The following tables list the members exposed by BGGroup.
Public Properties
| Name | Description | |
|---|---|---|
 | Active | OpcGroup Active state property assignement. A get is from the 'Active' property of the underlying OpcdataBind object. On set the associated OPC server group is modified. Errors are reported in the GeneralErrors event. |
| HandleClient | OpcGroup Client Handle property assignement. A get is from the OpcGroup property. Use OpcGrp.GetStat() to refresh the properties if this may be necessary. On set the OPC server is updated. Errors are reported in the GeneralErrors event. |
| KeepAliveRate | OpcGroup KeepAlive feature of OPC DA V3 servers. A get returns the revised rate of the last set call. On set the OPC server is updated. A value of 0 disables or indicates a disabled KeepAlive handling. Errors are reported in the GeneralErrors event. |
| LocaleID | OpcGroup LocaleID property assignement. A get is from the OpcGroup property. Use OpcGrp.GetStat() to refresh the properties if this may be necessary. On set the OPC server is updated. Errors are reported in the GeneralErrors event. |
| Name | OpcGroup name property assignement. A get is from the OpcGroup property. Use OpcGrp.GetStat() to refresh the properties if this may be necessary. On set the OPC server is updated. Errors are reported in the GeneralErrors event. |
| OpcNetGroup | Get the underlying OpcGroup object. |
| PercentDeadband | OpcGroup PercentDeadband property assignement. A get is from the OpcGroup property. Use OpcGrp.GetStat() to refresh the properties if this may be necessary. On set the OPC server is updated. Errors are reported in the GeneralErrors event. |
| TimeBias | OpcGroup TimeBias property assignement. A get is from the OpcGroup property. Use OpcGrp.GetStat() to refresh the properties if this may be necessary. On set the OPC server is updated. Errors are reported in the GeneralErrors event. |
| UpdateRate | OpcGroup UpdateRate property assignement. A get is from the OpcGroup property. Use OpcGrp.GetStat() to refresh the properties if this may be necessary. On set the OPC server is updated. Errors are reported in the GeneralErrors event. |
Public Methods
| Name | Description | |
|---|---|---|
 | AddItems | Available in the OPCDA.NET Professional Edition only. A set of items is added to the group. If the group is in active state then the server makes a data change callback with the current value and then each time the value of one or multiple items changes. Added items can also be used in read or write operations. For read and write operations the items don't necessarily be added first. If the item name is specified in the read/write call and the item is not yet member of the group then it is added within the read/write handling. |
| Dispose | The request handling thread is terminated and the associated OpcGroup object is disposed. |
| Read | Overloaded. Available in the OPCDA.NET Professional Edition only. Read a set of items with the items identified by the server handle that was returned in a previous AddItems call. The item values are read by executing an asynchronous read and returned to the user as an argument of the completion handler. |
| Refresh | Available in the OPCDA.NET Professional Edition only. Force a callback to DataChangeEventHandler() for all active items in the group (whether they have changed or not). Inactive items are not included in the callback. If the call fails then a BGException is thrown and no Callback will occur. Calling Refresh for an InActive Group will fail with E_FAIL. Calling refresh for an Active Group, where all the items in the group are InActive also fails the call with E_FAIL. Functionally this method is similar to what could be achieved by doing a READ of all of the active items in a group. NOTE: all of the results must be returned in a single callback. Thus if the items in the group require multiple physical transactions to one or more physical devices then the server must wait until all of them are complete before invoking OnDataChange. The expected behavior is that this Refresh will not affect the timing of normal OnDataChange callbacks which are based on the UpdateRate. For example, if the update rate is 1 hour and this method is called after 45 minutes then the server should still do its internal ‘checking’ at the end of the hour (15 minutes after the Refresh call). Calling this method may affect the contents of that next callback (15 minutes later) since only items where the value or status changed during that 15 minutes would be included. Items which had changed during the 45 minutes preceding the Refresh will be sent (along with all other values) as part of the Refresh Transaction. They would not be sent a second time at the end of the hour. The value sent in response to the Refresh becomes the ‘last value sent’ to the client when performing the normal subscription logic. |
| Remove | Remove this group. |
| RemoveItems | Available in the OPCDA.NET Professional Edition only. The specified items are removed from the group in the OPC server. |
 | RevertToSelf | |
| Write | Available in the OPCDA.NET Professional Edition only. Write a set of items with the items identified either by the fully qualified item ID or by the server handle that was returned in a previous AddItems call. If an item is specified by the item id and it does not yet exist in the BGGroup internal list of added items then the item is added by executin AddItems. The item values are written by executing an asynchronous write call. The success of the write call is reported for each item in argument of the completion handler. Error that happen in the write request handlding are reported in the requestErrors array. For the items for which the server accepted the write request the success of the actual write is reported in the OPCWriteResult argument. |
| WriteVQT | Available in the OPCDA.NET Professional Edition only. WriteVQT sets the item value, quality and timestamp. This method is supported by oPD DA V3 servers only. The items are identified either by the fully qualified item ID or by the server handle that was returned in a previous AddItems call. If an item is specified by the item id and it does not yet exist in the BGGroup internal list of added items then the item is added by executin AddItems. The item values are written by executing an asynchronous WriteVQT call. The success of the WriteVQT call is reported for each item in argument of the completion handler. Error that happen in the WriteVQT request handlding are reported in the requestErrors array. For the items for which the server accepted the WriteVQT request the success of the actual WriteVQT is reported in the OPCWriteVQTResult argument. |
