User Manual
VCom Inc.
AP5857 Manual; ml_ap5857_08 (Oct 2005)
Approved: R.B.
22
5.6.3 Downstream Settings
The Downstream Settings Menu provides access to the settings used to configure the downstream chain. To
access this menu from the Main Menu, type “3” to display the Downstream Settings Menu.
Figure 5.7 Downstream Settings Menu
*** VCom Inc. AP5857 Downstream Settings ***
1)RF Frequency (MHz) 5808.000
2)Output EIRP (dBm) 26.0
3)Downstream Modulation 64QAM
4)Downstream Interleaver 16,8
5)Output Mute Muted
CATV Frequency (MHz) 609.000
Downstream Demodulator Status Locked
Downstream Demodulator SNR 35.0 dB
X)Exit
ENTER)Refresh
Select>_
Downstream RF Frequency
This setting allows the user to set the downstream output RF frequency (center frequency of the carrier).
Valid frequencies are multiples of 1.0 MHz. If the frequency is within the setting limits but the step size is
not correct, the frequency will be rounded to the nearest valid step size boundary.
To change the Downstream Output Frequency, type “1”. The local interface prompt will change to:
Output Frequency [5802.000 to 5820.000 MHz](5808.000)>_
Enter the new frequency or press ENTER to use the current value.
Downstream Output EIRP
This setting allows the user to set the downstream output EIRP (Effective Isotropic Radiated Power).
Valid levels are multiples of 0.5 dBm. If the level is within the setting limits but the step size is not correct,
the level will be rounded to the nearest valid step size boundary
To change the Downstream Output EIRP, type “2”. The local interface prompt will change to:
Output EIRP[15.0 to 28.0 dBm](26.0) _
Enter the new level or press ENTER to use the current value.
Downstream Modulation
This setting allows the user to set the downstream modulation to either 64QAM or 256QAM. Valid inputs are
64 or 256. To change the Downstream modulation, type “3”. The local interface prompt will change to:
Downstream Modulation[64, 256 QAM](64) _
Enter the new modulation or press ENTER to use the current value. Note that the symbol rate automatically
set along with the modulation. Symbol rates are 5.05964 Msym/sec for 64QAM and 5.36054 Msym/sec for
256QAM.
Downstream Interleaver