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Skywatcher HEQ5 & SNPro 6.4.3 discrepancy

For whatever reason, there is a 10 to 15 arc minute west + RA and 8 to 14 arc minute
south neg Dec discrepancy between where my Skywatcher HEQ5 scope (Version 3.27
of the SynScan hand controller firmware) is pointing at and where SNP 6.4.3 Mac shows
it's pointing at in the main window. For example, I do a single star alignment with the
hand controller on Alpheratz and have it centered perfectly in the Cameras FOV attached
to the scope. I have a USB to Serial port converter plugged into the Mac and then have
the RJ-12 cable plugged into the Hand Controller. In the "Telescope" tab, I click on
"Configure" button, select the device, which port to use and telescope interface, which
succeeds fine. Then click on the "Connect" button and it talks to the mount to get the
current position. In the SNP window, it always shows the white "Position circle" being
offset about 13 arc minutes to the west and about 8 arc minutes south.

The hand controller shows Alpheratz as being at:
RA 00h 08m 30 sec
Dec +29° 05' 54"

and SNP says it's at:(for J2000 coordinates)
RA 00h 08m 23.2s
Dec 29° 05' 25"

So there should be less than 1 arc minute of discrepancy between where they say it is -
but it's way off in where SNP points too.

I have tried doing 2 and 3 star alignments with the HEQ5 and it makes no difference at
all. Using the HEQ5 Hand Controller, I can slew to various objects and all of them are
always within 5 arc minutes of Center.

With SNP, it's 10 to 15 arc minutes west and 8 to 10 arc minutes off when slewing to
other objects.

The HEQ5 mount and SNP have the exact same date, time , DST, Time Zone data
entered and exactly the same Long and Lat coordinates entered for this location, so that is
not a factor.


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