StarTech.com ICUSB422IS - Manual (Page 6)

Instruction Manual
3
Switch Settings
The default settings on the ICUSB422IS are set at 2-wire RS-485 mode. If you require
RS422, change the mode pin to the “422” position (ON). Maintain all other settings
unchanged.
Switch Description
Note: If the mode is set to 422, the ECHO setting will take no effect. The echo mode
is useful for the program to detect if the RS-485 bus were in a collision. If the echoed
data is not equal to the transmitted data, then the bus has been in a collission.
Switch
Pin #
Switch
Function
Switch
Positions
Description
1
RS-485
(OFF)
(Default)
2-wire RS-485 mode
RS-422 (ON) 4-wire RS-422 mode
2
ECHO (OFF)
Transmitting data will be echoed
back
NO ECHO
(ON)
(Default)
No echo data
3
NO TERM
(OFF)
(default)
Termination Resistor is Disabled
TERM (ON) Termination Resistor is Enabled
4 RVD
(OFF) Reserved for Future Use
(ON) Reserved for Future Use