Can I Use RS-485 and RS-422 Protocols Simultaneously With NI Hardware?

Updated Nov 22, 2023



  • PXIe-8431/16
  • PCIe-8431/16
  • PXIe-8433
  • PXI-8433/4

I have a NI PCI/PXI serial card. For some of the ports, I would like to use the RS-485 protocol. For the others, I would like to use the RS-422 protocol. Can I use both at the same time?

Yes, you are able to use both the RS-485 and the RS-422 protocols simultaneously with the same PCI/PXI, as long as your NI hardware supports the RS-485 protocol. All NI RS-485 PCI and PXI cards also support RS-422. This includes the NI 8431 and NI 8433 series cards. 

Additional Information

The RS-485 protocol is a superset of the RS-422 protocol. In other words, the RS-485 protocol was built on the standards of the RS-422 protocol.
Therefore, using the RS-485 protocol also makes use of the RS-422 protocol.
You will always be able to use the RS-422 protocol within the RS-485 protocol.