channel. Each of the ships sensors can be connected,
in parallel, to four switchboards to provide sufficient
outputs for each display console in the system.
Figure 3-4 shows the front panel of the RDDS.
When the VIDEO SELECT or RADAR SELECT
switches are in the REMOTE position, switching
circuits within the RDDS allow the display console on
an output channel to select any of the sensors
inputting to the RDDS as the source of its sensor
display. The display consoles select the sensor
(radar/sonar) and video level by sending control
signals to the RDDS. In the event of a console control
signal problem, manual selection of sensor and video
may be performed at the RDDS front panel.
TACTICAL DATA DISTRIBUTION
Tactical data is digital data received from or
transmitted to the CDS computer. Tactical data from
the computer (output data) is used by the display
system to generate symbol displays and alert/switch
indications on the display consoles and alphanumeric
displays on the digital display indicator (DDI), also
called the auxiliary cathode readout (ACRO).
Tactical data going to the computer (input data)
results from operator actions (switch depressions,
trackball movement, and so forth) at the display
Figure 3-5 illustrates the data path of tactical data.
This data path can vary depending on the type of
system installed on your ship. Systems using the
console internally generated and refreshed symbols
(CIGARS) modification will not have a separate
symbol generator. Systems using the direct computer
interface (CDI) CIGARS consoles will not have the
pulse amplifier/symbol generator.
In this section, we examine the format of the
different data words and messages used by the CDS
system. This is followed by a brief description of
some of the equipment used to display tactical data.
COMPUTER DATA WORD FORMATS
This section describes the contents and functions
of the computer words outputted to the display
Figure 3-4.The RDDS front panel.
External Function (EF) Word
The external function (EF) word is used to
interrogate the addressed console for input data. In
addition, for CIGARS consoles, portions of the word