4.3.3 Flow Sequence

1

Query the server using WITSML v1.4.1.1 AP to determine well/wellbore/log/curve hierarchy.

2

Open WebSocket using HTTP call to WebSocket URL.

3

Protocol 0: Send RequestSession message, requesting Protocol 1 and requesting the server role as a producer.

4

Send OpenSession message which defines the supported protocols.

5

Protocol 1: Send Start message, which may contain throttling parameters.

6

Send ChannelDescribe message, which lists the channels of interest as an Energistics URI, for example: well(idwell)/wellbore(idwellbore)/log(idlog)/logCurveInfo(mnemonic)

7

• If the producer cannot provide the channel data in the ChannelDescribe message, it sends a ProtocolException message with an appropriate error code and a description of the error (see the ETP Specification, Appendix A).
• If the requested channels are recognized, it sends ChannelMetadata messages, which each contains a channel URI. for example: eml://witsml14/well(uidWell)/wellbore(uidWellbore)/log(uidLog)/logCurveInfo(mnemonic)

8

To specify the required channels and their starting points, send ChannelStreamingStart.

9

Begin a sending loop, sending the requested ChannelData messages.

10

Update the displays with data from the received ChannelData messages.

11

(Optional) While sending data, send channel change messages, as appropriate: ChannelDataChange, ChannelStatusChange, ChannelRemove.

(Optional) While receiving data, send data flow control messages, as appropriate: ChannelStreamingStop, ChannelStreamingStart.

To terminate data transfer, send CloseSession.