Comtech EF Data CDM-625 - Manual (Page 174)

CDM-625 Advanced Satellite Modem Revision 15
Front Panel Operation MN-CDM625
5–74
For statistics logging, you define a measurement interval (see CONFIG: Stats); then, during this
interval, Eb/No, Transmit Power Level Increase (TPLI), and Receive Signal Level (RSL) are
observed 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