COM DA migration - how to refer to subscription?

[brudert]

Hello,

I'm developing an application as interface between our old OPC DA interface and your OPC UA SDK.
It bases on your com_da_migration example.
There you create several ComDa groups in relation to the sampling rate.
My thinking was to relate a DA Group for each subscription instead of sampling rate. In our client application we group the OPCItems in Topics.

We have applications with thousands of OPCitems. It would unnecessarily limit our performance if we would manage this mass of items in just a handful of groups. Especially because each group is polled in the whole group, depending on the sampling rate. In our COM DA implementation we are able to enable or disable individual groups (by topic), so we can scale the sample load.

I know, the Session object contains a list of subscriptions. But how can i access it from IoManager (e.g. at beginStartMonitoring) and how consistent are these subscriptions. how often does the subscription id change?

Any Ideas?

Best Regards