OPC DA Packet Structure|Classic OPC: DA, A&E, HDA, XML-DA, etc.|Forum|OPC Foundation

I’m trying to understand the packet structure of an OPC DA 3 packet. My issue is that i’m working on a VB program to write OPC tags to a system that will only accept the value if the quality is “Bad – Not Connected” (00001000 binary). The VB program built so far can write the value to the appropriate tag but the quality is “Good” (11000000). With the quality being good the control system on the other end takes no action. If I can capture some packets in wireshark  and try to analyse them it’s very difficult because there are thousand of tags, some in good quality and some in bad-not connected at any given time so i can’t place exactly where in a packet the quality tags reside. If i knew the packet structure i might be able to use VB to inject bad-not connected into the quality field so the control system accepts the value and acts on it. 

Also, I’m using Advosol OPCDA.NET to tie VB to OPC.

Any help would be greatly appreciated.

Chris