Comtech EF Data CDM-550T, Manual

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Front Panel Operation CDM-550T Satellite Modem
6–34 Rev. 1.3
(MON, ALARMS) RECEIVE (Receive alarms)
The screen will indicate if there are any Receive Traffic Faults. If not, it will
display ‘NONE’. Pressing ENTER takes the user back to the previous menu.
(MON, ALARMS) TRANSMIT (Transmit alarms)
The screen will indicate if there are any Transmit Traffic Faults. If not, it will
display ‘NONE’. Pressing ENTER takes the user back to the previous menu.
If the user selects RX-PARAMS, the following sub-menu is displayed:
6.2.6.2 (MONIT) RX-PARAMS (Receive Parameters)
If the demodulator is locked, this screen shows the following:
Eb/No This shows the value of Eb/No calculated by the demodulator. The value referred to
here is the energy per information bit (Ebi), divided by the noise spectral density
(No).
dF
The frequency offset of the received carrier, in kHz, with a displayed resolution of
100 Hz.
BER This is an estimate of the corrected BER.
BUF
(Buffer fill state) This shows the fill state (in percent), of the receive Buffer. After a
reset, it will read 50. A value <50 indicates that the buffer is emptying, and >50
indicates that it is filling.
AGC A number between 0 and 99 indicating the gain setting of the coarse AGC loop in
the demod. It has a limited dynamic range, and should not be taken as an accurate
measurement of signal level.
If the demodulator is not locked, this screen shows the message
‘DEMODULATOR NOT LOCKED’. Pressing ENTER or CLEAR will take the
user back to the previous menu.
RX TRAFFIC: AGC ALARM
REDUCE COMPOSITE I/P LVL
TX TRAFFIC: NO CLOCK
DETECTED FROM INTERFACE
RX:EbNo=05.7dB dF=+11.7k
BER=3.4E-9 BUF=50 AGC=24