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cRIO UART COM Interface

Hello everyone!


I am currently utilizing the PXIe-7822R FPGA and have configured two pins to function as Tx/Rx for UART communication protocol.


The communication is functioning correctly, as I am able to send commands to my MCU and receive responses.


Now, I am attempting to configure a COM interface in order to establish a serial communication for flashing firmware onto my MCU.


Any tips or assistance would be greatly appreciated!

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Message 1 of 5

Hi henrique,


@henrique.kuhn wrote:

I am currently utilizing the PXIe-7822R FPGA …

Now, I am attempting to configure a COM interface in order to establish a serial communication for flashing firmware onto my MCU.

The thread title is about "cRIO", the message text about "PXIe": what exactly are you talking about?

Why don't you use the COM port present on your cRIO or PXI controller?

Best regards,

using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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Message 2 of 5

I made a mistake, it wasn't supposed to be cRIO.


I need to create a COM interface that points to the FPGA pins I created to communicate through UART with the MCU connected to these pins.


I am not connecting my MCU through the USB port of the PXI controller. Instead, I am powering the MCU through the SMU of the PXI and conducting UART communication via the PXIe-7822R. However, in order to flash a firmware or to use a serial interface software, such as Termite, requires a COM port to communicate with the MCU.


I would like to know if there is any way I can create this COM interface that is directed to the Tx/Rx pins I created for UART communication with the MCU.



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Message 3 of 5

You can’t (easily) do that. In order to provide a COM port to your system that other applications could use you would need to write a device driver. Depending on the OS you run on your PXI chassis this would be a Windows or Linux device driver. Both are programmed in C and would need to use the C interface to FlexRIO to access your RIO hardware. It’s not impossible but unless you have actual device driver development experience already, nearly impossible!

Rolf Kalbermatter
DEMO, TU Delft
My Blog
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Message 4 of 5

Are you trying to run the Termite/programmer/etc software on the PXI chassis directly, or on a separate machine? If a separate machine, then I'd recommend forwarding another COM port to that one. Since you're controlling those pins in software already, you could use a standard COM port with ready-to-go drivers and just read data from that port, then write it to your customized port.


If on the same computer, I think you could use something like this to create a virtual serial port and connect it to a named pipe, which LabVIEW could then talk to (I think). I haven't tried it, but I know there are a bunch of virtual serial port programs out there.


Alternatively, the com0com program/project looks to be able to connect a COM port to a TCP port, which LabVIEW can definitely read (

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