SG-4 subtle problems with USB - serial connection

Discussion in 'Specialty Cameras SG-4, AllSky, ST-I' started by Maneesh Yadav, Jun 22, 2017.

  1. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

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    I was having intermittent and incredibly annoying problems where, just as I was starting to get my SG-4 autoguider working programs start freezing. Using the SBIG SG-4 Interface software I could setup, test, expose, calibrate and (for awhile) track fine. Then out of the blue almost everything would work but if I tried "Start Autoguiding" the program would just freeze and become nonresponsive.

    I chalked it up to perhaps some flakiness of the software on my hardware setup. I then got the guider working in MaximDL through the ASCOM driver, everything was working (though the guiding seemed to be jumping too much) and after I tried hitting "stop tracking" all of MaximDL froze (I'm running 5.12 currently).

    Then I simply couldn't connect to the autoguider via either MaximDL or the interface software. When I tried connecting to the guider via interface software, I got a suspicious debug log(attached) that suggests windows really doesn't want to open COM5 where the guider is on. Resetting the computer seemed to allow me to connect again. I am going to try attributing this behavior to the serial to USB convertor, I'll pick up a FTDI US232R-10-BLK as the manual suggests; but I thought I'd ask if the driver devs have any insight or magic switches to help me solve my quite fragile interface to the SG-4 autoguider. I don't seem to see any firmware that I need to download if that is the cause.
     

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    Last edited: Jun 22, 2017
  2. Colin Haig

    Colin Haig Staff Member

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    A couple of suggestions for you:
    Download the latest FTDI driver:
    http://www.ftdichip.com/FTDrivers.htm

    Disable USB Selective Suspend under Windows Power Management on the serial port, the USB hub (if there is one), and the USB Root Hub.

    Disable Serial Enumeration (Device Manager, Ports (COM and LPT), and for each com port, on the properties, advanced tab)
     
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  3. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

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    Thanks again Colin!
     
  4. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

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    Woohoo!
    Using the US232R-10-BLK for the SG-4 and following Colin's advice on serial settings seems to fix the fragility of the connection to the autoguider. What a pathological thing to deal with, other USB to serial convertors work *for the most part*, they just blow up access to the COM port every 10 minutes or so.

    A a quick question, I tried using the ASCOM interface to the SG-4 through maximDL. I followed the advice here:
    https://diffractionlimited.com/help/maximdl/Autoguiding.htm
    https://diffractionlimited.com/help/maximdl/Autoguider_Troubleshooting.htm

    Using default settings and calibrating with maximDL etc. the guider seemed to be moving the haywire (the object moves out of field in under a minute). Using the supplied SG-4 software and turning guiding on that way I empirically get round stars in 10min exposures and the log file makes sense. I'm happy using the SG-4 specific software for now but it seems that MaximDL doesn't hook into the "push button"-ness of the SG-4 and uses it to guide like any other guiding camera. Is there a way to control the autoguiding from MaximDL to just make it easy to avoid having guiding on while slewing and letting things settle between exposures?
     
    Last edited: Jul 4, 2017
  5. Doug

    Doug Staff Member

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    It's not going to work. The SG-4 isn't designed for non-standalone autoguiding. The computer imaging capability is there just as an aid in focusing. Once you've figured out your focus position you don't need the PC anymore.
     
  6. Maneesh Yadav

    Maneesh Yadav Cyanogen Customer

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    Ah so I can just leave it in guiding mode, watch the light for status, and not worry about the SG4 locking on a star mid slew and moving the scope around madly?
     
  7. Colin Haig

    Colin Haig Staff Member

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    Maneesh, I'm glad to hear the advice worked, you're very welcome!
     
  8. Doug

    Doug Staff Member

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    It's not likely to latch onto a star that's a blurry line. That said, it also won't know to look for a new guide star. I'd suggest you stop guiding and restart it at the destination.
     
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