The following tables list the members exposed by Group.
Public Constructors
| Name | Description | |
|---|---|---|
 | Group Constructor | Construct a group object associated with the specified server |
Public Properties
| Name | Description | |
|---|---|---|
 | ClientHandle | The client handle for this group |
| groupHandle | Server handle for the group |
| groupName | The optional name of the group |
| isActive | current group active state |
| isDisabled | Current group disabled state |
| localeID | The LocaleId defeind for the group. |
| percentDeadband | The deadband definition |
| requestedUpdateRate | The update rate of the group |
| revisedUpdateRate | The server revised update rate of the group |
| SubscriptionModePoll | Force subscriptions to be polled. Otherwise callbacks are used if the regCallback endpoint is available. Setting this property has only effect if it's done before Group.RegisterList() is called. After that it can be read to determine the actual subscription mode being used. |
Public Methods
| Name | Description | |
|---|---|---|
 | AddItems | The defined items are added to the associated UA interop group. |
| Cancel | Request that the server cancel an outstanding transaction. ( IOPCAsyncIO2::Cancel2 ) |
| ClearItemDeadband | Clears the individual item PercentDeadband, effectively reverting them back to the deadband value set in the group. ( Available in OPC DA V3 servers only ). |
| ClearItemSamplingRate | Clears the sampling rate on individual items, which was previously set with SetItemSamplingRate. ( Available in OPC DA V3 servers only ). The item will revert back to the update rate of the group. |
| CompleteHandlers | Defines the OnCompletion handlers for asynchronous read and write |
| Create | The group is created for UA association. |
| Dispose | The group is disposed and the associated list in the server is deleted. |
| GetItemAttributes | Get the attibutes of all items in the group. |
| GetItemDeadband | Gets the deadband values for each of the requested items. ( Available in OPC DA V3 servers only ). |
| GetItemSamplingRate | Gets the sampling rate on individual items, which was previously set with GetItemSamplingRate ( Available in OPC DA V3 servers only ). |
| GetKeepAlive | Returns the currently active keep-alive time for the group subscription. ( Available in OPC DA V3 servers only ). |
| GetState | Returns the current state of the group. |
| Read | Overloaded. Read the value, quality and timestamp information for one or more items in a group. The function runs to completion before returning. |
| Refresh | Force a data change callback . |
| RemoveItems | The set of items is removed from the UA interop group. |
| SetActiveState | Sets one or more items in a group to active or inactive. This controls whether or not valid data can be obtained from Read CACHE for those items and whether or not they are included in the IAdvise subscription to the group. |
| SetClientHandles | Changes the client handle for one or more items in a group. IOPCItemMgt::SetClientHandles ) |
| SetDataTypes | Changes the requested data type for one or more items in a group. |
| SetEnable | Enables or disables the subscription of this group |
| SetItemDeadband | Overrides the deadband specified for the group for each item. ( Available in OPC DA V3 servers only ). |
| SetItemSamplingRate | Sets the sampling rate on individual items. ( Available in OPC DA V3 servers only ). This overrides the update rate of the group as far as collection from the underlying device is concerned. The update rate associated with individual items does not effect the callback period. |
| SetKeepAlive | Sets the keep-alive time for the group subscription. Only OPC DA V3 servers support the keep alive feature. The OPCDA.NET Professional Edition emulates the keep alive feature for servers that don't implement the OPC DA V3 IOPCGroupStateMgt2 interface. Some servers may implement the interface but not the method. In this case the OpcServer.DeclareV2 property has to be set to force the emulation to be used. The emulation has a client side thread that makes periodically GetStatus server calls and executes keepalive DataChange callbacks accourding the OPC DA V3 keep alive specification. Clients can set the keep-alive time for a subscription to cause the server to provide client callbacks on the subscription when there are no new events to report. Clients can then be assured of the health of the server and subscription without resorting to pinging the server with calls to GetStatus(). Using this facility, a client can expect a callback (data or keep-alive) within the specified keep-alive time. Servers shall reset their keep-alive timers when real data is sent (i.e. it is not acceptable to constantly send the keep-alive callback at a fixed period equal to the keep-alive time irrespective of data callbacks). |
| SetName | Change the name of the OPC group. ( IOPCGroupStateMgt::SetName ) The name must be unique. The name cannot be changed for public groups. |
| SetState | Modifiy some of the group attributes. |
| SetUpdateRate | Changes the subscription update rate. |
| ValidateItems | The defined items are check if they exist. |
| Write | Overloaded. Writes values to one or more items in a group. The function runs to completion. The values are written to the DEVICE. That is, the function should not return until it verifies that the device has actually accepted (or rejected) the data. |