Reported by 952:
This is needed to map EDD Bit_Enumerated variables to OPC UA but we agreed that it may be of general interest.

An OptionSet consists of an array of { Bit#, Label/Name }
Variables of this type will have the DataType ArrayOfBool where each Bool represents one Option (one Bit).
The EnumStrings property is used to specify the label/name for each Bit# (the string is empty for Bits that have no meaning).
Sub-variables may be exposed for each array element where the BrowseName is "Bit_#", the DisplayName is the label and the Value is the Bool.