Port conflict between AM5 and EAF

skyrunner

I am trying to set up my new AM5 mount to be controlled by a PC running NINA. I am finding that both the AM5 and the EAF focuser try to use the same virtual COM port on my Windows machine, causing conflicts. Does anyone know a way to manually set the COM port being used by the EAF or the AM5?

Software@ZWO

Hi Skyrunner, EAF is a USB-HID device, while the serial communication protocol is used for communication between AM5 and PC. Generally speaking, there should be no conflict between the two. Please send us some screenshots or a video. We will analyze this problem.

Best Regards

skyrunner

Thanks, I will post a video soon which shows the problem.

skyrunner

The video is here: https://clipchamp.com/watch/RGhdA0mkZSb

I am using NINA and you can see at first that when I connect the focuser then it successfully drives the focus motor backwards and forwards. At about 40s I connect the AM5 mount and then go back to driving the focuser backwards and forwards. At about 1:16 the focuser disconnects and the reported position goes to 0. At 1:35 I disconnect and reconnect the focuser. At 2:15 I disconnect the AM5 and then show that focuser works properly again without errors.

After playing around a bit I have discovered that the problem is related to the use of a USB hub, either the one on the back of my ASI533MC camera or a separate powered hub. The main camera feed works fine without problems on the USB3 connection, but both a guide camera and the focuser experience disconnects when the miniPC is connected to the mount via a hub. If the focuser or the guide camera is connected directly to the miniPC via a separate dedicated USB port all works correctly. It is also the case that if I use my laptop in place of the miniPC it also all works fine even with the USB hub in place.

So my feeling is that it's a problem with the software associated with driving the USB hub which is somehow interacting with the AM5 connection. I guess another possibility is that the AM5 is overloading the miniPC though I guess this is less likely?

Any help with this problem much appreciated - I don't have enough USB connections on the miniPC to be able to use it without a hub. I have tried resetting the COM ports and the hub-related HID connections but this hasn't helped.

Thanks
Gordon

Software@ZWO

skyrunner According to your description and video, I think this problem is caused by the insufficient power supply of EAF. One way is not to use HUB, but to connect EAF directly to the computer. Since your miniPC needs to use HUB, you can use a HUB with the power supply.

Best Regards

skyrunner

I also thought that might be the issue so I used an external powered hub instead, but I still saw the same behaviour when the EAF was connected through the powered hub.

skyrunner

OK, I now have found a workaround. As long as I connect the AM5 through a USB hub (either powered or unpowered), rather than directly to the miniPC, then everything appears to be working ok. I have no idea why this solves the problem but it seems to be working fine so far in my tests.

Software@ZWO

This phenomenon is really confusing. I'm asking other technicians. I want to see if anyone can explain it. Thank you for your feedback. If there is any progress on this issue, I will let you know.