4 Streaming Channel Data (Protocol 1: ChannelStreaming)
|For Standard||ETPW20 v1|
Protocol Stability Index:3 – Stable (for more information on stability indexes, see 1.1.2 ETP Protocols in Scope ).
Protocol 1 (P1) allows “true” real-time streaming of channel data (i.e., no polling required).
A channel is the measurement of one physical property versus a range of some other dimension, usually time, depth or both. Because data (a new index and its corresponding property) continue to be added, WITSML refers to these as growing objects. WITSML v2.0 has several growing objects, including a log (which grows systematically), and trajectories and cuttings intervals (which grow randomly). For more information on the organization of these domain objects, see the WITSML Technical Usage Guide v2.0.
Also, notifications—like alarms, alerts and annotations—which are not explicitly modeled in XML, can be streamed in real time as channels; this functionality replaces the Message object in previous versions of WITSML.
This chapter provides examples describing the basic steps for streaming these objects.