DCOM Issues

Many OPC systems use Distributed Component Object Model (DCOM) for communications over a network. Unfortunately, OPC systems can be affected by several problems when DCOM is used, such as:

Although ClearSCADA uses OPC-based technology, it is unaffected by the problems commonly associated with DCOM. This is because the ClearSCADA server is an in-process COM server—it uses data access components to act as the transport mechanism between the server and clients.

Data access components (dbclient.dll) are installed on the clients and use standard Windows TCP/IP sockets. This avoids the problems caused by DCOM as it means that OPC messages are transported between the ClearSCADA server and clients via the TCP/IP socket that is controlled by ClearSCADA.

By installing Data Access Components on client PCs, you set the client PCs so that:

To set up your system so that it is not affected by DCOM related issues, we strongly recommend that you:


Disclaimer

ClearSCADA 2017 R3