The Central Equipment Group (CEG) is composed
of a basic cabinet and power supply that can
accommodate up to five equipment modules. Typical
equipment modules contained in the CEG are the
central data buffer (CDB), the sensor converter group
(SCG), the sensor data distribution switchboards
(SDDSs), and the analog switchboard. A typically
configured CEG, housed in the basic AN/UYQ-21
equipment cabinet, is shown in figure 4-4. One CEG
is capable of driving up to 16 tactical data system
(TDS) display consoles; converting sensor azimuth,
elevation, and range data into a digital X- and
Y-sweep data format; and switching sensor data from
up to 24 inputs to 40 display units.
CENTRAL DATA BUFFER (CDB)
The central data buffer (CDB) provides the
interface between the computer and the display
groups. The CDB converts parallel computer data to
serial data for use by the display consoles. The CDB
distributes data from the computer to the display
groups in real time using high-speed multiplexing.
The CDB has three functional areas as shown in
figure 4-5. They are the computer interface unit
(CIU), the scanner control circuits, and the display
multiplexer unit (DMU). One CIU is required for
each computer in the system. A fully configured
CDB can have four DMUs.
Computer Interface Unit
The computer interface unit (CIU) provides the
interface between the system computers and the
DMUs. Conversion of the parallel computer data to
serial data for use by the display consoles is
accomplished in the CIU. The CIU also receives
serial data from the display consoles, via the DMU,
converts the data to parallel, and sends it to the
computer. The CIU can be simultaneously connected
to all four DMUs by the system computer (auto mode)
or manually from the front panel control switches.
Figure 4-4.A typically configured central
equipment group (CEG).
Display Multiplexer Unit (DMU)
The display multiplexer unit (DMU) transfers
serial data between the CIU and the display consoles.
Computer output data is received from the CIU in
serial form and buffered to provide final drive to the
Serial data from the display
consoles is buffered by the DMU and transferred to