Hi,
   In the course of debugging and adding features to the new FivePoint
script today, I learned from Ralph Marson that the new observe command
that blocks until the telescope acquires the commanded position for
three timing events (TEs) is not yet completely implemented.  However,
they have reached the point where an "on-source" flag is being
computed.  There is a standalone script (PositionStreamClient) that
will display the value of this flag every TE (48 msec) along with the
commanded and actual azimuth and elevation and echo it all to stdout.
I was able to pipe the output of this to "awk" and compute the
position following error and send it to a file.  I then ran this
"recorder" during a FivePoint scan on each antenna. Some multi-page PDF
plots are attached.

   In both cases, the first page is an overview, and the later pages
are zoomed into the five transitions of most interest, and include the
value of the on-source flag. In summary it appears that the on-source
flag is mostly doing what you would hope.  The new FivePoint script
will inherit this functionality as soon as it is implemented.  In the
plots, one can also see some interesting servo vagaries, such as
ringing in the AEC azimuth acquisition, and a sawtooth pattern in the
Vertex elevation tracking.  In terms of overall tracking quality, I
would not call it "good", particularly when compared to an SMA
antenna.  In both cases, the elevation was moderate (33 degrees), and
azimuth error has not been corrected to cross-elevation.

Todd