1.2.2 Operation With Cdm-600L (Clm-9600L) And Sdm-300L3; Operation With Cdm-600L (Clm-9600L) And Crs-150 - Comtech EF Data CRS-170A Installation And Operation Manual

CRS-170A L-Band 1:1 Redundancy Switch
Introduction
Figure 1-9. CDM-625/A 1:1 IP Redundancy Router Mode – 'B' Online (Switchover)

1.2.2 Operation with CDM-600L (CLM-9600L) and SDM-300L3

Operation with two CDM-600L (CLM-9600L) modems requires an additional CRS-150 1:1 switch
for terrestrial data switching and 1:1 control, while operation with two SDM-300L3 modems
requires an additional SMS-301 1:1 switch to handle terrestrial data and control. Thus, there are
three functional configurations for the CRS-170A.

1.2.3 Operation with CDM-600L (CLM-9600L) and CRS-150

The CRS-150 connects to two modems (an online unit and a standby unit), monitors the fault
status of these two units, and controls the routing of data to and from the two units. IF signals,
10MHz reference signals, DC power for the BUC and LNB, and FSK signaling to the BUC are
switched in the CRS-170A under control of the CRS-150. In the case of an equipment failure,
automatic switching takes place to protect the traffic circuit.
At the heart of the CRS-150 is a Controller State Machine that is responsible for fault monitoring
and control of switching functions – it is implemented in a CPLD.
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