Comtech EF Data CDM-550T - Manual (Page 67)

CDM-550T Satellite Modem Revision 3
Front Panel Operation MN/CDM550T.IOM
6.2.6.1.3 (MONIT: 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:
TX TRAFFIC: NO CLOCK
DETECTED FROM INTERFACE
6.2.6.2 (MONIT:) RX-PARAMS (Receive Parameters)
If the demodulator is locked, this screen shows the following:
RX:EbNo=05.7dB dF=+11.7k
BER=3.4E-9 BUF=50 AGC=24
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.
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