Nikon DTM-350 Instruction Manual page 146

･When uploading a duplicate point that has been already referred to by
a Station or Backsight, the "!Duplicate PT" error is shown and that Pt:
name/ number is informed. (See p.8-9)
･When the duplicate point is *not* referred to by a Station or Backsight
and the point type is UP/CC/MP, then that point will be automatically
overwritten by the new uploaded point.
･Even if the duplicate point is *not* referred to by a Station or
Backsight, the point will not be replaced when the point type is a SS/
SO/CP measurement record.
3
3-118