Interfacing To Your Round Card; Interfacing To The Hardware - Intel 80188EB User Manual

Interfacing to Your
Round Card

Interfacing to the Hardware

© National Instruments Corporation
This chapter describes how to connect the Fieldbus Round Card to any
external electronics, and how to develop your Field Device application
to interface to the NI-FBUS Function Block Shell.
The 2 4 female connector on the bottom side of the Fieldbus Round
Card, W2, is a user electronics connector that contains signals you can
connect to any user-supplied electronics. There are three sets of signals:
3VOUT, Serial Port 0, and Serial Port 1.
The three sets of signals have a common ground pin. See the W2 item
in Figure 2-2, Bottom Side of 80188EB-Based Fieldbus Round Card, in
Chapter 2, Hardware Installation, for the pinout of the user electronics
connector.
The signals are described as follows:
• 3VOUT—The Fieldbus Round Card has a 3.9 V at 8 mA output
that you can use to power the user electronics.
To activate the 3.9 V output on the W2 connector of the Round
Card, place a 0
resistor. Doing this increases the current draw from the Fieldbus to
32 mA in the quiescent state. R18 and R35 are located on the
bottom side of the Round Card.
• Serial Port 0—The Transmit and Receive pins of the
microprocessor serial port 0 are available at the user electronics
connector. You can use this port as an asynchronous serial link to
the user electronics board. This port can perform interrupt-driven
serial communication. The 3O pin is the Transmit pin and the 3I pin
is the Receive pin. Both of these pins provide 3 V-compatible
signals.
• Serial Port 1—The Transmit and Receive pins of the processor
serial port 1 are available at the user electronics connector. This
port cannot perform interrupt-driven serial communication. The
resistor on R18 and replace R35 with a 0
4-1 80188EB-Based Fieldbus Round Card User Manual
Chapter
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