User Manual

Marine Systems
Aviation Recorders
Page 4--27
Initial Issue165M1161--00
Aug. 23/10
4.4. Reset the AIS AtoN From the ARM HyperTerminal Console
When the AIS AtoN is running and trace messages are displayed on the ARM
HyperTerminal console, the unit can be reset at any time by holding the “Ctrl” key
and typing “C” twice quickly. This eliminates the need to cycle t he power and restart
the AIS AtoN. Trace messages should scroll through the HyperTe rminal screen.
4.5. Troubleshoot the HyperTerminal
Since the HyperTerminal provides a direct portal to the AtoN CPU, in rare circum-
stances it may stop displaying trace messages. Use the following instructions to dis-
play trace messages.
(1) Press “ESC,” and a “Hit Any Key to Reboot” message appears. Press any key,
so the system reboots.
(2) If messages are not displayed once the unit is reset or a key is pressed, close
the HyperTerminal screen and re-- open it.
(3) If trace messages are not displayed after shutting down and re--opening the
HyperTerminal screen, do the following.
i. Shut down the computer and the turn off the AIS AtoN.
ii. Unplug all connections to the unit.
iii. Plug the connectors back into the unit, restart the AIS AtoN, and re--open
the HyperTerminal screen.
4.6. Resolve Failure Mode
The AtoN handles antenna failures, based upon whether the problem occurs during
a transmission or reception of a message.
4.6.1. For a Transmission Fault and Disabled Antenna
A disabled antenna is detected by the AIS AtoN DSP as an antenna with a high
VSWR during the transmission of a message. If a high VSWR is detected, the DSP
stops transmission before a message completes transmission.
4.6.2. For Receptio n Fault
The AIS AtoN uses a frequency synthesizer that incorporates a digital Phase Locked
Loop (PLL). If both receivers are locked, a “Lock Detect” status signal is sent, indi-
cating that the receivers are functioning. In Type 3 AtoNs, if either or both receivers
fail to lock then the “Lock Detect” status indicates a fault, and RATDMA transmis-
sions are stopped on the receiver that is not locked.