The following tables list the members exposed by BGServer.
Public Constructors
| Name | Description | |
|---|---|---|
 | BGServer Constructor | The created object can only be used from classes that derive from System.Windows.Forms.Form. The completion notification with the browse result is synchronized with the user interface thread by internally calling Form.BeginInvoke(). |
Public Fields
Public Properties
| Name | Description | |
|---|---|---|
 | DataBinds | List of currently existing BGDataBind instances for this BGServer instance. Instead of getting the BGDataBind object from the AddDataBind completion handler, the object can be searched in this list by the DataBind name. |
| DeclareV2 | Forces the wrapper to use OPC DA V2 functions to emulate OPC DA V3 methods where supported. |
| Groups | List of currently existing BGGroup instances for this BGServer instance. Instead of getting the BGGroup object from the AddGroup completion handler, the object can be searched in this list by the group name. |
| IsConnected | Indicates if the OPC server associated with this BGServer instance is currently connected. |
| Name | Indicates the ProgID name of the OPC server associated with this BGServer instance. |
| OpcNetServer | Get the underlying OpcServer object. |
| ServerCheckInterval | The OPC server connection is checked at this interval in milliseconds by executing a GetStatus call. The default interval is 10 seconds. The minimum is 1 sec. The GeneralError handler is called if the server does not respond or is not in 'running' state. |
| ServerResponseLimit | This is the time limit in milliseconds for the OPC server call handling. The default is 10 seconds. If the server call does not return within this time limit then the GeneralError handling method is called with a TIMEOUT error indication. The server access thread may continue to wait for the server call to finish or timeout. Further requests are not being handled before this happens. |
Public Methods
| Name | Description | |
|---|---|---|
 | AddDataBind | Available in the OPCDA.NET Professional Edition only. A new BGDataBind object is created and added to this BGServer instance. A BGDataBind is required for the user to ba able to make OpcDataBind subscriptions. The difference to the OpcDataBind class is only in the handling of the Subscribe calls. In the BGDataBind class these calls are queued and executed in a background thread in order to prevent the application to be unresponsive for some possibly long timeout intervals. |
| AddGroup | Overloaded. Available in the OPCDA.NET Professional Edition only. A new BGGroup object is created and added to this BGServer instance. In the OPC DA server a group is added to the associated server instance and the group is associated with the new BGGroup object. A BGGroup is required for data change handling and for read/write operations. |
| Browse | Available in the OPCDA.NET Professional Edition only. The specified branch is browsed with the specified filters. The browse result is returned to the user as an argument of the completion handler. OPC DA V3 server are browsed using the OPC DA3 Browse() method. For OPC DA V2 servers the browse call is emulated by calling the available OPC DA2 browse handling methods. |
| Connect | Overloaded. Available in the OPCDA.NET Professional Edition only. The specified local OPC DA server is connected. The server mus tbe connected before any other request can be handled. |
| Disconnect | Available in the OPCDA.NET Professional Edition only. The OPC DA server associated with this BGServer instance is disconnected. Existing BGGroup and BGDataBind objects are disposed and the associated groups in the server are removed for a proper server shutdown. |
| Dispose | The request handling thread is terminated. If the server is connected then existing groups and DataBinds are disposed and the server is disconencted. This method must be called for the application to terminate properly. |
| GetProperties | Available in the OPCDA.NET Professional Edition only. For the specified set of items the requested properties are read from the server. The result is returned to the user as an argument of the completion handler. For OPC DA V3 servers the OPC DA3 GetProperties() method is used. For OPC DA V2 servers the call is emulated by calling the available OPC DA2 properties handling methods. |
| GetStatus | Available in the OPCDA.NET Professional Edition only. A GetStatus server call is executed. The status returned by the OPC server is returned to the user as an argument of the completion handler. |
 | RevertToSelf |
Protected Methods
Public Events
| Name | Description | |
|---|---|---|
 | GeneralError | Available in the OPCDA.NET Professional Edition only. This event handler is called when an error occurs and the user did not specify a completion handler in the request. It is also called when a request handling timeout occurs. In this case it's called even with a user completion handler specified. The request completion handler will be called when the request handling finally terminates. This may be after a much longer time limit. |
| GeneralErrorExt | Available in the OPCDA.NET Professional Edition only. Extended event handler including the BGServer object related to the event. Install this handler if the application needs to determine the event source. This event handler is called when an error occurs and the user did not specify a completion handler in the request. It is also called when a request handling timeout occurs. In this case it's called even with a user completion handler specified. The request completion handler will be called when the request handling finally terminates. This may be after a much longer time limit. |