Hi Fra,
thanks for mentioning the tip on stopping the RA motor via FS2 commands!

Concerning Your question

Does anyone know if it is really mandatory that fs-2 has version 1.26? Maybe can be related with all of the problems?

the AstroElektronik versions page states the following change with version 1.21 (May 3, 2002)

V1.21 Fehler korrigiert: Die Ausführung der LX200 Befehle :Qn und :Qs war nicht korrekt.

translating to "corrected error: incorrect execution of commands :Qn and :Qs".
These slewing commands (north and south) might be relevant for smooth operation. :whistle:

Another problem had been tackeld with version 1.25 (sep 22, 2004):

V1.25 Fehler beseitigt: In allen bisherigen Software-Versionen war ein Fehler der sich so bemerkbar macht: Wenn eine höhere Betriebsspannung als 12V verwendet wird und wenn M2_Freq2 auf 0 Hz eingestellt ist, dann gibt es manchmal einen kleinen Ruck wenn der Deklinations-Motor anhält. Das fällt insbesondere dann auf, wenn die Getriebeuntersetzung klein ist, und wenn mit einer kleinen Korrektur-Geschwindigkeit gearbeitet wird.

stating that under certain circumstances the Dec motor would trip resulting in a small image shift.

So my conclusion would be to upgrade to the most recent version (well recent meaning version 1.26 dating from dec 21, 2009). Upon request Michael Koch will send You an eeprom with the latest version for small money (used to be less than € 20 including postage within Germany). Exchanging the chip is no problem due to the socket on the "mainboard" that is being used.



Hellriegel replied to the topic 'USB hubs - a never ending story' in the forum. 4 years ago

stash is correct about the power consumption of DSLRs as well as all separately powered devices draw hardly any current from the hub.
However beware that non-powered USB2 devices can draw up to 0.5 A and USB3 devices up to 0.9A per port. Using a 10 port hub with a 2.5A power supply might be on the low side.
To complicate things even more the USB-C connector (which I have not seen on astro devices yet but only on cell phones and tablets) may draw up to 3A per port. So don't charge Your cell phone from the same hub when using it for internet connections ;-)

And to top all this: USB-PD (USB Power Delivery) may request 5V, 12V or even 20V and up to 5A (= 100W max power) from the charging device! These values are considered for USB connected displays for example. But it will take some time before we see devices like these at our telescopes.


Hi Chris,
I put the answer to Your question on a new thread .



Hellriegel created a new topic ' USB hubs - a never ending story' in the forum. 4 years ago

This is an answer to a question calberts asked in a thread on FS2 controllers . I Thought it better to open a new thread to answer.

Hi Chris,

USB hubs (or rather USB as such) are a major and most annoying topic. You will find an number of concerning topics in this forum

Only recently we tested 7 different powered USB hubs (USB2 as well as USB3) connected to the controlling PC of our public observatory and than connected to two different Fujitsu laptops, all running KStars/EKOS/INDI
The hubs were connected to the PC/laptops by high qualitiy "active" 3m USB2 and USB3 cables which had been tested successfully separately with every single device. The hubs then were step-wise "loaded" with a Canon 750D, a QHY5LII mono, a MGen autoguider, and a SonyA7II - no mount controller was attached since that worked over a RS232 serial connection. But I found mount controllers are a minor issue on hubs.

Result of our tests: only 3 out of 7 hubs worked at all with all devices attached (one USB3 hub, the two others were USB2) - but only one of the USB2 hubs worked satisfying when connected to the laptops as well!
Connected to the laptops one or another hub would work with more or less devices attached. Some hubs worked part-time with only some of the devices connected, some combinations of hub and devices failed completely. Different USB cables between hub and devices were tested and these obviously come in different qualities as well. Starting streaming from the QHY also seemed to degrade the stability of the connections. And to some extent bugs or some kind of sensitivity on the side of the INDI drivers might as well interfere and stop devices from working at all.

Our results which, i am afraid, will differ from those of others with different setups, are as follows:
USB2 tends to be more stable/reliable with most devices; hub power should be at least 3,5A at 5V. Use high quality cables as well. The male connectors should fit firmly and not shaky. And make sure not to use a mere charging USB cable! (Happened to us while testing) ;-) Streaming devices should connect directly to an USB port at the PC. We believe one has to try out combining material until it works reliable - and that may change with an additional device.

I still wonder how people get these USB devices to work, especially cameras, connected to a RasPi?!

PS: At our observatory we changed to a compact € 300 PC with 10 USB ports that are connected to two internal hubs (USB2 and USB3) and use long (>= 2m) USB cables to connect to the devices. (OK, one USB hub is used to power some cross-hair LEDs).



I confirm this problem.

Only when using the virtual mount controller and manually repositioning the mount closer to the destination coordinates (looking at a highly enlarged KStars view) the status of the mount changes from "slewing" to "tracking". From what I see in my logs Herrhausen has precisely described the probable cause.

At present I have no working setup therefore I can only give some speculative thoughts on this:
- in the FS2 configuration menu there is a choice between two different formats for RA/Dec coordinates. Possibly the selected format has an influence on how the FS2 tries to reposition.

@ Herrhausen: did the lx200basic always successfully change to tracking on consecutive slews? (Just wondering?!)



Thank You, Eric, for clarifying.
And yes, sometimes user don't behave as expected ;) - I ought to know after having developed user applications for some years long ago.


Hi Eric,
thanks for replying that fast.

How do you observe that the hour angle is offset?

My mount is parked at the meridian at DEC 0° and synchronized with KStars at that position. Comparing the actual sky with the sky map of KStars already showes the offset.

Is your real location really matching the geographic location setting in KStars ?

Well, at first look: yes it did. My location is 8° 30' east of Greenwich which I entered as -08 30 in the KStars location settings (as used to from other software).
Considering Your second question it struck me that if the minus sign was ignored the result would be the sky view shifted in KStars by about 17° which would result in an correct view.
Playing around with the longitude value in the locations settings I finally recognized that positions east of Greenwich are not indicated by a minus sign - that's all. Problem solved - Just another user error.
It might be a good idea to supplement the longitude tooltip with something like "Locations west of Greenwich must be prefixed with a minus sign"

CS Michael


I came back to KStars/Ekos/INDI just a couple of weeks ago.

Present Problem:
The KStars star map is 1h (15°) late with respect to the meridian. I.E. the hour angle of every object on the star map is off by -1 h.
I checked the system time/date information using the timedatectl command that gave correct values:
=> timedatectl

  • Local time: So 2018-09-30 16:05:01 CEST
  • Universal time: So 2018-09-30 14:05:01 UTC
  • RTC time: So 2018-09-30 14:05:01
  • Time zone: Europe/Berlin (CEST, +0200)
  • System clock synchronized: yes
  • systemd-timesyncd.service active: yes
  • RTC in local TZ: no
Local time as shown in the upper left corner of KStars is identical to the above local time from timedatectl.
The geographic location settings in KStars are
  • UT offset: 1 (which is correct ignoring the Daylight Saving Time DST
  • DST rule: EU (European union - which is correct as well)
There is no GPS device involved and the INDI tab in KStars settings has "KStars updates all devices" marked.
My mount controller (Astro-Electronic FS-2) does not communicate date/time to KStars

So, where is the cause of my problem?
I would be glad if anyone had any suggestion for me ;-)