HDAtoXi   Historian OPC .NET (Xi) Express Interface Converter

The HDAtoXi Converter is an OPC HDA Historian server that makes one OPC .NET (Xi) Express Interface server accessible from OPC HDA client applications. The HDAtoXi Converter has a simple configuration and makes all Xi serverJournal (historical) objects accessible from classic OPC HDA clients.. The HDAtoXi configuration can restrict the Xi server access to read-only. More detailed access restrictions can be defined in the configuration of the Advosol Xi servers. To minimize DCOM issues the HDAtoXi server should be installed on the same machine as the OPC HDA client application. The remote communication then is through WCF and can be configured for the needed security level.

Xi Communication Security
The OPC Xi specification was designed with communication security as a main consideration. Management and data read/write operations are handled through different endpoints, which can be separately configured with appropriate communication settings. Xi management methods associate handles with object identifiers and the read/write data methods only communicate handles with the data. This makes data hard to interpret by an eavesdropper even if it's communicated without encryption.

The Xi communication options are defined in the Xi server configuration.
Xi clients (HDAtoXi) can only choose among the options defined in the server configuration. The HDAtoXi configuration can define communication preferences as:
- Endpoint names
- Binding schemes (http, https, tcp)
- Secure yes/no
and the HDAtoXi server at run-time selects the available endpoint that best matches the preference configuration.

The HDAtoXi converter server is OPC Compliance tested in the configuration shown on the right. The OPC Compliance Tool (CTT) client accesses the Advosol Historian Test server (built with the Advosol HDANSrv OPC Historian .Net Server Toolkit through the HDAtoXi and XiTOCO converter servers. The CTT client calls all OPC HDA specified methods with different arguments and checks the server response. Calls are also made with invalid arguments to check the server's error handling.

HDAtoXi as a Tunneler or Security Gateway Solution
DAtoXi used in combination with the XiTOCO Converter wraps OPC HDA to Xi and back to OPC HDA. Remote OPC HDA servers can be accessed through an Xi connection.

The Express Interface communication has significant advantages over Tunneler products: The communication can be configured to a security level appropriate for the application TCP or HTTP communication can be chosen. TCP communication offers high performance but requires firewall configuration. HTTP communication on standard ports works without configuration efforts. The standardized OPC .NET (Xi) interface is used instead of a proprietary Tunneler interface. Either side converter can easily be replaced with any Xi client respectively server.

Test the HDAtoXi converter with Internet accessible Xi servers.

Xi Converter Products Comparison
Advosol offers multiple products with Xi converter features. The capabilities differ, allowing you to select the product best suited for you application needs.

Requirements

• Windows XP, Vista, Windows 7, Windows Server 2003/2008
• .NET 3.5 SP1 or 4.0 with WCF

XMLDA.NET is a .NET XML DA client component that supports access to OPC DA and XML DA servers. The OPC client application can be designed as an XML DA web service client and ican be built as a Windows Forms orASP.NET application. All DCOM handling is XMLDA.NET internally.