COM port too high!

[StuartT]

When I connect my telescope, I have to check Windows Device Manager to see what Prolific COM port has been assigned and then make sure that is selected in ASCOM.

But ASCOM only has COM ports up to 16, so what happens when Windows has given it a number higher than that?

 

[Dr_Ju_ju]

Under devices if you right click on the computer name & select "Show Hidden Devices", then under Ports you will see the ports that the system has previously used....  right clicking & deleting each of the hidden ports, then when re-connecting the USB to serial device, a lower port number will be applied....

[AstroKeith]

This is probably be caused by shutting down the computer without disconnecting the USB, or pulling out the USB lead. Windows keeps that 'assigned' port reserved. 

Solution, is ...

open control panel, then device manager, then 'view - hidden', then ports. You should a long list of identical assignments. Just right click on one. Choose uninstall, but DONT CHECK THE DELETE DRIVER SOFTWARE box. Repeat!

[Ian McCallum]

You can also renumber the port to a lower number, if you wish.

[Varavall]

16 minutes ago, StuartT said:

When I connect my telescope, I have to check Windows Device Manager to see what Prolific COM port has been assigned and then make sure that is selected in ASCOM.

But ASCOM only has COM ports up to 16, so what happens when Windows has given it a number higher than that?

 

Try this https://www.startech.com/en-eu/faq/change-com-port-number-windows

I pull and push my usb cables in/out of the computer and shutdown with all connected without problems. The point to remember is that COM ports are assigned to devices at each usb port, so if you have a hub as well at the telescope the cables need to be connected to their same ports at the hub and the cable from the hub connected to the same usb port on the computer each time. That way the COM port for each device remains static. Hope that makes sense!

[scotty38]

Also, just for future reference, if you don't want to go through the windows device manager dance, just click the "Binocular" icon near Ports in EQMOD then it'll connect to the port, no need to go searching manually.

[StuartT]

Thanks so much everyone for these very helpful answers!

Problem solved! 🙂

[Tomatobro]

You might find this utility useful for FTDI and USB ports

http://www.nirsoft.net/utils/usb_devices_view.html