Comtech EF Data CRS-500 - Manual (Page 41)

CRS-500 1:N Redundancy System Revision 2
Introduction MN-CRS500
1–15
Note the following:
• Depending on the modem type, the Redundant Modem has multi-band Rx/Tx capability.
• Each CRS-282xx ISU is band-specific, as is any Traffic Modem within the redundancy
setup.
• Regardless of bandwidth, when a Traffic Modem fails, the Redundant Modem will be
connected to the appropriate IF signal through the appropriate ISU.
For example, if a Traffic Modem configured for L-Band Tx/Rx fails, the Redundant
Modem will automatically route the failed Traffic Modem’s Tx signal to the CRS-282TL
ISU and its Rx signal to the CRS-282RL ISU.
The selected ISUs will then route the signal to the appropriately configured Traffic
Modem in the 1:N redundancy setup.
1.3.3.1 CRS-282xx ISU Front Panel
On the next page, Figure 1-20 shows the front panel of a CRS-282xx ISU. Depending on whether
a 70/140 MHz or L-Band Tx/Rx interface is needed, the appearance varies based on the IF
connector required for interconnection between the modem rear panels and the CRS-282xx
Tx/Rx ISU front panels. See Chapter 4. CABLES AND CONNECTIONS for further details.
1.3.3.2 CRS-282xx ISU Rear Panel
On the next page, Figure 1-21 shows the rear panel of the CRS-282xx ISU. The Tx and Rx ISUs are
connected to the DSU rear panel connector labeled “TO CRS SWITCH IF CONTROL” via the
daisy-chained DB-9F  DB-9F connector cable CA-0000386. See Chapter 4. CABLES AND
CONNECTIONS for further details.