PCI Multi-port Serial Card
2
RS-485 User: Since the factory jumper settings are initially set at
2-wire RS-485 mode. There is no need to change any jumper
settings from the default settings.
RS-422 User: Change the mode jumper away from the”485”
position. Keep the other settings unchanged.
1.
Mode Jumpers:
Mode Settings for all S1~S4 Ports (JP1):
Jumper Name
Jumper Positions
Mode and Termination Resistor
Setting
422/485
422
4-wire RS-422 mode
485
(Default)
2-wire RS-485 mode
S1L/S1H
S1L
(Default)
Reserved for Future Use. Please do
NOT change it.
NO ECHO/ECHO
NO ECHO
(Default)
No echo data
ECHO
Transmitting data will be echoed
back
S2L/S2H
S2L
(Default)
Reserved for Future Use. Please do
NOT change it.
Please note that if the mode were set at “422” mode, the ECHO settings
will take no effect.
The Echo mode is useful for the application program to detect if the
RS-485 bus were in a collision. If the echoed data was not equal to the
transmitted data, then the bus was in a collision.
422
S1L
NO ECHO
S2L
3. Jumper Settings
485
S1H
NO ECHO
S2H
