What's new in QuickOPC-COM 5.00

From OPC Labs Knowledge Base

Key changes: Redesign for Usability

Technology

  • Windows Vista, Windows 7 and Windows Server 2008 support.
  • Unicode is now used throughout the product.

Components

  • Added ability to specify percent deadband with subscriptions.
  • New method ChangeItemSubscription allows modification of subscription parameters without having to unsubscribe first.
  • New BrowseNodes method combines capabilities of both BrowseLeaves and BrowseBranches methods.
  • When browsing for OPC servers, version independent ProgId of the server can now be retrieved if available.
  • When browsing for OPC servers, a ServerCategories object is now provided, with information about specifications that the OPC server claims to support.
  • New VarType enumeration makes it easy to specify data types used in OPC.
  • DAVtq object (holding value, timestamp and quality combination) can be converted to a string, fully describing contents of all its elements.
  • New DAReadWriteMethod, DAAccessRights, DABrowseFilter, DADataSource, and DAPropertyId enumerations facilitate specifying the values using symbolic constants.
  • Method that deal with multiple elements at once return an array of OperationResult objects or objects derived from it, such as ValueResult or DAVtqResult. These objects contain error (exception) information as well as the actual result.
  • Methods that deal with multiple elements at once can be passed an arbitrary State object can be used to hold application-defined information for each element, and this State object is then available in the OperationResult objects returned by the method call.
  • Previously, methods that accepted State parameter allowed it in form of a string (BSTR) only. Any value (including objects) is now allowed in State parameters.
  • The interfaces are now modeled after the .NET product, taking into account the Microsoft recommendations that also apply to COM.
  • The generated events have uniform signature with “sender” and “event arguments” parameters, which reduces the coding needed to further process the event notifications in a generic way.
  • OPC interoperability has been improved, based on tests with many OPC servers, and participation in OPC Interoperability Workshops.
  • One-shot operations use a set of OPC groups separate from those that are created for subscription-based operations, resulting in more predictable behavior.
  • BrowseAccessPaths method now returns array of strings, not a dictionary.
  • Error messages have been improved and enhanced.

Tools and Instrumentation

  • The EasyOPC-DA Options utility has been redesigned, reducing the number of pages to three.
  • Added more useful settings to EasyOPC-DA Options utility, and allowed setting a special “Infinite” value wherever appropriate by simple check of a box.
  • The default event logging settings now only log the most important events.

Documentation

  • All interfaces, classes, properties and methods now have descriptive “help strings” in type libraries, making it possible for the development environments to provide friendly developer’s experience (such as IntelliSense).
  • Brand new and comprehensive “Concepts” document.
  • The reference documentation is now generated from the code and has been greatly enhanced.
  • Code example for each method in a Reference.

Packaging

  • OPC Core Components that are redistributed with the product have been updated to a newer version.
  • Examples, and other parts that do not directly belong to the core software, have been moved to a separate installation, QuickOPC-COM Bonus Pack.
  • .NET components have been moved to a separate product installation, called QuickOPC.NET.
  • “Hidden” licenses are now being supported for OEM usage.

Removed

  • Components providing Web service interfaces were removed, and will possibly be re-designed and become a separate product installation.
  • OPC Item Generator utility has been moved to QuickOPC Bonus Pack.
  • Support for operating systems older than Windows XP, or older than Windows Server 2003, has been removed.
  • Methods that provide server-wide operations are now considered as “advanced”, and were removed.