Use the Connection section of the Server tab to define the connection to the OPC DA Server:
- Mode—Specify the type of connection that is to be used between the driver and the OPC DA server:
- In Process—The OPC DA server is located on the computer on which the ClearSCADA database resides. Access to the server is via a direct connection, using a dynamic-linked library file (DLL) that is loaded into the process.
In a hot-standby system the location of the OPC DA server will change depending on which server is currently main.
Select this option if you want the driver to connect to another ClearSCADA server on the same machine(s) as the ClearSCADA OPC Server is implemented as an in-process dynamic-linked library. Running the ClearSCADA OPC Server in-process minimizes the communications overhead between the OPC client driver and the target ClearSCADA server.
- Local Server—The OPC server is located locally, on the computer on which the ClearSCADA database resides. The OPC DA server runs as a separate executable (EXE), and as such requires a separate connection to access that server.
In a hot-standby system the location of the OPC DA server will change depending on which server is currently main.
You typically use this option to enable ClearSCADA to communicate with a third-party OPC server.
Enter the Domain Name, User Name and Password for that connection, in the fields below.
- Remote Server—The OPC server is located on another node (computer) to the server(s) on which the ClearSCADA database resides. The OPC DA server runs as a separate executable (EXE) on the other computer.
Select this option to enable ClearSCADA to communicate with an OPC DA server that is located on another node to the ClearSCADA server(s).
Specify the name of the Remote Node, along with the Domain Name, User Name and Password required to connect to that node, in the fields below.
- In Process—The OPC DA server is located on the computer on which the ClearSCADA database resides. Access to the server is via a direct connection, using a dynamic-linked library file (DLL) that is loaded into the process.
- Remote Node—Use when a Remote Server connection is specified, to specify the node (computer or workstation connected to the ClearSCADA network) on which the OPC DA server resides. Use the browse button to display a Reference browse window and select the required node from the window.
- Domain Name—Applies if the connection type is Local Server or Remote Server. Enter the WindowsTM domain name that is used for authenticating users when connecting to the OPC server.
- User Name—Applies if the connection mode is Local Server or Remote Server. Enter the WindowsTM user name that is to be used for the OPC connection. This has to be the name of a user whose privileges allow the relevant access to the OPC DA server. Enter the corresponding password in the field below.
- Password—Applies if the connection mode is Local Server or Remote Server. Enter the WindowsTM password that is to be used for the OPC connection.
- Reconnect Interval—This allows you to specify the interval, in seconds, between attempts to connect to the OPC DA server, Enter the required interval in the OPC Time Format. You can enter the value directly in the field, or use the Interval window (accessed via the field's browse button) to specify the required value.