This OPC UA Variable represents the last scanned AutoID Identifier. The DataType can be one of the DataTypes defined in the ScanData Union defined in 9.4.2. Due to the use case for limited OPC UA Clients, the DataType is normally String or ByteString.
The Variable can be provided for simple applications where OPC UA Clients are limited to Data Access functionality. Such OPC UA Clients are typically limited to built-in DataTypes like String or ByteString too. The use of this Variable implies the following restrictions.
- Only one AutoID Identifier can be delivered for a scan.
- The frequency of scans is limited to the sampling interval set by the OPC UA Client.
- The delivery of scan results depends on the MonitoredItem settings or Read behaviour of the OPC UA Client.
It is recommended that complex applications use scan Methods and Events.