2-Port RS422/485 Serial PCI Card
3
RS422 mode
2.
Termination Resistor Enable/Disable: This jumper enables/disables
the 120 Ohm termination resistor between DATA+ and DATA- of
the RS485 transceiver:
JP7 (for S1)
JP8(for S2)
Description
Termination Resistor Disabled
(Default)
Termination Resistor Enabled
3.
Echo or No Echo Settings: This jumper is to set the
transmission data will be echoed back or not.
The Echo
mode is useful for the application program to detect if the RS485
bus has collision. If the echoed data was not equal to the
transmitted data, then the bus was in a collision. This setting only
affects the RS485 2-wire mode. It doesn’t affect RS485 4-wire,
RS422, and RS232 modes.
JP3 (for S1)
JP4(for S2)
Description
485
-4W
485
-2W
422
OFF ON
OFF ON
