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Summary of information for OPC objects




Obj or disp(Obj) displays summary information for the OPC object Obj.

If Obj is an array of objects, disp outputs a table of summary information about the objects in the array.

Summary information includes the following information as appropriate for each item in dObj.

  • ItemID: The item ID for that element.

  • Value: The number and data type of the values for that element.

  • Start TimeStamp: The time of the first value in the element. The time is displayed in the format specified by the OPC date display format that can you set using opc.setDateDisplayFormat

  • End TimeStamp: The time of the last value in the element.

  • Quality: The number of unique qualities contained in the element. If all values have the same quality, that HDA quality is displayed.

You can get more information about a OPC HDA data objects by using the showValues method.

Alternatively, you can display summary information for Obj by excluding the semicolon when:

  • Creating a toolbox object, using the opcda, addgroup, or additem functions

  • Configuring property values using dot notation


Display the summary of a data access client:

da = opcda('localhost', 'My.Server.1')
da =

Summary of OPC Data Access Client Object: localhost/My.Server.1

   Server Parameters
      Host      : localhost
      ServerID  : My.Server.1
      Status    : disconnected
      Timeout   : 10 seconds

   Object Parameters
      Group     : 0-by-1 dagroup object
      Event Log : 0 of 1000 events

Display the summary information for an array of data access clients:

da2 = opcda('localhost', 'My.Second.Server.1');
[da da2]
   OPC Data Access Object Array:

   Index:  Status:         Name:
   1       disconnected    localhost/My.Server.1
   2       disconnected    localhost/My.Second.Server.1

Load the OPC HDA example data file and display the hdaDataSmall object:

load opcSampleHdaData;

Version History

Introduced before R2006a