PR-680/680L User Manual
45
USB
H
UB
T
YPE
Virtually all modern computers today supply current through the Universal Serial Bus (USB) hub to
power external devices when necessary. Typically, the current supplied is 500 mA. Some external USB
hubs supply only 100 mA or no current at all. The
USB Hub Type
option provides the means of selecting
the power available to the instrument via the PC. If there is insufficient current available for the USB
device (PR-680/680L), Windows will issue a warning and disable the device.
D
ETERMINING
USB
H
UB
P
OWER ON
W
INDOWS
XP
1.
Click
on
.
2.
Right
click on
My Computer
in the
start
menu.
3.
Click
on
Properties
to access the
System Properties
screen.
4.
Click
on
Hardware
.
FIGURE 90 - SYSTEM PROPERTIES SCREEN
5.
Click on
Device
Manager.
6.
Expand the Universal Serial Bus controllers selection by clicking on the +. icon.
7.
Right click on USB Root Hub.
8.
Click on Propertie
s
.
9.
Click on
Power
. The
Total power available
is displayed as illustrated in