The following tables list the members exposed by OpcHDAServer.
Public Constructors
| Name | Description | |
|---|---|---|
 | OpcHDAServer Constructor | Overloaded. |
Public Fields
| Name | Description | |
|---|---|---|
 | AuthenticationWindowsIntegrated | |
| CallbackHandler | Notification callback handler. |
| PreferredEndpoint | With UA option only. Use this endpoint at connect if possible. |
| UaAccessWithoutSecurityPreferred | With UA option only. Request to access the UA server with least security if true, otherwise with highest. |
Public Properties
| Name | Description | |
|---|---|---|
 | ConnectStatus | Current server connect status. Contains either 'Connected', 'Disconnected' or the Connect() exception message. This property doesn't reliably indicate if the server is actually connected and accessible. The main purpose is to give access to the exception message of a failed connect. For UA servers the property is not set. Check the UA trace log for detailed error information. For UA servers the application has to catch exceptions and so gets the exception information. |
| HostInfo | Server access information ( domain, user, password ) |
 | onNotifyUntrustedCertificate | handler that is called when the server certificate is untrusted |
| ServerName | Name of the connected HDA server |
| UaAppConfigFileAutoCreate | If not null then an application configuration file is created unless it already exists. The defined name is used as the appliction name. |
| UaConfigFileName | With UA option only. The name of the file with the UA client configuration. The name can be an absolute file path or a file name relative to the application executable directory. When the class instance is created the name is set to xxx.Ua.Config.Xml with xxx being the name of the application executable. The application can overwrite the name before Connect() is called. |
| UaNamespaceURIs | NamespaceURIs that match the NodeIDs persisted in the client application. If the application doesn't set this property before Connect() then the URIs are tried to be loaded from the file app.url.XML in the same directory as the app.exe executable. url is the UA server URL without the xxx:// This XML file is auto-generated at Connect() if the application didn't set this property. |
| UaTraceMask | Mask of enabled UA trace events |
| uaWrapper | With UA option only. UA wrapper instance. The applicaiton can use this link to access UA wrapper methods directly. The link is null for instancs of non-UA servers. |
| Version | Version number of the HDA .Net Wrapper |
Public Methods
| Name | Description | |
|---|---|---|
 | AdviseProcessed | This asynchronous function computes the aggregate values, qualities, and timestamps from the history database from the specified start time at the interval for one or more items. This function is intended to be used to update the client software with new data as it becomes available; e.g., update a trend with new data on a periodic basis. The results are returned via the client's DataChange event handler. |
| AdviseRaw | This asynchronous function reads the values, qualities, and timestamps from the history database from the specified start time at the update interval for one or more items. This function is intended to be used to update the client software with new data as it becomes available; e.g., update a trend with new data on a periodic basis. The results are returned via the client's DataChange event handler. |
| CancelAnnotations | This synchronous function cancels the outstanding operation. The actual implementation is server specific, but the server shall respond via the client's CancelComplete event handler. |
| CancelPlayback | This function cancels the outstanding operation. The actual implementation is server specific, but the server shall respond via the CancelComplete event handler. |
| CancelRead | This synchronous function cancels the outstanding operation. The actual implementation is server specific, but the server shall respond via the client's CancelComplete event handler unless a FAILED error code is returned from the call. If a FAILED error code is returned, there will be no callback to the client's CancelComplete event handler. |
| CancelUpdate | This synchronous function cancels the outstanding operation. The actual implementation is server specific, but the server shall respond via the client's CancelComplete event handler. |
| ChangeUser | Signal the server that the client has changed the user credentials of its proxy blanket. |
| Connect | Overloaded. Connect to the named OPC Server on the named machine |
| ConvertToSystemType | Converts a VarEnum to a system type |
| CreateBrowse | Overloaded. DEPRECIATED! This synchronous function creates a new OPCHDA_BROWSER object. The filters will be applied to all method calls to this instance of the browser. The server is expected to validate the filter arrays. The server must support a single client having simultaneous access to multiple browse interfaces. Filtering is optional behavior for a server. If a server does not support filtering, or only supports filtering on some of the requested attributes, the server shall return an interface to a browser which is only filtered on the accepted attributes. A server which does not support filtering shall return a pointer to an unfiltered browser interface. Filter operations are additive. To successfully pass filter criteria, the item must successfully satisfy all of the filter criteria. Implementation of filtering and browsing is server specific, however it is anticipated that servers with hierarchical name spaces may only apply filters to leaves, causing them to return branches which have no leaves which satisfy the criteria. It is anticipated that a client may create one browser to locate a particular area of the hierarchy, obtain a fully qualified branch name using GetBranchPosition, then pass that branch name to another browser which is using a different filter set. Servers may optionally support wild cards for string filters. To represent a single character the “?” shall be used. To represent multiple characters the “*” shall be used. |
| DeleteAtTime | Overloaded. This asynchronous function is intended to be used to delete specific data from the history database; e.g., lab data that is incorrect and cannot be correctly reproduced. The results are returned via the client's UpdateComplete event handler.
This function deletes the values and qualities in the history database for the specified timestamps for one or more items. |
| DeleteRaw | Overloaded. This asynchronous function deletes the values, qualities, and timestamps from the history database for the specified time domain for one or more items. This function is intended to be used to delete data that has been accidentally entered into the history database; e.g., deletion of data from a source with incorrect timestamps. The results are returned via the client's UpdateComplete event handler. |
| Disconnect | Disconnect from the OPC server. The COM interface are released. All browser interfaces created for this server object are released. |
| GetAggregates | This synchronous function returns the list of aggregates supported by the server. The OPC defined aggregates are defined in specification section 5.3.3. Vendor specific aggregates also are supported. The vendor supplied aggregates are made available to allow the client to use all the functions available to their specific server. If no aggregates are supported, the function shall return a count of 0 and NULL pointers. |
| GetErrorString | Overloaded. Return the description for the specified error. If any error occurs a ThrowExceptionForHR is thrown. |
| GetHistorianStatus | This synchronous function returns the information on the current status of the server. The start time is optional and may be returned as a NULL pointer. |
| GetItemAttributes | Overloaded. Depreciated. This synchronous function returns the item attributes supported by the server. The OPC defined attribute types are defined in specification section 5.2. Vendor specific attributes also are supported. The vendor supplied attributes are made available to allow the client to access and display vendor specific information. Attribute data types are intended to allow query filtering when browsing item ids. If no attributes are supported by the server, the function shall return a count of 0 and NULL pointers. |
| GetItemHandles | Given a list of ItemIDs and client handles, this function returns the server handles for each item. The returned server handles must be used in all requests to read or update history. The supplied client handles are included in the returns of all read and update requests. |
| GetLocaleID | Get the current default LocalID. ( IOPCCommon::GetLocaleID ) |
| Insert | Overloaded. This asynchronous function inserts values and qualities into the history database for the specified timestamps for one or more items. If a value exists at the specified timestamp, the new value shall not be inserted; instead errors shall indicate an error. This function is intended to insert new values at the specified timestamps; e.g., the insertion of lab data to reflect the time of data collection. The results are returned via the client's UpdateComplete event handler. |
| InsertReplace | Overloaded. This asynchronous function inserts or replaces values and qualities at the specified timestamps for one or more items. If the item has a value at the specified timestamp, the new value and quality shall replace the old one. If there is no value at that timestamp, the function shall insert the new data. This function is intended to unconditionally insert/replace values and qualities; e.g., correction of values for bad sensors. The results are returned via the client's UpdateComplete event handler. |
| IsAvailableNT | Query the current security configuration of the OPC server to determine if the current server configuration provides OPC Security by NT credentials. |
| IsAvailablePriv | Query the current security configuration of the OPC server to determine if the current server configuration provides OPC Security by private credentials. |
| isConnected | Indicates if this client did connect to the OPC server. It doesn't mean that the server is accessible. The server connection may be interrupted or the server terminated. |
| Logoff | Remove the private credential established by the previous call to Logon(). OPC Security reverts to the state before the first call of Logon(), there are no private credentials active for the client. |
| Logon | Changes the identity of the client application’s user. Future access to any security objects will be authorized with the new user’s credentials until a subsequent call to Logoff() or Logon(). For OPC Servers which also implement IOPCSecurityNT, access checking with NT credentials will be disabled until Logoff() is called. |
| QueryAvailableLocaleIDs | Query the LocaleIDs supported by the OPC Server. ( IOPCCommon::QueryAvailableLocaleIDs ) If any error occurs a ThrowExceptionForHR is thrown. |
| QueryCapabilities | Overloaded. public int QueryCapabilities( out UpdateCapabilities capabilities ) |
| QueryMinImpersonationLevel | Information method to help a client to determine the minimal impersonation level the server requires to gain proper access to secured data sources. |
| ReadAnnotations | Overloaded. This asynchronous function reads the annotations from the history database in the specified time domain for the specified item IDs. This function is intended to read annotations for an item at specified timestamps. The results are returned via the client's ReadAnnotations event handler. |
| ReadAtTime | Overloaded. This synchronous function reads the values and qualities from the history database for the specified timestamps for one or more items. This function is intended to provide values to correlate with other values with a known timestamp. For example, the values of sensors when lab samples were collected. |
| ReadAttribute | Overloaded. This synchronous function reads the attribute values and timestamps from the history database for the specified time domain for an item. If the current values for the attributes are desired, startTime shall be set to "NOW" and endTime shall be null (Nothing). |
| ReadModified | Overloaded. This synchronous function reads the values, qualities, timestamps, user ID, and timestamp of the modification from the history database for the specified time domain for one or more items. The purpose of this function is to read values from history that have been modified/replaced. If ReadRaw, ReadProcessed, or ReadAtTime has returned a quality of OPCHDA_EXTRADATA, indicating that there are values which have been superseded, this function reads those values which were superseded. Only values that have been modified/replaced or deleted are read by this function. |
| ReadProcessed | Overloaded. This synchronous function computes aggregate values, qualities, and timestamps from data in the history database for the specified time domain for one or more items. The time domain is divided into subintervals of duration resampleInterval. The specified aggregate is calculated for each subinterval beginning with startTime by using the data within the next resampleInterval. This function is intended to provide values calculated with respect to the resample interval. For example, this function can provide hourly statistics such as Maximum, Minimum, Average, etc. for each item during the specified time domain when resampleInterval is 1 hour. |
| ReadProcessedWithUpdate | The playback functionality of a History server provides the capability to get an initial set of data from the History server and then get continual updates of historical data. This is different than the Asynchronous Advise methods in that those methods are centered around the current time. The playback interface supports methods that retrieval data from the past and then supply updates from stored data. Typically the updates are sent at a rate that is more frequent than the time the data was stored. For example, the request could be to send 10 minutes worth of data every minute. This operation initially retrieves data from the start time to the end time. After the initial response it periodically (every updateInterval) responds with numIntervals worth of data divided into resampleInterval sized bins. The time of the last value returned in the initial response is used as the start time for the first update. After that, the time of the last value returned in an update is used as the start time for the next update. This function is intended to be used to playback processed history data. By controlling the update interval, the data can be displayed on trends in real time, in slower motion, or faster than real time. The results are returned via the client's Playback event handler. |
| ReadRaw | Overloaded. This synchronous function reads the values, qualities, and timestamps from the history database for the specified time domain for one or more items. When 'bounds' is TRUE, the bounding values for the time domain are returned. This function is intended for use by clients wanting the actual data saved within the historian. The actual data may be compressed or may be all data collected for the item depending on the historian and the storage rules invoked when the item values were saved. The optional bounding values are provided to allow clients to interpolate values for the start and end times when trending the actual data on a display. |
| ReadRawWithUpdate | The playback functionality of a History server provides the capability to get an initial set of data from the History server and then get continual updates of historical data. This is different than the Asynchronous Advise methods in that those methods are centered around the current time. The playback interface supports methods that retrieval data from the past and then supply updates from stored data. Typically the updates are sent at a rate that is more frequent than the time the data was stored. For example, the request could be to send 10 minutes worth of data every minute. This function is intended to be used to playback raw history data. By controlling the update interval, the data can be displayed on trends in real time, in slower motion, or faster than real time. This function initially retrieves data from the start time to the end time. After the initial response it periodically (every updateInterval) responds with an updateDuration amount of data. The time of the last value returned in the initial response is used as the start time for the first update. After that, the time of the last value returned in an update is used as the start time for the next update. The results are returned via the client's Playback event handler. |
| ReleaseItemHandles | This synchronous function releases associations between server handles and client handles for specific HDA items. |
| Replace | Overloaded. This asynchronous function replaces values and qualities in the history database at the specified timestamps for one or more items. If no value exists at the specified timestamp, the new value shall not be inserted; instead errors shall indicate an error. This function is intended to replace existing values at the specified timestamp; e.g., correct lab data that was improperly processed, but inserted into the history database. The results are returned via the client's UpdateComplete event handler. |
| SetClientName | Define a client name. ( IOPCCommon::SetClientName ) |
| SetLocaleID | Set the default LocaleId for this session. ( IOPCCommon::SetLocaleID ) |
| ValidateItemIDs | This synchronous function validates that specific HDA item IDs are known to the server. |
| WriteUaLog | For internal use only. The method is called from the UA Option to pass trace notification to the application. |
Public Events
| Name | Description | |
|---|---|---|
 | ShutdownRequested | ShutdownRequest Event Handler |
| UaTraceNotification | UA Trace Notifcation |