Specifications

76 MDS 4790/9790 Series I/O Guide MDS 05-3438A01, Rev. E
7.1 Local Problem-Solving
Front Panel LEDs
The first indication of a problem is usually an illuminated ALARM LED
on the front panel. In normal operation, only the green (
ACTIVE) LED
should be lit (and, in a master station configured for redundant opera-
tion, one of the yellow
STBY LEDs).
In a redundant master station, the LEDs show the state of the A and B
transceiver boards. In a non-redundant master station, the LEDs show
the state of the A transceiver board.
Refer to Figure 32 and the text that follows for an explanation of the
LED indicators.
Invisible place holder
Figure 32. LED Indicators
Table 18. Explanation of Front Panel LEDs
LED
Name
Color Meaning When Lit
ACTIVE
Green Transceiver board (A or B) is the selected unit.
STBY
Yellow Transceiver board (A or B) is currently in stand-by mode.
(Functional on master station configured for redundant
operation only.)
ALARM
Red A major or minor alarm event has occurred; use the front
panel’s Active Radio Status screen to list current alarm
events (see Page 73).
RX ALR
Red Difficulty receiving—may be due to an antenna problem,
receiver fault, or other condition causing no or a weak
received signal level.
TX ALR
Red Transmit circuitry fault.
I/O ALR
Red A data framing or parity error has occurred over the data
port.
A
B
ACTIVE STBY ALARM RX ALR TX ALR I/O ALR
ACTIVE STBY ALARM RX ALR TX ALR I/O ALR