Monitor: Cnc (Carrier-In-Carrier Parameters); Monitor: Stats (Statistics); Monitor: Stats Ip - Comtech EF Data CDM-750 Installation And Operation Manual

CDM-750 Advanced High-Speed Trunking Modem
Front Panel Operation
Rx-Params: EsNo=>23.5 dB
BER=9.4E-07 ModCod:18
Note the following:
Item Description
This shows the value of the Es/No calculated by the demodulator. Es/No is the energy per Symbol
received (Es) divided by the noise spectral density (No). Note that the Es/No reading assumes that
Es/No a linear, non-distorted carrier is being received. If a carrier is operating at or near saturation and
there are nonlinear distortions, the Es/No reading may be inaccurate, especially when
demodulating 16APSk and 32APSK carriers.
ΔF
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.
Rx-Level A dBm reading indicating the signal level of the desired receive carrier. Resolution: 0.5dB.
ModCod The current ModCod.
5.2.2.3.5

Monitor: CnC (Carrier-in-Carrier Parameters)

CnC-Params:
When enabled and locked, this read-only screen displays the CnC performance data. Note the
following:
•
The Monitor: CnC screen refreshes once every second.
•
CnC parameters need to be within the tolerances specified in Sect. 1.4.8 DoubleTalk
Carrier-in-Carrier
•
Ideal operation occurs when the CnC Ratio is 0 db. Ratios that are higher or lower –
approaching ±7 dB – will cause degradation. Ratios beyond ±7 dB may cause complete
unlock of circuit.
•
The Delay in a properly working CnC link is typically between 230 ms and 290 ms.
Delay when bench-testing CnC operation is typically less than 100 µs.
5.2.2.3.6

Monitor: Stats (Statistics)

IP
◄ ►
Use the
.
ENTER
Freq-offset=-123.4kHz
Ratio:+1dB
®
(CnC).
BasebandFraming
arrow keys to select IP, BasebandFraming, or Compression, and then press
⌂F=+005.0
RxLevel=-31dBm
Delay=230.4ms
Compression
5–34
Revision 1
MN-CDM750
kHz
34
TM