Emerson USB Fieldbus Interface User Manual page 9

January 2019
2.3 Power modes
The USB Fieldbus Interface has two power modes:
• Mode 1 - The interface does not supply power to the connected fieldbus
device or segment. The fieldbus device or segment is powered by an
external source.
Mode 1 is the default.
• Mode 2 - The interface powers the connected fieldbus device or segment
and no external power is needed.
In Mode 2, it can provide current of up to 85 mA (typically sufficient for
three or four fieldbus devices on the same segment).
You can configure Mode 2 using the USB Fieldbus Interface Configuration
utility. For more information, see
WARNING!
Choose only one power mode. Never attempt to use two power sources at
the same time. Doing so can disrupt communications and may compromise
automation safety.
Section 4.3.
User's Manual
9