It seems the radio button widget doesn't have a binding for an infotable input. It has SelectedText, SelectedValue (base type as String) and SelectionChanged without base type.
The possible selections are configured by assigning a state definition (State) by selecting one of the defined states in the mashup environment. For example, if you have three running conditions for a motor (On/Off/Auto) and you wanted an operator to set the running condition, you would define a state definition with those three states. Then, that state definition could be used whenever you want to have an On/Off/Auto button on a mashup