Owner's manual
  Configuration 
Sealevel Systems SeaPORT+4 Page 7 
Switch Examples Continued 
Port 4 Port 3 Port 2 Port 1 
Figure 3: Electrical Interface Configuration 
Port 1 :  RS-232 
The corresponding shunt is in the 232 position. The switches will have 
no effect. 
Port 2 : RS-485 two wire communication with no echo. 
  The corresponding shunt is in the 422/485 position. Switches 485 2, 
NE 2, and Port 2 L, L, T, PU, and PD are all in the ON position.   
Port 3 : RS-422 with 120 ohm termination. 
  The corresponding shunt is in the 422/485 position. Switches 485 3, 
NE 3, and Port 2 L, L, PU, and PD are all in the OFF position, T is in 
the ON position. 
Port 4 : RS-485 two wire communication with echo. 
  The corresponding shunt is in the 422/485 position. Switches 485 4, 
and Port 2 L, L, T, PU, and PD are all in the ON position, NE 4 is in 
the OFF position. 
RS 232
RS 232
RS 232 RS 232RS 422/485
RS 422/485 RS 422/485
RS 422/485
Port 3
 L
 L
 T
 PU
 PD
ON
12345678
OFF
910
Port 4
 L
 L
 T
 PU
 PD
ON
12345678
OFF
910
Port 1
 L
 L
 T
 PU
 PD
Port 2
 L
 L
 T
 PU
 PD
E1
E4E3E2
E5
E6
E7
E8
SW2
SW4










