Comtech EF Data CDM-625A Installation And Operation Manual page 184

Advanced satellite modem (18 kbps – 25 mbps)
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CDM-625A Advanced Satellite Modem
Front Panel Operation
For statistics logging, you first define a measurement interval (see CONFIG: Stats); then, during
this interval, you will observe Eb/No, Transmit Power Level Increase (TPLI), and Receive Signal
Level (RSL) at a rate of once every second.
Per the example, at the end of the defined measurement interval period, the modem calculates
statistics data in the order that follows (from left to right on the top line):
(16.0,16.0) First, the Eb/No is calculated: The minimum Eb/No value observed in the
interval is provided first, and then the average Eb/No value observed follows. If the
measured values are ≥16.0 dB, then 16.0 is displayed.
(9.0,9.0) Next, the TPLI is calculated: The maximum TPLI observed in the interval is
provided first, and then the average TPLI value observed follows.
(16.5,16.5) Finally, the RSL is calculated: The minimum value observed in the interval is
provided first, and then the average RSL value observed follows (note that both values
are negative).
If the demod has lost lock during the measurement interval, the
minimum Eb/No will show 'LOSS' rather than indicate a value –
however, the average value (while the demod was locked) will still be
calculated and shown.
If, on the other hand, the demodulator has been unlocked for the entire
measurement interval, the average Eb/No will also show 'Loss' (i.e., the
display will show 'Loss,Loss').
In addition, If AUPC is not enabled, the values of maximum and average
TPLI will both show '0.0'.
Example 1:
08.0,13.5,2.5,1.8,30.0,25.1 means:
(08.0) Minimum Eb/No observed in the measurement interval = 8.0 dB
(13.5) Average Eb/No observed in the measurement interval = 13.5 dB
(2.5) Maximum TPLI observed in the measurement interval = 2.5 dB
(1.8) Average TPLI observed in the measurement interval = 1.8 dB
(30.0) Minimum RSL is observed in the measurement interval = -30.0 dB
(25.1) Average RSL is observed in the measurement interval = -25.1 dB
Example 2:
Loss,04.5,0.0,0.0,29.0,29.0 means:
(Loss) There was a loss of demod lock during the measurement interval
(04.5) Average Eb/No observed in the measurement interval = 4.5 dB
(0.0) Maximum TPLI observed in the measurement interval = 0 dB
(0.0) A verage T PLI obs erved in t he m easurement i nterval = 0 dB (which indicates no
AUPC activity, or that AUPC is disabled.)
(29.0) Minimum RSL is observed in the measurement interval = -29.0 dB
(29.0) Average RSL is observed in the measurement interval = -29.0 dB
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Revision 0
MN-CDM625A

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