Connecting to OPC Classic (COM)

OPC-DA Connection

The OPC-DA connection, provided by the OPC-COM module, provides a link to a classic, COM-based OPC server. The connection supports OPC-DA versions 2 and 3. To create a new connection, go to go OPC Connections>Servers and click "Create new OPC Server Connection". Select "OPC-DA" from the server connection list. A list of OPC-DA servers installed on the machine will be presented. Select the desired server to create the connection.

Connections to OPC servers will be held open while the Ignition gateway is running. All subscriptions to the server will use the same connection.

Connecting to Remote Servers

While not recommended due to the inherent insecurity and instability of DCOM, the OPC-COM module offers the ability to connect to remote OPC servers over DCOM. To create a remote connection, start by following the instructions above, but select "Other Server" when selecting an OPC server to connect to.

On the following screen, fill out the basic information. The ProgId is not crucial, as the server's specific CLSID (unique ID) will be used to connect.

Expand the advanced options by selecting the "advanced options" check box. Fill in the options:

Remote Server

Select this box to specify that this is a server not located on the local machine, that will use a DCOM connection.

Host Machine

The computer name or IP address of the machine running the remote server.

CLSID

When connecting to a remote machine, it is currently required that you manually enter the CLSID of the server. This id can be found in the registry of the machine hosting the server under:

HKEY_CLASSES_ROOT\OPCServerName\CLSID