Comtech EF Data CDM-840 - Manual (Page 95)

CDM-840 Remote Router Revision 2
Ethernet-based Remote Product Management MN-CDM840
6–27
• Gold Code (000000 to 262141) – The Gold-n Index descrambling code indicates the Physical
Layer spreading sequence number. The default setting is all 0s.
• Es/No Alarm Point (0.1 to 16.0) –This value, as calculated by the demodulator, is the energy
per symbol bit (Es) divided by the noise spectral density (No). Enter the Es/No Alarm Point
value, in dB.
Click [Submit] to save.
The Alternate column and its defined Symbol and Data rates are used only when
the Automatic Demod Configuration Switch has been enabled.
• Roll Off (read-only) – The Rx Alpha Rolloff (α) dictates how fast the spectral edges of the
carrier are attenuated beyond the 3 dB bandwidth. Roll Off is identified here as 20%, 25%, or
35%.
• Frame (read-only) – The Framing type is identified here as either Normal or Auto.
• Pilots (read-only) – Pilots operation is identified here as Off, On, or Auto.
• Spectrum Invert (read-only) – Spectrum Inversion operation is identified here as either
Normal or Rx Spectrum Inverted.
Automatic Demod Configuration Switch
The Automatic Demod Configuration Switch allows the user to enable and configure the
“Alternate Demod” functionality. The primary purpose of this functionality is allow a user to pre-
stage a new configuration for the outbound carrier – i.e., increase, decrease, or move the
CTOG-250’s Outbound carrier. It is expected that this will be done as part of normal operations.
The recommended procedure is as follows:
Step Task
1 Define the new desired outbound carrier parameters (symbol rate, frequency).
2 Configure the “Alternate Demod” configuration for all CDM-840s on the same Outbound Carrier (CTOG-
250).
3 Configure the CTOG-250 to the new matching Tx parameters.
4 At this point, all of the CDM-840s will unlock from the old carrier, wait the “Intitial Switch Timer” seconds and
then try to Receive Lock to the “Alternate Demod” configuration.