Installation
SMS-758 Modem Protection Switch
2–4
MN/SMS758 Rev. 3
2.4 External Connections
All connections between the switch and other equipment are made through rear panel
connections. Table 2-1 lists these connectors, and Figure 2-1 shows the locations. The
uses of these connectors are described in the following sections.
J26
1
J25
J24
J23
8
7
J22
J21
6
5
4
PRIME MOD INPUTS
J20
J19
J18
3
2
1
1
J17
DOWN
LINK
J7
1
2
J1
J2
RS485
EXTERNAL
J3
90-264 VAC
RS232
RS485
MODEM
CONTROL
OFF-LINE
IF OUTPUTS
2
J27
1
2
3
J28
J29
J30
MOD
4
5
6
J31
J32
DEMOD
IF OUTPUTS
BACKUP
MOD INPUTS
7
8
J33
J34
J35
J36
2
A10
A9
J38
A8
J5
J6
REMOTE/FAULT
A6
A7
J4
ON-LINE STATUS
A5
ON-LINE STATUS
A4
J16
2
A2
A3
J11
BACK-UP
DEMODS
1
A1
J37
PRIME INTERFACE
SWITCH MODULES
BACKUP INTERFACE
SWITCH MODULES
J12
1
2
INPUTS
J8
J9
J10
3
4
J13
J14
J15
3
4
J39
GND
J12
1
2
DOWN
LINK
INPUTS
J8
J9
J10
6
7
J13
J14
J15
3
4
FOR SEVEN DOWNLINK
OPERATION
D/L
SW
IN
5
J7
D/L
SW
OUT
BU
DMD
OUT
J16
J11
Figure 2-1. SMS-758 Rear Panel
