SMS-758 Modem Protection Switch
Installation
MN/SMS758 Rev. 3
2–3
2.2.2 Modem Setup
J28 through J35 are the eight IF outputs available to connect to the customer-supplied
uplink power combiners.
J7 through J10, and J12 through J15, are the downlink inputs available for use with up to
eight customer-supplied downlink splitters. The following steps describe the uplink and
downlink connections:
1. Connect the IF output cables 1 through 8 to the appropriate customer-furnished
uplink signal combiner inputs.
2. Connect the downlink input cables 1 through 4, or 1 through 7, to the appropriate
customer-furnished downlink splitters.
3. When using the 7 downlink option, connect J16 (backup 2 output) to J7, and
specify 7 downlinks/1 backup in the System menu.
Note: Be sure to terminate all unused IF outputs and downlink inputs with the
supplied 75
Ω
BNC terminations.
2.3 System Requirements
The switch, with all interface assemblies installed (Figure 2-1), is capable of operating as
a 2:8 protection switch. This means that two full-duplex standby modems back up eight
full-duplex primary modems.
Note: When IDR interface AS/0895 is used, only one backup is available.
The switch can be configured in any combination including:
•
TX only modems.
•
RX only modems.
•
Mixed interfaces (limited to two).
•
Multiple uplinks (limited to eight).
•
Multiple downlinks (limited to four with 2 backups, 7 with 1 backup).
•
Multiple data rate and code rate operation.
•
Refer to Section 3.2 for a complete explanation of the configuration function.
