Access sbRIO/cRIO Built-in Serial Port from FPGA

Issue Details

• My Single-Board RIO/CompactRIO has a built-in RS-232/RS-485 port, which I would like to access from FPGA, however, it does not show as an available resource in Project Explorer. Is it possible to access it through FPGA?
• I have an RS-232/RS-485 device that I need to send a command and receive data from. I have this working on the scan mode, can I use the external serial port to communicate with the FPGA?

Solution

Built-in Serial ports of cRIO or sbRIO cannot be directly accessed through FPGA. These ports are accessible only from Real-Time section, where they show up as a standard VISA resource. It is recommended to use Serial VIs and functions to communicate with devices connected to those ports. Additional functions are also available in the VISA palette.

If your application requires serial communication to be implemented on FPGA, there are several ways to do it, however additional hardware may be necessary:
 

• You can use 987x C-Series Modules that come equipped with additional Serial Ports, that can be programmed and accessed by FPGA Interface.

• You can also try to implement serial communication on NI FPGA using standard Digital Inputs and Outputs.