Thanks for your suggestions. No joy on Serial 2, but have reconfigured serial 1 as you suggest and this appears to be working OK without usb cameras attached - I’ll test it tonight as clear skies. Does that mean there is a problem with Serial 2, dirty connection?

The laptop is an old Dell Latitude with Pentium M if you can still remember these. During lockdown I restored by original DEC Digital 386 25SL 2 Mb RAM and 40MB HDD and VGA display! I can still run my original Distant Suns from floppy disks...

I've been having problems with intermittent serial connection / read time out errors. I use Argo serial 2 at 9600 baud, Meade startup protocol on com 1, via db9 serial port using Argo serial cable. I am connecting to Meade planetarium (Autostar Suite), on an old laptop running Windows XP. Sometimes it connects no problem, sometimes it won't connect at all, and sometimes it connects for a period then issues a read timeout error?

I'm assuming the problem is at the laptop end, which is also running cameras drawing power from the two available USB ports. Do you think this is a power issue, or something else?

Anyone had this problem, any ideas?
Thanks in anticipation, Tom