QuickOPC User's Guide and Reference
Connection-less Approach
Fundamentals > Connection-less Approach

OPC (Client-Server model) is inherently stateful. For starters, connections to OPC servers are long-living entities with rich internal state, and other objects in OPC model such as OPC groups have internal state too. QuickOPC hides most of the OPC’s stateful nature by providing a connection-less (stateless) interface for OPC tasks.

This transformation from a stateful to a stateless model is actually one of the biggest advantages you gain by incorporating QuickOPC. There are several advantages to a stateless model from the perspective of your application. Here are the most important of them:

The internal state of QuickOPC components (including e.g. the connections to OPC servers) outlives the lifetime of the individual instances of the main EasyDAClientEasyAEClient or EasyUAClient object.  You can therefore create an instance of this object as many times as you wish, without incurring performance penalty to OPC communications. This characteristic comes extremely handy in programming server-side Web applications and similar scenarios: You can implement your code on page level, and make OPC requests from the page code itself. The OPC connections will outlive the page round-trips (if this was not the case, the OPC server would become bogged down quickly).

See Also