User's Manual

Operating States
28 The transceiver has the following six operating states:
(1) Off. In this state power is not applied to the transceiver and it is switched off.
(2) Initialise. When power is applied to the transceiver it enters initialise state. The
transceiver automatically loads any software or configuration files and supplies
DC power to the azimuth encoder. On completion of initialisation the transceiver
switches to Standby state.
(3) Standby. In this state the transceiver establishes communication with the display
system and reports its status to the display system. The transceiver receives and
acts on commands from the display system and provides azimuth and heading
line data from the encoder to the display system. The transceiver does not radiate
RF in this state.
(4) Transmit. On receipt of a Run command from the display system, provided the
display system has defined all the operating conditions, the transceiver switches
from Standby to Run state. The transceiver initially outputs an RF signal into the
antenna at low power. This enables the VSWR to be checked without the risk of
damage to the transceiver, e.g. from an open circuit into the antenna. If the VSWR
is within limits then the transceiver automatically switches to full power. If the
VSWR is high, indicating an antenna fault, a warning message is sent to the
display system and the transceiver does not radiate on full power. The radar
returns are then processed to provide radar video to the display system. Note that
the time from switch on to being ready to enter the run state is less than 2 minutes.
(5) Degraded. The transceiver continuously runs background performance checks
on forward power, reverse power and receiver sensitivity. If any of these
parameters is outside predetermined levels a warning message is sent to the
display system indicating the nature of the fault. The transceiver continues to
operate, but with reduced performance and functionality. The fault should be
investigated at the earliest opportunity.
(6) Fault. If the performance or functionality is degraded such that the transceiver
cannot operate it enters the fault state and a fault message is sent to the display
system. The transceiver stops radiating RF and there is no video to the display.
Operating Range
29 In either the Transmit or Degraded states the radar operates in one surface picture mode
with a range of interest of 48 nm. The operating range is determined by the Range Scales
selected on the display. 24 nm mode is applied when a range scale of 24 nm or less is selected.
48 nm operating range is selected for range scales greater than 24 nm.
KH1264
Chap ter 3
Is sue 2 Page 3.9