2-Port RS232/422/485 Combo Serial to USB2.0 Adapter
3
RS485 4-wire mode
ON
1 2 3 4
M1
M0
TERM ON
TERM ON
RS422 mode
ON
1 2 3 4
M1
M0
TERM ON
TERM ON
RS232 mode
(Note:
Both Pin 3 and 4 have to
be set at OFF to work in RS232
Mode)
ON
1 2 3 4
M1
M0
TERM ON
TERM ON
The image above shows how the TERM ON pins modifies the circuit
The TERM ON pins can apply 1K pull-up & pull-down resistors