in the DA3.0 Specification from the OPC Foundation ( wich LabView uses as Interface), a shame that theres not a easy way in LabView to do it, even the expensive DSC does not providethe functions. I will use the DLLs provided from OPC Foundation to do it or buy the AcconAGLink DLLs for direkt PLC communication.

[Julien_De_Freitas]

Hi,

I had a closer look at your problem.

It's now possible in your case to create in LabVIEW tags on runtime.

You need to use NI OPC servers configuration software.

Regards