CRS-170A L-Band 1:1 Redundancy Switch
Introduction
70/140 MHz band, and will not handle the high current BUC power supply multiplexed onto the
transmit coaxial cable. Similarly, the SDM‐300L3 requires an SMS‐301 switch together with the
CRS‐170A.
In both cases, the CRS‐170A is controlled by the supporting data switch, and places the "A" or "B"
modem RF online to match the data switch state. The CDM‐600L (CLM‐9600L) modems supply
redundant power to the CRS‐170A through the CRS‐150. The SMS‐301 itself has redundant power
supplies, and feeds power to the CRS‐170A through the control cable. Online/standby modem
configuration matching is provided by the CRS‐150 controller communication with the CDM‐600L
(CLM‐9600L) modem. The SMS‐301 does not automatically configure the standby modem.
THE CRS‐150 IS AN ACCESSORY PRODUCT DESIGNED SPECIFICALLY FOR THE
COMTECH EF DATA CDM‐600 AND CDM‐600L (CLM‐9600L) MODEMS, AND MUST
NOT BE USED WITH ANY OTHER EQUIPMENT.
1.1.1 Modem Side Connectors
The modem side connectors, shown in Figure 1‐2 and outlined in the accompanying table,
provide all necessary external connections between the CRS‐170A L‐Band 1:1 Redundancy
Switch module and the specified Comtech EF Data modems.
Name
RX A
RX B
Control A
Control B
TX A
TX B
J6 TX B
J5 TX A
Ref Des
Connector Type
J1
Type 'N'
J2
Type 'N'
J3
DB-9F (9-pin Type 'D' female)
J4
DB-9F (9-pin Type 'D' female)
J5
Type 'N'
J6
Type 'N'
Figure 1-2. CRS-170A – Modem Side Connectors
J3 Control A
J2 RX B
J4 Control B
Function
RF Input to Modem A
RF Input to Modem B
Control Interface with Modem A
Control Interface with Modem B
RF Output from Modem A
RF Output from Modem B
1–3
Revision 9
MN/CRS170A.IOM
J1 RX A