Park Air Systems 6525, User Documentation

Page: 18 / 54

31-3MDR00HB Page 18 Operation
Draft
Controls and Indicators
Introduction
This topic describes the MDR’s front panel (see Fig 5) controls, indicators and connectors.
Fig 5 MDR Front Panel
Controls and Indicators
Ready Indicator
A green indicator that lights when the MDR is ready for use and no BIT faults have been detected.
Alarm Indicator
A red indicator that either flashes, or lights, when a BIT fault has been detected. BIT indications are
classified as either Alerts or Alarms.
If an ‘alert’ condition is detected, the Alarm indicator flashes, the Ready indicator remains lit, and the
MDR remains operational. A BIT ‘alert’ is indicated if:
‰
The MDR’s RF output power has reduced from its setting by more than 1 dB but not more than
3 dB
‰
The supply volts falls below 21.6 V
‰
The RF PA temperature has exceeded 80
o
C.
Any other BIT condition results in an alarm. When detected, the Alarm indicator lights and the Ready
indicator becomes unlit; the MDR cannot be used.
When the Alarm indicator flashes, or is lit, the front panel display indicates the nature of the Alert or Alarm
Receive Indicator
An amber indicator that lights as follows:
In AM-Voice mode When a signal above the squelch threshold is received, or when
the squelch is defeated.
In VDL 2 mode Lights on Sync and remains lit until the end of message.
In AM Analogue ACARS mode Lit when a signal is received.
In AM Digital ACARS mode Lights on Sync and remains lit until the end of message.
Transmit Indicator
An amber indicator that lights when the transmit circuit is keyed and producing output power.