Application Control Application Control



This indicates detection of the OPC HDA IOPCHDA AsyncUpdate command.
OPC (OLE for process control), currently known as "OPen Connectivity", is a standards specification by the OPC Foundation designed for communication between multi-vendor devices and control applications. OPC Historical Data Access (OPC HDA) is used to exchange archived data, i.e. a data historian, as opposed to real-time data from field sensors.