Testing the Pulsar controller
A few years ago I bought a custom-built mount from Jaques Suurmond in Zeeland.
The mount was old-fashioned, with a wormgear in R.A. allowing tracking
and guiding via a CCD camera. However, in Declination the mount allowed
only about +/- 1 deg excursion, for more one had to manually loosen a screw
and move the scope by hand. Herman ten Haaf has recently upgraded the mount
to a real Goto-mount, by adding a worm wheel also in Declination. He added
strong 24 V stepper motors. I checked out two different guiding systems
for the mount: The FS2 from Mr. Koch in Germany, and the Hungarian Pulsar
control. I decided for the Pulsar - mainly because it is being distributed
by a colleague of Herman here in the Netherlands, Peter Pulles (see http://www.ecliptica.org)
and because from reading the manual I got the impression that the FS2 would
not store the pointing positions of the telescope when switched off. The
Pulsar, on the other hand, does have a so-called "parking position" which
after power cycling lets me go back observing immediately. As I am dreaming
of a remote-controlled observatory, this functionality is vital.
30 Dec 2007, dvk
Anyway, a few weeks ago I reinstalled the mount in my observatory (see
http://www.koschny.de/The_Koschny_Observatory.html and navigate to 'Modifications
2007'. Herman still has my large telescope (a 16" Cassegrain) for some
mechanical modifications, thus I have mounted my small 102 mm William Optics
refractor on the mount.
Here is the log of me trying to start using the Pulsar controller.
Some time in November
I have put the mount on the pier. I plug in the cable between controller
box and R.A. and Dec motors. The power cable goes into a power supply from
Conrad Electronics set to 24 V, the hand controller is connected. I switch
everything on and - the mount moves as expected. Great! Not first light,
but first sound... The sound is interesting, by the way, it steps up in
octaves it seems. I unplug everything again.
22 Dec 2007
I put the cables properly in place, with the power supply located in my
little isolated room next to the telescope, as the power supply is not
rated for outdoors. Another check with the hand controller and it seems
Then I also connect a PC via and RS 232 cable. I download the control
software (release 2.59) from the internet at http://www.astronomy.hu/pulsar.htm.
I press 'connect' and it connects. Again, great! A little window pops up
with arrow buttons for N/S/E/W. I press them and the telescope visibly
moves. Then I go to the other window which shows all sorts of features,
e.g. the setup, a simulation of the handbox with all the shortkeys, and
more. The 'catalog' menu is empty. So I download catalogues and press 'Upload
catalogue'. However, even after it says that the upload was done, I can't
select anything in the catalog menues. Hm. Also, I realize that when I
press 'south' the mount moves 'north' and vice versa. The 'east' and 'west'
buttons seem to not work at all. After some pressing buttons nothing works
any more. I give up for today, as it has -4 deg C. Will have to play more
29 Dec 2007
It is clear - at least for a few hours. I take advantage of that and polar-align
my mount. Also, I did some reading and found the buttons for swapping N/S
and E/W directions.
30 Dec 2007
More time to play... I decide to go through the menu in the hand controller
and check all the items. I realize that there is no good instruction book
or user manual where this is documented in a systematic way. So I produce
my own table, which is available here. I find the buttons to change the
slew speed, again, I didn't really understand the description in the instructions
so it took me a while. But now I can switch between a fast 'slew speed'
and a slow 'adjustment rate'. It seems to me that this does not work properly
in the PC software which I downloaded from the internet - there are buttons
which are marked 'guiding', 'center', 'find', 'slew', but once pressed
I only get the small speed, I cannot go back to the fast one.
Concerning the catalog - now all the data is there, which I uploaded
the last time. So apparently it needs a power cycle to get the catalog
into the system.
Already my conclusions are clear - I expect the controller to be quite
good, I still have to learn how to use all the features and need a clear
night to do some 'goto' tests. I haven't even started to get into the Periodic
Error Correction, or tested the 'parking position', which is why I bought
this controller to begin with (that means that I can go to the parking
position, switch everything off, and come back a week later and after switchon
the mount knows where it is and GoTo's should work...).
The culprit is that the useage is - at least to me - not really intuitive
and a good user manual would have been comforting. An example: There is
a menu item 'Autostop global' and one 'Autostop loc.'. The second one comes
with the option 'RA limit ON/OFF' and one can anwer 'YES' or 'NO'. While
I assume that 'YES' means 'ON' this to me is not really unambigious. I
would have preferred a toogle between ON and OFF rather than YES and NO.
There are instructions both in German and English, but they are written
by users and I had the feeling they already know a lot about the useage
and thus did not write it down in a way that the beginner can understand
it. So, here there is room for improvement!
Having said that, I admit that Peter Pulles, who sold the controller
to me, even offered to come by and help me installing everything. I had
to try it myself, of course. But I think this is a great offer which I
will probably take up very soon. And, to be even more constructive, I have
put the document with the menu list and some instructions on line for others
to use too, see here
(created from a Word document). The table is not yet completely filled
in, I'll continue to do so as I go on.