Impulse 2403 - Manual (Page 8)

Configuration
Sealevel Systems SeaPORT+4 Page 5
Switch Descriptions
Figure 1: Switches SW2 and SW4
L
485 option, OFF for 422.
OFF: No
effect
ON : Connects TX+ to RX+ for two-wire operation
L
485 option, OFF for 422.
OFF: No
effect
ON : Connects TX- to RX- for two-wire operation
PU
485 option, OFF for 422.
OFF: No
effect
ON : Adds a 1 K ohm pull-up resistor to RX+
PD
485 option, OFF for 422.
OFF: No
effect
ON : Adds a 1 K ohm pull-down resistor to RX-
T
422 and 485 option.
OFF: No
effect
ON : Adds a 120 ohm termination resistor between RX+ and RX-
ON
12
3
4
5
6
7
8
OF
F
91
0
Port 3
L
L
T
PU
PD
Port 4
L
L
T
PU
PD
SW2
Port 1
L
L
T
PU
PD ON
12
3
4
5
6
7
8
OF
F
91
0
Port 2
L
L
T
PU
PD
SW4