4.1.3 Simple Streamer: Sensor Initiates the Connection
| Topic Version | 1 | Published | 10/16/2017 | |
| For Standard | ETPW14 v1 | |||
When the sensor/producer initiates the connection, the first steps in the flow sequence change as shown in the table below. (The gray cells are the same as defined in Section 4.1.2.2 Flow Sequence ).
|
Producer (Sensor)/ETP Client |
Consumer (Aggregator)/ETP Server |
|
|---|---|---|
|
1 |
Provide an ETP WebSocket server at a known URL. |
|
|
2 |
Protocol 0: Open WebSocket via HTTP call to WebSocket URL |
|
|
3 |
Send RequestSession message, requesting Protocol 1 and requesting the server role as a consumer. Include ProtocolCapabilities of SimpleStreamer = true. |
|
|
4 |
Send OpenSession. |
|
|
5 |
Protocol 1: Send Start message, which may contain throttling parameters. |
|
|
6 |
Send ChannelMetadata message(s), which contains local identifiers for the channel(s). |
|
|
7 |
Decode ChannelMetadata, assigning channels to a well/wellbore/log/logCurveInfo hierarchy. This decoding and assigning of channels must be completed before any channel data can be received. |
|
|
8 |
Begin a sending loop, sending ChannelData messages for all channel data as they are available. |
|
|
9 |
Decode each ChannelData message and append it to the appropriate WITSML log object and/or makes it available as ETP channel data to other consumers. |
|
|
10 |
Protocol 0: To terminate data transfer, send CloseSession. |