Mocomtech CRS-300 - Manual (Page 142)

CRS-300 1:10 Redundancy Switch Revision 16
Cables and Connections MN/CRS300.IOM
4–82
4.11.2 Multiple Transponder IF Connections (Using IF Switch)
The CRS-280 IF (70/140 MHz) Switch provides complete isolation of the IF signals. The
Redundant Modem’s IF signals are routed to the Traffic Modem’s IF path when the RMI is
online. The CRS-300 automatically senses the presence of the CRS-280. The CRS-300, upon
switching, leaves the offline modem with its IF on, and the CRS-280’s relays isolate any
undesired signals.
Figure 4-37 provides a generic example of multiple transponder IF connections – in this
instance, a 1:1 configuration using a CRS-280 IF Switch with CDM-600 modems. Using
PL/0946-2 (50
Ω) or PL/0813-8 (75Ω) BNC to BNC IF cables, observe the following for all
modem/switch configurations:
From the Redundant Modem:
• Connect the “Rx IF” BNC connector on the Redundant Modem to the BNC
connector on the CRS-280 switch labeled ‘TO REDUNDANT MODEM Rx’.
• Connect the “Tx IF” BNC connector on the redundant modem to the BNC
connector on the CRS-280 switch labeled ‘Tx FROM REDUNDANT MODEM’.
From the Tx Traffic Modems:
• Connect the “Rx IF” BNC connector on each Traffic Modem to a BNC connector
on the CRS-280 switch labeled ‘Rx # (where Rx # designates Rx 1 through Rx 10)
TO TRAFFIC MODEM
’.
• Connect the “Tx IF” BNC connector on each Traffic Modem to a BNC connector
on the CRS-280 switch labeled ‘Tx # (where Tx #designateis Tx 1 through Tx 10)
FROM TRAFFIC MODEM
’.
Note : If using the CDM-Qx modem with the CRS-280 IF (70/140 MHz) Switch, or the
CDM-QxL modem with the CRS-280L (L-Band) Switch, use no more than one Mod / Demod per
CDM-Qx/QxL chassis.
Additionally, when using the CRS-280L (L-Band) IF Switch, detailed installation information is
provided in the CRS-280L 1:N Redundancy Switch Installation and Operation Manual.