Transmission Echo; Termination Resistor - StarTech.com PCI2S232485I Instruction Manual

Transmission Echo

This jumper determines if transmission data will be echoed back. The Echo mode is useful to detect
if the RS485 bus has data collision. If the echoed data is not equal to the transmitted data, then there
is collision. This setting only affects the RS485 2-wire mode. It doesn't affect RS485 4-wire, RS422 or
RS232 modes.
JP2 (for S1 port)/JP5 (for S2 port)

Termination Resistor

This jumper enables/disables the 120 Ohm termination resistor between DATA+ and DATA- of the RS485
transceiver:
JP2 (for S1 port)/JP5 (for S2 port)
NOTE: All other headers and jumpers on the card that are not documented, should not be altered/used.
Description
No data echo.
Transmission data will be echoed back
Description
Termination Resistor Disabled
Termination Resistor Enabled
4
(Default)
(Default)