sbRIO-9651 : FPGA RS-485 baud rate beyond 230400 ? Error -1073807330

[jbeale1]

I am using a sbRIO-9651 and the FPGA CLIP file in "Additional Peripherals"  it shows six serial ports Serial1 ... Serial6. The first four are described as "RS-232 Serial Port" and the last two "RS-485 Serial Port".  On Serial6 (RS-485) I have configured TX, RX and TX Enable pins.

In my .vi on the Real Time I can set my "VISA Configure Serial Port (Instr).vi" with a baud rate. A baud rate of 115200 or 230400 works, but the rate I want to use (256000) generates a runtime error.  "  Error -1073807330  VISA: (Hex 0xBFFF001E) The specified state of the attribute is not valid, or is not supported as defined by the resource."  

I suspect the FPGA hardware is capable of 256k bps but I am not sure if this is a basic limitation of the NI UART IP block, or is just some setting I need to change to allow an expanded range of baud rates (?)

[ikelli · Accepted solution]

Hello,

The maximum baud rate for these serial ports is 230,400 bps, so it is a limitation on the UART connection.  In the manual you can find more specific information if you need it!  http://www.ni.com/pdf/manuals/376962c.pdf#page=8

[jbeale1]

Thank you for your reply. I thought there must be a manual, but I had not been aware of it until now.