1 Adding a data subscription

The REST API can be used to create a stream event subscription. The EK80 system provides the possibility of subscribing to a variety of data. Once a subscription has been established, data will be sent to the subscription endpoint and clients can access it.

Context

Using the REST API requests and responses you can set up a subscription for EK80 data. List of supported and avaliable subscription types is found in the Swagger documentation.

In order to set up a subscription you will need to:

•

Create a subscription.

•

Create a communication endpoint.

•

Add the subscription to the endpoint.

Procedure

Start EK80 in Normal or Replay operating mode.

Acquire the Channel ID for the appropriate channel.

Note

The Channel ID name may differ when using Normal mode versus using Replay mode, depending on the raw file.

Open the EK80 Subscription API.

The REST API is opened using Swagger documentation.

http://localhost:12345/swagger

Find the Channel ID.

Under ping-configuration operations, perform a GET request:

/api/sounder/ping-configuration/channel-list

The Response Body will provide a full list of available channels in the form of their Channel ID. Example of a Channel ID:

"WBT 1034758-15 ES200-7C_ES"

Make a note of the Channel ID for the channel you would like to subscribe to. this will be used to create a data subscription

Create the data subscription.

There are several output subscriptions available. As an example bottom detection is used in this procedure.

/api/sounder/data-output/bottom-detection-subscriptions
{
  "channel-id": "WBT 582156-15 ES120-7C_ES",
  "settings": {
    "upper-detector-limit": 10,
    "lower-detector-limit": 1000,
    "bottom-back-step": -50
  },
  "subscription-name": "BottomDepth",
  "subscriber-name": "ClientPC"
}

Open the EK80 Subscription API.

The REST API is opened using Swagger documentation.

http://localhost:12346/swagger

Locate the operation:

Create a bottom detection data subscription

/api/sounder/data-output/bottom-detection-subscriptions

Fill in the specifications for the request.

Open the Example Value and right-click in the structure. This copies the structure into the specifications field for the request.

Also make sure the Channel ID, being a part of this request is correct.

Enter appropriate subscription-name and subscriber-name values for the subscription in the subscription.

In this example BottomDepth and ClientPC has been selected.

Select Try it out!

This creates the new subscription.

Find the subscription-id.

In the Response Body of the response, you will find a number. This will be referred to as the subscription-id. Make a note of it. This will be used when adding a subscription to an endpoint.

Create a new communication endpoint.

Locate the operation:

Create a new communication end point

/api/sounder/data-output/communication-end-points

Fill in the specifications for the request.

{
  "name": "DepthOutput",
  "configuration": "tcp://10.120.65.47:20034",
  "communication-type": "zero-mq"
}

Open the Example Value and right-click in the structure. This copies the structure into the specifications field for the request.

Fill in a suitable name for the endpoint, use the IP address of one of the LAN adapters in the EK80 computer. Select a suitable/unique port.

Select Try it out!.

Find the communication-end-point.

In the Response Body of the response, you will find a number. This request is referred to as the communication-end-point. Make a note of it to use it when adding a subscription to the endpoint.

Send a request to add the subscription to the endpoint.

Add a subscription to the communication end point

/api/sounder/data-output/communication-end-points/{endPointId}/data-subscriptions

Use the communication-end-point to fill in endPointId.

{
  "subscription-id": 1,
  "data-serialization": "protobuf"
}

Open the Example Value and right-click in the structure. This copies the structure into the specifications field for the request.

Fill in the subscription-id.

The plan is to provide the subscribed data as C structure ("c-struct") and/or according to the Protocol Buffer standard ("protobuf").

Note

Protocol Buffer (protobuf) is a Google mechanism for serializing structured data.

Select Try it out!.

The subscription is now connected to the endpoint and the port for the endpoint will provide data output for clients to use.