Powerstar UPS - ps1503-4
The Rockwell International Autonetics Marine and Aircraft System Division
(AM&ASD), now Boeing, began developing general purpose digital data bus
systems for naval applications in 1970. The first such system is the Data
Multiplex System (DMS) AN/USQ-82(V), a linear, coaxial, five-way redundant
digital data bus designed specifically to be compatible with a large number
of standard US Navy signal types, discrete, logic level, supervised
discrete, analog, synchro, serial digital, and parallel digital. The goal
of DMS was to allow the rapid incorporation of data bus technology into Navy
ships, and therefore required that modifications of user equipment be
minimized or avoided entirely.
DMS achieved this goal by including a large menu of options for user device
interfaces. The DMS terminals and the interface modules can be configured
for a wide variety of options which address interface signal details as well
as various protocols for digital devices. DMS also incorporates a number of
features to promote a high level of survivability, to ensure that it is
adequate to support critical shipboard systems. Finally, DMS is built to
military specifications, including shock, vibration, humidity,
electromagnetic emissivity, electromagnetic susceptibility, and many more.
In 1984 DMS completed US Navy Operational Evaluation (OPEVAL), and was
incorporated into the design of the Arleigh Burke (DDG 51) class destroyers
and, in a smaller application, in the Wasp (LHD 1) class amphibious assault
ships. DDG 51 is currently operating with machinery control, damage
control, steering, navigation, alarm and indication, and parts of the AEGIS
combat system communicating over DMS. LHD 1 uses DMS for the distribution
of navigation, wind, and radar antenna bearing data.
In 1984 the US Navy began investigating commercial data bus standards to see
if any might be used or might be adapted for navy use. The Survivable
Adaptable Fiber Optic Embedded Network (SAFENET) committee was formed,
surveyed various topologies, and decided to adopt the
American National Standards
Institute (ANSI) X3T9.5 Fiber Distributed Data Interface (FDDI) token
ring architecture. SAFENET mandates, in addition to the FDDI medium, that a
SAFENET-compliant system must be designed to certain physical requirements
to promote durability and survivability, and must support certain protocols
and services.
To comply with SAFENET, while still providing the compatibility with
existing US Navy users systems, work began on the Fiber Optic Data Multiplex
System (FODMS) in 1988. FODMS is a FDDI-based data bus transparent to any
current application of DMS. FODMS is designed to operate in a SAFENET
environment. FODMS is based on two (2), redundant packet-switched, dual
counter-rotating ring FDDI networks, which are used to interconnect the
nodes, or Input Output Units (IOU's). The main bus medium conforms with the
physical requirements set forth in the SAFENET Standard of 20 December 1991.
The FODMS currently resides on the DDG 51 Flight IIA Class Destroyer ships.
The FODMS systems currently facilitates the following users; analog
navigation data to indicators and synchros for combat systems, digital
navigation data to combat systems, interior communication (IC) alarms and
indicators, integrated survivability management system, machinery control
system, and steering control system.
The FODMS reduces cost, increases performance, expandability, survivability
(self healing network rings), and simplifies the shipboard installation. It
also reduces Life Cycle Cost (LCC) for procurement, operational and support
of the system. The maintainability of FODMS has improved over its
predecessor. FODMS introduces true multicast and broadcast services, which
improve the distribution of digital navigation data to combat systems.
The GEDMS system will
be a technology refresh to the Fiber Optic Data Multiplex System (FODMS),
which is currently being installed on the Arleigh Burke DDG51 Flight II
Class of destroyer ships (DDG 79 – 110). The
GEDMS system will
increase the overall networking bandwidth by replacing the Fiber Distributed
Data Interface (FDDI) backbone associated with the FODMS system and
installing a Gigabit Ethernet backbone. The
GEDMS system provides
a means to transfer data, command or status messages between various types
of user source and user sink devices. For purposes of survivability, the
GEDMS system will
incorporate a Mesh Topology over two independent network backbones. Each
network will utilize Backbone Switch Enclosures (BSEs) for connection to
both network and user links via the fiber optic cable plant. The network
links (Switch-Switch) will establish the mesh topology backbone associated
with GEDMS. The user
links (Switch-User) will provide the connection of the Input/Output Units
(IOUs).