I had a pier crash yesterday night with the ASIAIR on my Astro-physics AP900 mount, due to meridian flip failure.

At first I though that it was a DST setting issue, but DST is turned off on the mount. I think there's an issue with the new ASIAIR firmware.

If I power on the mount with the mount controller connected but not the ASIAIR, the controller displays the correct settings: local time is correct (not taking DST into account), local sidereal time is correct, time zone is correct.

If I power on the mount with the ASIAIR connected but not the controller and connect the controller afterwards, the controller displays wrong settings : the UTC time is one hour ahead of local time instead of being one hour behind. In other words, time zone +1 E has been switched to +1 W in the mount controller when the ASIAIR synced to the mount. As a result, the local sidereal time is off by two hours.

I had used this setup for almost a year, without any meridian flip failure so I believe the new firmware is the culprit. There's nothing special in my workflow: PA, GOTO to target, guiding on, AUTORUN for the whole night with meridian flip enabled.

Another (probably unrelated) bug with the new firmware is that the autoguide calibration data does not seem to be stored anymore.

Thanks for your help!

Dan

  • w7ay replied to this.
    3 months later

    Hi,

    after more than two months I did not manage to solve those problems. I have reinstalled the app and the OS, nothing changed. The time zone information sent by the ASIAIR to the mount is wrong. Calibration data is still lost after power off.

    Does anyone has a clue or is it a "lost cause"?

    thanks !

    Dan

    dan_paris In other words, time zone +1 E has been switched to +1 W in the mount controller when the ASIAIR synced to the mount. As a result, the local sidereal time is off by two hours.

    I believe this is caused by a bug that I mentioned many months ago (perhaps more than a year), where ZWO coders did not distiinguish between the C trunc() function [the default C language casting from floating point numbers to integers] and the C round() function [that you have to explicitly call]. The two functions treat negative numbers between -1 and 0 differently from numbers between 0 and +1.

    I.e., the problem affected those who live between the Greenwich (prime) Meridian and 1º East longitude.

    I believe it was originally observed by some (professional) astronomer who stayed near Cambridge, England, and got move to the other side of the Greenwich meridian :-). He probably abandoned ASIAIR after that :-).

    It is amazing that after all these years that ZWO still has no idea how to fix the problem.

    Just keep pestering ZWO until they fix the bug. In the meantime, just use a different software that are written by people who know what they are doing.

    Chen

    Thanks Chen, it may indeed explain the problem, although my longitude is 2° East. One clue, maybe, is that the location transmitted by the ASIAIR to the mount, rather than being 2° East, is 358° West. I should be the same but who knows ?

    A first mystery is why the problem appeared last spring, after many months of successful use.

    A second mystery is why it occurred exactly at the same moment as a seemingly unrelated issue (guide calibration data not recorded anymore).

    I am wondering what @PMTeam@ZWO and @Tech@ZWO think about that?

    best regards,

    Dan

      dan_paris rather than being 2° East, is 358° West

      Ah, that is yet another long standing bug in ASIAIR -- not knowing there is a wrap around at the International Date Line. Modulo arithmetic mod 180º.

      It is funny because there is something in Number Theory called the Chinese Remainder Theorem, which depends on modulo arithmetic of relatively primed moduli :-).

      Chen

      8 days later
      16 days later

      any help @PMTeam@ZWO or @Tech@ZWO ?

      Thanks a lot !

      7 days later

      Any ideas @PMTeam@ZWO and @Tech@ZWO? Or should I put away my ASIAIR for real? :

      Thanks for your help,

      Dan

      a month later
      8 days later

      Still no solution since almost six months... is there still anyone from the ZWO staff around?

      Thanks,

      Dan

      21 days later

      bump

      Is there still anyone from ZWO team around on this forum?

      PMTeam@ZWO @Tech@ZWO

      Could you please post in here about this issue? This is a pretty major one as outlined by @w7ay .

      Is this issue being worked on?

        Unfortunately, it seems that @PMTeam@ZWO and the rest of the staff have left the boat...

        Corsair

        I've pretty much given up on expecting MF to work with the Air and my AM5. I've resorted to setting my iPad date/time to UTC. I suspect the issue with "go away" when we move off of DST in November. But really want this fixed. I can't leave my mount unattended because of this.

        @hyiger The problem I am reporting is not a DST-related issue I believe (otherwise I'd be off by one hour rather than two hours). And it won't explain the autoguide calibration problem.

        Really wish @Tech@ZWO and @PMTeam@ZWO would follow this up.

        Daresay we are due for an update to the ASIAIR, soon.

        Or perhaps @Walf@ZWO since the rest of the ZWO staff apparently left this forum?

        Went to the ZWO website and saw the pop up for closure for National Day. They won't be back until October 6th at the earliest.

        13 days later

        @Tech@ZWO @PMTeam@ZWO

        Please keep an eye on this bug, too. Could well be related to some of the other bugs being reported.