© Systems, Inc. 2202 Manual | SL9097 6/ Sealevel 2021
Switch Examples
Figure 2: RS422/485 Interface Configuration
485
Mode Selection
OFF : 422 Mode
The transmitter lines TX+ and TX- are always driven
ON :
485 Mode
The transmitter lines TX+ and TX- are switched to high impedance when the device is
not actively transmitting data
NE
485 option, OFF for 422
OFF : The receiver is always enabled. In a two-wire setup the receiver will echo back all
transmitted data.
ON :
The receiver is disabled when the transmitter is enabled. In a two-wire setup the receiver
will not echo back transmitted data.
Switch positions 1 and 2 are for port 1 and switch positions 3 and 4 for port 2.
ON
1
2
3
4
O
F
F
485 1
NE 1
485 2
NE 2
SW3