Technical Description of TANDBERG MCU with software version D3
D12925 Rev. 03
15
4.1.5 LEDs
Description
The TANDBERG MCU has 24 LEDs (Light Emitting Diodes) on the front panel, each giving
various information as shown below.
4.1.5.1 Description of PRI Alarms
A PRI cable consists of four wires (2 pairs of wires): One pair for Transmit (TX) and one pair
for Receive (RX) signals.
Red Alarm
Red alarm or
Loss of signal (LOS)
means that there is no signal and thus no framing info
received. (This has same effect as pulling out the PRI cable).
Yellow Alarm
Yellow alarm or
Remote Alarm Indicator (RAI)
means that the MCU is receiving framing info,
but in this framing info the other side tells the MCU that it is not reading the MCU’s transmitted
framing info. Typically, this may be a broken connector in the TX part of the MCU PRI cable.
This could also indicate weak or noisy signal in the TX part of the MCU PRI cable.