A copy of a set containing Time of Flight data can be made with different units. This will not work with data that does not contain the correct fields (see the Open Genie reference manual for details).
Simply select an existing set from the left hand box, along with the desired units from the second box, and click "Ok". A new set will then be created and become the current set. The number of the resulting set is shown to the far left, i.e. "Set n =". In this case Set 4 is being created from Set 1 with Channel number units.