About DCOM security

The OPC Classic server is implemented as a Microsoft COM object. DCOM (Distributed COM) provides the framework and the services required to deploy COM objects in a distributed environment. One of these services is security. In order to connect to OPC Classic servers, you need to ensure that the security settings of the network allow you to do so. You need to set the permissions and security settings for the correct people, or user groups, across the server network.

Note: DCOM security leverages the underlying Microsoft® Windows® operating system security services. If you are familiar with Windows security issues, you will find that there are a few security issues unique to the distributed environment.

To better understand the security issues that can affect a connection between an OPC Classic client and the OPC Classic server, this section provides an overview of DCOM-related security. The topic of DCOM security (and Windows security for that matter) is extensive and can be confusing. What is presented here is a synopsis of the issues that affect OPC Classic client / server interactions.

DCOM security topics can be broken down into four areas (for definition purposes):