CHAPTER 13
DATA CONVERSION DEVICES AND
SWITCHBOARDS
INTRODUCTION
Data conversion is the process of modifying a signal into a form usable by the
destination equipment.
This conversion can be analog-to-digital (A/D),
digital-to-analog (D/A), or digital-to-digital (D/D). An analog-to-digital converter
is a device that converts a continuously variable input signal into a representative
number sequence. A digital-to-analog converter (DAC) produces an analog signal
proportional to the digital value. In digital-to-digital conversion, data is
manipulated into a form usable by the destination equipment. This could consist
of changing the logic levels of the signal or shifting data.
Switchboards are used to interconnect various combat direction systems’
equipments with each other and with other shipboard systems.
After completing this chapter, you should be able to:
Define digital-to-analog and analog-to-digital conversion
Define sampling, quantization, encoding, Gray code, and binary-coded
decimal (BCD) as these terms apply to data conversion
Describe the operation of synchro systems
Describe the operation of a multiplexing data converter
Describe the operation of manual and remotely controlled digital and
analog switchboards
TOPIC 1—FUNDAMENTALS OF DATA
CONVERSION
Shipboard data conversion equipment handles a
variety of types of data when communicating with other
shipboard subsystems and equipment. In a number of
instances, digital equipment must communicate with
one or more analog or digital devices. A variety of
equipment is installed throughout the fleet. Data
conversion equipments encompass a large number of
multifunction (MULTIPLEXED) and single function
devices.
In general terms data conversion falls into three
main categories:
analog-to-digital conversion,
digital-to-analog conversion, and digital-to-digital
conversion. Within each of these categories, there are
several different types of conversions, each unique in
its own way.
ANALOG-TO-DIGITAL (A/D) AND
DIGITAL-TO-ANALOG (D/A)
CONVERSIONS
An analog signal is a signal that varies continuously
with time. Its amplitude or other variables such as
frequency or phase represent a value within a given set
of limits. For instance, different values may be
expressed or transmitted by changing the amplitude of
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