LOOPBACK TEST 4. —Loopback test 4 is used
to check the operation of the computer interface, the
crypto device, and the data terminal interface
circuitry. When this test is selected, the audio circuits
are disabled and the data from the computer is sent to
the memory in the data terminal. Upon receipt of the
end of transmit signal, the data in memory is sent back
to the computer for evaluation.
DTS FAULT ISOLATION TESTS. —The DTS
fault isolation tests are built-in tests (BIT) designed to
test and isolate a fault to a particular circuit board.
REMOTE CONTROL UNIT
The C-12428/USQ-125 remote control unit (CU)
enables the operator to control the data terminal from
a remote location. The control unit, used with the
data terminal, forms the data terminal set (DTS). The
control unit is used by the operator to enter operating
parameters, start and stop link operations, and change
link modes. One model, shown in figure 7-4, consists
of a 486DX2/66 MHz AT compatible personal
computer in a rugged chassis for shipboard operation.
The keyboard/trackball unit is in a special detachable
enclosure that also serves as a front cover for the CU.
A 386 or better personal computer maybe substituted
for the control unit when loaded with the proper
software and connected to the data terminal.
Figure 7-4.—The C-12428/USQ-125 Control Unit.
THE JOINT TACTICAL INFORMATION
DISTRIBUTION SYSTEM (LINK-16)
The Joint Tactical Information Distribution
System (Link-16) is a new tactical data link that was
introduced to the fleet in 1994. Link-16 has been
referred to by several names and acronyms. The
Tactical Digital Information Link (TADIL) is a term
used by the U. S. Joint Services. The TADIL
designation for Link-16 is TADIL J. The Joint
Tactical Information Distribution System (JTIDS)
refers to the communications component of Link-16.
The communications component includes the terminal
software, hardware, RF equipments, and the
waveforms they generate. The NATO terms for
JTIDS is the Multifunctional Information Distribution
System (MIDS). For our purposes, we will use the
term Link-16 when referring to this system.
FEATURES OF LINK-16
Link-16 allows for the exchange of real-time
tactical information between units of the Navy, the
Joint Services, and the members of NATO. Although
some of the functions are identical to the functions of
Link-11 and Link-4A, Link-16 also provides data
exchange elements that the other link systems lack.
These include the following:
Nodelessness
Jam resistance
Flexibility of communication operations
Separate transmission and data security
features
Increased numbers of participants
Increased data capacity
Network navigation features
Secure voice capabilities
7-4
