Quantum and Evolution Series Installation and Operating Handbook
7-9
•
When there is no receive path fault then the message ‘Rx OK since HH:MM:SS on
DD/MM/YY’ is displayed (where the time and date format is as explained above).
When a receive path fault exists then a fault message is displayed instead that
indicates the nature of the fault.
•
The transmit carrier status, which displays one of the following.
o
'
Normal
': the carrier is on.
o
'
Mute-Ext
': the carrier is muted due to an alarm detected by the modem
hardware.
o
'
Mute-Ter
': the carrier is muted due to either the terrestrial Tx RTS pin being
active (this is an input signal that can be used to mute the carrier under
external control as required) or some other problem being experienced with
the terrestrial interface.
o
'
Mute-1:1
': the carrier is muted due to being the Standby modem in a 1-for-1
Standby system.
o
'
Mute-Brk
': the carrier is muted due to a power outage.
o
'
Mute-Flt
': the carrier is muted due to an alarm detected by the modem
software.
o
'
Mute-Cfg
': the carrier is muted due to the modem being in the process of
reconfiguring.
o
'
Mute-Off
': the carrier has been muted by the user.
Status-Demodulator Screen
This screen is constantly updated with the following information:
•
The receive path Eb/No figure (energy per bit to spectral noise density ratio). This is
replaced by Es/No (energy per symbol to spectral noise density ratio) when the
Down
arrow is selected.
•
The receive path final bit error rate (BER). Please note that this figure gives only a
crude indication of BER linked directly to the Eb/No measurement. In most instances
the actual BER is significantly better when measured using either the internal PRBS
BERT or external equipment.
•
The receive path power level.
•
The receive path buffer fill status.
•
The receive signal frequency offset from the carrier centre frequency. This is the
measured error of the received carrier, relative to the expected frequency. It can be
used to determine any frequency shift due to the satellite and frequency conversion
equipment.
•
Number of Doppler buffer slips in relation to overflows and underflows (shown on the
display as
O
and
U
respectively). The counts can be cleared by pressing the
0
key
while on this screen. The counts are also cleared when the demodulator goes out of
Eb/No:6.3dB BER:<1.0E-12
Rx power:-33dBm Buffer: 57%
Freq offset:0.0Hz O:1 U:0
