ConfigChannelHandler

This chapter describes the class ConfigChannelHandler that contains public methods such as synchronous and asynchronous requests.

The ConfigChannelHandler class contains the following public methods:

  • setOnDataReceivedHandler - Sets handler to handle logical operations related to configuration.
  • _waitForDone - Waiting for the main threads to complete. The CommonBackend class calls this for you.
  • processPacketsReceivedDuringSynchronousRequest - Responses received during a xxxSynchronously(); request that are not the expected response are buffered. Requires that setOnDataReceivedHandler must be called before.
  • _getFrontendApiVersionSynchronously - Requests frontend API version, called by the CommonBackend class, no need to be called manually.
  • _sendBackendApiCompatibility - Sends backend API compatibility level after comparing frontend and backend versions, called by the CommonBackend class, no need to be called manually.
  • _requestFrontendApiVersion - Requests frontend API version, called by the CommonBackend class, no need to be called manually.

Synchronous requests:

  • requestDatabaseParametersSynchronously - Requests the parameters of the database specified in the project in the Database Engineering panel (database address, user, password, database name, and specific database options).
  • getWinCcOaSystemOfFrontendSynchronously - Requests information about the system of the WinCC OA project. The response contains the name and number of the system.
  • requestArchiveGroupDeltaSynchronously - Requests the list of archive groups in the database and WinCC OA.
  • requestMetadataDeltaSynchronously - Requests the list of data points (name, type, archive group, etc.) in WinCC OA
  • requestRedundancyInfoSynchronously - Requests the current state of the redundancy.
  • amI_RBackend - Requests if the backend is redundant.

Asynchronous requests (the response is received in the callback set via external handler: setOnDataReceivedHandler, onWriteRequest, etc.):

  • requestDatabaseParameters - Same as requestDatabaseParametersSynchronously.
  • requestMetadataDelta - Same as requestMetadataDeltaSynchronously.
  • requestArchiveGroupDelta - Same as requestArchiveGroupDeltaSynchronously.
  • getWinCcOaSystemOfFrontend - Same as getWinCcOaSystemOfFrontendSynchronously.
  • requestRedundancyInfo - Same as requestRedundancyInfoSynchronously.
  • requestRedundancyBackendType - Same as amI_RBackend.
  • requestValuesNewerThan - Requests values from the Frontend that have been changed since the last timestamp is written.
  • requestCurrentAlerts - Requests current alerts from the Frontend.
  • sendArchiveGroupNextBackupUpdate - Sends the time of the next predictable backup according to the settings of the archive group.
  • sendSegmentMetadataList - Sends lists of segments with actual states to the Frontend.
  • sendMonitoringUpdate - Sends information about the state of the backend (database connection, errors, information about the last error, etc.) for display in the WinCC OA UI.
  • _doLogMessage - Directly send a log message. Use CommonBackend::getLoggingInterface() instead.

For more information, see Database parameters, Wincc OA project system information, Metadata, Last values DatabaseActivityMonitor handlers and DataReceivedHandler.