F U L L - D U P L E X / H A L F - D U P L E X
SWITCH— In the FULL-DUPLEX position, this
switch enables full-duplex operation of the data
converter and the computer I/O adapter. It also
enables loop back processing of the transmit sidetone
data for input to the computer. In the HALF-
DUPLEX position, the DTS operates in the half-
duplex mode and the transmit sidetone is disabled
from being processed and input to the computer.
Link-11 uses the half-duplex mode.
SIDEBAND SELECT SWITCH— When the
SIDEBAND SELECT switch is placed in the LSB or
USB position, the DTS processes only the lower
sideband or upper sideband of the received signal.
When the switch is in the DIV position, the DTS
combines both the upper sideband and the lower
sideband signals to create frequency diversity data for
input to the computer.
When the switch is in the
AUTO position, the DTS selects the signal with the
best receive quality for processing. The AUTO
position is the normal position of this switch.
DATA RATE SWITCH— Selects the data rate
that the data converter uses. When the switch is in the
DUAL 1200 position, the data converter can transmit
and receive two unrelated streams of data at 1200 bps.
When the switch is in either the 1200 or 2400
position, the data converter transmits and receives a
single data stream at 1200 or 2400 bps, respectively.
When the switch is in the TADIL A position, the data
rate is controlled by the DATA RATE switch on the
TADIL A control panel. The TADIL A position is
the normal position for Link-11.
SYNC MODE SWITCH— The SYNC MODE
switch selects the mode of synchronization used by
the DTS receive circuitry and is used in conjunction
with the TIMING STORED/CORRECTED switch on
the TADIL A control panel. The normal operating
position for the SYNC MODE switch is in the
FAST/CONT position.
When the switch is in the FAST/CONT position,
both the fast and continuous synchronization circuits
of the DTS are selected. Synchronization is initially
obtained during the five-frame preamble and
maintained continuously during the data portion of the
2-14
transmission. The TIMING switch on the TADIL A
control panel must be in the CORRECTED position.
When the FAST position is selected,
synchronization is only during the five-frame
preamble. If the CONT position of this switch is
selected, only the continuous synchronization circuits
are selected. Synchronization is obtained only during
the data portion of the transmission. The TIMING
switch on the TADIL A control panel must be in the
CORRECTED position for both of these modes.
The INHIBIT position of this switch disables both
the fast and continuous synchronization circuits of the
DTS. The DTS will maintain the time base that was
stored when the switch was turned to INHIBIT. For
synchronization to be held, the unit with its sync
mode inhibited must maintain its original geographic
relationship to all other units in the net. This position
is used when the received signal contains interference
that could cause loss of synchronization.
OPERATE/SELF TEST SWITCH— This
switch must be in OPERATE for normal on-line
operations. When the switch is placed in the SELF
TEST mode, the DTS is placed in an off-line mode
and the fault isolation circuitry is enabled.
CONTROL ON/OFF SWITCH— When the
CONTROL switch is placed to the ON position,
+28Vdc is applied to the fault isolation control panel,
the mode control panel, the TADIL A control panel,
and the address control panel.
TADIL A Control Panel
The TADIL A control panel provides the control
switches and indicators required to control and
monitor Link-11 operations. Figure 2-16 shows the
AN/USQ-59 TADIL A control panel.
XMT DATA ERROR INDICATOR— This
indicator is lighted when the DTS detects an error
while transmitting data in the TADIL A, or Link-11,
mode.
