pcie-8431/8, RS 485, Two wires mode not available

[Ser.v]

Hello all,

i hope you are doing well,

recently i bought a eight channels pcie-8431,  to establish communication with a product that handle half-duplex RS-485 protocol 

i read that this model of pci is differencial but its possible to use the "two wire" method.

Would be helpfull if someone can give me a clue of how to do this, Thank you for your time.

Extra information: Im trying to change the setting though NIMAX --- Advanced settings, but that option is disabled (attached you will find an image)

[Ser.v]

I forgot to mentioned that the PCIe-8431 has
TX+
TX-
RX+
RX-

And the product that im trying to connect has
D+
D-

Currently im connecting
TX+ with D+  
RX- with D-

I don't know if this connection is correct

[ZYOng]

See Set Up 2-Wire (Half-Duplex) Communication with RS-485 Port

Basically short Tx+ and Rx+ to D+, and Tx- and Rx- to D-

[Ser.v]

Thank you ZyOng,

i already did the test but i didnt receive the expected information.

In the post shared by you, mentions that its necessary to change the tranceiver mode from 4 wires to 2 wires mode.

but that option its not available in my NIMAX, do you know if i need extra drivers or any particular version of NIMAX?

Also, the PCIe- that im using is the 8431/8 and in the post mention only the following devices as compatible:

Hardware

• RS-485
• NI-9871
• PXI-8431/4
• PCIe-8431/4
• PCI-8431/4
• PCIe-8433/2
• USB-485
• PXI-8423/4

[rolfk]

Did you install NI-Serial and if you did which version?. Without that the board is at best available as a standard serial port if at all.

[Ser.v]

Hello Rolfk

Yes, the version of NI-Serial that i've istalled is 2025 Q4

And I'm currently using LV 2023 Q3