This OPC UA Variable of DataType UtcTime belongs to the Variable LastScanData and represents the point of time the last AutoID Identifier was scanned. The value of this Variable shall be equal to the SourceTimestamp of the Variable LastScanData.
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 UtcTime. 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.