Overview¶

The configuration has to be JSON-formatted. It is divided into the following categories:

Client

basic configuration of the Lablink client (JSON object)

UniversalAPI

basic configuration related to the REST API server (JSON object)

Channels

configuration of the data exchange channels, accessible through the REST API and via Lablink

In the following, the configuration parameters for these categories are listed.

Basic Lablink Client Configuration¶

Required parameters for category Client

ClientName: client name
GroupName: group name
ScenarioName: scenario name
labLinkPropertiesUrl: URI to Lablink configuration
syncHostPropertiesUrl: URI to sync host configuration (currently not supported, use dummy value here)

Optional parameters for category Client

ClientDescription: description of the client
ClientShell: activate Lablink shell (default: false).

Universal API Configuration¶

Required parameters for category UniversalAPI

NodeId: node ID of Universal API instance

Optional parameters for UniversalAPI

EndpointPrefix: prefix for URL of REST API
Port: port of REST API server (default: 7000)

Channel Configuration¶

Required configuration parameters for each channel defined in category Channels

Id: channel Id (may contain dashes /)
Payload: describes the type of information which is exchanged over the channel, must be either samples or events
Datatype: type of data exchanged via this channel, must be either float, complex, integer, string or boolean
DPName: datapoint name of Lablink service associated to channel (must not contain dashes /)

Optional configuration parameters for each channel defined in category Channels

Readable: this flag indicates if the channel can be read via the REST API
Writable: this flag indicates if the channel can be written via the REST API
Unit: the (physical) unit associated with the channel
Range: allowed range of values; for payloads of type float and integer this should be an object with attributes Min and Max; for payloads of type string this should be an array of allowed values
Rate: expected refresh-rate in Hertz of this channel; does not apply to channels which have event payloads.
TimeSource: allowed values are synchronized, unsynchronized or unknown
Source: allowed values are unknown, process, test, calculated or simulated
Validity: allowed values are unknown, valid, invalid, questionable or indeterminate

Example Configuration¶

The following is an example configuration for a UniversalApiClient client:

{
   "Channels": [
      {
         "DPName": "channel1",
         "Datatype": "float",
         "Id": "test/channel1",
         "Payload": "samples",
         "Range": {
            "Max": 15.0,
            "Min": 5.0
         },
         "Readable": true,
         "Source": "calculated",
         "Validity": "valid",
         "Writable": false
      },
      {
         "DPName": "channel2",
         "Datatype": "float",
         "Id": "test/channel2",
         "Payload": "samples",
         "Readable": false,
         "TimeSource": "unsynchronized",
         "Writable": true
      }
   ],
   "Client": {
      "ClientDescription": "Universal data exchamge API client example.",
      "ClientName": "UniversalAPIClient",
      "ClientShell": true,
      "GroupName": "UniversalAPIClientDemo",
      "ScenarioName": "UniversalAPIClientExample",
      "labLinkPropertiesUrl": "http://localhost:10101/get?id=ait.all.llproperties",
      "syncHostPropertiesUrl": "http://localhost:10101/get?id=ait.test.universalapiclient.sync-host.properties"
   },
   "UniversalAPI": {
      "EndpointPrefix": "uapi-test",
      "NodeId": "lablink-uapi-test",
      "Port": 7000
   }
}