OPC

The CygNet OPC implementation includes the following components:

a dedicated current value service, the OPC Interface Service (OPCIS), which provides connectivity with local or remote OPC servers to transfer real-time data from remote devices into the CygNet system (OPC Interface Service)
a native CygNet OPC DA Server (CygNet OPC Server)
a native CygNet OPC HDA Server (CygNet OPC HDA Server)
two utilities for troubleshooting communications and synchronizing points (CygNet OPC Check Utility and the CygNet OPC Sync Utility)

The following table contains definitions of specific terminology used in CygNet OPC implementations.

Component	Description
OPC Interface Service (OPCIS)	The CygNet current value service that communicates with an external OPC server.
OPC Data Point	A point in the OPCIS that represents data from the OPC server. See OPCIS Data Points.
OPC Group Facility	Defines an OPC group. Each group represents a connection to an OPC server. All tags in an OPCIS belong to a group, which is represented by an OPC Group Facility. See OPCIS Groups.
OPC Group Facility Points	A set of points that define the parameters for the group connection to the OPC server.
OPC Server	A third-party OPC Data Access (DA) server. Must be compliant with the OPC DA (OPC Data Access) specification, versions 1.0a, 2.0a, 2.05a, and 3.0. CygNet has its own read-write OPC (DA) Server.
OPC DA Client	A third-party utility used to test OPC DA connections and view data, for example, MatrikonOPC Explorer.
OPC HDA Server	An OPC Historical Data Access (HDA) server. Must be compliant with the OPC HDA (OPC Historical Data Access) specification, versions 1.0, 1.1, and 1.2. CygNet has its own OPC HDA Server.
OPC HDA Client	A third-party utility used to test OPC HDA connections and view data, for example, MatrikonOPC HDA Explorer.

To address questions or circumstances beyond the scope of the CygNet Help, Additional CygNet Resources are available.