Re: UPDATE: Serial port connectivity issues

Christopher Erickson

...and all sleeve busing fans replaced with ball-bearing fans!

Christopher Erickson
Consulting Engineer
Summit Kinetics
Waikoloa, HI 96738


From: ap-gto@... [mailto:ap-gto@...] On Behalf Of Steve Reilly
Sent: Monday, October 28, 2013 11:29 AM
To: ap-gto@...
Subject: RE: RE: Re: [ap-gto] UPDATE: Serial port connectivity issues

If the observatory is a fixed installation I couldn’t imagine running on anything else. The laptop is great for portability but limited as to what can be connected without using hubs and converters. I have all the serial ports I need and a bunch of USB 2/3 ports to choose from and can add more if needed. When I build an observatory computer the main consideration in motherboard choice is expansion slots. Forget the 2/3 PCIe slots for video cards, it’s not a gaming machine. 1 PCIe slot for video is plenty and then you need expansions slots for add-on cards to support Serial cards and USB cards. A prime example is one that would have say 3 PCI expansion slots and 1 or 2 PCI Express X1 slots.


I use an APC 7900 for remote power control but I’ve heard the less expensive Digital Loggers switch works well too. I keep power on all 4 PCs on 24/7 and laptop when using. Here in Virginia I average $200 a month for a 4,100 square foot home and observatory.


As for remote, many use IP addressable power control switches as mentioned above, I also have an IP camera that can pan and has ir that I can switch off when imaging. But you could also power off the PC and have it set in BIOS to start in the on state when power is restored. You can also wake by network. There are many ways to accommodate the needs of remote. But one this is certain, at least for me, if the observatory is a long ways remote, I’ll have someone that can reasonably respond nearby if needed in an emergency. Cause stuff happens.





From: ap-gto@... [mailto:ap-gto@...] On Behalf Of ngliatis@...
Sent: Monday, October 28, 2013 3:01 PM
To: ap-gto@...
Subject: RE: RE: Re: [ap-gto] UPDATE: Serial port connectivity issues



Hi Steve, 


I run the observatory on a DELL E6420 laptop. Which begs the a desktop PC better? Also:


- Do you power off all the telescope outlets after a session (cameras/focusers/mount) or leave it on?

- Do you power off the PC or does it stay on 24/7?

- If yes, what is the order?


Is there a standard way of operating a remote observatory or is it arbitrary? I think a lot of this depends on operating habits as well. 




---In ap-gto@..., <ap-gto@...> wrote:

Build a new PC as a backup  If you plan on building a PC use true PCI serial cards and forget hubs and converters. I use StarTech’s 4 port serial cards and have never had an issue. In fact my observatory computer uses two of these on a Windows 7 Pro 64 bit build. See






From: ap-gto@... [mailto: ap-gto@... ] On Behalf Of ngliatis@...
Sent: Monday, October 28, 2013 2:23 PM
To: ap-gto@...
Subject: RE: Re: [ap-gto] UPDATE: Serial port connectivity issues



Hi Joe,

I have taken out all the Prolific-based adapters. At this point I'm suspecting the Meade DSI autoguider camera. It is a known fact that these cameras have a very high current demand, and they do not use their own power supply. I just bought a nice Startech 2.0/3.0 hub to dedicate to it. I will also keep the 4-port Keyspan in place. My plan of attack also consists of the following:

- Check all USB cabling thoroughly, from the scope to the hub/PC.

- Build a new PC as a backup

- Any future serial-USB will be FTDI-based as discussed


If you have any other suggestions I'd be glad to hear them.




---In ap-gto@... , < ap-gto@... > wrote:



    We discussed the problems with PROLIFIC chips versus the more reliable FTDI based USB-Serial converters.

I was just visiting OPTEC to download the latest (serial port based)  TCF-S focuser software – and noticed OPTEC’s warning on their webpage. It reads:


Known Technical Issues:

USB-to-Serial Converter Issues.
NOTE: If a USB-to-serial converter is needed to interface to an Optec instrument, it is necessary to confirm that the converter is compatible with the Optec control software. Many low cost converters using the Prolific chip set will not work with the Optec control software. We suggest that the converter use the FTDI chip set for best compatibility. The #17690 single port and the #17691 4-port USB-to-serial converter sold by Optec uses the FTDI chip set.
*************************************************   Yet another warning about PROLIFIC support problems for their own various products, from a manufacturer and supplier of  the FTDI based KEYSPAN hubs.   HTH Joe Z.


From: ngliatis@...

Sent: Monday, October 28, 2013 10:52 AM

Subject: [ap-gto] UPDATE: Serial port connectivity issues


Well it looks like this issue is not resolved. Last night after I had everything connected, the serial hub once again dropped the connection. What is interesting is that my QHY CCD camera also dropped. There could be a USB under-power issue that I need to use a 2.0 USB powered hub. I noticed this started happening when I hooked both camera and autoguider directly to the PC. Is there a possibility that the built-in USB ports do not provide enough amperage to handle everything?




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