Comtech EF Data MM200 - Manual (Page 29)

MM200 High-Speed Microwave Modem User Interfaces
TM086 - Rev. 4.1 4-5
4.3.2 MODULATOR (menu) *
The Modulator Menu Screens are listed below:
Screen Name Selections and Descriptions L2
FREQUENCY (Hz) {50 – 90 MHz}
Controls the current center band of the
operating frequency width, or the
individual channel frequency if the System
Frequency Control is set to ‘User’. RW
CHANNELS {Auto, 1 - 4}
Controls the number of channel cards
where 0 = auto, and 1 – 4 = the number of
cards. Increase this number for better
performance. Lower this number for
better bandwidth efficiency. RW
SYMB RATE (SPS) {3.5 – 28 Msps}
Controls the total Symbol Rate. RO
MODULATION {QAM4, QAM16, QAM32, QAM64,
QAM128, QAM256}
Displays the current Modulation Scheme.
Performance is increased by using the
lowest QAM Mode possible for the
required bandwidth. RO
BANDWIDTH (Hz) Enters the 3 dB bandwidth of the
modulated IF Output. When the radio
must meet a particular spectral mask, set
this number to something below the
masks 3 dB points (i.e. 5% less). For best
performance, do not allow the MM200s
bandwidth to be greater than the radios 1
dB bandwidth. RW
UTILIZATION (%) * Displays the percentage of the data being
transferred that is being used by the
selected interfaces. Must be less than
100% (Maximize this number for best
bandwidth efficiency by lowering the
symbol rate, QAM Mode, or the number of
channels). RO
MAX PAYLOAD (Hz) Displays the maximum total data rate that
is useable for the current settings. RO
SPECTRUM {Normal, Inverted}
Used for inverting the spectrum. If the
unit cannot lock to the signal after passing
through the radio, try these settings. RW
TX POWER {0 to –25 dBm}
Sets the IF Output Power in 1 dB steps. RW
TX ENABLE {Off, On}
Forces the Carrier to Off or On. RW