Figure 7-2.—The CP-2205(P)(V)/USQ-125 data terminal block diagram.
terminal has the following three major components: a
processor board, a CDS interface board, and the
power supply. Figure 7-2 is a block diagram of the
CP-2205(P)(V)/USQ-125 data terminal. The
processor board performs modulation/demodulation
and error detection and correction, and provides the
interface with the radio set. The CDS interface board
provides the interface with the CDS computer. The
CP-2205(P)(V)/USQ-125 data terminal performs
many of the same functions as previous Link-11 data
terminal sets. These functions include the following:
Data conversion
Data error detection and correction
Control code generation and detection
Synchronization
Encryption device data transfer
Computer and radio control signals for two-
way Link-11 data transfers
In addition, the CP-2205(P)(V)/USQ-125 data
terminal provides the following new features:
Both multi-tone and single-tone waveform
operations
Enhanced Link Quality Analysis (ELQA)
Maximum useable frequency (MUF) option
Multi-Frequency Link
On-line and Off-line System Test Options
Multi-Tone Waveform Link
Multi-tone link operations are basically the same
as in the previous Link-11 data terminal sets and are
called conventional Link-11 waveforms. The data
terminal generates the 605-Hz Doppler tone and 15
data tones. The frequencies of the data tones are the
same as described in chapter 4. Message formats and
modes are also the same.
Single-Tone Waveform Link
Single-tone waveform link updates the 1960’s
technology used in data communications. The single-
ton waveform is a 1,800-Hz phase-modulated
waveform containing the Link-11 data in a serial bit
stream. The single-tone waveform is most commonly
used with the wire-line option of the USQ-125 data
terminal. The CP-2205(P)(V)/USQ-125 data terminal
wire-line option provides an interface port that can be
used with a standard wire-line or a satellite modem.
Using this option expands the means in which Link-
11 data can be exchanged, overcoming the limitations
of the traditional UHF and HF radio links.
Enhanced Link Quality Analysis (ELQA)
The Enhanced Link Quality Analysis option of the
data terminal incorporates almost all of the functions
of the LMS-11. This allows the operator to monitor
and evaluate the performance of the link net.
Information that can be displayed includes the
7-2
