
Pluto User Manual A4
www.diamondsystems.com
Page
18
4. INTERFACE CONNECTOR DETAILS
This section describes the functions associated with the Pluto
baseboard’s PC/104-
Plus
bus expansion stack,
utility, I/O interface, and power connectors in greater detail. Section 3.1.1 contains a list of ready-to-use interface
cables included in
Diamond’s Pluto Cable Kit.
Many of the signals present on Pluto’s interface connectors are derived directly from signals on the attached ETX
CPU
module’s high density ETX bus connectors. Please refer to the particular ETX module’s user manual for
further details on the definition and utilization of these signals. Additional information on these signals appears in
the ETX 3.0 specification, which is available from t
he ETX Industrial Group’s website (
http://www.etx-
ig.de/specs/specs.php
). Also available from that site is the latest ETX Design Guide, which provides further
details on the ETX connector signal functions and interface considerations. Several other relevant specifications
are referenced below.
4.1 PC/104-
Plus
stacking location (CONA1, PC104+)
These connectors accommodate the addition of either PC/104 (ISA bus only), PC/104-
Plus
(ISA and PCI buses),
or PCI-104 (PCI bus only) modules on top of the Pluto baseboard. Specifications and other details on all three of
these expansion module standards are available from the website of the PC/104 Consortium
(
http://www.pc104.org
).
4.1.1
PC/104-
Plus
ISA Bus (CONA1)
The 64- and 40-pin header connectors in location CONA1 carry the PC/104-
Plus
expansion stack location’s 104-
pin ISA bus signals. These signals, generated by Pluto
’s ETX CPU module, are essentially identical in function
and signaling to those of the 16-bit PC/AT bus, except for the physical design.
A 64-pin header incorporates the 8-bit
“PC bus” connector signals, while a 40-pin header incorporates additional
signals associated with the full 16-bit
“PC/AT bus.” The signal names and functions for CONA1 are listed in the
table on the following page.
Note:
The Pluto baseboard does not provide a means for supplying -5V or -12V DC power to the
PC/104-
Plus
ISA bus. Most PC/104 and PC/104-
Plus
modules do not require these voltages to
be supplied by the bus.