Mocomtech CDM-QX - Manual (Page 33)

CDM-Qx/QxL Multi-Channel Satellite Modem with DoubleTalk™ Carrier-in-Carrier® Revision 7
Introduction MN/CDMQx.IOM
1–9
connectors at 50
Ω impedance, or N-type female connectors at 50Ω impedance. This
option also must be configured in the factory at the time of order.
• The fourth hardware option is the Quad E1 Data Interface Module. This gives the user
1 to 4 ports of E1, (each are D&I capable). These ports must use a synchronous E1
reference. This option also must be configured in the factory at the time of order.
1.3.6.2 CDM-QxL L-Band
Fully configured, the CDM-QxL will meet or exceed all of the applicable requirements in
IESS-315 and is available with a full range of industry standard digital interfaces. The modem
expands the capabilities into L-Band frequencies. Utilizing advanced technology and proprietary
digital signal processing techniques, the design eliminates analog circuitry to perform modem
signal processing, resulting in higher reliability and reduced packaging size.
1.3.7 Data Interfaces
The CDM-Qx/QxL can be ordered with a number of interfaces. Each data interface can operate
on a Modulator or Demodulator. This allows the user to exchange interface cards for different
applications. The interfaces offered include:
• EIA/TIA-530
o (EIA-422) DCE (at rates up to 12 Mbps)
o V.35 DCE (at rates up to 12 Mbps)
• G.703 Balanced T1 & E1 (DB-15) with D&I++
• G.703 Unbalanced T1, E1, & E2 (BNC)
• EIA/TIA-612/613 HSSI (50-pin SCSI connector, to 20 Mbps)
• 1 to 4 Ports of G.703 (E1 with D&I ) Quad E1 Interface Card, (RJ-45)
1.3.8 Verification
The CDM-Qx/QxL includes many test modes and loopbacks for rapid verification of the correct
functionality of the unit. Of particular interest is the IF loopback (grouped as modem), which
permits the user to perform a quick diagnostic test without having to disturb external cabling.
During loopback, all of the receive configuration parameters on the selected Demodulator are
temporarily changed to match those of the selected Modulator, and an internal RF switch
connects the modulator output to the demodulator input. When normal operation is again
selected, all of the previous values are restored.
1.3.9 AUPC
An important feature in the CDM-Qx/QxL is the addition of Automatic Uplink Power Control
(AUPC). This feature enables the modem to automatically adjust its output power to maintain the
Eb/No of the remote end of the satellite link constant. This provides protection against rain
fading, a particularly severe problem with Ku-band links.