You have two options for developing OPC clients in LabVIEW that allow you to connect to OPC systems : LabVIEW DataSocket, which is available in the LabVIEW Development System, or the LabVIEW Datalogging and Supervisory Control (DSC) Module.

LabVIEW DataSocket

You can use DataSocket to open a connection to a data item published on an OPC server using the opc protocol. This option works well for applications with the following conditions:

• You do not need to log data automatically or add alarming, scaling, and security.
• You have a small application with references to only one or two OPC data items.
• You do not need to configure settings such as the update rate or deadband.
• You need to connect to an OPC server that supports OPC version 1.0 or 2. x. If you need to use OPC version 3.0, you must use the DSC Module.

LabVIEW DSC Module

The DSC Module extends the LabVIEW graphical development environment with additional functionality for the rapid development of distributed measurement, control, and high-channel count monitoring applications. The DSC Module also extends the data services portion of the LabVIEW shared variable, which you can bind to data items published on an OPC server.

The DSC Module is ideal for applications with the following conditions:

• You need to log data automatically or enable alarming, scaling, and security.
• You have many OPC data items. The DSC Module can locate all OPC servers installed on the computer or network and read available information about the server capabilities and data items directly from the OPC server. You then can browse data items and configure settings such as the update rate and deadband.
• You need to access OPC items from shared variables.
• You need to connect to an OPC server that supports OPC version 3.0.

You can use the DSC Module as an OPC client to access OPC servers, including the NI OPC Servers that the DSC Module provides. Use the NI OPC Servers application, available by selecting Start»All Programs»National Instruments»NI OPC Servers»NI OPC Servers, to transfer data from industrial devices and systems to client applications on a host machine. The NI OPC Servers application enables data sharing between a variety of applications, such as human-machine interface software, manufacturing execution systems, and enterprise resource planning applications.

Refer to ni.com/labviewdsc for information about or to purchase the DSC Module.