Metadata message

The metadata is generated by the values entered in the Common Configurator. The metadata serves as an overview of the individual pieces of information and their assignment to the corresponding IDs. The metadata can be viewed in such a way that the connections can be seen as the database level, the datapoints as the table level and the datapoint definitions as the column level.

Each connector that wants to receive the metadata of the MSSQL Connector must subscribe to the following metadata topic:

Find the correct topic for your connector here:

• MSSQL
• MySQL
• Oracle
• Postgre

A new metadata message is sent when the MSSQL Connector is started, restarted or the configuration changes.

The most recent metadata message is retained, so when a new connector connects to the MSSQL Connector, the newest metadata message will be published to it.

A possible example of a metadata message from the MSSQL Connector, where it is important to note that the array dimension is used to transfer the fetchsize via the metadata:

{
   "seq":8,
   "connections":[
      {
         "name":"Connection_9",
         "type":"sql",
         "dataPoints":[
            {
               "name":"READ_ONLY",
               "topic":"ie/d/j/simatic/v1/sqlc1/dp/r/Connection_9/READ_ONLY",
               "pubTopic":"ie/d/j/simatic/v1/sqlc1/dp/w/Connection_9/READ_ONLY",
               "dataPointDefinitions":[
                  {
                     "name":"ID",
                     "id":"DP121",
                     "dataType":"DWord",
                     "accessMode":"r",
                     "valueRank":1,
                     "arrayDimensions":[
                        1
                     ],
                     "acquisitionCycleInMs":5000,
                     "acquisitionMode":"Select"
                  },
                  {
                     "name":"DATE_COLUMN",
                     "id":"DP122",
                     "dataType":"Date",
                     "accessMode":"r",
                     "valueRank":1,
                     "arrayDimensions":[
                        1
                     ],
                     "acquisitionCycleInMs":5000,
                     "acquisitionMode":"Select"
                  },
                  {
                     "name":"DATETIME_COLUMN",
                     "id":"DP123",
                     "dataType":"DateTime",
                     "accessMode":"r",
                     "valueRank":1,
                     "arrayDimensions":[
                        1
                     ],
                     "acquisitionCycleInMs":5000,
                     "acquisitionMode":"Select"
                  }
               ],
               "publishType":"bulk"
            }
         ]
      }
   ],
   "applicationName":"MSSQL Connector",
   "statustopic":"ie/s/j/simatic/v1/sqlc1/status"
}