it all depends. Your goals would need some more description - but if I should choose between PI SDK and PI OPC I would clearly go for PI SDK as it exposes more of the PI Servers functionality.
However, if you are in the early development phase and you can wait for the release of AF SDK with RDA, you should look into this one: vcampus.osisoft.com/.../15224.aspx
Alarms and Events is the part that needs clarification. If you look into PI Notifications - PI OPC is out of the game anyhow.
Thanks for the reply.
When do you expect the release of AF SDK with RDA? We will need to have a PI solution within a month or two.
Correct me if I understand wrong, PI Notification is not part of PI SDK, right? So if our application needs to receive alarms and events notification from PI server, we will also need to use PI Notification?
Let me tell you a bit more about what our application currently is doing. Our app connects to an InTouch application using DDE to receive alarm state change notification, retrieve alarm values and unit of measure, write ack request back to InTouch. We retrieve historical data by accessing InTouch histoian database via SQL query. We have learned that most of our new customers have OSI PI products so we need to extend our app to support OSI PI with all aforementioned functions.
I understand we can retrieve data and historical data using PI SDK and get alarms and events through PI notification (correct?), how about the write request to PI server? Is it supported in PI SDK?
Neil, expected release of the AF SDK with RDA is Q32012, see PI System Roadmap.
PI Notifications are part of the AF SDK - so AF SDK with RDA would allow you to work with only the AF SDK and one technology. If you can't wait for the RDA release you will have to write a applicaiton mixing the PI SDK (for historica data access, read/write) and AF SDK for the PI Notifications (read/write).