Step 3 (for client): Configuring the OPC Classic client default DCOM settings

If you have not altered the default DCOM settings on your client machine then you will not need to alter anything here. However, if you have altered the default DCOM settings, then you should check the following configuration and alter it where necessary.

1. Go to Control Panel > Administrative Tools > Component Services. The Component Services dialog opens.

2. In the tree on the left hand side, go to Console Root > Component Services > Computers > My Computer > DCOM Config > CSense Server.

3. Open the CSense Server property sheet and configure the following tabs:

   • Security tab

   • Identity_tab

Note: When configuring these settings, remember that a client and server negotiate to the highest level of authentication when the configured authentication levels differ.

Security tab

On this tab you specify to the operating system that you will allow access to OPC Classic client(s) on this computer (which is what allows remote OPC Classic servers to call back OPC Classic clients).

Launch and Activation Permissions

Settings configured in this section grant permissions to OPC Classic servers to activate objects and launch applications on this OPC Classic client.

1. Select the Customize radio button and click Edit.

2. Define the users or user groups that are allowed to activate objects and launch applications. This engages activation security which, as a rule, should always be more restricted than the authorization security. (Read more on activation security.) By default, you should ensure that the following are listed under Group or user names:

   • SYSTEM

   • The Administrators group for your machine

   • INTERACTIVE

3. For each of the groups or user names, highlighted it and ensure that the following permission check boxes are selected: Local Launch, Remote Launch, Local Activation, Remote Activation.

4. Click OK.

5. Click Apply.

Access Permissions

Settings configured in this section grant permissions to OPC Classic servers that are allowed to supply data to this OPC Classic client.

1. Select the Customize radio button and click Edit.

2. Define the users or user groups that are allowed to access this client. Either allow all network users to access the OPC Classic client, or only allow named, defined users, according to your requirements. This sets the authorization security of the OPC Classic client. By default, you should ensure that the following are listed under Group or user names:

4. • SELF

   • SYSTEM

   • The Administrators group for your machine

5. For each of the groups or user names, highlighted it and ensure that the following permission check boxes are selected: Local Access, Remote Access.

6. Click OK.

7. Click Apply.

Identity tab

The setting configured on this tab determines which user account is used to run the application. Ensure that the account selected is The launching user.

Related:

• What needs to be configured?

Configuring the OPC Classic server:

• Step 1: Configuring domain user accounts

• Step 2: Configuring firewall settings

• Step 3: Configuring server-specific DCOM settings

• Step 4: Configuring the OPCEnum settings

Configuring the OPC Classic client:

• Step 1: Configuring domain user accounts

• Step 2: Configuring firewall settings

• Step 3: Configuring client-specific DCOM settings