I am pleased to announce the release of PI Web API 2017 R2, our suite of REST services for interacting with the PI System. The PI Web API is a member of the Developer Technologies suite of products. Click to see our Technical Support Product Release Bulletin which in turn will direct you to the right pages in our Download Center. We have stopped shipping the dedicated PI Web API install kit. Instead, PI Web API is part of PI AF Services 2017 R2.
There are many enhancements and bug fixes in this release. I encourage you to read the Release Notes to learn about what we did. Improving performance is Job #1! You'll find many work items that were directed at improving speeds of data retrieval and search. I wanted to mention two features:
WebId 2.0: we have received many comments about our WebId concept which are unique identifiers to just about everything you reference through PI Web API. While accurate, they can get to be a bit big. To address this, we have introduced WebId 2.0. We now have different types of WebId that vary in length and precision. It is even possible to create WebIds yourself if you already have access to AF SDK object ids. Let me know if this is interesting to you.
Channels: we have received a lot of positive feedback about our websocket "Channel" implementation. One of your biggest problems, it seems, is that you can't be completely sure if the channel is healthy if you have not received data updates for a while. For technical reasons, we are unable to implement the web socket standard RFC6455 "Ping" and "Pong" features to ascertain health. What we have done instead is allow you to request a periodic "heartbeat" response which consists of an empty message if there are no data values to send.
I hope you can upgrade to PI Web API 2017 R2 soon. Let me know what you think!