The RefreshGroup class offers a set of functions for simplified asynchronuous server access. These methods are not defined in the OPC standard and the RefreshGroup class is actually a software layer above the OpcGroup class. It handles the OPC group management functions internally and allows a simple access to items by just specifiyng the item name. A data cache is maintained for all added or referenced items. This cache is updated from the OPC group data callback function. The user can always read up-to-date values from the cache but also can attach his own callback handler.
Overload List
| Overload | Description |
|---|---|
| AddRefreshGroup(Int32,RefreshEventHandler) | Create a RefreshGroup object. The RefreshGroup class offers a set of functions for simplified asynchronuous server access. These methods are not defined in the OPC standard and the RefreshGroup class is actually a software layer above the OpcGroup class. It handles the OPC group management functions internally and allows a simple access to items by just specifiyng the item name. A data cache is maintained for all added or referenced items. This cache is updated from the OPC group data callback function. The user can always read up-to-date values from the cache but also can attach his own callback handler. |
| AddRefreshGroup(RefreshEventHandler) | Create a RefreshGroup object with an update rate of 500 ms. The RefreshGroup class offers a set of functions for simplified asynchronuous server access. These methods are not defined in the OPC standard and the RefreshGroup class is actually a software layer above the OpcGroup class. It handles the OPC group management functions internally and allows a simple access to items by just specifiyng the item name. A data cache is maintained for all added or referenced items. This cache is updated from the OPC group data callback function. The user can always read up-to-date values from the cache but also can attach his own callback handler. |