BACnet bit strings data types are mapped to OPC UA Structure DataTypes derived from the OptionSet DataType defined in OPC 10000-5.

The OptionSet structure contains the field value as ByteString and the field validBits as ByteString. The validBits field indicates which bits in the field value are valid.

All DataTypes defined in this clause are derived from the OptionSet DataType and expose the list of bit names defined in the tables as 0:PropertyType OptionSetValues of the DataType node. The OptionSetValues 0:PropertyType provides an array of LocalizedText.