Spectra Precision FAST Survey Reference Manual - Manual (Page 129)

p127
Entering point 2 as a target leads to presentation of the coordinates for 2. Since this is an "angle-only" measurement,
turn off the slope distance "SD" option and turn off the "Use Known Elev" option. The "Zenith Angle" option is also
irrelevant but can be left on or off. The goal of Observations is to load in advance all targets that will be used for the
multiple backsight measurement. So if in this case, our goal is to backsight control points 2, 3 and 4, we would select
those point IDs. Note that if the current job contains no points 2, 3 and 4, then you can simply enter them as targets, and
the program will automatically find them in the control file where they don't exist in the current job. However, if the
current job contains points 2, 3 and 4, you would need to use the "From List" icon to the immediate right of the Target
prompt and then select the "Control" file option at the top of the List Points dialog as shown below. This ensures the
selection of point 2 from the control file.
The process of loading, in advance, all targets to be used is then repeated for points 3 and 4. Additional points are
added by tapping the "Add" button shown below: