Operation With Sdm-300L3 Modems And Sms-301 Switch - Comtech EF Data CRS-170A Installation And Operation Manual

CRS-170A L-Band 1:1 Redundancy Switch
Introduction
Set the DIP switches on the CRS-170A antenna side to establish modem-
specific operation. For the CDM-600L (CLM-9600L), place the Mode switch
in the SDM-300L/CDM-600L (Dumb Controller) position and push the
Switch Condition switches to the OFF position.
Section 4.10 CRS-170A DIP Switch Settings
1.3.3.2

Operation with SDM-300L3 Modems and SMS-301 Switch

SMS-301 Redundancy Switch Installation and Operation Manual
(CEFD P/N MN/SMS301.IOM)
Figure 1-11. Comtech EF Data SMS-301 1:1 Redundancy Switch
The SMS-301 1:1 Redundancy Switch (
with 70/140 MHz IF SDM-300A modems. All operation as a 70/140 MHz modem switch applies except
that the RF switching is done in the CRS-170A. The BNC IF connectors are replaced by Type 'N'
connectors, as BNC connectors and internal switching are not suitable for L-Band operation. Signals on
the 'J14 | Status/Faults' connector are modified to provide +12VDC power output and A/B switch
control outputs to the CRS-170A. The SMS-301 has its own redundant power supplies, so the CRS-170A
receives redundant power.
Operation here is similar to operation of the CRS-150 1:1 Redundancy Switch with CDM-600L (CLM-
9600L) Online and Backup modems. The SMS-301 operates as the principal switch and controller, with
the CRS-170A providing the required switching for L-Band signals, references, and power supplies that
the SMS-301 cannot handle.
The SMS-301 connects to the Online and Backup SDM-300L3 modems, monitors the fault status of these
two units, and controls the routing of data to and from the 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 SMS-301. In the case of equipment failure, automatic switching takes place to protect the traffic
circuit.
Set the DIP switches on the CRS-170A antenna side to establish modem-
specific operation. For the SDM-300L3, place the Mode switch in the
SDM-300L/CDM-600L (Dumb Controller) position and push the Switch
Condition switches to the OFF position.
Section 4.10 CRS-170A DIP Switch Settings
) is modified from the standard version that operates
Figure 1-11
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MN/CRS170A.IOM
Revision 14