Comtech EF Data CDM-840 - Manual (Page 102)

CDM-840 Remote Router Revision 2
Ethernet-based Remote Product Management MN-CDM840
6–34
• Tx Scrambler – Use the drop-down list to select the Tx Scrambler as Off or Normal.
• Roll Off – The Tx Alpha Rolloff (α) dictates how fast the spectral edges of the carrier are
attenuated beyond the 3 dB bandwidth. With 20% rolloff the edge falls off more quickly
than with 25% and 35%.
Use the drop-down list to set the expected filter Tx Alpha Rolloff (α) of the carrier as 20%,
25%, or 35%. The default selection is 20%.
• Spectrum Invert – Use the drop-down list to select the Tx Spectrum Invert as Normal or Tx
Spectrum Inverted.
• Power Level (-40 to 0) – Enter the Tx power level in dBm.
• Carrier State – Use the drop-down list to select the Tx Carrier State as Off or On.
Select or enter the desired FEC Type, Tx Frequency, MODCOD, Tx Scrambler, Spectrum
Invert, and Carrier State settings. Click [Submit] to save.
RTI Configuration
• Transmit Inhibit – Use the drop-down list to Disable or Enable RTI operation.
• Wait Time – Enter a time, in seconds, to delay execution of the RTI function (when Enabled).
The range is from 1 to 5 seconds.
• State (read-only) – The operational status of the RTI function is displayed here.
Click [Submit] to save.
RTI means RECEIVE/TRANSMIT INHIBIT. When selected, it will prevent the Tx carrier
from being transmitted until the demodulator is locked. To avoid the Tx Carrier
from being turned off when the demodulator loses lock for a very short period of
time, the demodulator must be unlocked continuously for the selected time period
(1 to 5 seconds) before the transmit carrier is inhibited.