[WriteLog] USB to Serial adaptors on WinXP Pro

Dave Henderson nr1dx@tellink.net
Wed, 13 Mar 2002 19:26:43 +0000


<SNIP>

>BTW I've tested the port with both TNC on RTTY and with rig control and it
>works well, but only with the power cord connected to the notebook
>computer... on battery power its not communicating with either device.
>
>Does anybody know enough about USB to explain that... it's not much of an
>issue... but always nice to know.

Suspect it has to do with the power management scheme on the laptop. The 
USB standard (?) calls for the USB port to provide some level of power to 
what ever is plugged into it (up to a point). Many laptops however don't 
provide any power at the USB port, period,  because of the potential for 
relative high current drain /shorter battery life. Sounds like on yours it 
may be  "selectable". Go to the power management menus (probably in the 
control panel or on the <START>menu) and see what is checked and not 
checked there. If you don't mind the battery drain there may be a 
"firmware" switch you can throw to turn on USB power during battery operation.

Dave
NR1DX
PS: Good work on finding that alternative driver by the way .....  you 
should send an email to the tech support folks who made your original 
device so that they and future buyers can benefit.