FCUSB Disconnect

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Jon
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FCUSB Disconnect

Post by Jon » Sat Aug 10, 2013 12:29 pm

I recently installed my FCUSB on my windows 7/64bit desktop to check operation of my JMI motofocus. The FCUSB seemed to install properly and the newly installed FocuMate software recognizes it. After it was first installed, it seemed to work fine except when I try to slow the motor speed down. Then, the FCUSB disconnected for some reason. The system reconnects when told to "connect" in the focusmate software and running the motor shows movement in the on screen focus position in the software but, the motor does not move and after a few seconds, the "disconnect" notification comes up. Now, the focusmate software indicated FCUSB found! when initialized but, when trying to run the motor, it loses it's connection all the time.

So, I checked out the motor and connections using my hand box and the system works as advertised. The power light is on on the FCUSB, The USB connection is not lost. and the mini jack cable works fine with the hand box.

Any suggestions?

dpanderson
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Re: FCUSB Disconnect

Post by dpanderson » Sun Aug 11, 2013 5:11 pm

Does it only lose connection when trying to run at slow speed? If so, I suspect the motor may be taking enough current that it sags the voltage and resets the FCUSB. If you have a powered USB hub (one that has a separate power supply that plugs into a wall outlet) and see if that helps.

We might also want to try a different FCUSB. Drop an email to me at doug@shoestringastronomy.com
Doug Anderson
Shoestring Astronomy
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Hata
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Re: FCUSB Disconnect

Post by Hata » Sat Dec 07, 2013 10:16 am

I also met the same problem and found that it will be a lot of improvement if the power is from AC outlet.

If using NB battery, change to another USB port is no any improvement to me.

Don't have a chance to add a powered USB hub now.

For your reference.

Hata

bambula50
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Re: FCUSB Disconnect

Post by bambula50 » Sun Jan 24, 2016 12:05 pm

Hello,

I observe very similar issue with my FCUSB device connected to JMI Motofocus for Celestron C11. When I press "Motor Full" or "Motor Click/Hold"-type button in FocusPal window quite often tool lost connection with FCUSB box - I get disconnection message but motor is still turned on, FCUSB does not react to "Motor Off" button and LED is permanently green (instead of being red). FCUSB is powered by D-Link DUB-H7 USB hub with external power supply (5V/3A). I measured power parameters on USB socket which FCUSB is connected to - it is 5.08-5.12V and current 50-60mA when motor is turned on. D-Link hub is attached to "master" Windows7 computer (where FocusPal tool is installed on) via 3-meter long active USB repeater (Vivanco USB 2.0 Extender). Do you know what is wrong ? How can I solve my problem ?

Best regards,
Mario

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Re: FCUSB Disconnect

Post by dpanderson » Sun Jan 24, 2016 12:42 pm

Mario,

Anything you can do to reduce the amount of cable of the power supply for your hub and the USB cable between hub and FCUSB should help. When the motor first turns on, it takes a surge of current which then creates a voltage drop across long cables. If the voltage at the FCUSB gets too low during this surge, it will reset itself and its connection to the computer.
Doug Anderson
Shoestring Astronomy
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bambula50
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Re: FCUSB Disconnect

Post by bambula50 » Sun Jan 24, 2016 1:35 pm

Hello Doug,

Thank you very much for your suggestions - I'll do some tests ASAP. From the other side I found something like buffer for my Motofocus: http://astrolabo.com/2008/06/12/raliser ... -9-ou-12v/ (article in French :D ). Fact is that my JMI Motofocus is originally controlled by hand controller powered by 9V battery (when I press any button on it there is 8.3 - 8.4V voltage on motor, in opposite of 5V delivered by FCUSB). Does it make sense to built such buffer in my case ? Additional benefit is to separate power lines. What is your opinion ?

Best regards,
Mario

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Re: FCUSB Disconnect

Post by dpanderson » Sun Jan 24, 2016 1:55 pm

Yes, the buffer you mentioned should definitely help.
Doug Anderson
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bambula50
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Re: FCUSB Disconnect

Post by bambula50 » Sun Mar 06, 2016 12:29 pm

Hello Doug,

I spent whole February for tests and building of buffer/driver circuit. I need to say that after driver assembly JMI motor works much, much better - it has significantly more power to rotate focuser knob. Unfortunately driver circuit didn't resolve 'disconnection' issue. Many times FCUSB device is not recognized by my 2 computers (no-name and HP), even if device is connected to USB 3.0 hub through 1.2m cable (this hub is directly connected to PC through 0.5m cable). I tested 4 different hubs and negative results are repeatable. Is it possible that FCUSB works properly only when it is attached to PC directly (HID limit) ?

Best regards,
Mario

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Re: FCUSB Disconnect

Post by dpanderson » Sun Mar 06, 2016 1:36 pm

Hi Mario,

I've not heard of a situation like yours in the 10 or so years we have been selling the FCUSB. Maybe we should try a different FCUSB to see if perhaps yours has an issue. Please email me at doug@shoestringastronomy.com with your shipping address.
Doug Anderson
Shoestring Astronomy
http://www.ShoestringAstronomy.com

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