tests and operating practices for EMI reduction.
MIL-STD-1310 entitled Shipboard Bonding,
Grounding, and Other Techniques for Electromagnetic
Compatibility and Safety, is a military standard for the
proper construction of bonding straps and grounding,
cables. It is the reference for all shipboard
electromagnetic capability (EMC) installations. It
contains drawings that depict the proper shape of and
lists materials required to construct bonding straps and
grounding leads for shipboard electrical/electronics
installation.
The Naval Shore Electronics Criteria handbook,
Electromagnetic Radiation Hazards, NAVSEA OP
3565 Volumes 1 and 2, (parts 1 and 2) (NAVELEX
0967-LP-624-6010) has information on the reduction
of EMI at shorebased facilities. All facets of grounding,
shielding, and equipment bonding are contained in this
highly informative handbook.
The Handbook of Shipboard Electromagnetic
Shielding Practices, NAVSEA S9407-AB-HBK-010,
provides specifications for cable spacing/shielding
requirements and installation procedures that will
minimize the effects of electromagnetic interference
(EMI) on electronic equipment installed in naval
vessels.
It is intended for use by ship designers,
planning engineers, personnel engaged in the
installation of electronic equipment, overhaul and
repair shipyards, tenders, and other repair and
installation activities.
SUMMARYFUNDAMENTALS AND
OPERATIONS OF COMPUTERS
This chapter has introduced you to computer
functions, types of computers (mainframe computers,
minicomputers, and microcomputers), operational
uses, modes of operation, capabilities and limitations,
and operational requirements. The following
information summarizes important points you should
have learned:
COMPUTER FUNCTIONS Computers gather,
process, store, disseminate, and display data. Data may
be gathered manually or automatically or by a
combination of both. Once processed, it can be stored
either internally in memory banks or externally on disk
or tape. Data maybe disseminated and stored, or it may
be sent to a display device.
MAINFRAME COMPUTERS Mainframe
computers are large computers. Those used aboard
Navy vessels are designed for ruggedness and are
general-purpose, digital data computers with
1-16
multiprocessing capability. They usually have operator
and remote consoles and a maintenance panel/display
control unit (DCU). They have specific power and
cooling requirements.
MINICOMPUTERS Minicomputers are mid-
range computers.
They are capable of stand-alone
(self-contained) operation, or they maybe an embedded
processor in a system or other type of digital device.
They usually have a control and maintenance panel
(CMP) or computer control panel. Like the mainframe,
they have a rugged frame when used aboard ship, and
they have specific power and cooling requirements.
MICROCOMPUTERS Microcomputers (per-
sonal computers) are small, lightweight computers.
Their central processing unit is contained on a single
integrated chip (IC) and the entire computer system is
contained on a handful of printed circuit boards in a
small compact frame or cabinet.
FUNCTIONAL OPERATION OF COM-
PUTERS Computers exchange data with other
computers, peripherals, and subsystems through a
coordinated series of interrupts, requests, and
acknowledges. The signal flow is coordinated by the
operational program.
INTERFACING Interfacing between the
computer and other systems, subsystems, and
equipment includes cabling and associated connectors.
Methods of interfacing include both parallel and serial
data transfers.
OPERATIONAL USES Operational uses of
computers include tactical and Naval Tactical
Command Support Systems.
COMPUTER SYSTEM CONFIGURA-
TIONS Each system must be configured for
operation and maintenance. The hardware and
software must be compatible and must be set up to work
together.
MODES OF OPERATION Computer systems
may be operated in online, offline, and battle short
modes. Maintenance may be performed online if there
is enough memory; otherwise it will be performed
offline. Battle short mode is used when it is necessary
to run the system continuously even though an
overtemperature condition exists.
OPERATIONAL SYSTEM REQUIRE-
MENTS The operational capabilities and limitations
can be controlled at the equipment, or through
switchboards, control panels, or commands to the
software. Effective operation depends on adherence to