Comtech EF Data CDM-570 - Manual (Page 102)

CDM-570/570L Satellite Modem with Optional IP Module Revision 12
Front Panel Operation MN/CDM570L.IOM
5–16
5.2.2.1.3.5 (CONFIG: Tx) Frq (Frequency)
Tx IF Freq:1156.3456 MHz
(◄ ►,▲ ▼,ENT)
To edit the Transmit IF Frequency: First, use the ◄ ► arrow keys to select a digit to edit, and then
use the ▲ ▼ arrow keys to edit the value of that digit. Press ENTER when done.
For the CDM-570L, the range of frequencies is from 950 to 2000 MHz, with a resolution of 100
Hz. Furthermore, if using the CONFIG: ODUÆBUC menus and a BUC LO frequency other
than zero is selected and it is defined whether the mix is high-side or low-side, the display
changes to include the calculated Transmit RF frequency of the modem / BUC combination, as
per the following example:
Tx IF Freq:1156.3456 MHz
RF=14156.3456(◄ ►,▲ ▼,ENT)
As the Tx IF frequency is edited, the RF frequency is automatically updated. However, for the
CDM-570, the range of frequencies permitted is from 50 to 90 MHz and from 100 to 180 MHz,
with a resolution of 100 Hz, as per the following example:
Tx IF Freq:0085.1234 MHz
(◄ ►,▲ ▼,ENT)
Note the leading zeros, which are included to maintain compatibility with the CDM-570L firmware.
5.2.2.1.3.6 (CONFIG: Tx) On/Off
Tx Output State: Off On
Rx-Tx Inhibit(◄ ►,ENTER)
Use the ◄ ► arrow keys to select On, Off, or Rx-Tx Inhibit, and then press ENTER.
(CONFIG:Tx) On/Off: Rx-Tx Inhibit
RTI-Timeout Value: 10s
7s 4s 2s 1s (◄ ►,ENTER)
Use the ◄ ► arrow keys to select the RTI Timeout value (in seconds) as 10s, 7s, 4s, 2s, or 1s,
and then press ENTER.
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 (10, 7, 4, 2, or 1 seconds) before the transmit
carrier is inhibited.
Having this feature enabled does not affect the internal IF loopback feature.
Be aware, however, that if an external IF loopback is attempted (connecting