Comtech EF Data CDM-700 - Manual (Page 110)

CDM-700 High Speed Satellite Modem Revision 5
Front Panel Operation MN/CDM700.IOM
6–56
Monitor:
Æ Rx-Params
Screen 1 (Use the ▲ ▼ arrow keys to scroll):
Eb/No >19.5dB BER=1.0E-10
ΔF= +0.0k Buf=48 RSL=-39
▼
Screen 2 (Use the
▲ ▼ arrow keys to scroll):
ΔF= +0.0k Buf=48 RSL=-39
▲
FER1 7.1E-05 ▼
Screen 3 (Use the
▲ ▼ arrow keys to scroll):
FER1 7.1E-05
FER2 N/A
▲
If the demodulator is locked, information as indicated in the preceding example is displayed:
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).
BER This is an estimate of the corrected BER.
ΔF
This is the frequency offset of the received carrier, in kHz, with a displayed
resolution of 100 Hz.
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.
RSL
(Receive Signal Level) This shows a value in dBm, indicating the input power
of the desired carrier as seen by the demodulator. If the signal level is below
the AGC range of the demod, this will display RSL <-99
FER1
or
FER2
(GBEI Frame Error Rate) This shows a value indicating the input LINK
ERRORS Per Total Frames Received. FER is meaningful until one of the
counters (usually Total Frames) overflows. Reset statistics to re-start FER.
Good for 32 hours at 155 Mbps or 64 hours at 75Mbps.
If the demodulator is not locked, the message ‘Demod: Not Locked’ appears, but the
receive signal level continues to display: