I tried to post several times but for whatever reason the posts did not go through .
I wrote code to do just this kind of thing using OPC-DA .NET SDK – but same principles with OPC-UA.
I listened to a PLC tag and read in PLC data and sent my data to both a database sqllite and also another application via a virtual com port . This is straightforward since you have your own app – your programmers should be able to do it with ease.
There are many ways to do this:
OPC foundation SDK’s, Opensource AB drivers, Opensource code found on g i t_h u b.
Converter Systems
https: git hub com [fwd slash] convertersystems
Since you have your own program – perhaps HMI perhaps not – Advanced HMI (vb .NET)
Many other open source models as well.