FREQUENTLY ASKED QUESTIONS 

1. What OPC Standards are supported ?
Advosol Inc. offers .Net Client Development Components for:

• Data Access  ( OPC DA ) 
• Historical Data Access  ( OPC HDA )
• Alarms & Events  ( OPC AE )
• XML-DA web services  ( XML-DA )
• OPC .NET (Xi)
• OPC UA

Server development Kits are offered for:

• Data Access  ( OPC DA ) 
• Alarms & Events  ( OPC AE )
• Historical Data Access  ( OPC HDA )
• XML-DA web services  ( XML-DA )
• OPC .NET (Xi)
• OPC UA
   

2. 64bit Systems?
The most common issue on 64bit systems are missing 64bit OPC Core Components.
.NET applications are often built for 'Any CPU' and such applications run in 64bit mode on 64bit machines. The 64bit Core Components are required when either the server or the client run in 64bit mode.
Missing OPC Core Components are usuall indicated by errors like:
    Retrieving the COM class factory for component with CLSID {13486D51-4821-11D2-A494-3CB306C10000} failed

32bit and 64bit OPC Core Components can be download form the OPC Foundation web site. The current version setups allow both to be installed on the same machine.
Advosol provides the OPC Core Components installers with its products.

3. How  can remote OPC DA servers be accessed?
The DCOM, Firewall and Windows security settings for remote OPC server access are the main cause of troubles getting Remote OPC server access to work. Advosol offers the free OpcSecurityAnalyzer utility as tool to find the proper configuration settings.
Tunnelling and Bridging solutions eliminate teh remote DCOM communication. Tunnelling solutions use a proprietary TCP communication and require a matching module on both sides.
The Advosol bridging products use the OPC specified XML-DA communication. With .NET3 (WCF) the coommunication can be configured to achieve the same performance as a tunnelling approach. An XML-DA gateway is installed at the OPC DA server location. Through the gateway, XML-DA clients located anywhere can access the OPC DA server. The client applications can be implemented as XML-DA clients or OPC DA clients can use the Advosol OPC DA to XML-DA gateway.

4. Is there an OPC standard for .Net OPC DA  ?
The OPC Foundation has sample code for an OPC DA .Net interface but there is no specification. The available .Net interface wrapper products have an interface similar to the OPC DA custom or automation interface, with some changes required by .Net.
Advosol Inc. additionally offers an OPC DA client component with an XML-DA interface. Clients can be implemented as XML-DA clients even if still OPC DA servers have to be accessed.

5. What are the software license conditions ?
The developer tools are offered as Personal, Single Developer and Company Site licenses. The Single Developer license is trnasferable, the Personal license is not. There is a one time fee and the software may be integrated into the application at no further costs. Applications can be distributed without royalty fees.
Products for the system integrator such as gateways are sold as per-CPU licenses.

6. Are there royalty fees ?
Applications created with the help of Advosol toolkits and software components for which you bought a Personal, Single Developer or Company Sites license may be freely distributed. No royalty fees are due.

7. Is source code available ?
Source code is available for all products. For some products a source license is offered in the online store. Contact Advosol's sales department for a quote if no source license is in the online store.

8. Is support available ?
Product usage email/phone support is included in the product license for a period of 90 days from purchase date. Service subscriptions are available to extend the support period for 12 month.

9. How do I get updates ?
During the support period updates can be download from the online store free of charge. If your support period has expired then you can buy a service subscription to extend the support period for 12 month.

10. Can I evaluate the software free of charge  ?
Evaluation licenses are available and the software can be downloaded free of charge. Only a simple registration is required. Billing information needs not be provided.

11. Difference OPC DA Server Toolkit Standard Edition and Professional Edition?
The DANS-PE Toolkit Professional Edition offers additional additional features and performance tuning options. A description of these features can be found in the OPC DA .NET Server Toolkit product page.

12. OPC Server Access from ASP.NET applications ?
In ASP.NET application we recommend using the XMLDA.NET client component.
Web applications have a different lifetime behavior than DCOM based OPC servers. DCOM have a permanent connection and the clients have to connect/disconnect. Web applications are stateless and basically each access is independent of others. XMLDA.NET takes care of these differences and automatically connects/disconnects the OPC DA server.

13. Visual Studio Versions ?
The Advosol components can be used with all recent Visual Studio Versions. The product installer determines the installed versions and sets up the menu links to the newest version. However, the setup can be configured to install the wizards and Help also in older versions. There is little difference between VS 2010, 2008 and VS2005. VS2003 has a different Wizard concept and is built for .NET1.1.
VS2010 supports .NET4. The target .NET version can be configured for versions >2.

14. Download Files ?
The Advosol product download files are EXE setup files, NOT ZIP files.
The download files must be stored with the EXE file type. The Installer is started when the file is executed. The Installer works on all .NET versions.
The download files are Authenticode signed.

15. Multiple OPC DA Server Instances ?
Many OPC DA servers are implemented to support a single device and can run only as one instance per machine. A second server instance would fail or work improperly, e.g. because a communication port is not available.
However, DCOM in the default configuration starts a separate server instance for each connecting client user account. A remote client typically accesses the server in another user account than a local client application.
To prevent DCOM from starting multiple server instances the OPC server DCOM configuration needs to be changed to a ‘Specific User’ account instead of the 'Launching User'. This configuration definition is in the DCOMCNFG Identity tab. The option ‘Interactive User’ is not recommended.
A DANsrv based OCP DA server can be implemented to run as multiple instances to support multiple devices. In this case each server instance must have its executables in a different directory and must be configured with a unique CLSID and ProgID. For clients these instances of the same OPC server appear as different OPC servers.