Appeal No. 1998-3380
Application 08/542,591
The invention is related to an interface device having a
circuit which resides within an interface circuit unit and
includes a power supply, a driver, a central processing unit
(CPU), an oscillator, a modem, and a medium attachment unit
(MAU). The power supply and the driver are connected to
selected pins of the serial port connector. The MAU is
connected to the connectors for connection to a Fieldbus. The
power supply provides a power output for powering the other
components of the interface circuit. The power supply
generates a stabilized DC output from power drawn from the
serial port of the computer to which interface device is
coupled. Because the interface device is powered entirely
from the computer, the interface device does not need to draw
any power from the Fieldbus to which it is connected. As
such, the interface device does not load down the Fieldbus
when it is coupled thereto. The CPU processes data in
accordance with the Fieldbus protocol. The modem converts
data that has been formatted by the CPU into Fieldbus-
compatible signals. Conversely, the modem also converts
appeal.
-2-
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 Next
Last modified: November 3, 2007