Hi,

I have been developing a VB.NET application to read and write tags from a Siemens S7-300 PLC.
The OPC Server I am using is Archestra DASSIDIRECT v2.0.

The problem I am having is the read and write takes an extremely long time up to 2 minutes.
For example to complete a multiple tag write of 1125 tags it takes upto 2 minutes and during that time the VB.NET application and the OPC Server (both on the same PC) consumes 100% of the CPU making the computer unusable.

Similarly doing a read of 32 tags can take up to 2 minutes.
Attached is the code for the Read and Writing.
The Write code is used to write 1125 tags to the PLC however this can be changed to increase to up to 2250 tags.
The Read code is used to read and write 32 REALs to the PLC.
The code is structured very simple one function to setup everything then one function to read once and one function to write once.

To put it simply the performance and CPU utilization is unacceptable.
Is there anything wrong with the code I have written or any explanation as to why this is happening?

Am I asking too much on this product?
Note: I purchased this product because on an initial test it worked quite well compared to an OPC.NET component that we were previously using and allowed options like multiple tag writes however when I switched over our program to using this component the system just freezes up when we read and write.

Thanks,
Ben