What is DCOM?

Distributed Component Object Model (DCOM) is a proprietary Microsoft Windows technology. It enables software components to communicate directly over a network. Components on a server and a client need to be configured and must correspond with each other to enable the DCOM network communication.

Windows lists components requiring DCOM communication in the Management Console, accessed using the Component Services dialog box.

Why do you need DCOM for OPC Classic?

OPC Classic DA (Data Access), A&E (Alarms & Events), and HDA (Historical Data Access) communications are based on COM and DCOM technology. Indeed, OPC clients and servers use COM to communicate with each other when deployed on the same machine and use DCOM for the remote communications across a network.

How to configure DCOM to enable remote OPC communications?

You can download our DCOM configuration guidelines document from here to properly to configure DCOM and enable remote communications between your OPC client and OPC server components. These guidelines include detailed instructions on how to configure DCOM related settings in the OPC server machine and in the OPC client machine.

Are you looking for a solution to eliminate DCOM?

We recommend you the OPCNet Broker product, which is our OPC tunneling product. Indeed, it allows you to securely establish remote OPC communications using a single TCP port. Click here to learn more about OPCNet Broker and how it can secure your OPC connections and data flows. OPCNet Broker enables OPC Classic communications through firewalls and NAT and across domains.

Are you looking for a solution to support Windows DCOM Server Security Feature Bypass vulnerability fix?

Alternative and secure solutions exist to support the latest Windows DCOM hardening update and still allow remote OPC Classic communications. Refer here for our blog post on the subject.