Mount / FTDI COM Port Gremlins

[Midnight_lightning]

I have been having gremlins for the past couple of months, devices disconnecting, camera won't work, Polemaster/PHD locks up etc etc and have been trying to get to the bottom of it.

I suspected my USB hub and poor cabling so got a Pegasus Power Box ultimate (UPB) to allow a tidy up. I have been migrating devices to the UPB over the past week and testing. 

Last night I had major issues with the mount and COM ports - still on the old hub at this point. EQMOD kept crashing and seemed to be causing PHD/SGP/Polemaster to lock up (when I closed EQMOD PHD and SGP came back). 

I found that EQMOD couldn't find the port that the FTDI cable was using, as shown in Device Manager, and nothing I tried would fix it, including a dozen reboots and trying different USB ports and the UPB. 

I wondered whether the FTDI cable was faulty and tried a direct connection to a different laptop and it suddenly worked fine. So knowing the cable was OK I connected back to the UPV and my original laptop and it all worked fine.

It wasn't a great imaging night, too much cloud around, but I lost the whole session and am worried this will happen again. I have no idea what the root cause of the issue was or why it suddenly started working. 

Does anyone have any thoughts on this, and perhaps a process for debugging and fixing COM port issues.

Finally, my mount is an EQ6 R Pro with a USB port. I haven't managed to find any information about this on the Sky Watcher site but have seen some threads that suggest this port can be used with a standard USB-B to USB-A cable. Does anyone have any experience of using this port?  

 

 

[david_taurus83]

Been discussed recently actually. I start rambling on a bit about Eqmod but the info is there about using the USB port on the mount. You need to download the Prolific driver from Skywatcher and set baud rate to something different. Perhaps its your laptop that's playing up though?

https://stargazerslounge.com/topic/388361-controlling-eq6r-using-usb/

[Midnight_lightning]

Thanks David.

I have wondered about my Laptop, its a Dell XPS and the best, most powerful, laptop I have owned but I cant be sure its not implicated. I have an old, underpowered, lap top and will try using that and see if it makes a difference.

[malc-c]

Have a read of this thread which discusses the methods and options of connecting mounts to computers, especially the changes to the com port setting when using mounts fitted with USB ports 

One other thing, you mentioned laptops.  Whilst the differential between laptops and desktop PCs are getting less and less, by deign with a laptop being a mobile platform there are lots of power saving options built in, which can include disabling USB ports at various thresholds or loads.  It could be that a function of the laptop, either in its BIOS or under windows power setting is causing the loss of he com port.

In the 10 years of running my observatory using a desktop PC and FTDI cable EQDIR I've never had any issues of com ports dropping out mid session, but looking at posts on here where people experience this, the often common denominator is that a laptop is used as the controlling PC

[Midnight_lightning]

56 minutes ago, malc-c said:

Have a read of this thread which discusses the methods and options of connecting mounts to computers, especially the changes to the com port setting when using mounts fitted with USB ports 

One other thing, you mentioned laptops.  Whilst the differential between laptops and desktop PCs are getting less and less, by deign with a laptop being a mobile platform there are lots of power saving options built in, which can include disabling USB ports at various thresholds or loads.  It could be that a function of the laptop, either in its BIOS or under windows power setting is causing the loss of he com port.

In the 10 years of running my observatory using a desktop PC and FTDI cable EQDIR I've never had any issues of com ports dropping out mid session, but looking at posts on here where people experience this, the often common denominator is that a laptop is used as the controlling PC

I did see that thread but thanks for raising it. I have gone through power settings on the laptop and USB controllers but will have another look. I haven't checked BIOS so that is worth a look. Not part of the current issues but I have on a couple of occasions been imaging fine for several hours and then suddenly had lots of issues, which could be indicative of the point you make above.  The last time this happened the EFW driver got corrupted - took me hours to work out and only fixed by reinstalling the driver - again , maybe pointing to laptop issue?

[StevieDvd]

Here's a page with how to look up the ports used and change them.

Note at the bottom it mentions that Windows can get befuddled with com ports used if the application using the usb virtual com port does not release the port when it is closed.

Also, from FTDI there is a utility for checking changing the ports as mentioned in their COMPort Assignment manual

HTH

Steve

[Midnight_lightning]

1 hour ago, StevieDvd said:

Here's a page with how to look up the ports used and change them.

Note at the bottom it mentions that Windows can get befuddled with com ports used if the application using the usb virtual com port does not release the port when it is closed.

Also, from FTDI there is a utility for checking changing the ports as mentioned in their COMPort Assignment manual

HTH

Steve

Thanks Steve, that looks really helpful, will spend some time going through it all.

I spotted another issue, not sure if its connected to the woes above, but using SGP if I take a short 1x1 Frame and Focus shot (Scope Cap On) I get a nice smooth image. If I do the same at 4x4 the image has horizontal lines and some vertical banding. 

I have tried a wide range of USB Traffic settings and they don't make any difference. Also, I don't get this issue in Sharpcap or EZ_cap.

If anyone has come across this please let me know.