Comtech EF Data SMS-451 - Manual (Page 22)

SMS-451 Sateliite Switch Revision 0
Introduction MN/SMS451.IOM
1–8
1.1.3 SMS-451T Description
Note: The SMS-451T 1:1 ESC Protection Switch can only be used in conjunction with an
SMS-451A switch. All controls for the switch are provided by the SMS-451A Switch.
SWITCH STATUS
PWR1 PWR2
PWR1
ESC 1
ESC 2
PWR2
Figure 1-7. SMS-451T
The switch (Figure 1-7) adds 1:1 ESC switching capability to the SMS-451A 1:1 satellite
modem switch. The ESC channel is compatible with the optional ESC channels used on
the ESC-450 framing unit.
The switch also provides redundancy for the ESC channel of the prime framing unit with
the ESC channel of one backup framing unit.
A system consists of the following assemblies:
Switch Top Assembly AS/1941
ESC 1 PCB AS/1862
ESC 2 PCB AS/1863
Chassis Assembly AS/1942
Front Panel Assembly AS/1855-1
Power Supply PS/AC40W03P02
A block diagram of the switch is shown in Figure 1-8.